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FFmpeg/libavcodec/hevc_parse.c
Andriy Gelman ad326379c6 lavc/h2645_parse: Don't automatically remove nuh_layer_id > 0 packets
HEVC standard supports multi-layer streams (ITU-T H.265 02/2018 Annex
F). Each NAL unit belongs to a particular layer defined by nuh_layer_id
in the header.

Currently, all NAL units that do not belong to a base layer are
automatically removed in ff_h2645_packet_split(). Some data may
therefore be lost when future filters/decoders are designed to support
multi-layer streams.

A better approach is to forward nuh_layer_id > 0 packets and let blocks
down the chain decide how to process them. The condition to remove
packets has been moved to hevcdec and cbs.

Found-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Andriy Gelman <andriy.gelman@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2020-01-17 17:43:52 -03:00

146 lines
5.1 KiB
C

/*
* 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
*/
#include "bytestream.h"
#include "h2645_parse.h"
#include "hevc.h"
#include "hevc_parse.h"
static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets *ps,
HEVCSEI *sei, int is_nalff, int nal_length_size,
int err_recognition, int apply_defdispwin, void *logctx)
{
int i;
int ret = 0;
H2645Packet pkt = { 0 };
ret = ff_h2645_packet_split(&pkt, buf, buf_size, logctx, is_nalff,
nal_length_size, AV_CODEC_ID_HEVC, 1, 0);
if (ret < 0) {
goto done;
}
for (i = 0; i < pkt.nb_nals; i++) {
H2645NAL *nal = &pkt.nals[i];
if (nal->nuh_layer_id > 0)
continue;
/* ignore everything except parameter sets and VCL NALUs */
switch (nal->type) {
case HEVC_NAL_VPS:
ret = ff_hevc_decode_nal_vps(&nal->gb, logctx, ps);
if (ret < 0)
goto done;
break;
case HEVC_NAL_SPS:
ret = ff_hevc_decode_nal_sps(&nal->gb, logctx, ps, apply_defdispwin);
if (ret < 0)
goto done;
break;
case HEVC_NAL_PPS:
ret = ff_hevc_decode_nal_pps(&nal->gb, logctx, ps);
if (ret < 0)
goto done;
break;
case HEVC_NAL_SEI_PREFIX:
case HEVC_NAL_SEI_SUFFIX:
ret = ff_hevc_decode_nal_sei(&nal->gb, logctx, sei, ps, nal->type);
if (ret < 0)
goto done;
break;
default:
av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n", nal->type);
break;
}
}
done:
ff_h2645_packet_uninit(&pkt);
if (err_recognition & AV_EF_EXPLODE)
return ret;
return 0;
}
int ff_hevc_decode_extradata(const uint8_t *data, int size, HEVCParamSets *ps,
HEVCSEI *sei, int *is_nalff, int *nal_length_size,
int err_recognition, int apply_defdispwin, void *logctx)
{
int ret = 0;
GetByteContext gb;
bytestream2_init(&gb, data, size);
if (size > 3 && (data[0] || data[1] || data[2] > 1)) {
/* It seems the extradata is encoded as hvcC format.
* Temporarily, we support configurationVersion==0 until 14496-15 3rd
* is finalized. When finalized, configurationVersion will be 1 and we
* can recognize hvcC by checking if avctx->extradata[0]==1 or not. */
int i, j, num_arrays, nal_len_size;
*is_nalff = 1;
bytestream2_skip(&gb, 21);
nal_len_size = (bytestream2_get_byte(&gb) & 3) + 1;
num_arrays = bytestream2_get_byte(&gb);
/* nal units in the hvcC always have length coded with 2 bytes,
* so put a fake nal_length_size = 2 while parsing them */
*nal_length_size = 2;
/* Decode nal units from hvcC. */
for (i = 0; i < num_arrays; i++) {
int type = bytestream2_get_byte(&gb) & 0x3f;
int cnt = bytestream2_get_be16(&gb);
for (j = 0; j < cnt; j++) {
// +2 for the nal size field
int nalsize = bytestream2_peek_be16(&gb) + 2;
if (bytestream2_get_bytes_left(&gb) < nalsize) {
av_log(logctx, AV_LOG_ERROR,
"Invalid NAL unit size in extradata.\n");
return AVERROR_INVALIDDATA;
}
ret = hevc_decode_nal_units(gb.buffer, nalsize, ps, sei, *is_nalff,
*nal_length_size, err_recognition, apply_defdispwin,
logctx);
if (ret < 0) {
av_log(logctx, AV_LOG_ERROR,
"Decoding nal unit %d %d from hvcC failed\n",
type, i);
return ret;
}
bytestream2_skip(&gb, nalsize);
}
}
/* Now store right nal length size, that will be used to parse
* all other nals */
*nal_length_size = nal_len_size;
} else {
*is_nalff = 0;
ret = hevc_decode_nal_units(data, size, ps, sei, *is_nalff, *nal_length_size,
err_recognition, apply_defdispwin, logctx);
if (ret < 0)
return ret;
}
return ret;
}