/* * 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/channel_layout.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_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" #include "codec_desc.h" #include "codec_par.h" #endif struct AVCodecParameters; /** * @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. * @{ */ #if FF_API_BUFFER_MIN_SIZE /** * @ingroup lavc_encoding * minimum encoding buffer size * Used to avoid some checks during header writing. * @deprecated Unused: avcodec_receive_packet() does not work * with preallocated packet buffers. */ #define AV_INPUT_BUFFER_MIN_SIZE … #endif /** * @ingroup lavc_encoding */ 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 … /** * Use fixed qscale. */ #define AV_CODEC_FLAG_QSCALE … /** * 4 MV per MB allowed / advanced prediction for H.263. */ #define AV_CODEC_FLAG_4MV … /** * Output even those frames that might be corrupted. */ #define AV_CODEC_FLAG_OUTPUT_CORRUPT … /** * Use qpel MC. */ #define AV_CODEC_FLAG_QPEL … #if FF_API_DROPCHANGED /** * Don't output frames whose parameters differ from first * decoded frame in stream. * * @deprecated callers should implement this functionality in their own code */ #define AV_CODEC_FLAG_DROPCHANGED … #endif /** * Request the encoder to output reconstructed frames, i.e.\ frames that would * be produced by decoding the encoded bistream. These frames may be retrieved * by calling avcodec_receive_frame() immediately after a successful call to * avcodec_receive_packet(). * * Should only be used with encoders flagged with the * @ref AV_CODEC_CAP_ENCODER_RECON_FRAME capability. * * @note * Each reconstructed frame returned by the encoder corresponds to the last * encoded packet, i.e. the frames are returned in coded order rather than * presentation order. * * @note * Frame parameters (like pixel format or dimensions) do not have to match the * AVCodecContext values. Make sure to use the values from the returned frame. */ #define AV_CODEC_FLAG_RECON_FRAME … /** * @par decoding * Request the decoder to propagate each packet's AVPacket.opaque and * AVPacket.opaque_ref to its corresponding output AVFrame. * * @par encoding: * Request the encoder to propagate each frame's AVFrame.opaque and * AVFrame.opaque_ref values to its corresponding output AVPacket. * * @par * May only be set on encoders that have the * @ref AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability flag. * * @note * While in typical cases one input frame produces exactly one output packet * (perhaps after a delay), in general the mapping of frames to packets is * M-to-N, so * - Any number of input frames may be associated with any given output packet. * This includes zero - e.g. some encoders may output packets that carry only * metadata about the whole stream. * - A given input frame may be associated with any number of output packets. * Again this includes zero - e.g. some encoders may drop frames under certain * conditions. * . * This implies that when using this flag, the caller must NOT assume that * - a given input frame's opaques will necessarily appear on some output packet; * - every output packet will have some non-NULL opaque value. * . * When an output packet contains multiple frames, the opaque values will be * taken from the first of those. * * @note * The converse holds for decoders, with frames and packets switched. */ #define AV_CODEC_FLAG_COPY_OPAQUE … /** * Signal to the encoder that the values of AVFrame.duration are valid and * should be used (typically for transferring them to output packets). * * If this flag is not set, frame durations are ignored. */ #define AV_CODEC_FLAG_FRAME_DURATION … /** * Use internal 2pass ratecontrol in first pass mode. */ #define AV_CODEC_FLAG_PASS1 … /** * Use internal 2pass ratecontrol in second pass mode. */ #define AV_CODEC_FLAG_PASS2 … /** * loop filter. */ #define AV_CODEC_FLAG_LOOP_FILTER … /** * Only decode/encode grayscale. */ #define AV_CODEC_FLAG_GRAY … /** * error[?] variables will be set during encoding. */ #define AV_CODEC_FLAG_PSNR … /** * Use interlaced DCT. */ #define AV_CODEC_FLAG_INTERLACED_DCT … /** * Force low delay. */ #define AV_CODEC_FLAG_LOW_DELAY … /** * Place global headers in extradata instead of every keyframe. */ #define AV_CODEC_FLAG_GLOBAL_HEADER … /** * Use only bitexact stuff (except (I)DCT). */ #define AV_CODEC_FLAG_BITEXACT … /* Fx : Flag for H.263+ extra options */ /** * H.263 advanced intra coding / MPEG-4 AC prediction */ #define AV_CODEC_FLAG_AC_PRED … /** * interlaced motion estimation */ #define AV_CODEC_FLAG_INTERLACED_ME … #define AV_CODEC_FLAG_CLOSED_GOP … /** * Allow non spec compliant speedup tricks. */ #define AV_CODEC_FLAG2_FAST … /** * Skip bitstream encoding. */ #define AV_CODEC_FLAG2_NO_OUTPUT … /** * Place global headers at every keyframe instead of in extradata. */ #define AV_CODEC_FLAG2_LOCAL_HEADER … /** * Input bitstream might be truncated at a packet boundaries * instead of only at frame boundaries. */ #define AV_CODEC_FLAG2_CHUNKS … /** * Discard cropping information from SPS. */ #define AV_CODEC_FLAG2_IGNORE_CROP … /** * Show all frames before the first keyframe */ #define AV_CODEC_FLAG2_SHOW_ALL … /** * Export motion vectors through frame side data */ #define AV_CODEC_FLAG2_EXPORT_MVS … /** * Do not skip samples and export skip information as frame side data */ #define AV_CODEC_FLAG2_SKIP_MANUAL … /** * Do not reset ASS ReadOrder field on flush (subtitles decoding) */ #define AV_CODEC_FLAG2_RO_FLUSH_NOOP … /** * Generate/parse ICC profiles on encode/decode, as appropriate for the type of * file. No effect on codecs which cannot contain embedded ICC profiles, or * when compiled without support for lcms2. */ #define AV_CODEC_FLAG2_ICC_PROFILES … /* 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 … /** * Export encoder Producer Reference Time through packet side data */ #define AV_CODEC_EXPORT_DATA_PRFT … /** * Decoding only. * Export the AVVideoEncParams structure through frame side data. */ #define AV_CODEC_EXPORT_DATA_VIDEO_ENC_PARAMS … /** * Decoding only. * Do not apply film grain, export it instead. */ #define AV_CODEC_EXPORT_DATA_FILM_GRAIN … /** * The decoder will keep a reference to the frame and may reuse it later. */ #define AV_GET_BUFFER_FLAG_REF … /** * The encoder will keep a reference to the packet and may reuse it later. */ #define AV_GET_ENCODE_BUFFER_FLAG_REF … /** * 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*. */ 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. * * @{ */ AVHWAccel; /** * HWAccel is experimental and is thus avoided in favor of non experimental * codecs */ #define AV_HWACCEL_CODEC_CAP_EXPERIMENTAL … /** * 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 … /** * 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 … /** * 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 … /** * Some hardware decoders (namely nvdec) can either output direct decoder * surfaces, or make an on-device copy and return said copy. * There is a hard limit on how many decoder surfaces there can be, and it * cannot be accurately guessed ahead of time. * For some processing chains, this can be okay, but others will run into the * limit and in turn produce very confusing errors that require fine tuning of * more or less obscure options by the user, or in extreme cases cannot be * resolved at all without inserting an avfilter that forces a copy. * * Thus, the hwaccel will by default make a copy for safety and resilience. * If a users really wants to minimize the amount of copies, they can set this * flag and ensure their processing chain does not exhaust the surface pool. */ #define AV_HWACCEL_FLAG_UNSAFE_OUTPUT … /** * @} */ enum AVSubtitleType { … }; #define AV_SUBTITLE_FLAG_FORCED … AVSubtitleRect; 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); /** * Allocate an AVCodecContext and set its fields to default values. The * resulting struct should be freed with avcodec_free_context(). * * @param codec if non-NULL, allocate private data and initialize defaults * for the given codec. It is illegal to then call avcodec_open2() * with a different codec. * If NULL, then the codec-specific defaults won't be initialized, * which may result in suboptimal default settings (this is * important mainly for encoders, e.g. libx264). * * @return An AVCodecContext filled with default values or NULL on failure. */ AVCodecContext *avcodec_alloc_context3(const AVCodec *codec); /** * Free the codec context and everything associated with it and write NULL to * the provided pointer. */ 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); /** * 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(struct AVCodecParameters *par, const AVCodecContext *codec); /** * Fill the codec context based on the values from the supplied codec * parameters. Any allocated fields in codec that have a corresponding field in * par are freed and replaced with duplicates of the corresponding field in par. * Fields in codec that do not have a counterpart in par are not touched. * * @return >= 0 on success, a negative AVERROR code on failure. */ int avcodec_parameters_to_context(AVCodecContext *codec, const struct AVCodecParameters *par); /** * Initialize the AVCodecContext to use the given AVCodec. Prior to using this * function the context has to be allocated with avcodec_alloc_context3(). * * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(), * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for * retrieving a codec. * * Depending on the codec, you might need to set options in the codec context * also for decoding (e.g. width, height, or the pixel or audio sample format in * the case the information is not available in the bitstream, as when decoding * raw audio or video). * * Options in the codec context can be set either by setting them in the options * AVDictionary, or by setting the values in the context itself, directly or by * using the av_opt_set() API before calling this function. * * Example: * @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 * * In the case AVCodecParameters are available (e.g. when demuxing a stream * using libavformat, and accessing the AVStream contained in the demuxer), the * codec parameters can be copied to the codec context using * avcodec_parameters_to_context(), as in the following example: * * @code * AVStream *stream = ...; * context = avcodec_alloc_context3(codec); * if (avcodec_parameters_to_context(context, stream->codecpar) < 0) * exit(1); * if (avcodec_open2(context, codec, NULL) < 0) * exit(1); * @endcode * * @note Always call this function before using decoding routines (such as * @ref avcodec_receive_frame()). * * @param avctx The context to initialize. * @param codec The codec to open this context for. If a non-NULL codec has been * previously passed to avcodec_alloc_context3() or * for this context, then this parameter MUST be either NULL or * equal to the previously passed codec. * @param options A dictionary filled with AVCodecContext and codec-private * options, which are set on top of the options already set in * avctx, can be NULL. On return this object will be filled with * options that were not found in the avctx codec context. * * @return zero on success, a negative value on error * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(), * av_dict_set(), av_opt_set(), av_opt_find(), avcodec_parameters_to_context() */ int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options); #if FF_API_AVCODEC_CLOSE /** * Close a given AVCodecContext and free all the data associated with it * (but not the AVCodecContext itself). * * 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. * * @deprecated 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. */ attribute_deprecated int avcodec_close(AVCodecContext *avctx); #endif /** * 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]); /** * 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, const AVPacket *avpkt); /** * Supply raw packet data as input to a decoder. * * Internally, this call will copy relevant AVCodecContext fields, which can * influence decoding per-packet, and apply them when the packet is actually * decoded. (For example AVCodecContext.skip_frame, which might direct the * decoder to drop the frame contained by the packet sent with this function.) * * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE * larger than the actual read bytes because some optimized bitstream * readers read 32 or 64 bits at once and could read over the end. * * @note The AVCodecContext MUST have been opened with @ref avcodec_open2() * before packets may be fed to the decoder. * * @param avctx codec context * @param[in] avpkt The input AVPacket. Usually, this will be a single video * frame, or several complete audio frames. * Ownership of the packet remains with the caller, and the * decoder will not write to the packet. The decoder may create * a reference to the packet data (or copy it if the packet is * not reference-counted). * Unlike with older APIs, the packet is always fully consumed, * and if it contains multiple frames (e.g. some audio codecs), * will require you to call avcodec_receive_frame() multiple * times afterwards before you can send a new packet. * It can be NULL (or an AVPacket with data set to NULL and * size set to 0); in this case, it is considered a flush * packet, which signals the end of the stream. Sending the * first flush packet will return success. Subsequent ones are * unnecessary and will return AVERROR_EOF. If the decoder * still has frames buffered, it will return them after sending * a flush packet. * * @retval 0 success * @retval 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). * @retval 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) * @retval AVERROR(EINVAL) codec not opened, it is an encoder, or requires flush * @retval AVERROR(ENOMEM) failed to add packet to internal queue, or similar * @retval "another negative error code" legitimate decoding errors */ int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt); /** * Return decoded output data from a decoder or encoder (when the * @ref AV_CODEC_FLAG_RECON_FRAME flag is used). * * @param avctx codec context * @param frame This will be set to a reference-counted video or audio * frame (depending on the decoder type) allocated by the * codec. Note that the function will always call * av_frame_unref(frame) before doing anything else. * * @retval 0 success, a frame was returned * @retval AVERROR(EAGAIN) output is not available in this state - user must * try to send new input * @retval AVERROR_EOF the codec has been fully flushed, and there will be * no more output frames * @retval AVERROR(EINVAL) codec not opened, or it is an encoder without the * @ref AV_CODEC_FLAG_RECON_FRAME flag enabled * @retval "other negative error code" 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. * @retval 0 success * @retval 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). * @retval AVERROR_EOF the encoder has been flushed, and no new frames can * be sent to it * @retval AVERROR(EINVAL) codec not opened, it is a decoder, or requires flush * @retval AVERROR(ENOMEM) failed to add packet to internal queue, or similar * @retval "another negative error code" 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. * @retval 0 success * @retval AVERROR(EAGAIN) output is not available in the current state - user must * try to send input * @retval AVERROR_EOF the encoder has been fully flushed, and there will be no * more output packets * @retval AVERROR(EINVAL) codec not opened, or it is a decoder * @retval "another negative error code" 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 { … }; AVCodecParserContext; 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 */
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