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FFmpeg
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Modules | |
| Frame parsing | |
Macros | |
| #define | FF_INPUT_BUFFER_PADDING_SIZE 32 |
| Required number of additionally allocated bytes at the end of the input bitstream for decoding. | |
Enumerations | |
| enum | AVDiscard { AVDISCARD_NONE =-16, AVDISCARD_DEFAULT = 0, AVDISCARD_NONREF = 8, AVDISCARD_BIDIR = 16, AVDISCARD_NONINTRA = 24, AVDISCARD_NONKEY = 32, AVDISCARD_ALL = 48 } |
Functions | |
| AVCodec * | avcodec_find_decoder (enum AVCodecID id) |
| Find a registered decoder with a matching codec ID. | |
| AVCodec * | avcodec_find_decoder_by_name (const char *name) |
| Find a registered decoder with the specified name. | |
| attribute_deprecated int | avcodec_default_get_buffer (AVCodecContext *s, AVFrame *pic) |
| attribute_deprecated void | avcodec_default_release_buffer (AVCodecContext *s, AVFrame *pic) |
| attribute_deprecated int | avcodec_default_reget_buffer (AVCodecContext *s, AVFrame *pic) |
| int | avcodec_default_get_buffer2 (AVCodecContext *s, AVFrame *frame, int flags) |
| The default callback for AVCodecContext.get_buffer2(). | |
| attribute_deprecated unsigned | avcodec_get_edge_width (void) |
| Return the amount of padding in pixels which the get_buffer callback must provide around the edge of the image for codecs which do not have the CODEC_FLAG_EMU_EDGE flag. | |
| 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 do not use any horizontal padding. | |
| void | avcodec_align_dimensions2 (AVCodecContext *s, int *width, int *height, int linesize_align[AV_NUM_DATA_POINTERS]) |
| 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]. | |
| int | avcodec_enum_to_chroma_pos (int *xpos, int *ypos, enum AVChromaLocation pos) |
| Converts AVChromaLocation to swscale x/y chroma position. | |
| enum AVChromaLocation | avcodec_chroma_pos_to_enum (int xpos, int ypos) |
| Converts swscale x/y chroma position to AVChromaLocation. | |
| attribute_deprecated int | avcodec_decode_audio3 (AVCodecContext *avctx, int16_t *samples, int *frame_size_ptr, AVPacket *avpkt) |
| Wrapper function which calls avcodec_decode_audio4. | |
| int | avcodec_decode_audio4 (AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, const AVPacket *avpkt) |
| Decode the audio frame of size avpkt->size from avpkt->data into frame. | |
| int | avcodec_decode_video2 (AVCodecContext *avctx, AVFrame *picture, int *got_picture_ptr, const AVPacket *avpkt) |
| Decode the video frame of size avpkt->size from avpkt->data into picture. | |
| int | avcodec_decode_subtitle2 (AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, AVPacket *avpkt) |
| Decode a subtitle message. | |
| #define FF_INPUT_BUFFER_PADDING_SIZE 32 |
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
This is mainly needed because some optimized bitstream readers read 32 or 64 bit at once and could read over the end.
Note: If the first 23 bits of the additional bytes are not 0, then damaged MPEG bitstreams could cause overread and segfault.
Definition at line 624 of file avcodec.h.
Referenced by a64multi_encode_init(), aac_adtstoasc_filter(), aac_decode_frame(), aac_encode_init(), aac_sync(), aacPlus_encode_init(), ac3_sync(), adpcm_encode_init(), alac_encode_init(), alloc_and_copy(), alloc_buffers(), ape_tag_read_field(), apng_read_header(), append_extradata(), asf_parse_packet(), asf_read_stream_properties(), atrac3_decode_init(), audio_decode_example(), av_fast_padded_malloc(), av_fast_padded_mallocz(), av_grow_packet(), av_packet_from_data(), av_packet_merge_side_data(), av_packet_new_side_data(), av_packet_split_side_data(), av_parser_change(), av_parser_parse2(), av_shrink_packet(), avcodec_copy_context(), avcodec_decode_subtitle2(), avcodec_encode_audio2(), avcodec_encode_video2(), avi_read_header(), avio_close_dyn_buf(), avui_encode_init(), cdxl_decode_frame(), codec_reinit(), cook_decode_init(), dca_parse_params(), decode_frame(), decode_init(), decode_plane(), dshow_add_device(), dts_probe(), dump_extradata(), dv_decode_video_segment(), encode_init(), extract_header(), extract_mpeg4_header(), Faac_encode_init(), ff_alloc_extradata(), ff_alloc_packet2(), ff_combine_frame(), ff_flac_parse_picture(), ff_h264_decode_nal(), ff_hevc_extract_rbsp(), ff_id3v2_parse_apic(), ff_mjpeg_find_marker(), ff_mpeg_update_thread_context(), ff_mpv_encode_picture(), ff_parse_mpeg2_descriptor(), fixup_vorbis_headers(), flac_read_header(), flic_decode_frame_8BPP(), flv_queue_extradata(), g2m_init_buffers(), h264_mp4toannexb_filter(), h264_new_context(), handle_packets(), hevc_parse_sdp_line(), id3_has_changed_values(), iff_read_header(), imc_decode_frame(), imx_dump_header(), init(), jacosub_read_header(), jpg_decode_data(), latm_decode_audio_specific_config(), libopus_encode_init(), libvorbis_encode_init(), libx265_encode_init(), matroska_parse_tracks(), mjpega_dump_header(), mov2textsub(), mov_read_extradata(), mov_read_stsz(), mov_rewrite_dvd_sub_extradata(), mov_text_encode_init(), mov_write_dvc1_structs(), mp3_header_decompress(), mpc8_parse_seektable(), mpegts_push_data(), mss2_decode_frame(), mxg_update_cache(), new_pes_packet(), noise(), ogg_new_buf(), ogg_new_stream(), ogg_read_page(), ogg_save(), ogm_header(), packet_alloc(), parse_fmtp_config(), parse_packed_headers(), parse_vtrk(), pcx_decode_frame(), qt_rtp_parse_packet(), rdt_parse_b64buf(), read_apic(), read_header(), read_kuki_chunk(), read_packet(), read_sl_header(), recode_subtitle(), redspark_read_header(), rm_read_audio_stream_info(), sdp_parse_fmtp_config_h264(), shorten_decode_frame(), spdif_write_packet(), Stagefright_init(), tak_read_header(), text2movsub(), theora_header(), tiff_unpack_fax(), transcode_init(), utvideo_encode_init(), vc1_decode_frame(), vc1_decode_init(), vfw_read_header(), video_decode_example(), wma_decode_superframe(), wmv2_encode_init(), write_extradata(), write_frame(), wv_get_value_float(), and xwma_read_header().
| enum AVDiscard |
Find a registered decoder with a matching codec ID.
| id | AVCodecID of the requested decoder |
Definition at line 2907 of file utils.c.
Referenced by add_input_streams(), audio_decode_example(), avcodec_get_name(), avcodec_get_type(), avcodec_open2(), avcodec_string(), choose_decoder(), dshow_cycle_formats(), ff_load_image(), filter_codec_opts(), find_codec_or_die(), find_decoder(), list_formats(), open_codec_context(), open_input_file(), open_stream(), show_codecs(), smvjpeg_decode_init(), stream_component_open(), and video_decode_example().
| AVCodec* avcodec_find_decoder_by_name | ( | const char * | name | ) |
Find a registered decoder with the specified name.
| name | name of the requested decoder |
Definition at line 2912 of file utils.c.
Referenced by find_codec_or_die(), show_help_codec(), stream_component_open(), and v4l2_read_header().
| attribute_deprecated int avcodec_default_get_buffer | ( | AVCodecContext * | s, |
| AVFrame * | pic | ||
| ) |
Definition at line 833 of file utils.c.
Referenced by avcodec_decode_audio3().
| attribute_deprecated void avcodec_default_release_buffer | ( | AVCodecContext * | s, |
| AVFrame * | pic | ||
| ) |
Definition at line 1079 of file utils.c.
Referenced by avcodec_decode_audio3().
| attribute_deprecated int avcodec_default_reget_buffer | ( | AVCodecContext * | s, |
| AVFrame * | pic | ||
| ) |
| int avcodec_default_get_buffer2 | ( | AVCodecContext * | s, |
| AVFrame * | frame, | ||
| int | flags | ||
| ) |
The default callback for AVCodecContext.get_buffer2().
It is made public so it can be called by custom get_buffer2() implementations for decoders without CODEC_CAP_DR1 set.
Definition at line 712 of file utils.c.
Referenced by alloc_frame_buffer(), avcodec_default_get_buffer(), avcodec_get_context_defaults3(), ff_thread_release_buffer(), get_buffer(), submit_packet(), and thread_get_buffer_internal().
| attribute_deprecated unsigned avcodec_get_edge_width | ( | void | ) |
Return the amount of padding in pixels which the get_buffer callback must provide around the edge of the image for codecs which do not have the CODEC_FLAG_EMU_EDGE flag.
| void avcodec_align_dimensions | ( | AVCodecContext * | s, |
| int * | width, | ||
| int * | height | ||
| ) |
| void avcodec_align_dimensions2 | ( | AVCodecContext * | s, |
| int * | width, | ||
| int * | height, | ||
| int | linesize_align[AV_NUM_DATA_POINTERS] | ||
| ) |
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 CODEC_CAP_DR1 has been opened.
Definition at line 276 of file utils.c.
Referenced by avcodec_align_dimensions(), and update_frame_pool().
| int avcodec_enum_to_chroma_pos | ( | int * | xpos, |
| int * | ypos, | ||
| enum AVChromaLocation | pos | ||
| ) |
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
| xpos | horizontal chroma sample position |
| ypos | vertical chroma sample position |
Definition at line 448 of file utils.c.
Referenced by avcodec_chroma_pos_to_enum().
| enum AVChromaLocation avcodec_chroma_pos_to_enum | ( | int | xpos, |
| int | ypos | ||
| ) |
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
| xpos | horizontal chroma sample position |
| ypos | vertical chroma sample position |
| attribute_deprecated int avcodec_decode_audio3 | ( | AVCodecContext * | avctx, |
| int16_t * | samples, | ||
| int * | frame_size_ptr, | ||
| AVPacket * | avpkt | ||
| ) |
Wrapper function which calls avcodec_decode_audio4.
Decode the audio frame of size avpkt->size from avpkt->data into samples. Some decoders may support multiple frames in a single AVPacket, such decoders would then just decode the first frame. In this case, avcodec_decode_audio3 has to be called again with an AVPacket that contains the remaining data in order to decode the second frame etc. If no frame could be outputted, frame_size_ptr is zero. Otherwise, it is the decompressed frame size in bytes.
In practice, avpkt->data should have 4 byte alignment at minimum and samples should be 16 byte aligned unless the CPU doesn't need it (AltiVec and SSE do).
| avctx | the codec context | |
| [out] | samples | the output buffer, sample type in avctx->sample_fmt If the sample format is planar, each channel plane will be the same size, with no padding between channels. |
| [in,out] | frame_size_ptr | the output buffer size in bytes |
| [in] | avpkt | The input AVPacket containing the input buffer. You can create such packet with av_init_packet() and by then setting data and size, some decoders might in addition need other fields. All decoders are designed to use the least fields possible though. |
| int avcodec_decode_audio4 | ( | AVCodecContext * | avctx, |
| AVFrame * | frame, | ||
| int * | got_frame_ptr, | ||
| const AVPacket * | avpkt | ||
| ) |
Decode the audio frame of size avpkt->size from avpkt->data into frame.
Some decoders may support multiple frames in a single AVPacket. Such decoders would then just decode the first frame and the return value would be less than the packet size. In this case, avcodec_decode_audio4 has to be called again with an AVPacket containing the remaining data in order to decode the second frame, etc... Even if no frames are returned, the packet needs to be fed to the decoder with remaining data until it is completely consumed or an error occurs.
Some decoders (those marked with 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 samples. It is safe to flush even those decoders that are not marked with CODEC_CAP_DELAY, then no samples will be returned.
| avctx | the codec context | |
| [out] | frame | The AVFrame in which to store decoded audio samples. The decoder will allocate a buffer for the decoded frame by calling the AVCodecContext.get_buffer2() callback. When AVCodecContext.refcounted_frames is set to 1, the frame is reference counted and the returned reference belongs to the caller. The caller must release the frame using av_frame_unref() when the frame is no longer needed. The caller may safely write to the frame if av_frame_is_writable() returns 1. When AVCodecContext.refcounted_frames is set to 0, the returned reference belongs to the decoder and is valid only until the next call to this function or until closing or flushing the decoder. The caller may not write to it. |
| [out] | got_frame_ptr | Zero if no frame could be decoded, otherwise it is non-zero. Note that this field being set to zero does not mean that an error has occurred. For decoders with CODEC_CAP_DELAY set, no given decode call is guaranteed to produce a frame. |
| [in] | avpkt | The input AVPacket containing the input buffer. At least avpkt->data and avpkt->size should be set. Some decoders might also require additional fields to be set. |
Definition at line 2455 of file utils.c.
Referenced by audio_decode_example(), avcodec_decode_audio3(), decode_audio(), decode_audio_frame(), decode_packet(), decoder_decode_frame(), main(), movie_push_frame(), process_frame(), try_decode_frame(), and wrap().
| int avcodec_decode_video2 | ( | AVCodecContext * | avctx, |
| AVFrame * | picture, | ||
| int * | got_picture_ptr, | ||
| const AVPacket * | avpkt | ||
| ) |
Decode the video frame of size avpkt->size from avpkt->data into picture.
Some decoders may support multiple frames in a single AVPacket, such decoders would then just decode the first frame.
| avctx | the codec context | |
| [out] | picture | The AVFrame in which the decoded video frame will be stored. Use av_frame_alloc() to get an AVFrame. The codec will allocate memory for the actual bitmap by calling the AVCodecContext.get_buffer2() callback. When AVCodecContext.refcounted_frames is set to 1, the frame is reference counted and the returned reference belongs to the caller. The caller must release the frame using av_frame_unref() when the frame is no longer needed. The caller may safely write to the frame if av_frame_is_writable() returns 1. When AVCodecContext.refcounted_frames is set to 0, the returned reference belongs to the decoder and is valid only until the next call to this function or until closing or flushing the decoder. The caller may not write to it. |
| [in] | avpkt | The input AVPacket containing the input buffer. You can create such packet with av_init_packet() and by then setting data and size, some decoders might in addition need other fields like flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least fields possible. |
| [in,out] | got_picture_ptr | Zero if no frame could be decompressed, otherwise, it is nonzero. |
Definition at line 2309 of file utils.c.
Referenced by decode_packet(), decode_video(), decode_write_frame(), decoder_decode_frame(), ff_load_image(), main(), movie_push_frame(), process_frame(), smvjpeg_decode_frame(), try_decode_frame(), and wrap().
| int avcodec_decode_subtitle2 | ( | AVCodecContext * | avctx, |
| AVSubtitle * | sub, | ||
| int * | got_sub_ptr, | ||
| AVPacket * | avpkt | ||
| ) |
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 CODEC_CAP_DR1 is not available for subtitle codecs. This is for simplicity, because the performance difference is expect 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 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 CODEC_CAP_DELAY, then no subtitles will be returned.
| avctx | the codec context | |
| [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. |
| [in,out] | got_sub_ptr | Zero if no subtitle could be decompressed, otherwise, it is nonzero. |
| [in] | avpkt | The input AVPacket containing the input buffer. |
Definition at line 2686 of file utils.c.
Referenced by decoder_decode_frame(), process_frame(), transcode_subtitles(), try_decode_frame(), and wrap().
1.8.2
