ffmpeg/libavformat/av1.h

105 lines
3.8 KiB
C
Raw Normal View History

/*
* AV1 helper functions for muxers
*
* 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 AVFORMAT_AV1_H
#define AVFORMAT_AV1_H
#include <stdint.h>
#include "avio.h"
typedef struct AV1SequenceParameters {
uint8_t profile;
uint8_t level;
uint8_t tier;
uint8_t bitdepth;
uint8_t monochrome;
uint8_t chroma_subsampling_x;
uint8_t chroma_subsampling_y;
uint8_t chroma_sample_position;
uint8_t color_description_present_flag;
uint8_t color_primaries;
uint8_t transfer_characteristics;
uint8_t matrix_coefficients;
uint8_t color_range;
} AV1SequenceParameters;
/**
* Filter out AV1 OBUs not meant to be present in ISOBMFF sample data and write
* the resulting bitstream to the provided AVIOContext.
*
* @param pb pointer to the AVIOContext where the filtered bitstream shall be
* written; may be NULL, in which case nothing is written.
* @param buf input data buffer
* @param size size of the input data buffer
*
* @return the amount of bytes written (or would have been written in case
* pb had been supplied) in case of success, a negative AVERROR
* code in case of failure
* @note One can use NULL for pb to just get the output size.
*/
int ff_av1_filter_obus(AVIOContext *pb, const uint8_t *buf, int size);
/**
* Filter out AV1 OBUs not meant to be present in ISOBMFF sample data and return
* the result in a data buffer, avoiding allocations and copies if possible.
*
avformat/av1: Improve filtering AV1 OBUs Both ISOBMFF as well as Matroska require certain OBUs to be stripped before muxing them. There are two functions for this purpose; one writes directly into an AVIOContext, the other returns a freshly allocated buffer with the undesired units stripped away. The latter one actually relies on the former by means of a dynamic buffer. This has several drawbacks: The underlying buffer might have to be reallocated multiple times; the buffer will eventually be overallocated; the data will not be directly copied into the final buffer, but rather first in the write buffer (in chunks of 1024 byte) and then written in these chunks. Moreover, the API for dynamic buffers is defective wrt error checking and as a consequence, the earlier code would indicate a length of -AV_INPUT_BUFFER_PADDING_SIZE on allocation failure, but it would not return an error; there would also be no error in case the arbitrary limit of INT_MAX/2 that is currently imposed on dynamic buffers is hit. This commit changes this: The buffer is now parsed twice, once to get the precise length which will then be allocated; and once to actually write the data. For a 22.7mb/s file with average framesize 113 kB this improved the time for the calls to ff_av1_filter_obus_buf() when writing Matroska from 753662 decicycles to 313319 decicycles (based upon 50 runs a 2048 frames each); for another 1.5mb/s file (with average framesize of 7.3 kB) it improved from 79270 decicycles to 34539 decicycles (based upon 50 runs a 4096 frames). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: James Almer <jamrial@gmail.com>
2020-01-23 16:08:32 +00:00
* @param in input data buffer
* @param out pointer to pointer for the returned buffer. In case of success,
* it is independently allocated if and only if `*out` differs from in.
* @param size size of the input data buffer. The size of the resulting output
* data buffer will be written here
* @param offset offset of the returned data inside `*out`: It runs from
* `*out + offset` (inclusive) to `*out + offset + size`
* (exclusive); is zero if `*out` is independently allocated.
*
* @return 0 in case of success, a negative AVERROR code in case of failure.
* On failure, *out and *size are unchanged
* @note *out will be treated as unintialized on input and will not be freed.
*/
int ff_av1_filter_obus_buf(const uint8_t *in, uint8_t **out,
int *size, int *offset);
/**
* Parses a Sequence Header from the the provided buffer.
*
* @param seq pointer to the AV1SequenceParameters where the parsed values will
* be written
* @param buf input data buffer
* @param size size in bytes of the input data buffer
*
* @return >= 0 in case of success, a negative AVERROR code in case of failure
*/
int ff_av1_parse_seq_header(AV1SequenceParameters *seq, const uint8_t *buf, int size);
/**
* Writes AV1 extradata (Sequence Header and Metadata OBUs) to the provided
* AVIOContext.
*
* @param pb pointer to the AVIOContext where the av1C box shall be written
* @param buf input data buffer
* @param size size in bytes of the input data buffer
*
* @return >= 0 in case of success, a negative AVERROR code in case of failure
*/
int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size);
#endif /* AVFORMAT_AV1_H */