/* * copyright (c) 2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVCODEC_AVCODEC_H #define AVCODEC_AVCODEC_H /** * @file * @ingroup libavc * Libavcodec external API header */ #include "libavutil/samplefmt.h" #include "libavutil/attributes.h" #include "libavutil/avutil.h" #include "libavutil/buffer.h" #include "libavutil/dict.h" #include "libavutil/frame.h" #include "libavutil/log.h" #include "libavutil/pixfmt.h" #include "libavutil/rational.h" #include "codec.h" #include "codec_desc.h" #include "codec_par.h" #include "codec_id.h" #include "defs.h" #include "packet.h" #include "version_major.h" #ifndef HAVE_AV_CONFIG_H /* When included as part of the ffmpeg build, only include the major version * to avoid unnecessary rebuilds. When included externally, keep including * the full version information. */ #include "version.h" #endif /** * @defgroup libavc libavcodec * Encoding/Decoding Library * * @{ * * @defgroup lavc_decoding Decoding * @{ * @} * * @defgroup lavc_encoding Encoding * @{ * @} * * @defgroup lavc_codec Codecs * @{ * @defgroup lavc_codec_native Native Codecs * @{ * @} * @defgroup lavc_codec_wrappers External library wrappers * @{ * @} * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge * @{ * @} * @} * @defgroup lavc_internal Internal * @{ * @} * @} */ /** * @ingroup libavc * @defgroup lavc_encdec send/receive encoding and decoding API overview * @{ * * The avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/ * avcodec_receive_packet() functions provide an encode/decode API, which * decouples input and output. * * The API is very similar for encoding/decoding and audio/video, and works as * follows: * - Set up and open the AVCodecContext as usual. * - Send valid input: * - For decoding, call avcodec_send_packet() to give the decoder raw * compressed data in an AVPacket. * - For encoding, call avcodec_send_frame() to give the encoder an AVFrame * containing uncompressed audio or video. * * In both cases, it is recommended that AVPackets and AVFrames are * refcounted, or libavcodec might have to copy the input data. (libavformat * always returns refcounted AVPackets, and av_frame_get_buffer() allocates * refcounted AVFrames.) * - Receive output in a loop. Periodically call one of the avcodec_receive_*() * functions and process their output: * - For decoding, call avcodec_receive_frame(). On success, it will return * an AVFrame containing uncompressed audio or video data. * - For encoding, call avcodec_receive_packet(). On success, it will return * an AVPacket with a compressed frame. * * Repeat this call until it returns AVERROR(EAGAIN) or an error. The * AVERROR(EAGAIN) return value means that new input data is required to * return new output. In this case, continue with sending input. For each * input frame/packet, the codec will typically return 1 output frame/packet, * but it can also be 0 or more than 1. * * At the beginning of decoding or encoding, the codec might accept multiple * input frames/packets without returning a frame, until its internal buffers * are filled. This situation is handled transparently if you follow the steps * outlined above. * * In theory, sending input can result in EAGAIN - this should happen only if * not all output was received. You can use this to structure alternative decode * or encode loops other than the one suggested above. For example, you could * try sending new input on each iteration, and try to receive output if that * returns EAGAIN. * * End of stream situations. These require "flushing" (aka draining) the codec, * as the codec might buffer multiple frames or packets internally for * performance or out of necessity (consider B-frames). * This is handled as follows: * - Instead of valid input, send NULL to the avcodec_send_packet() (decoding) * or avcodec_send_frame() (encoding) functions. This will enter draining * mode. * - Call avcodec_receive_frame() (decoding) or avcodec_receive_packet() * (encoding) in a loop until AVERROR_EOF is returned. The functions will * not return AVERROR(EAGAIN), unless you forgot to enter draining mode. * - Before decoding can be resumed again, the codec has to be reset with * avcodec_flush_buffers(). * * Using the API as outlined above is highly recommended. But it is also * possible to call functions outside of this rigid schema. For example, you can * call avcodec_send_packet() repeatedly without calling * avcodec_receive_frame(). In this case, avcodec_send_packet() will succeed * until the codec's internal buffer has been filled up (which is typically of * size 1 per output frame, after initial input), and then reject input with * AVERROR(EAGAIN). Once it starts rejecting input, you have no choice but to * read at least some output. * * Not all codecs will follow a rigid and predictable dataflow; the only * guarantee is that an AVERROR(EAGAIN) return value on a send/receive call on * one end implies that a receive/send call on the other end will succeed, or * at least will not fail with AVERROR(EAGAIN). In general, no codec will * permit unlimited buffering of input or output. * * A codec is not allowed to return AVERROR(EAGAIN) for both sending and receiving. This * would be an invalid state, which could put the codec user into an endless * loop. The API has no concept of time either: it cannot happen that trying to * do avcodec_send_packet() results in AVERROR(EAGAIN), but a repeated call 1 second * later accepts the packet (with no other receive/flush API calls involved). * The API is a strict state machine, and the passage of time is not supposed * to influence it. Some timing-dependent behavior might still be deemed * acceptable in certain cases. But it must never result in both send/receive * returning EAGAIN at the same time at any point. It must also absolutely be * avoided that the current state is "unstable" and can "flip-flop" between * the send/receive APIs allowing progress. For example, it's not allowed that * the codec randomly decides that it actually wants to consume a packet now * instead of returning a frame, after it just returned AVERROR(EAGAIN) on an * avcodec_send_packet() call. * @} */ /** * @defgroup lavc_core Core functions/structures. * @ingroup libavc * * Basic definitions, functions for querying libavcodec capabilities, * allocating core structures, etc. * @{ */ /** * @ingroup lavc_encoding * minimum encoding buffer size * Used to avoid some checks during header writing. */ #define AV_INPUT_BUFFER_MIN_SIZE 16384 /** * @ingroup lavc_encoding */ typedef struct RcOverride{ int start_frame; int end_frame; int qscale; // If this is 0 then quality_factor will be used instead. float quality_factor; } RcOverride; /* encoding support These flags can be passed in AVCodecContext.flags before initialization. Note: Not everything is supported yet. */ /** * Allow decoders to produce frames with data planes that are not aligned * to CPU requirements (e.g. due to cropping). */ #define AV_CODEC_FLAG_UNALIGNED (1 << 0) /** * Use fixed qscale. */ #define AV_CODEC_FLAG_QSCALE (1 << 1) /** * 4 MV per MB allowed / advanced prediction for H.263. */ #define AV_CODEC_FLAG_4MV (1 << 2) /** * Output even those frames that might be corrupted. */ #define AV_CODEC_FLAG_OUTPUT_CORRUPT (1 << 3) /** * Use qpel MC. */ #define AV_CODEC_FLAG_QPEL (1 << 4) /** * Don't output frames whose parameters differ from first * decoded frame in stream. */ #define AV_CODEC_FLAG_DROPCHANGED (1 << 5) /** * Use internal 2pass ratecontrol in first pass mode. */ #define AV_CODEC_FLAG_PASS1 (1 << 9) /** * Use internal 2pass ratecontrol in second pass mode. */ #define AV_CODEC_FLAG_PASS2 (1 << 10) /** * loop filter. */ #define AV_CODEC_FLAG_LOOP_FILTER (1 << 11) /** * Only decode/encode grayscale. */ #define AV_CODEC_FLAG_GRAY (1 << 13) /** * error[?] variables will be set during encoding. */ #define AV_CODEC_FLAG_PSNR (1 << 15) #if FF_API_FLAG_TRUNCATED /** * Input bitstream might be truncated at a random location * instead of only at frame boundaries. * * @deprecated use codec parsers for packetizing input */ #define AV_CODEC_FLAG_TRUNCATED (1 << 16) #endif /** * Use interlaced DCT. */ #define AV_CODEC_FLAG_INTERLACED_DCT (1 << 18) /** * Force low delay. */ #define AV_CODEC_FLAG_LOW_DELAY (1 << 19) /** * Place global headers in extradata instead of every keyframe. */ #define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22) /** * Use only bitexact stuff (except (I)DCT). */ #define AV_CODEC_FLAG_BITEXACT (1 << 23) /* Fx : Flag for H.263+ extra options */ /** * H.263 advanced intra coding / MPEG-4 AC prediction */ #define AV_CODEC_FLAG_AC_PRED (1 << 24) /** * interlaced motion estimation */ #define AV_CODEC_FLAG_INTERLACED_ME (1 << 29) #define AV_CODEC_FLAG_CLOSED_GOP (1U << 31) /** * Allow non spec compliant speedup tricks. */ #define AV_CODEC_FLAG2_FAST (1 << 0) /** * Skip bitstream encoding. */ #define AV_CODEC_FLAG2_NO_OUTPUT (1 << 2) /** * Place global headers at every keyframe instead of in extradata. */ #define AV_CODEC_FLAG2_LOCAL_HEADER (1 << 3) /** * timecode is in drop frame format. DEPRECATED!!!! */ #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13) /** * Input bitstream might be truncated at a packet boundaries * instead of only at frame boundaries. */ #define AV_CODEC_FLAG2_CHUNKS (1 << 15) /** * Discard cropping information from SPS. */ #define AV_CODEC_FLAG2_IGNORE_CROP (1 << 16) /** * Show all frames before the first keyframe */ #define AV_CODEC_FLAG2_SHOW_ALL (1 << 22) /** * Export motion vectors through frame side data */ #define AV_CODEC_FLAG2_EXPORT_MVS (1 << 28) /** * Do not skip samples and export skip information as frame side data */ #define AV_CODEC_FLAG2_SKIP_MANUAL (1 << 29) /** * Do not reset ASS ReadOrder field on flush (subtitles decoding) */ #define AV_CODEC_FLAG2_RO_FLUSH_NOOP (1 << 30) /* Unsupported options : * Syntax Arithmetic coding (SAC) * Reference Picture Selection * Independent Segment Decoding */ /* /Fx */ /* codec capabilities */ /* Exported side data. These flags can be passed in AVCodecContext.export_side_data before initialization. */ /** * Export motion vectors through frame side data */ #define AV_CODEC_EXPORT_DATA_MVS (1 << 0) /** * Export encoder Producer Reference Time through packet side data */ #define AV_CODEC_EXPORT_DATA_PRFT (1 << 1) /** * Decoding only. * Export the AVVideoEncParams structure through frame side data. */ #define AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS (1 << 2) /** * Decoding only. * Do not apply film grain, export it instead. */ #define AV_CODEC_EXPORT_DATA_FILM_GRAIN (1 << 3) /** * The decoder will keep a reference to the frame and may reuse it later. */ #define AV_GET_BUFFER_FLAG_REF (1 << 0) /** * The encoder will keep a reference to the packet and may reuse it later. */ #define AV_GET_ENCODE_BUFFER_FLAG_REF (1 << 0) struct AVCodecInternal; /** * main external API structure. * New fields can be added to the end with minor version bumps. * Removal, reordering and changes to existing fields require a major * version bump. * You can use AVOptions (av_opt* / av_set/get*()) to access these fields from user * applications. * The name string for AVOptions options matches the associated command line * parameter name and can be found in libavcodec/options_table.h * The AVOption/command line parameter names differ in some cases from the C * structure field names for historic reasons or brevity. * sizeof(AVCodecContext) must not be used outside libav*. */ typedef struct AVCodecContext { /** * information on struct for av_log * - set by avcodec_alloc_context3 */ const AVClass *av_class; int log_level_offset; enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */ const struct AVCodec *codec; enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */ /** * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). * This is used to work around some encoder bugs. * A demuxer should set this to what is stored in the field used to identify the codec. * If there are multiple such fields in a container then the demuxer should choose the one * which maximizes the information about the used codec. * If the codec tag field in a container is larger than 32 bits then the demuxer should * remap the longer ID to 32 bits with a table or other structure. Alternatively a new * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated * first. * - encoding: Set by user, if not then the default based on codec_id will be used. * - decoding: Set by user, will be converted to uppercase by libavcodec during init. */ unsigned int codec_tag; void *priv_data; /** * Private context used for internal data. * * Unlike priv_data, this is not codec-specific. It is used in general * libavcodec functions. */ struct AVCodecInternal *internal; /** * Private data of the user, can be used to carry app specific stuff. * - encoding: Set by user. * - decoding: Set by user. */ void *opaque; /** * the average bitrate * - encoding: Set by user; unused for constant quantizer encoding. * - decoding: Set by user, may be overwritten by libavcodec * if this info is available in the stream */ int64_t bit_rate; /** * number of bits the bitstream is allowed to diverge from the reference. * the reference can be CBR (for CBR pass1) or VBR (for pass2) * - encoding: Set by user; unused for constant quantizer encoding. * - decoding: unused */ int bit_rate_tolerance; /** * Global quality for codecs which cannot change it per frame. * This should be proportional to MPEG-1/2/4 qscale. * - encoding: Set by user. * - decoding: unused */ int global_quality; /** * - encoding: Set by user. * - decoding: unused */ int compression_level; #define FF_COMPRESSION_DEFAULT -1 /** * AV_CODEC_FLAG_*. * - encoding: Set by user. * - decoding: Set by user. */ int flags; /** * AV_CODEC_FLAG2_* * - encoding: Set by user. * - decoding: Set by user. */ int flags2; /** * some codecs need / can use extradata like Huffman tables. * MJPEG: Huffman tables * rv10: additional flags * MPEG-4: global headers (they can be in the bitstream or here) * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger * than extradata_size to avoid problems if it is read with the bitstream reader. * The bytewise contents of extradata must not depend on the architecture or CPU endianness. * Must be allocated with the av_malloc() family of functions. * - encoding: Set/allocated/freed by libavcodec. * - decoding: Set/allocated/freed by user. */ uint8_t *extradata; int extradata_size; /** * This is the fundamental unit of time (in seconds) in terms * of which frame timestamps are represented. For fixed-fps content, * timebase should be 1/framerate and timestamp increments should be * identically 1. * This often, but not always is the inverse of the frame rate or field rate * for video. 1/time_base is not the average frame rate if the frame rate is not * constant. * * Like containers, elementary streams also can store timestamps, 1/time_base * is the unit in which these timestamps are specified. * As example of such codec time base see ISO/IEC 14496-2:2001(E) * vop_time_increment_resolution and fixed_vop_rate * (fixed_vop_rate == 0 implies that it is different from the framerate) * * - encoding: MUST be set by user. * - decoding: the use of this field for decoding is deprecated. * Use framerate instead. */ AVRational time_base; /** * For some codecs, the time base is closer to the field rate than the frame rate. * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration * if no telecine is used ... * * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2. */ int ticks_per_frame; /** * Codec delay. * * Encoding: Number of frames delay there will be from the encoder input to * the decoder output. (we assume the decoder matches the spec) * Decoding: Number of frames delay in addition to what a standard decoder * as specified in the spec would produce. * * Video: * Number of frames the decoded output will be delayed relative to the * encoded input. * * Audio: * For encoding, this field is unused (see initial_padding). * * For decoding, this is the number of samples the decoder needs to * output before the decoder's output is valid. When seeking, you should * start decoding this many samples prior to your desired seek point. * * - encoding: Set by libavcodec. * - decoding: Set by libavcodec. */ int delay; /* video only */ /** * picture width / height. * * @note Those fields may not match the values of the last * AVFrame output by avcodec_receive_frame() due frame * reordering. * * - encoding: MUST be set by user. * - decoding: May be set by the user before opening the decoder if known e.g. * from the container. Some decoders will require the dimensions * to be set by the caller. During decoding, the decoder may * overwrite those values as required while parsing the data. */ int width, height; /** * Bitstream width / height, may be different from width/height e.g. when * the decoded frame is cropped before being output or lowres is enabled. * * @note Those field may not match the value of the last * AVFrame output by avcodec_receive_frame() due frame * reordering. * * - encoding: unused * - decoding: May be set by the user before opening the decoder if known * e.g. from the container. During decoding, the decoder may * overwrite those values as required while parsing the data. */ int coded_width, coded_height; /** * the number of pictures in a group of pictures, or 0 for intra_only * - encoding: Set by user. * - decoding: unused */ int gop_size; /** * 像素格式，请参阅AV_PIX_FMT_xxx。 * 如果从标题中知道，可以由解复用器设置。 * 如果解码器更清楚，可能会被其覆盖。 * * @note 由于帧重新排序，此字段可能与avcodec_receive_frame（）上次输出的AVFrame值不匹配。 * * - encoding: Set by user. * - decoding: Set by user if known, overridden by libavcodec while * parsing the data. */ enum AVPixelFormat pix_fmt; /** * If non NULL, 'draw_horiz_band' is called by the libavcodec * decoder to draw a horizontal band. It improves cache usage. Not * all codecs can do that. You must check the codec capabilities * beforehand. * When multithreading is used, it may be called from multiple threads * at the same time; threads might draw different parts of the same AVFrame, * or multiple AVFrames, and there is no guarantee that slices will be drawn * in order. * The function is also used by hardware acceleration APIs. * It is called at least once during frame decoding to pass * the data needed for hardware render. * In that mode instead of pixel data, AVFrame points to * a structure specific to the acceleration API. The application * reads the structure and can change some fields to indicate progress * or mark state. * - encoding: unused * - decoding: Set by user. * @param height the height of the slice * @param y the y position of the slice * @param type 1->top field, 2->bottom field, 3->frame * @param offset offset into the AVFrame.data from which the slice should be read */ void (*draw_horiz_band)(struct AVCodecContext *s, const AVFrame *src, int offset[AV_NUM_DATA_POINTERS], int y, int type, int height); /** * 回调以选择像素格式。仅解码，可由调用者在avcodec_open2（）之前设置。 * * 由一些解码器调用，以选择将用于输出帧的像素格式。 * 这主要用于设置硬件加速，然后提供的格式列表包含相应的hwaccel像素格式以及“software”格式。也可以从\ref sw_pix_fmt检索软件像素格式。 * * 当编码帧属性（如分辨率、像素格式等）更改，并且这些新属性支持多个输出格式时，将调用此回调。 * 如果选择了硬件像素格式，但初始化失败，可能会立即再次调用回调。 * * This callback may be called from different threads if the decoder is * multi-threaded, but not from more than one thread simultaneously. * * @param fmt list of formats which may be used in the current * configuration, terminated by AV_PIX_FMT_NONE. * @warning Behavior is undefined if the callback returns a value other * than one of the formats in fmt or AV_PIX_FMT_NONE. * @return the chosen format or AV_PIX_FMT_NONE */ enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt); /** * 非B帧之间的最大B帧数 *注意：相对于输入，输出将延迟max_b_frames+1。 * - encoding: Set by user. * - decoding: unused */ int max_b_frames; /** * qscale factor between IP and B-frames * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset). * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). * - encoding: Set by user. * - decoding: unused */ float b_quant_factor; /** * qscale offset between IP and B-frames * - encoding: Set by user. * - decoding: unused */ float b_quant_offset; /** * Size of the frame reordering buffer in the decoder. * For MPEG-2 it is 1 IPB or 0 low delay IP. * - encoding: Set by libavcodec. * - decoding: Set by libavcodec. */ int has_b_frames; /** * qscale factor between P- and I-frames * If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset). * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). * - encoding: Set by user. * - decoding: unused */ float i_quant_factor; /** * qscale offset between P and I-frames * - encoding: Set by user. * - decoding: unused */ float i_quant_offset; /** * luminance masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float lumi_masking; /** * temporary complexity masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float temporal_cplx_masking; /** * spatial complexity masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float spatial_cplx_masking; /** * p block masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float p_masking; /** * darkness masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float dark_masking; /** * slice count * - encoding: Set by libavcodec. * - decoding: Set by user (or 0). */ int slice_count; /** * slice offsets in the frame in bytes * - encoding: Set/allocated by libavcodec. * - decoding: Set/allocated by user (or NULL). */ int *slice_offset; /** * sample aspect ratio (0 if unknown) * That is the width of a pixel divided by the height of the pixel. * Numerator and denominator must be relatively prime and smaller than 256 for some video standards. * - encoding: Set by user. * - decoding: Set by libavcodec. */ AVRational sample_aspect_ratio; /** * motion estimation comparison function * - encoding: Set by user. * - decoding: unused */ int me_cmp; /** * subpixel motion estimation comparison function * - encoding: Set by user. * - decoding: unused */ int me_sub_cmp; /** * macroblock comparison function (not supported yet) * - encoding: Set by user. * - decoding: unused */ int mb_cmp; /** * interlaced DCT comparison function * - encoding: Set by user. * - decoding: unused */ int ildct_cmp; #define FF_CMP_SAD 0 #define FF_CMP_SSE 1 #define FF_CMP_SATD 2 #define FF_CMP_DCT 3 #define FF_CMP_PSNR 4 #define FF_CMP_BIT 5 #define FF_CMP_RD 6 #define FF_CMP_ZERO 7 #define FF_CMP_VSAD 8 #define FF_CMP_VSSE 9 #define FF_CMP_NSSE 10 #define FF_CMP_W53 11 #define FF_CMP_W97 12 #define FF_CMP_DCTMAX 13 #define FF_CMP_DCT264 14 #define FF_CMP_MEDIAN_SAD 15 #define FF_CMP_CHROMA 256 /** * ME diamond size & shape * - encoding: Set by user. * - decoding: unused */ int dia_size; /** * amount of previous MV predictors (2a+1 x 2a+1 square) * - encoding: Set by user. * - decoding: unused */ int last_predictor_count; /** * motion estimation prepass comparison function * - encoding: Set by user. * - decoding: unused */ int me_pre_cmp; /** * ME prepass diamond size & shape * - encoding: Set by user. * - decoding: unused */ int pre_dia_size; /** * subpel ME quality * - encoding: Set by user. * - decoding: unused */ int me_subpel_quality; /** * maximum motion estimation search range in subpel units * If 0 then no limit. * * - encoding: Set by user. * - decoding: unused */ int me_range; /** * slice flags * - encoding: unused * - decoding: Set by user. */ int slice_flags; #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG-2 field pics) #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1) /** * macroblock decision mode * - encoding: Set by user. * - decoding: unused */ int mb_decision; #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits #define FF_MB_DECISION_RD 2 ///< rate distortion /** * custom intra quantization matrix * Must be allocated with the av_malloc() family of functions, and will be freed in * avcodec_free_context(). * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL. * - decoding: Set/allocated/freed by libavcodec. */ uint16_t *intra_matrix; /** * custom inter quantization matrix * Must be allocated with the av_malloc() family of functions, and will be freed in * avcodec_free_context(). * - encoding: Set/allocated by user, freed by libavcodec. Can be NULL. * - decoding: Set/allocated/freed by libavcodec. */ uint16_t *inter_matrix; /** * precision of the intra DC coefficient - 8 * - encoding: Set by user. * - decoding: Set by libavcodec */ int intra_dc_precision; /** * Number of macroblock rows at the top which are skipped. * - encoding: unused * - decoding: Set by user. */ int skip_top; /** * Number of macroblock rows at the bottom which are skipped. * - encoding: unused * - decoding: Set by user. */ int skip_bottom; /** * minimum MB Lagrange multiplier * - encoding: Set by user. * - decoding: unused */ int mb_lmin; /** * maximum MB Lagrange multiplier * - encoding: Set by user. * - decoding: unused */ int mb_lmax; /** * - encoding: Set by user. * - decoding: unused */ int bidir_refine; /** * minimum GOP size * - encoding: Set by user. * - decoding: unused */ int keyint_min; /** * number of reference frames * - encoding: Set by user. * - decoding: Set by lavc. */ int refs; /** * Note: Value depends upon the compare function used for fullpel ME. * - encoding: Set by user. * - decoding: unused */ int mv0_threshold; /** * Chromaticity coordinates of the source primaries. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorPrimaries color_primaries; /** * Color Transfer Characteristic. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorTransferCharacteristic color_trc; /** * YUV colorspace type. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorSpace colorspace; /** * MPEG vs JPEG YUV range. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorRange color_range; /** * This defines the location of chroma samples. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVChromaLocation chroma_sample_location; /** * Number of slices. * Indicates number of picture subdivisions. Used for parallelized * decoding. * - encoding: Set by user * - decoding: unused */ int slices; /** Field order * - encoding: set by libavcodec * - decoding: Set by user. */ enum AVFieldOrder field_order; /* audio only */ int sample_rate; ///< samples per second #if FF_API_OLD_CHANNEL_LAYOUT /** * number of audio channels * @deprecated use ch_layout.nb_channels */ attribute_deprecated int channels; #endif /** * audio sample format * - encoding: Set by user. * - decoding: Set by libavcodec. */ enum AVSampleFormat sample_fmt; ///< sample format /* The following data should not be initialized. */ /** * Number of samples per channel in an audio frame. * * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame * except the last must contain exactly frame_size samples per channel. * May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the * frame size is not restricted. * - decoding: may be set by some decoders to indicate constant frame size */ int frame_size; /** * Frame counter, set by libavcodec. * * - decoding: total number of frames returned from the decoder so far. * - encoding: total number of frames passed to the encoder so far. * * @note the counter is not incremented if encoding/decoding resulted in * an error. */ int frame_number; /** * number of bytes per packet if constant and known or 0 * Used by some WAV based audio codecs. */ int block_align; /** * Audio cutoff bandwidth (0 means "automatic") * - encoding: Set by user. * - decoding: unused */ int cutoff; #if FF_API_OLD_CHANNEL_LAYOUT /** * Audio channel layout. * - encoding: set by user. * - decoding: set by user, may be overwritten by libavcodec. * @deprecated use ch_layout */ attribute_deprecated uint64_t channel_layout; /** * Request decoder to use this channel layout if it can (0 for default) * - encoding: unused * - decoding: Set by user. * @deprecated use "downmix" codec private option */ attribute_deprecated uint64_t request_channel_layout; #endif /** * Type of service that the audio stream conveys. * - encoding: Set by user. * - decoding: Set by libavcodec. */ enum AVAudioServiceType audio_service_type; /** * desired sample format * - encoding: Not used. * - decoding: Set by user. * Decoder will decode to this format if it can. */ enum AVSampleFormat request_sample_fmt; /** * This callback is called at the beginning of each frame to get data * buffer(s) for it. There may be one contiguous buffer for all the data or * there may be a buffer per each data plane or anything in between. What * this means is, you may set however many entries in buf[] you feel necessary. * Each buffer must be reference-counted using the AVBuffer API (see description * of buf[] below). * * The following fields will be set in the frame before this callback is * called: * - format * - width, height (video only) * - sample_rate, channel_layout, nb_samples (audio only) * Their values may differ from the corresponding values in * AVCodecContext. This callback must use the frame values, not the codec * context values, to calculate the required buffer size. * * This callback must fill the following fields in the frame: * - data[] * - linesize[] * - extended_data: * * if the data is planar audio with more than 8 channels, then this * callback must allocate and fill extended_data to contain all pointers * to all data planes. data[] must hold as many pointers as it can. * extended_data must be allocated with av_malloc() and will be freed in * av_frame_unref(). * * otherwise extended_data must point to data * - buf[] must contain one or more pointers to AVBufferRef structures. Each of * the frame's data and extended_data pointers must be contained in these. That * is, one AVBufferRef for each allocated chunk of memory, not necessarily one * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(), * and av_buffer_ref(). * - extended_buf and nb_extended_buf must be allocated with av_malloc() by * this callback and filled with the extra buffers if there are more * buffers than buf[] can hold. extended_buf will be freed in * av_frame_unref(). * * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call * avcodec_default_get_buffer2() instead of providing buffers allocated by * some other means. * * Each data plane must be aligned to the maximum required by the target * CPU. * * @see avcodec_default_get_buffer2() * * Video: * * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused * (read and/or written to if it is writable) later by libavcodec. * * avcodec_align_dimensions2() should be used to find the required width and * height, as they normally need to be rounded up to the next multiple of 16. * * Some decoders do not support linesizes changing between frames. * * If frame multithreading is used, this callback may be called from a * different thread, but not from more than one at once. Does not need to be * reentrant. * * @see avcodec_align_dimensions2() * * Audio: * * Decoders request a buffer of a particular size by setting * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may, * however, utilize only part of the buffer by setting AVFrame.nb_samples * to a smaller value in the output frame. * * As a convenience, av_samples_get_buffer_size() and * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2() * functions to find the required data size and to fill data pointers and * linesize. In AVFrame.linesize, only linesize[0] may be set for audio * since all planes must be the same size. * * @see av_samples_get_buffer_size(), av_samples_fill_arrays() * * - encoding: unused * - decoding: Set by libavcodec, user can override. */ int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags); /* - encoding parameters */ float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0) float qblur; ///< amount of qscale smoothing over time (0.0-1.0) /** * minimum quantizer * - encoding: Set by user. * - decoding: unused */ int qmin; /** * maximum quantizer * - encoding: Set by user. * - decoding: unused */ int qmax; /** * maximum quantizer difference between frames * - encoding: Set by user. * - decoding: unused */ int max_qdiff; /** * decoder bitstream buffer size * - encoding: Set by user. * - decoding: unused */ int rc_buffer_size; /** * ratecontrol override, see RcOverride * - encoding: Allocated/set/freed by user. * - decoding: unused */ int rc_override_count; RcOverride *rc_override; /** * maximum bitrate * - encoding: Set by user. * - decoding: Set by user, may be overwritten by libavcodec. */ int64_t rc_max_rate; /** * minimum bitrate * - encoding: Set by user. * - decoding: unused */ int64_t rc_min_rate; /** * Ratecontrol attempt to use, at maximum, of what can be used without an underflow. * - encoding: Set by user. * - decoding: unused. */ float rc_max_available_vbv_use; /** * Ratecontrol attempt to use, at least, times the amount needed to prevent a vbv overflow. * - encoding: Set by user. * - decoding: unused. */ float rc_min_vbv_overflow_use; /** * Number of bits which should be loaded into the rc buffer before decoding starts. * - encoding: Set by user. * - decoding: unused */ int rc_initial_buffer_occupancy; /** * trellis RD quantization * - encoding: Set by user. * - decoding: unused */ int trellis; /** * pass1 encoding statistics output buffer * - encoding: Set by libavcodec. * - decoding: unused */ char *stats_out; /** * pass2 encoding statistics input buffer * Concatenated stuff from stats_out of pass1 should be placed here. * - encoding: Allocated/set/freed by user. * - decoding: unused */ char *stats_in; /** * Work around bugs in encoders which sometimes cannot be detected automatically. * - encoding: Set by user * - decoding: Set by user */ int workaround_bugs; #define FF_BUG_AUTODETECT 1 ///< autodetection #define FF_BUG_XVID_ILACE 4 #define FF_BUG_UMP4 8 #define FF_BUG_NO_PADDING 16 #define FF_BUG_AMV 32 #define FF_BUG_QPEL_CHROMA 64 #define FF_BUG_STD_QPEL 128 #define FF_BUG_QPEL_CHROMA2 256 #define FF_BUG_DIRECT_BLOCKSIZE 512 #define FF_BUG_EDGE 1024 #define FF_BUG_HPEL_CHROMA 2048 #define FF_BUG_DC_CLIP 4096 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders. #define FF_BUG_TRUNCATED 16384 #define FF_BUG_IEDGE 32768 /** * strictly follow the standard (MPEG-4, ...). * - encoding: Set by user. * - decoding: Set by user. * Setting this to STRICT or higher means the encoder and decoder will * generally do stupid things, whereas setting it to unofficial or lower * will mean the encoder might produce output that is not supported by all * spec-compliant decoders. Decoders don't differentiate between normal, * unofficial and experimental (that is, they always try to decode things * when they can) unless they are explicitly asked to behave stupidly * (=strictly conform to the specs) */ int strict_std_compliance; #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software. #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences. #define FF_COMPLIANCE_NORMAL 0 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things. /** * error concealment flags * - encoding: unused * - decoding: Set by user. */ int error_concealment; #define FF_EC_GUESS_MVS 1 #define FF_EC_DEBLOCK 2 #define FF_EC_FAVOR_INTER 256 /** * debug * - encoding: Set by user. * - decoding: Set by user. */ int debug; #define FF_DEBUG_PICT_INFO 1 #define FF_DEBUG_RC 2 #define FF_DEBUG_BITSTREAM 4 #define FF_DEBUG_MB_TYPE 8 #define FF_DEBUG_QP 16 #define FF_DEBUG_DCT_COEFF 0x00000040 #define FF_DEBUG_SKIP 0x00000080 #define FF_DEBUG_STARTCODE 0x00000100 #define FF_DEBUG_ER 0x00000400 #define FF_DEBUG_MMCO 0x00000800 #define FF_DEBUG_BUGS 0x00001000 #define FF_DEBUG_BUFFERS 0x00008000 #define FF_DEBUG_THREADS 0x00010000 #define FF_DEBUG_GREEN_MD 0x00800000 #define FF_DEBUG_NOMC 0x01000000 /** * Error recognition; may misdetect some more or less valid parts as errors. * - encoding: Set by user. * - decoding: Set by user. */ int err_recognition; /** * Verify checksums embedded in the bitstream (could be of either encoded or * decoded data, depending on the codec) and print an error message on mismatch. * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the * decoder returning an error. */ #define AV_EF_CRCCHECK (1<<0) #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection #define AV_EF_IGNORE_ERR (1<<15) ///< ignore errors and continue #define AV_EF_CAREFUL (1<<16) ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliances as errors #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error /** * opaque 64-bit number (generally a PTS) that will be reordered and * output in AVFrame.reordered_opaque * - encoding: Set by libavcodec to the reordered_opaque of the input * frame corresponding to the last returned packet. Only * supported by encoders with the * AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability. * - decoding: Set by user. */ int64_t reordered_opaque; /** * Hardware accelerator in use * - encoding: unused. * - decoding: Set by libavcodec */ const struct AVHWAccel *hwaccel; /** * Hardware accelerator context. * For some hardware accelerators, a global context needs to be * provided by the user. In that case, this holds display-dependent * data FFmpeg cannot instantiate itself. Please refer to the * FFmpeg HW accelerator documentation to know how to fill this. * - encoding: unused * - decoding: Set by user */ void *hwaccel_context; /** * error * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR. * - decoding: unused */ uint64_t error[AV_NUM_DATA_POINTERS]; /** * DCT algorithm, see FF_DCT_* below * - encoding: Set by user. * - decoding: unused */ int dct_algo; #define FF_DCT_AUTO 0 #define FF_DCT_FASTINT 1 #define FF_DCT_INT 2 #define FF_DCT_MMX 3 #define FF_DCT_ALTIVEC 5 #define FF_DCT_FAAN 6 /** * IDCT algorithm, see FF_IDCT_* below. * - encoding: Set by user. * - decoding: Set by user. */ int idct_algo; #define FF_IDCT_AUTO 0 #define FF_IDCT_INT 1 #define FF_IDCT_SIMPLE 2 #define FF_IDCT_SIMPLEMMX 3 #define FF_IDCT_ARM 7 #define FF_IDCT_ALTIVEC 8 #define FF_IDCT_SIMPLEARM 10 #define FF_IDCT_XVID 14 #define FF_IDCT_SIMPLEARMV5TE 16 #define FF_IDCT_SIMPLEARMV6 17 #define FF_IDCT_FAAN 20 #define FF_IDCT_SIMPLENEON 22 #if FF_API_IDCT_NONE // formerly used by xvmc #define FF_IDCT_NONE 24 #endif #define FF_IDCT_SIMPLEAUTO 128 /** * bits per sample/pixel from the demuxer (needed for huffyuv). * - encoding: Set by libavcodec. * - decoding: Set by user. */ int bits_per_coded_sample; /** * Bits per sample/pixel of internal libavcodec pixel/sample format. * - encoding: set by user. * - decoding: set by libavcodec. */ int bits_per_raw_sample; /** * low resolution decoding, 1-> 1/2 size, 2->1/4 size * - encoding: unused * - decoding: Set by user. */ int lowres; /** * thread count * is used to decide how many independent tasks should be passed to execute() * - encoding: Set by user. * - decoding: Set by user. */ int thread_count; /** * Which multithreading methods to use. * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread, * so clients which cannot provide future frames should not use it. * * - encoding: Set by user, otherwise the default is used. * - decoding: Set by user, otherwise the default is used. */ int thread_type; #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once /** * Which multithreading methods are in use by the codec. * - encoding: Set by libavcodec. * - decoding: Set by libavcodec. */ int active_thread_type; #if FF_API_THREAD_SAFE_CALLBACKS /** * Set by the client if its custom get_buffer() callback can be called * synchronously from another thread, which allows faster multithreaded decoding. * draw_horiz_band() will be called from other threads regardless of this setting. * Ignored if the default get_buffer() is used. * - encoding: Set by user. * - decoding: Set by user. * * @deprecated the custom get_buffer2() callback should always be * thread-safe. Thread-unsafe get_buffer2() implementations will be * invalid starting with LIBAVCODEC_VERSION_MAJOR=60; in other words, * libavcodec will behave as if this field was always set to 1. * Callers that want to be forward compatible with future libavcodec * versions should wrap access to this field in * #if LIBAVCODEC_VERSION_MAJOR < 60 */ attribute_deprecated int thread_safe_callbacks; #endif /** * The codec may call this to execute several independent things. * It will return only after finishing all tasks. * The user may replace this with some multithreaded implementation, * the default implementation will execute the parts serially. * @param count the number of things to execute * - encoding: Set by libavcodec, user can override. * - decoding: Set by libavcodec, user can override. */ int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size); /** * The codec may call this to execute several independent things. * It will return only after finishing all tasks. * The user may replace this with some multithreaded implementation, * the default implementation will execute the parts serially. * @param c context passed also to func * @param count the number of things to execute * @param arg2 argument passed unchanged to func * @param ret return values of executed functions, must have space for "count" values. May be NULL. * @param func function that will be called count times, with jobnr from 0 to count-1. * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no * two instances of func executing at the same time will have the same threadnr. * @return always 0 currently, but code should handle a future improvement where when any call to func * returns < 0 no further calls to func may be done and < 0 is returned. * - encoding: Set by libavcodec, user can override. * - decoding: Set by libavcodec, user can override. */ int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count); /** * noise vs. sse weight for the nsse comparison function * - encoding: Set by user. * - decoding: unused */ int nsse_weight; /** * profile * - encoding: Set by user. * - decoding: Set by libavcodec. */ int profile; #define FF_PROFILE_UNKNOWN -99 #define FF_PROFILE_RESERVED -100 #define FF_PROFILE_AAC_MAIN 0 #define FF_PROFILE_AAC_LOW 1 #define FF_PROFILE_AAC_SSR 2 #define FF_PROFILE_AAC_LTP 3 #define FF_PROFILE_AAC_HE 4 #define FF_PROFILE_AAC_HE_V2 28 #define FF_PROFILE_AAC_LD 22 #define FF_PROFILE_AAC_ELD 38 #define FF_PROFILE_MPEG2_AAC_LOW 128 #define FF_PROFILE_MPEG2_AAC_HE 131 #define FF_PROFILE_DNXHD 0 #define FF_PROFILE_DNXHR_LB 1 #define FF_PROFILE_DNXHR_SQ 2 #define FF_PROFILE_DNXHR_HQ 3 #define FF_PROFILE_DNXHR_HQX 4 #define FF_PROFILE_DNXHR_444 5 #define FF_PROFILE_DTS 20 #define FF_PROFILE_DTS_ES 30 #define FF_PROFILE_DTS_96_24 40 #define FF_PROFILE_DTS_HD_HRA 50 #define FF_PROFILE_DTS_HD_MA 60 #define FF_PROFILE_DTS_EXPRESS 70 #define FF_PROFILE_MPEG2_422 0 #define FF_PROFILE_MPEG2_HIGH 1 #define FF_PROFILE_MPEG2_SS 2 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3 #define FF_PROFILE_MPEG2_MAIN 4 #define FF_PROFILE_MPEG2_SIMPLE 5 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag #define FF_PROFILE_H264_BASELINE 66 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED) #define FF_PROFILE_H264_MAIN 77 #define FF_PROFILE_H264_EXTENDED 88 #define FF_PROFILE_H264_HIGH 100 #define FF_PROFILE_H264_HIGH_10 110 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA) #define FF_PROFILE_H264_MULTIVIEW_HIGH 118 #define FF_PROFILE_H264_HIGH_422 122 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA) #define FF_PROFILE_H264_STEREO_HIGH 128 #define FF_PROFILE_H264_HIGH_444 144 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA) #define FF_PROFILE_H264_CAVLC_444 44 #define FF_PROFILE_VC1_SIMPLE 0 #define FF_PROFILE_VC1_MAIN 1 #define FF_PROFILE_VC1_COMPLEX 2 #define FF_PROFILE_VC1_ADVANCED 3 #define FF_PROFILE_MPEG4_SIMPLE 0 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1 #define FF_PROFILE_MPEG4_CORE 2 #define FF_PROFILE_MPEG4_MAIN 3 #define FF_PROFILE_MPEG4_N_BIT 4 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7 #define FF_PROFILE_MPEG4_HYBRID 8 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 1 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 2 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 32768 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4 #define FF_PROFILE_VP9_0 0 #define FF_PROFILE_VP9_1 1 #define FF_PROFILE_VP9_2 2 #define FF_PROFILE_VP9_3 3 #define FF_PROFILE_HEVC_MAIN 1 #define FF_PROFILE_HEVC_MAIN_10 2 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE 3 #define FF_PROFILE_HEVC_REXT 4 #define FF_PROFILE_VVC_MAIN_10 1 #define FF_PROFILE_VVC_MAIN_10_444 33 #define FF_PROFILE_AV1_MAIN 0 #define FF_PROFILE_AV1_HIGH 1 #define FF_PROFILE_AV1_PROFESSIONAL 2 #define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT 0xc0 #define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1 #define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT 0xc2 #define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS 0xc3 #define FF_PROFILE_MJPEG_JPEG_LS 0xf7 #define FF_PROFILE_SBC_MSBC 1 #define FF_PROFILE_PRORES_PROXY 0 #define FF_PROFILE_PRORES_LT 1 #define FF_PROFILE_PRORES_STANDARD 2 #define FF_PROFILE_PRORES_HQ 3 #define FF_PROFILE_PRORES_4444 4 #define FF_PROFILE_PRORES_XQ 5 #define FF_PROFILE_ARIB_PROFILE_A 0 #define FF_PROFILE_ARIB_PROFILE_C 1 #define FF_PROFILE_KLVA_SYNC 0 #define FF_PROFILE_KLVA_ASYNC 1 /** * level * - encoding: Set by user. * - decoding: Set by libavcodec. */ int level; #define FF_LEVEL_UNKNOWN -99 /** * Skip loop filtering for selected frames. * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_loop_filter; /** * Skip IDCT/dequantization for selected frames. * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_idct; /** * Skip decoding for selected frames. * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_frame; /** * Header containing style information for text subtitles. * For SUBTITLE_ASS subtitle type, it should contain the whole ASS * [Script Info] and [V4+ Styles] section, plus the [Events] line and * the Format line following. It shouldn't include any Dialogue line. * - encoding: Set/allocated/freed by user (before avcodec_open2()) * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2()) */ uint8_t *subtitle_header; int subtitle_header_size; /** * Audio only. The number of "priming" samples (padding) inserted by the * encoder at the beginning of the audio. I.e. this number of leading * decoded samples must be discarded by the caller to get the original audio * without leading padding. * * - decoding: unused * - encoding: Set by libavcodec. The timestamps on the output packets are * adjusted by the encoder so that they always refer to the * first sample of the data actually contained in the packet, * including any added padding. E.g. if the timebase is * 1/samplerate and the timestamp of the first input sample is * 0, the timestamp of the first output packet will be * -initial_padding. */ int initial_padding; /** * - decoding: For codecs that store a framerate value in the compressed * bitstream, the decoder may export it here. { 0, 1} when * unknown. * - encoding: May be used to signal the framerate of CFR content to an * encoder. */ AVRational framerate; /** * 标称非加速像素格式，参见AV_PIX_FMT_xxx。 * - encoding: unused. * - decoding: Set by libavcodec before calling get_format() */ enum AVPixelFormat sw_pix_fmt; /** * Timebase in which pkt_dts/pts and AVPacket.dts/pts are. * - encoding unused. * - decoding set by user. */ AVRational pkt_timebase; /** * AVCodecDescriptor * - encoding: unused. * - decoding: set by libavcodec. */ const AVCodecDescriptor *codec_descriptor; /** * Current statistics for PTS correction. * - decoding: maintained and used by libavcodec, not intended to be used by user apps * - encoding: unused */ int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far int64_t pts_correction_last_pts; /// PTS of the last frame int64_t pts_correction_last_dts; /// DTS of the last frame /** * Character encoding of the input subtitles file. * - decoding: set by user * - encoding: unused */ char *sub_charenc; /** * Subtitles character encoding mode. Formats or codecs might be adjusting * this setting (if they are doing the conversion themselves for instance). * - decoding: set by libavcodec * - encoding: unused */ int sub_charenc_mode; #define FF_SUB_CHARENC_MODE_DO_NOTHING -1 ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance) #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself #define FF_SUB_CHARENC_MODE_PRE_DECODER 1 ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv #define FF_SUB_CHARENC_MODE_IGNORE 2 ///< neither convert the subtitles, nor check them for valid UTF-8 /** * Skip processing alpha if supported by codec. * Note that if the format uses pre-multiplied alpha (common with VP6, * and recommended due to better video quality/compression) * the image will look as if alpha-blended onto a black background. * However for formats that do not use pre-multiplied alpha * there might be serious artefacts (though e.g. libswscale currently * assumes pre-multiplied alpha anyway). * * - decoding: set by user * - encoding: unused */ int skip_alpha; /** * Number of samples to skip after a discontinuity * - decoding: unused * - encoding: set by libavcodec */ int seek_preroll; #if FF_API_DEBUG_MV /** * @deprecated unused */ attribute_deprecated int debug_mv; #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames #endif /** * custom intra quantization matrix * - encoding: Set by user, can be NULL. * - decoding: unused. */ uint16_t *chroma_intra_matrix; /** * dump format separator. * can be ", " or "\n " or anything else * - encoding: Set by user. * - decoding: Set by user. */ uint8_t *dump_separator; /** * ',' separated list of allowed decoders. * If NULL then all are allowed * - encoding: unused * - decoding: set by user */ char *codec_whitelist; /** * Properties of the stream that gets decoded * - encoding: unused * - decoding: set by libavcodec */ unsigned properties; #define FF_CODEC_PROPERTY_LOSSLESS 0x00000001 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002 #define FF_CODEC_PROPERTY_FILM_GRAIN 0x00000004 /** * Additional data associated with the entire coded stream. * * - decoding: unused * - encoding: may be set by libavcodec after avcodec_open2(). */ AVPacketSideData *coded_side_data; int nb_coded_side_data; /** * A reference to the AVHWFramesContext describing the input (for encoding) * or output (decoding) frames. The reference is set by the caller and * afterwards owned (and freed) by libavcodec - it should never be read by * the caller after being set. * * - decoding: This field should be set by the caller from the get_format() * callback. The previous reference (if any) will always be * unreffed by libavcodec before the get_format() call. * * If the default get_buffer2() is used with a hwaccel pixel * format, then this AVHWFramesContext will be used for * allocating the frame buffers. * * - encoding: For hardware encoders configured to use a hwaccel pixel * format, this field should be set by the caller to a reference * to the AVHWFramesContext describing input frames. * AVHWFramesContext.format must be equal to * AVCodecContext.pix_fmt. * * This field should be set before avcodec_open2() is called. */ AVBufferRef *hw_frames_ctx; #if FF_API_SUB_TEXT_FORMAT /** * @deprecated unused */ attribute_deprecated int sub_text_format; #define FF_SUB_TEXT_FMT_ASS 0 #endif /** * Audio only. The amount of padding (in samples) appended by the encoder to * the end of the audio. I.e. this number of decoded samples must be * discarded by the caller from the end of the stream to get the original * audio without any trailing padding. * * - decoding: unused * - encoding: unused */ int trailing_padding; /** * The number of pixels per image to maximally accept. * * - decoding: set by user * - encoding: set by user */ int64_t max_pixels; /** * 对AVHWDeviceContext的引用，描述硬件编码器/解码器将使用的设备。 * 引用由调用者设置，然后由libavcodec拥有(并释放)。 * * This should be used if either the codec device does not require * hardware frames or any that are used are to be allocated internally by * libavcodec. If the user wishes to supply any of the frames used as * encoder input or decoder output then hw_frames_ctx should be used * instead. When hw_frames_ctx is set in get_format() for a decoder, this * field will be ignored while decoding the associated stream segment, but * may again be used on a following one after another get_format() call. * * For both encoders and decoders this field should be set before * avcodec_open2() is called and must not be written to thereafter. * * Note that some decoders may require this field to be set initially in * order to support hw_frames_ctx at all - in that case, all frames * contexts used must be created on the same device. */ AVBufferRef *hw_device_ctx; /** * Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated * decoding (if active). * - encoding: unused * - decoding: Set by user (either before avcodec_open2(), or in the * AVCodecContext.get_format callback) */ int hwaccel_flags; /** * Video decoding only. Certain video codecs support cropping, meaning that * only a sub-rectangle of the decoded frame is intended for display. This * option controls how cropping is handled by libavcodec. * * When set to 1 (the default), libavcodec will apply cropping internally. * I.e. it will modify the output frame width/height fields and offset the * data pointers (only by as much as possible while preserving alignment, or * by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that * the frames output by the decoder refer only to the cropped area. The * crop_* fields of the output frames will be zero. * * When set to 0, the width/height fields of the output frames will be set * to the coded dimensions and the crop_* fields will describe the cropping * rectangle. Applying the cropping is left to the caller. * * @warning When hardware acceleration with opaque output frames is used, * libavcodec is unable to apply cropping from the top/left border. * * @note when this option is set to zero, the width/height fields of the * AVCodecContext and output AVFrames have different meanings. The codec * context fields store display dimensions (with the coded dimensions in * coded_width/height), while the frame fields store the coded dimensions * (with the display dimensions being determined by the crop_* fields). */ int apply_cropping; /* * Video decoding only. Sets the number of extra hardware frames which * the decoder will allocate for use by the caller. This must be set * before avcodec_open2() is called. * * Some hardware decoders require all frames that they will use for * output to be defined in advance before decoding starts. For such * decoders, the hardware frame pool must therefore be of a fixed size. * The extra frames set here are on top of any number that the decoder * needs internally in order to operate normally (for example, frames * used as reference pictures). */ int extra_hw_frames; /** * The percentage of damaged samples to discard a frame. * * - decoding: set by user * - encoding: unused */ int discard_damaged_percentage; /** * The number of samples per frame to maximally accept. * * - decoding: set by user * - encoding: set by user */ int64_t max_samples; /** * Bit set of AV_CODEC_EXPORT_DATA_* flags, which affects the kind of * metadata exported in frame, packet, or coded stream side data by * decoders and encoders. * * - decoding: set by user * - encoding: set by user */ int export_side_data; /** * This callback is called at the beginning of each packet to get a data * buffer for it. * * The following field will be set in the packet before this callback is * called: * - size * This callback must use the above value to calculate the required buffer size, * which must padded by at least AV_INPUT_BUFFER_PADDING_SIZE bytes. * * In some specific cases, the encoder may not use the entire buffer allocated by this * callback. This will be reflected in the size value in the packet once returned by * avcodec_receive_packet(). * * This callback must fill the following fields in the packet: * - data: alignment requirements for AVPacket apply, if any. Some architectures and * encoders may benefit from having aligned data. * - buf: must contain a pointer to an AVBufferRef structure. The packet's * data pointer must be contained in it. See: av_buffer_create(), av_buffer_alloc(), * and av_buffer_ref(). * * If AV_CODEC_CAP_DR1 is not set then get_encode_buffer() must call * avcodec_default_get_encode_buffer() instead of providing a buffer allocated by * some other means. * * The flags field may contain a combination of AV_GET_ENCODE_BUFFER_FLAG_ flags. * They may be used for example to hint what use the buffer may get after being * created. * Implementations of this callback may ignore flags they don't understand. * If AV_GET_ENCODE_BUFFER_FLAG_REF is set in flags then the packet may be reused * (read and/or written to if it is writable) later by libavcodec. * * This callback must be thread-safe, as when frame threading is used, it may * be called from multiple threads simultaneously. * * @see avcodec_default_get_encode_buffer() * * - encoding: Set by libavcodec, user can override. * - decoding: unused */ int (*get_encode_buffer)(struct AVCodecContext *s, AVPacket *pkt, int flags); /** * Audio channel layout. * - encoding: must be set by the caller, to one of AVCodec.ch_layouts. * - decoding: may be set by the caller if known e.g. from the container. * The decoder can then override during decoding as needed. */ AVChannelLayout ch_layout; } AVCodecContext; /** * @defgroup lavc_hwaccel AVHWAccel * * @note Nothing in this structure should be accessed by the user. At some * point in future it will not be externally visible at all. * * @{ */ typedef struct AVHWAccel { /** * Name of the hardware accelerated codec. * The name is globally unique among encoders and among decoders (but an * encoder and a decoder can share the same name). */ const char *name; /** * Type of codec implemented by the hardware accelerator. * * See AVMEDIA_TYPE_xxx */ enum AVMediaType type; /** * Codec implemented by the hardware accelerator. * * See AV_CODEC_ID_xxx */ enum AVCodecID id; /** * Supported pixel format. * * Only hardware accelerated formats are supported here. */ enum AVPixelFormat pix_fmt; /** * Hardware accelerated codec capabilities. * see AV_HWACCEL_CODEC_CAP_* */ int capabilities; /***************************************************************** * No fields below this line are part of the public API. They * may not be used outside of libavcodec and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Allocate a custom buffer */ int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame); /** * Called at the beginning of each frame or field picture. * * Meaningful frame information (codec specific) is guaranteed to * be parsed at this point. This function is mandatory. * * Note that buf can be NULL along with buf_size set to 0. * Otherwise, this means the whole frame is available at this point. * * @param avctx the codec context * @param buf the frame data buffer base * @param buf_size the size of the frame in bytes * @return zero if successful, a negative value otherwise */ int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size); /** * Callback for parameter data (SPS/PPS/VPS etc). * * Useful for hardware decoders which keep persistent state about the * video parameters, and need to receive any changes to update that state. * * @param avctx the codec context * @param type the nal unit type * @param buf the nal unit data buffer * @param buf_size the size of the nal unit in bytes * @return zero if successful, a negative value otherwise */ int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size); /** * Callback for each slice. * * Meaningful slice information (codec specific) is guaranteed to * be parsed at this point. This function is mandatory. * * @param avctx the codec context * @param buf the slice data buffer base * @param buf_size the size of the slice in bytes * @return zero if successful, a negative value otherwise */ int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size); /** * Called at the end of each frame or field picture. * * The whole picture is parsed at this point and can now be sent * to the hardware accelerator. This function is mandatory. * * @param avctx the codec context * @return zero if successful, a negative value otherwise */ int (*end_frame)(AVCodecContext *avctx); /** * Size of per-frame hardware accelerator private data. * * Private data is allocated with av_mallocz() before * AVCodecContext.get_buffer() and deallocated after * AVCodecContext.release_buffer(). */ int frame_priv_data_size; /** * Initialize the hwaccel private data. * * This will be called from ff_get_format(), after hwaccel and * hwaccel_context are set and the hwaccel private data in AVCodecInternal * is allocated. */ int (*init)(AVCodecContext *avctx); /** * Uninitialize the hwaccel private data. * * This will be called from get_format() or avcodec_close(), after hwaccel * and hwaccel_context are already uninitialized. */ int (*uninit)(AVCodecContext *avctx); /** * Size of the private data to allocate in * AVCodecInternal.hwaccel_priv_data. */ int priv_data_size; /** * Internal hwaccel capabilities. */ int caps_internal; /** * Fill the given hw_frames context with current codec parameters. Called * from get_format. Refer to avcodec_get_hw_frames_parameters() for * details. * * This CAN be called before AVHWAccel.init is called, and you must assume * that avctx->hwaccel_priv_data is invalid. */ int (*frame_params)(AVCodecContext *avctx, AVBufferRef *hw_frames_ctx); } AVHWAccel; /** * HWAccel is experimental and is thus avoided in favor of non experimental * codecs */ #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL 0x0200 /** * Hardware acceleration should be used for decoding even if the codec level * used is unknown or higher than the maximum supported level reported by the * hardware driver. * * It's generally a good idea to pass this flag unless you have a specific * reason not to, as hardware tends to under-report supported levels. */ #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0) /** * Hardware acceleration can output YUV pixel formats with a different chroma * sampling than 4:2:0 and/or other than 8 bits per component. */ #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1) /** * Hardware acceleration should still be attempted for decoding when the * codec profile does not match the reported capabilities of the hardware. * * For example, this can be used to try to decode baseline profile H.264 * streams in hardware - it will often succeed, because many streams marked * as baseline profile actually conform to constrained baseline profile. * * @warning If the stream is actually not supported then the behaviour is * undefined, and may include returning entirely incorrect output * while indicating success. */ #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2) /** * @} */ enum AVSubtitleType { SUBTITLE_NONE, SUBTITLE_BITMAP, ///< A bitmap, pict will be set /** * Plain text, the text field must be set by the decoder and is * authoritative. ass and pict fields may contain approximations. */ SUBTITLE_TEXT, /** * Formatted text, the ass field must be set by the decoder and is * authoritative. pict and text fields may contain approximations. */ SUBTITLE_ASS, }; #define AV_SUBTITLE_FLAG_FORCED 0x00000001 typedef struct AVSubtitleRect { int x; ///< top left corner of pict, undefined when pict is not set int y; ///< top left corner of pict, undefined when pict is not set int w; ///< width of pict, undefined when pict is not set int h; ///< height of pict, undefined when pict is not set int nb_colors; ///< number of colors in pict, undefined when pict is not set /** * data+linesize for the bitmap of this subtitle. * Can be set for text/ass as well once they are rendered. */ uint8_t *data[4]; int linesize[4]; enum AVSubtitleType type; char *text; ///< 0 terminated plain UTF-8 text /** * 0 terminated ASS/SSA compatible event line. * The presentation of this is unaffected by the other values in this * struct. */ char *ass; int flags; } AVSubtitleRect; typedef struct AVSubtitle { uint16_t format; /* 0 = graphics */ uint32_t start_display_time; /* relative to packet pts, in ms */ uint32_t end_display_time; /* relative to packet pts, in ms */ unsigned num_rects; AVSubtitleRect **rects; int64_t pts; ///< Same as packet pts, in AV_TIME_BASE } AVSubtitle; /** * Return the LIBAVCODEC_VERSION_INT constant. */ unsigned avcodec_version(void); /** * Return the libavcodec build-time configuration. */ const char *avcodec_configuration(void); /** * Return the libavcodec license. */ const char *avcodec_license(void); /** * 分配AVCodecContext并将其字段设置为默认值。 * 应使用avcodec_free_context（）释放生成的结构。 * * @param codec 如果非null，为给定的编解码器分配私有数据并初始化默认值。然后用不同的编解码器调用avcodec_open2()是非法的。 * 如果为NULL，那么特定于编解码器的默认值将不会被初始化，这可能会导致不理想的默认设置(这主要对编码器很重要，例如libx264)。 * * @return AVCodecContext填充了默认值或失败时为NULL。 */ AVCodecContext *avcodec_alloc_context3(const AVCodec *codec); /** * 释放编解码器上下文和与之相关的所有内容，并将NULL写入提供的指针。 */ void avcodec_free_context(AVCodecContext **avctx); /** * Get the AVClass for AVCodecContext. It can be used in combination with * AV_OPT_SEARCH_FAKE_OBJ for examining options. * * @see av_opt_find(). */ const AVClass *avcodec_get_class(void); #if FF_API_GET_FRAME_CLASS /** * @deprecated This function should not be used. */ attribute_deprecated const AVClass *avcodec_get_frame_class(void); #endif /** * Get the AVClass for AVSubtitleRect. It can be used in combination with * AV_OPT_SEARCH_FAKE_OBJ for examining options. * * @see av_opt_find(). */ const AVClass *avcodec_get_subtitle_rect_class(void); /** * Fill the parameters struct based on the values from the supplied codec * context. Any allocated fields in par are freed and replaced with duplicates * of the corresponding fields in codec. * * @return >= 0 on success, a negative AVERROR code on failure */ int avcodec_parameters_from_context(AVCodecParameters *par, const AVCodecContext *codec); /** * 根据提供的编解码器参数的值填充编解码器上下文。 * 在编解码器中，在par中有相应字段的任何已分配字段将被释放，并用par中相应字段的副本替换。 * 不触及在par中没有对应项的编解码器中的字段。 * * @return >= 0 on success, a negative AVERROR code on failure. */ int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par); /** * 使用给定的AVCodec初始化AVCodecContext。 * 在使用此函数之前，必须使用avcodec_alloc_context3()来分配上下文。 * * 函数avcodec_find_decoder_by_name()、avcodec_find_encoder_by_name()、 * avcodec_find_decoder()和avcodec_find_encoder()为检索编解码器提供了一种简单的方法。 * * @note总是在使用解码例程(例如@ref avcodec_receive_frame())之前调用这个函数。 * * @code * av_dict_set(&opts, "b", "2.5M", 0); * codec = avcodec_find_decoder(AV_CODEC_ID_H264); * if (!codec) * exit(1); * * context = avcodec_alloc_context3(codec); * * if (avcodec_open2(context, codec, opts) < 0) * exit(1); * @endcode * * @param avctx 要初始化的上下文。 * @param codec 打开此上下文的编解码器。 * 如果一个非空的编解码器之前已经传递给avcodec_alloc_context3()或这个上下文， * 那么这个参数必须是NULL或等于之前传递的编解码器 * @param options 一个充满AVCodecContext和codec-private选项的字典。 * 返回时，该对象将被未找到的选项填充。 * * @return 成功为零，错误为负值 * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(), * av_dict_set(), av_opt_find(). */ int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options); /** * 关闭给定的AVCodecContext并释放与其关联的所有数据（但不是AVCodecContext本身）。 * * Calling this function on an AVCodecContext that hasn't been opened will free * the codec-specific data allocated in avcodec_alloc_context3() with a non-NULL * codec. Subsequent calls will do nothing. * * @note Do not use this function. Use avcodec_free_context() to destroy a * codec context (either open or closed). Opening and closing a codec context * multiple times is not supported anymore -- use multiple codec contexts * instead. */ int avcodec_close(AVCodecContext *avctx); /** * Free all allocated data in the given subtitle struct. * * @param sub AVSubtitle to free. */ void avsubtitle_free(AVSubtitle *sub); /** * @} */ /** * @addtogroup lavc_decoding * @{ */ /** * The default callback for AVCodecContext.get_buffer2(). It is made public so * it can be called by custom get_buffer2() implementations for decoders without * AV_CODEC_CAP_DR1 set. */ int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags); /** * The default callback for AVCodecContext.get_encode_buffer(). It is made public so * it can be called by custom get_encode_buffer() implementations for encoders without * AV_CODEC_CAP_DR1 set. */ int avcodec_default_get_encode_buffer(AVCodecContext *s, AVPacket *pkt, int flags); /** * Modify width and height values so that they will result in a memory * buffer that is acceptable for the codec if you do not use any horizontal * padding. * * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened. */ void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height); /** * Modify width and height values so that they will result in a memory * buffer that is acceptable for the codec if you also ensure that all * line sizes are a multiple of the respective linesize_align[i]. * * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened. */ void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height, int linesize_align[AV_NUM_DATA_POINTERS]); /** * Converts AVChromaLocation to swscale x/y chroma position. * * The positions represent the chroma (0,0) position in a coordinates system * with luma (0,0) representing the origin and luma(1,1) representing 256,256 * * @param xpos horizontal chroma sample position * @param ypos vertical chroma sample position */ int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos); /** * Converts swscale x/y chroma position to AVChromaLocation. * * The positions represent the chroma (0,0) position in a coordinates system * with luma (0,0) representing the origin and luma(1,1) representing 256,256 * * @param xpos horizontal chroma sample position * @param ypos vertical chroma sample position */ enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos); /** * Decode a subtitle message. * Return a negative value on error, otherwise return the number of bytes used. * If no subtitle could be decompressed, got_sub_ptr is zero. * Otherwise, the subtitle is stored in *sub. * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for * simplicity, because the performance difference is expected to be negligible * and reusing a get_buffer written for video codecs would probably perform badly * due to a potentially very different allocation pattern. * * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input * and output. This means that for some packets they will not immediately * produce decoded output and need to be flushed at the end of decoding to get * all the decoded data. Flushing is done by calling this function with packets * with avpkt->data set to NULL and avpkt->size set to 0 until it stops * returning subtitles. It is safe to flush even those decoders that are not * marked with AV_CODEC_CAP_DELAY, then no subtitles will be returned. * * @note The AVCodecContext MUST have been opened with @ref avcodec_open2() * before packets may be fed to the decoder. * * @param avctx the codec context * @param[out] sub The preallocated AVSubtitle in which the decoded subtitle will be stored, * must be freed with avsubtitle_free if *got_sub_ptr is set. * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero. * @param[in] avpkt The input AVPacket containing the input buffer. */ int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, AVPacket *avpkt); /** * 提供原始数据包数据作为解码器的输入。 * * 在内部，这个调用将复制相关的AVCodecContext字段， * 这些字段可能会影响每个包的解码，并在实际解码包时应用它们。 * (例如AVCodecContext。Skip_frame，它可能指示解码器丢弃与此函数一起发送的包所包含的帧。) * * @warning 输入缓冲区avpkt->data必须大于实际读取字节的AV_input_buffer_PADDING_SIZE， * 因为一些优化的比特流读取器一次读取32或64位，并且可以从末尾读取。 * * @note AVCodecContext必须用@ref avcodec_open2()打开，然后才能将数据包送入解码器。 * * @param avctx 编解码器上下文 * @param[in] avpkt 输入AVPacket。通常，这将是一个单一的视频帧，或几个完整的音频帧。 * 数据包的所有权仍然属于调用方，解码器不会对数据包进行写操作。 * 解码器可以创建对包数据的引用(如果包没有被引用计数，则复制它)。 * 与旧的api不同，包总是被完全消耗，如果它包含多个帧(例如一些音频编解码器)， * 将需要你调用avcodec_receive_frame()多次之后，你可以发送一个新的包。 * 它可以是NULL(或者数据设置为NULL，大小设置为0的AVPacket); * 在这种情况下，它被认为是一个刷新包，它标志着流的结束。 * 发送第一个flush包将返回成功。 * 后续的操作是不必要的，将返回AVERROR_EOF。 * 如果解码器仍然有帧缓冲， * 它将在发送flush包后返回它们。 * * @return 成功时为0，否则为负错误代码： * AVERROR(EAGAIN): input is not accepted in the current state - user * must read output with avcodec_receive_frame() (once * all output is read, the packet should be resent, and * the call will not fail with EAGAIN). * AVERROR_EOF: the decoder has been flushed, and no new packets can * be sent to it (also returned if more than 1 flush * packet is sent) * AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush * AVERROR(ENOMEM): failed to add packet to internal queue, or similar * other errors: legitimate decoding errors */ int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt); /** * 从解码器返回解码的输出数据。 * * @param avctx 编解码器上下文 * @param frame 这将设置为解码器分配的参考计数视频或音频帧（取决于解码器类型）。 * 请注意，在执行其他操作之前，该函数将始终调用av_frame_unref（frame）。 * * @return * 0: 成功，返回一帧 * AVERROR(EAGAIN): output is not available in this state - user must try * to send new input * AVERROR_EOF: the decoder has been fully flushed, and there will be * no more output frames * AVERROR(EINVAL): codec not opened, or it is an encoder * AVERROR_INPUT_CHANGED: current decoded frame has changed parameters * with respect to first decoded frame. Applicable * when flag AV_CODEC_FLAG_DROPCHANGED is set. * other negative values: legitimate decoding errors */ int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame); /** * Supply a raw video or audio frame to the encoder. Use avcodec_receive_packet() * to retrieve buffered output packets. * * @param avctx codec context * @param[in] frame AVFrame containing the raw audio or video frame to be encoded. * Ownership of the frame remains with the caller, and the * encoder will not write to the frame. The encoder may create * a reference to the frame data (or copy it if the frame is * not reference-counted). * It can be NULL, in which case it is considered a flush * packet. This signals the end of the stream. If the encoder * still has packets buffered, it will return them after this * call. Once flushing mode has been entered, additional flush * packets are ignored, and sending frames will return * AVERROR_EOF. * * For audio: * If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame * can have any number of samples. * If it is not set, frame->nb_samples must be equal to * avctx->frame_size for all frames except the last. * The final frame may be smaller than avctx->frame_size. * @return 0 on success, otherwise negative error code: * AVERROR(EAGAIN): input is not accepted in the current state - user * must read output with avcodec_receive_packet() (once * all output is read, the packet should be resent, and * the call will not fail with EAGAIN). * AVERROR_EOF: the encoder has been flushed, and no new frames can * be sent to it * AVERROR(EINVAL): codec not opened, it is a decoder, or requires flush * AVERROR(ENOMEM): failed to add packet to internal queue, or similar * other errors: legitimate encoding errors */ int avcodec_send_frame(AVCodecContext *avctx, const AVFrame *frame); /** * Read encoded data from the encoder. * * @param avctx codec context * @param avpkt This will be set to a reference-counted packet allocated by the * encoder. Note that the function will always call * av_packet_unref(avpkt) before doing anything else. * @return 0 on success, otherwise negative error code: * AVERROR(EAGAIN): output is not available in the current state - user * must try to send input * AVERROR_EOF: the encoder has been fully flushed, and there will be * no more output packets * AVERROR(EINVAL): codec not opened, or it is a decoder * other errors: legitimate encoding errors */ int avcodec_receive_packet(AVCodecContext *avctx, AVPacket *avpkt); /** * Create and return a AVHWFramesContext with values adequate for hardware * decoding. This is meant to get called from the get_format callback, and is * a helper for preparing a AVHWFramesContext for AVCodecContext.hw_frames_ctx. * This API is for decoding with certain hardware acceleration modes/APIs only. * * The returned AVHWFramesContext is not initialized. The caller must do this * with av_hwframe_ctx_init(). * * Calling this function is not a requirement, but makes it simpler to avoid * codec or hardware API specific details when manually allocating frames. * * Alternatively to this, an API user can set AVCodecContext.hw_device_ctx, * which sets up AVCodecContext.hw_frames_ctx fully automatically, and makes * it unnecessary to call this function or having to care about * AVHWFramesContext initialization at all. * * There are a number of requirements for calling this function: * * - It must be called from get_format with the same avctx parameter that was * passed to get_format. Calling it outside of get_format is not allowed, and * can trigger undefined behavior. * - The function is not always supported (see description of return values). * Even if this function returns successfully, hwaccel initialization could * fail later. (The degree to which implementations check whether the stream * is actually supported varies. Some do this check only after the user's * get_format callback returns.) * - The hw_pix_fmt must be one of the choices suggested by get_format. If the * user decides to use a AVHWFramesContext prepared with this API function, * the user must return the same hw_pix_fmt from get_format. * - The device_ref passed to this function must support the given hw_pix_fmt. * - After calling this API function, it is the user's responsibility to * initialize the AVHWFramesContext (returned by the out_frames_ref parameter), * and to set AVCodecContext.hw_frames_ctx to it. If done, this must be done * before returning from get_format (this is implied by the normal * AVCodecContext.hw_frames_ctx API rules). * - The AVHWFramesContext parameters may change every time time get_format is * called. Also, AVCodecContext.hw_frames_ctx is reset before get_format. So * you are inherently required to go through this process again on every * get_format call. * - It is perfectly possible to call this function without actually using * the resulting AVHWFramesContext. One use-case might be trying to reuse a * previously initialized AVHWFramesContext, and calling this API function * only to test whether the required frame parameters have changed. * - Fields that use dynamically allocated values of any kind must not be set * by the user unless setting them is explicitly allowed by the documentation. * If the user sets AVHWFramesContext.free and AVHWFramesContext.user_opaque, * the new free callback must call the potentially set previous free callback. * This API call may set any dynamically allocated fields, including the free * callback. * * The function will set at least the following fields on AVHWFramesContext * (potentially more, depending on hwaccel API): * * - All fields set by av_hwframe_ctx_alloc(). * - Set the format field to hw_pix_fmt. * - Set the sw_format field to the most suited and most versatile format. (An * implication is that this will prefer generic formats over opaque formats * with arbitrary restrictions, if possible.) * - Set the width/height fields to the coded frame size, rounded up to the * API-specific minimum alignment. * - Only _if_ the hwaccel requires a pre-allocated pool: set the initial_pool_size * field to the number of maximum reference surfaces possible with the codec, * plus 1 surface for the user to work (meaning the user can safely reference * at most 1 decoded surface at a time), plus additional buffering introduced * by frame threading. If the hwaccel does not require pre-allocation, the * field is left to 0, and the decoder will allocate new surfaces on demand * during decoding. * - Possibly AVHWFramesContext.hwctx fields, depending on the underlying * hardware API. * * Essentially, out_frames_ref returns the same as av_hwframe_ctx_alloc(), but * with basic frame parameters set. * * The function is stateless, and does not change the AVCodecContext or the * device_ref AVHWDeviceContext. * * @param avctx The context which is currently calling get_format, and which * implicitly contains all state needed for filling the returned * AVHWFramesContext properly. * @param device_ref A reference to the AVHWDeviceContext describing the device * which will be used by the hardware decoder. * @param hw_pix_fmt The hwaccel format you are going to return from get_format. * @param out_frames_ref On success, set to a reference to an _uninitialized_ * AVHWFramesContext, created from the given device_ref. * Fields will be set to values required for decoding. * Not changed if an error is returned. * @return zero on success, a negative value on error. The following error codes * have special semantics: * AVERROR(ENOENT): the decoder does not support this functionality. Setup * is always manual, or it is a decoder which does not * support setting AVCodecContext.hw_frames_ctx at all, * or it is a software format. * AVERROR(EINVAL): it is known that hardware decoding is not supported for * this configuration, or the device_ref is not supported * for the hwaccel referenced by hw_pix_fmt. */ int avcodec_get_hw_frames_parameters(AVCodecContext *avctx, AVBufferRef *device_ref, enum AVPixelFormat hw_pix_fmt, AVBufferRef **out_frames_ref); /** * @defgroup lavc_parsing Frame parsing * @{ */ enum AVPictureStructure { AV_PICTURE_STRUCTURE_UNKNOWN, //< unknown AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field AV_PICTURE_STRUCTURE_FRAME, //< coded as frame }; typedef struct AVCodecParserContext { void *priv_data; const struct AVCodecParser *parser; int64_t frame_offset; /* offset of the current frame */ int64_t cur_offset; /* current offset (incremented by each av_parser_parse()) */ int64_t next_frame_offset; /* offset of the next frame */ /* video info */ int pict_type; /* XXX: Put it back in AVCodecContext. */ /** * This field is used for proper frame duration computation in lavf. * It signals, how much longer the frame duration of the current frame * is compared to normal frame duration. * * frame_duration = (1 + repeat_pict) * time_base * * It is used by codecs like H.264 to display telecined material. */ int repeat_pict; /* XXX: Put it back in AVCodecContext. */ int64_t pts; /* pts of the current frame */ int64_t dts; /* dts of the current frame */ /* private data */ int64_t last_pts; int64_t last_dts; int fetch_timestamp; #define AV_PARSER_PTS_NB 4 int cur_frame_start_index; int64_t cur_frame_offset[AV_PARSER_PTS_NB]; int64_t cur_frame_pts[AV_PARSER_PTS_NB]; int64_t cur_frame_dts[AV_PARSER_PTS_NB]; int flags; #define PARSER_FLAG_COMPLETE_FRAMES 0x0001 #define PARSER_FLAG_ONCE 0x0002 /// Set if the parser has a valid file offset #define PARSER_FLAG_FETCHED_OFFSET 0x0004 #define PARSER_FLAG_USE_CODEC_TS 0x1000 int64_t offset; ///< byte offset from starting packet start int64_t cur_frame_end[AV_PARSER_PTS_NB]; /** * Set by parser to 1 for key frames and 0 for non-key frames. * It is initialized to -1, so if the parser doesn't set this flag, * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames * will be used. */ int key_frame; // Timestamp generation support: /** * Synchronization point for start of timestamp generation. * * Set to >0 for sync point, 0 for no sync point and <0 for undefined * (default). * * For example, this corresponds to presence of H.264 buffering period * SEI message. */ int dts_sync_point; /** * Offset of the current timestamp against last timestamp sync point in * units of AVCodecContext.time_base. * * Set to INT_MIN when dts_sync_point unused. Otherwise, it must * contain a valid timestamp offset. * * Note that the timestamp of sync point has usually a nonzero * dts_ref_dts_delta, which refers to the previous sync point. Offset of * the next frame after timestamp sync point will be usually 1. * * For example, this corresponds to H.264 cpb_removal_delay. */ int dts_ref_dts_delta; /** * Presentation delay of current frame in units of AVCodecContext.time_base. * * Set to INT_MIN when dts_sync_point unused. Otherwise, it must * contain valid non-negative timestamp delta (presentation time of a frame * must not lie in the past). * * This delay represents the difference between decoding and presentation * time of the frame. * * For example, this corresponds to H.264 dpb_output_delay. */ int pts_dts_delta; /** * Position of the packet in file. * * Analogous to cur_frame_pts/dts */ int64_t cur_frame_pos[AV_PARSER_PTS_NB]; /** * Byte position of currently parsed frame in stream. */ int64_t pos; /** * Previous frame byte position. */ int64_t last_pos; /** * Duration of the current frame. * For audio, this is in units of 1 / AVCodecContext.sample_rate. * For all other types, this is in units of AVCodecContext.time_base. */ int duration; enum AVFieldOrder field_order; /** * Indicate whether a picture is coded as a frame, top field or bottom field. * * For example, H.264 field_pic_flag equal to 0 corresponds to * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag * equal to 1 and bottom_field_flag equal to 0 corresponds to * AV_PICTURE_STRUCTURE_TOP_FIELD. */ enum AVPictureStructure picture_structure; /** * Picture number incremented in presentation or output order. * This field may be reinitialized at the first picture of a new sequence. * * For example, this corresponds to H.264 PicOrderCnt. */ int output_picture_number; /** * Dimensions of the decoded video intended for presentation. */ int width; int height; /** * Dimensions of the coded video. */ int coded_width; int coded_height; /** * The format of the coded data, corresponds to enum AVPixelFormat for video * and for enum AVSampleFormat for audio. * * Note that a decoder can have considerable freedom in how exactly it * decodes the data, so the format reported here might be different from the * one returned by a decoder. */ int format; } AVCodecParserContext; typedef struct AVCodecParser { int codec_ids[7]; /* several codec IDs are permitted */ int priv_data_size; int (*parser_init)(AVCodecParserContext *s); /* This callback never returns an error, a negative value means that * the frame start was in a previous packet. */ int (*parser_parse)(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size); void (*parser_close)(AVCodecParserContext *s); int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size); } AVCodecParser; /** * Iterate over all registered codec parsers. * * @param opaque a pointer where libavcodec will store the iteration state. Must * point to NULL to start the iteration. * * @return the next registered codec parser or NULL when the iteration is * finished */ const AVCodecParser *av_parser_iterate(void **opaque); AVCodecParserContext *av_parser_init(int codec_id); /** * Parse a packet. * * @param s parser context. * @param avctx codec context. * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished. * @param poutbuf_size set to size of parsed buffer or zero if not yet finished. * @param buf input buffer. * @param buf_size buffer size in bytes without the padding. I.e. the full buffer size is assumed to be buf_size + AV_INPUT_BUFFER_PADDING_SIZE. To signal EOF, this should be 0 (so that the last frame can be output). * @param pts input presentation timestamp. * @param dts input decoding timestamp. * @param pos input byte position in stream. * @return the number of bytes of the input bitstream used. * * Example: * @code * while(in_len){ * len = av_parser_parse2(myparser, AVCodecContext, &data, &size, * in_data, in_len, * pts, dts, pos); * in_data += len; * in_len -= len; * * if(size) * decode_frame(data, size); * } * @endcode */ int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int64_t pts, int64_t dts, int64_t pos); void av_parser_close(AVCodecParserContext *s); /** * @} * @} */ /** * @addtogroup lavc_encoding * @{ */ int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size, const AVSubtitle *sub); /** * @} */ /** * @defgroup lavc_misc Utility functions * @ingroup libavc * * Miscellaneous utility functions related to both encoding and decoding * (or neither). * @{ */ /** * @defgroup lavc_misc_pixfmt Pixel formats * * Functions for working with pixel formats. * @{ */ /** * Return a value representing the fourCC code associated to the * pixel format pix_fmt, or 0 if no associated fourCC code can be * found. */ unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt); /** * Find the best pixel format to convert to given a certain source pixel * format. When converting from one pixel format to another, information loss * may occur. For example, when converting from RGB24 to GRAY, the color * information will be lost. Similarly, other losses occur when converting from * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of * the given pixel formats should be used to suffer the least amount of loss. * The pixel formats from which it chooses one, are determined by the * pix_fmt_list parameter. * * * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from * @param[in] src_pix_fmt source pixel format * @param[in] has_alpha Whether the source pixel format alpha channel is used. * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur. * @return The best pixel format to convert to or -1 if none was found. */ enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list, enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr); enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt); /** * @} */ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode); int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size); int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count); //FIXME func typedef /** * Fill AVFrame audio data and linesize pointers. * * The buffer buf must be a preallocated buffer with a size big enough * to contain the specified samples amount. The filled AVFrame data * pointers will point to this buffer. * * AVFrame extended_data channel pointers are allocated if necessary for * planar audio. * * @param frame the AVFrame * frame->nb_samples must be set prior to calling the * function. This function fills in frame->data, * frame->extended_data, frame->linesize[0]. * @param nb_channels channel count * @param sample_fmt sample format * @param buf buffer to use for frame data * @param buf_size size of buffer * @param align plane size sample alignment (0 = default) * @return >=0 on success, negative error code on failure * @todo return the size in bytes required to store the samples in * case of success, at the next libavutil bump */ int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels, enum AVSampleFormat sample_fmt, const uint8_t *buf, int buf_size, int align); /** * Reset the internal codec state / flush internal buffers. Should be called * e.g. when seeking or when switching to a different stream. * * @note for decoders, this function just releases any references the decoder * might keep internally, but the caller's references remain valid. * * @note for encoders, this function will only do something if the encoder * declares support for AV_CODEC_CAP_ENCODER_FLUSH. When called, the encoder * will drain any remaining packets, and can then be re-used for a different * stream (as opposed to sending a null frame which will leave the encoder * in a permanent EOF state after draining). This can be desirable if the * cost of tearing down and replacing the encoder instance is high. */ void avcodec_flush_buffers(AVCodecContext *avctx); /** * Return audio frame duration. * * @param avctx codec context * @param frame_bytes size of the frame, or 0 if unknown * @return frame duration, in samples, if known. 0 if not able to * determine. */ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes); /* memory */ /** * Same behaviour av_fast_malloc but the buffer has additional * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0. * * In addition the whole buffer will initially and after resizes * be 0-initialized so that no uninitialized data will ever appear. */ void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size); /** * Same behaviour av_fast_padded_malloc except that buffer will always * be 0-initialized after call. */ void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size); /** * @return a positive value if s is open (i.e. avcodec_open2() was called on it * with no corresponding avcodec_close()), 0 otherwise. */ int avcodec_is_open(AVCodecContext *s); /** * @} */ #endif /* AVCODEC_AVCODEC_H */