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lavc: add a bitstream filter for extracting extradata from packets

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This is intended as a replacement for the 'split' function exported by
some parsers.
This commit is contained in:
Anton Khirnov 2016-08-21 17:08:34 +02:00
parent f6e2f8a9ff
commit 89b35a139e
5 changed files with 322 additions and 2 deletions
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18
doc/bitstream_filters.texi
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@ -21,6 +21,24 @@ Below is a description of the currently available bitstream filters.
@section dump_extradata
@section extract_extradata
Extract the in-band extradata.
Certain codecs allow the long-term headers (e.g. MPEG-2 sequence headers,
or H.264/HEVC (VPS/)SPS/PPS) to be transmitted either "in-band" (i.e. as a part
of the bitstream containing the coded frames) or "out of band" (e.g. on the
container level). This latter form is called "extradata" in Libav terminology.
This bitstream filter detects the in-band headers and makes them available as
extradata.
@table @option
@item remove
When this option is enabled, the long-term headers are removed from the
bitstream after extraction.
@end table
@section h264_mp4toannexb
@section imx_dump_header

1
libavcodec/Makefile
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@ -748,6 +748,7 @@ OBJS-$(CONFIG_AAC_ADTSTOASC_BSF) += aac_adtstoasc_bsf.o aacadtsdec.o \
mpeg4audio.o
OBJS-$(CONFIG_CHOMP_BSF) += chomp_bsf.o
OBJS-$(CONFIG_DUMP_EXTRADATA_BSF) += dump_extradata_bsf.o
OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF) += extract_extradata_bsf.o
OBJS-$(CONFIG_H264_MP4TOANNEXB_BSF) += h264_mp4toannexb_bsf.o
OBJS-$(CONFIG_HEVC_MP4TOANNEXB_BSF) += hevc_mp4toannexb_bsf.o
OBJS-$(CONFIG_IMX_DUMP_HEADER_BSF) += imx_dump_header_bsf.o

1
libavcodec/bitstream_filters.c
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@ -27,6 +27,7 @@
extern const AVBitStreamFilter ff_aac_adtstoasc_bsf;
extern const AVBitStreamFilter ff_chomp_bsf;
extern const AVBitStreamFilter ff_dump_extradata_bsf;
extern const AVBitStreamFilter ff_extract_extradata_bsf;
extern const AVBitStreamFilter ff_h264_mp4toannexb_bsf;
extern const AVBitStreamFilter ff_hevc_mp4toannexb_bsf;
extern const AVBitStreamFilter ff_imx_dump_header_bsf;

300
libavcodec/extract_extradata_bsf.c Normal file
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@ -0,0 +1,300 @@
/*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdint.h>
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "bsf.h"
#include "h2645_parse.h"
#include "h264.h"
#include "hevc.h"
#include "vc1_common.h"
typedef struct ExtractExtradataContext {
const AVClass *class;
int (*extract)(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size);
/* AVOptions */
int remove;
} ExtractExtradataContext;
static int val_in_array(const int *arr, int len, int val)
{
int i;
for (i = 0; i < len; i++)
if (arr[i] == val)
return 1;
return 0;
}
static int extract_extradata_h2645(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size)
{
static const int extradata_nal_types_hevc[] = {
HEVC_NAL_VPS, HEVC_NAL_SPS, HEVC_NAL_PPS,
};
static const int extradata_nal_types_h264[] = {
H264_NAL_SPS, H264_NAL_PPS,
};
ExtractExtradataContext *s = ctx->priv_data;
H2645Packet h2645_pkt = { 0 };
int extradata_size = 0;
const int *extradata_nal_types;
int nb_extradata_nal_types;
int i, ret = 0;
if (ctx->par_in->codec_id == AV_CODEC_ID_HEVC) {
extradata_nal_types = extradata_nal_types_hevc;
nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_hevc);
} else {
extradata_nal_types = extradata_nal_types_h264;
nb_extradata_nal_types = FF_ARRAY_ELEMS(extradata_nal_types_h264);
}
ret = ff_h2645_packet_split(&h2645_pkt, pkt->data, pkt->size,
ctx, 0, 0, ctx->par_in->codec_id);
if (ret < 0)
return ret;
for (i = 0; i < h2645_pkt.nb_nals; i++) {
H2645NAL *nal = &h2645_pkt.nals[i];
if (val_in_array(extradata_nal_types, nb_extradata_nal_types, nal->type))
extradata_size += nal->raw_size + 3;
}
if (extradata_size) {
AVBufferRef *filtered_buf;
uint8_t *extradata, *filtered_data;
if (s->remove) {
filtered_buf = av_buffer_alloc(pkt->size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!filtered_buf)
goto fail;
filtered_data = filtered_buf->data;
}
extradata = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!extradata) {
av_buffer_unref(&filtered_buf);
goto fail;
}
*data = extradata;
*size = extradata_size;
for (i = 0; i < h2645_pkt.nb_nals; i++) {
H2645NAL *nal = &h2645_pkt.nals[i];
if (val_in_array(extradata_nal_types, nb_extradata_nal_types,
nal->type)) {
AV_WB24(extradata, 1); // startcode
memcpy(extradata + 3, nal->raw_data, nal->raw_size);
extradata += 3 + nal->raw_size;
} else if (s->remove) {
AV_WB24(filtered_data, 1); // startcode
memcpy(filtered_data + 3, nal->raw_data, nal->raw_size);
filtered_data += 3 + nal->raw_size;
}
}
if (s->remove) {
av_buffer_unref(&pkt->buf);
pkt->buf = filtered_buf;
pkt->data = filtered_buf->data;
pkt->size = filtered_data - filtered_buf->data;
}
}
fail:
ff_h2645_packet_uninit(&h2645_pkt);
return ret;
}
static int extract_extradata_vc1(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size)
{
ExtractExtradataContext *s = ctx->priv_data;
uint32_t state = UINT32_MAX;
int has_extradata = 0, extradata_size = 0;
int i;
for (i = 0; i < pkt->size; i++) {
state = (state << 8) | pkt->data[i];
if (IS_MARKER(state)) {
if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) {
has_extradata = 1;
} else if (has_extradata) {
extradata_size = i - 3;
break;
}
}
}
if (extradata_size) {
*data = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!*data)
return AVERROR(ENOMEM);
memcpy(*data, pkt->data, extradata_size);
*size = extradata_size;
if (s->remove) {
pkt->data += extradata_size;
pkt->size -= extradata_size;
}
}
return 0;
}
static int extract_extradata_mpeg124(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size)
{
ExtractExtradataContext *s = ctx->priv_data;
int is_mpeg12 = ctx->par_in->codec_id == AV_CODEC_ID_MPEG1VIDEO ||
ctx->par_in->codec_id == AV_CODEC_ID_MPEG2VIDEO;
uint32_t state = UINT32_MAX;
int i;
for (i = 0; i < pkt->size; i++) {
state = (state << 8) | pkt->data[i];
if ((is_mpeg12 && state != 0x1B3 && state != 0x1B5 && state < 0x200 && state >= 0x100) ||
(!is_mpeg12 && (state == 0x1B3 || state == 0x1B6))) {
if (i > 3) {
*size = i - 3;
*data = av_malloc(*size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!*data)
return AVERROR(ENOMEM);
memcpy(*data, pkt->data, *size);
if (s->remove) {
pkt->data += *size;
pkt->size -= *size;
}
}
break;
}
}
return 0;
}
static const struct {
enum AVCodecID id;
int (*extract)(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size);
} extract_tab[] = {
{ AV_CODEC_ID_CAVS, extract_extradata_mpeg124 },
{ AV_CODEC_ID_H264, extract_extradata_h2645 },
{ AV_CODEC_ID_HEVC, extract_extradata_h2645 },
{ AV_CODEC_ID_MPEG1VIDEO, extract_extradata_mpeg124 },
{ AV_CODEC_ID_MPEG2VIDEO, extract_extradata_mpeg124 },
{ AV_CODEC_ID_MPEG4, extract_extradata_mpeg124 },
{ AV_CODEC_ID_VC1, extract_extradata_vc1 },
};
static int extract_extradata_init(AVBSFContext *ctx)
{
ExtractExtradataContext *s = ctx->priv_data;
int i;
for (i = 0; i < FF_ARRAY_ELEMS(extract_tab); i++) {
if (extract_tab[i].id == ctx->par_in->codec_id) {
s->extract = extract_tab[i].extract;
break;
}
}
if (!s->extract)
return AVERROR_BUG;
return 0;
}
static int extract_extradata_filter(AVBSFContext *ctx, AVPacket *out)
{
ExtractExtradataContext *s = ctx->priv_data;
AVPacket *in;
uint8_t *extradata = NULL;
int extradata_size;
int ret = 0;
ret = ff_bsf_get_packet(ctx, &in);
if (ret < 0)
return ret;
ret = s->extract(ctx, in, &extradata, &extradata_size);
if (ret < 0)
goto fail;
if (extradata) {
ret = av_packet_add_side_data(in, AV_PKT_DATA_NEW_EXTRADATA,
extradata, extradata_size);
if (ret < 0) {
av_freep(&extradata);
goto fail;
}
}
av_packet_move_ref(out, in);
fail:
av_packet_free(&in);
return ret;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_CAVS,
AV_CODEC_ID_H264,
AV_CODEC_ID_HEVC,
AV_CODEC_ID_MPEG1VIDEO,
AV_CODEC_ID_MPEG2VIDEO,
AV_CODEC_ID_MPEG4,
AV_CODEC_ID_VC1,
AV_CODEC_ID_NONE,
};
#define OFFSET(x) offsetof(ExtractExtradataContext, x)
static const AVOption options[] = {
{ "remove", "remove the extradata from the bitstream", OFFSET(remove), AV_OPT_TYPE_INT,
{ .i64 = 0 }, 0, 1 },
{ NULL },
};
static const AVClass extract_extradata_class = {
.class_name = "extract_extradata",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVBitStreamFilter ff_extract_extradata_bsf = {
.name = "extract_extradata",
.codec_ids = codec_ids,
.priv_data_size = sizeof(ExtractExtradataContext),
.priv_class = &extract_extradata_class,
.init = extract_extradata_init,
.filter = extract_extradata_filter,
};

4
libavcodec/version.h
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@ -28,8 +28,8 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 57
#define LIBAVCODEC_VERSION_MINOR 27
#define LIBAVCODEC_VERSION_MICRO 2
#define LIBAVCODEC_VERSION_MINOR 28
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \