ffmpeg/libavcodec/cbs_bsf.h

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/*
* 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_CBS_BSF_H
#define AVCODEC_CBS_BSF_H
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "bsf.h"
#include "codec_id.h"
#include "cbs.h"
#include "packet.h"
typedef struct CBSBSFType {
enum AVCodecID codec_id;
// Name of a frame fragment in this codec (e.g. "access unit",
// "temporal unit").
const char *fragment_name;
// Name of a unit for this BSF, for use in error messages (e.g.
// "NAL unit", "OBU").
const char *unit_name;
// Update the content of a fragment with whatever metadata changes
// are desired. The associated AVPacket is provided so that any side
// data associated with the fragment can be inspected or edited. If
// pkt is NULL, then an extradata header fragment is being updated.
int (*update_fragment)(AVBSFContext *bsf, AVPacket *pkt,
CodedBitstreamFragment *frag);
} CBSBSFType;
// Common structure for all generic CBS BSF users. An instance of this
// structure must be the first member of the BSF private context (to be
// pointed to by AVBSFContext.priv_data).
typedef struct CBSBSFContext {
const AVClass *class;
const CBSBSFType *type;
CodedBitstreamContext *input;
CodedBitstreamContext *output;
CodedBitstreamFragment fragment;
} CBSBSFContext;
/**
* Initialise generic CBS BSF setup.
*
* Creates the input and output CBS instances, and applies the filter to
* the extradata on the input codecpar if any is present.
*
* Since it calls the update_fragment() function immediately to deal with
* extradata, this should be called after any codec-specific setup is done
* (probably at the end of the FFBitStreamFilter.init function).
*/
int ff_cbs_bsf_generic_init(AVBSFContext *bsf, const CBSBSFType *type);
/**
* Close a generic CBS BSF instance.
*
* If no other deinitialisation is required then this function can be used
* directly as FFBitStreamFilter.close.
*/
void ff_cbs_bsf_generic_close(AVBSFContext *bsf);
/**
* Filter operation for CBS BSF.
*
* Reads the input packet into a CBS fragment, calls update_fragment() on
* it, then writes the result to an output packet. If the input packet
* has AV_PKT_DATA_NEW_EXTRADATA side-data associated with it then it does
* the same thing to that new extradata to form the output side-data first.
*
* If the BSF does not do anything else then this function can be used
* directly as FFBitStreamFilter.filter.
*/
int ff_cbs_bsf_generic_filter(AVBSFContext *bsf, AVPacket *pkt);
// Options for element manipulation.
enum {
// Pass this element through unchanged.
BSF_ELEMENT_PASS,
// Insert this element, replacing any existing instances of it.
// Associated values may be provided explicitly (as additional options)
// or implicitly (either as side data or deduced from other parts of
// the stream).
BSF_ELEMENT_INSERT,
// Remove this element if it appears in the stream.
BSF_ELEMENT_REMOVE,
// Extract this element to side data, so that further manipulation
// can happen elsewhere.
BSF_ELEMENT_EXTRACT,
};
#define BSF_ELEMENT_OPTIONS_PIR(name, help, field, opt_flags) \
{ name, help, OFFSET(field), AV_OPT_TYPE_INT, \
{ .i64 = BSF_ELEMENT_PASS }, \
BSF_ELEMENT_PASS, BSF_ELEMENT_REMOVE, opt_flags, name }, \
{ "pass", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_PASS }, .flags = opt_flags, .unit = name }, \
{ "insert", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_INSERT }, .flags = opt_flags, .unit = name }, \
{ "remove", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_REMOVE }, .flags = opt_flags, .unit = name }
#define BSF_ELEMENT_OPTIONS_PIRE(name, help, field, opt_flags) \
{ name, help, OFFSET(field), AV_OPT_TYPE_INT, \
{ .i64 = BSF_ELEMENT_PASS }, \
BSF_ELEMENT_PASS, BSF_ELEMENT_EXTRACT, opt_flags, name }, \
{ "pass", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_PASS }, .flags = opt_flags, .unit = name }, \
{ "insert", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_INSERT }, .flags = opt_flags, .unit = name }, \
{ "remove", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_REMOVE }, .flags = opt_flags, .unit = name }, \
{ "extract", NULL, 0, AV_OPT_TYPE_CONST, \
{ .i64 = BSF_ELEMENT_EXTRACT }, .flags = opt_flags, .unit = name } \
#endif /* AVCODEC_CBS_BSF_H */