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FFmpeg/libavcodec/h2645_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

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/*
* H.264/HEVC common parsing code
*
* 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 <string.h>
#include "config.h"
#include "libavutil/intmath.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "bytestream.h"
#include "hevc.h"
#include "h264.h"
#include "h2645_parse.h"
int ff_h2645_extract_rbsp(const uint8_t *src, int length,
H2645RBSP *rbsp, H2645NAL *nal, int small_padding)
{
int i, si, di;
uint8_t *dst;
nal->skipped_bytes = 0;
#define STARTCODE_TEST \
if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) { \
if (src[i + 2] != 3 && src[i + 2] != 0) { \
/* startcode, so we must be past the end */ \
length = i; \
} \
break; \
}
#if HAVE_FAST_UNALIGNED
#define FIND_FIRST_ZERO \
if (i > 0 && !src[i]) \
i--; \
while (src[i]) \
i++
#if HAVE_FAST_64BIT
for (i = 0; i + 1 < length; i += 9) {
if (!((~AV_RN64(src + i) &
(AV_RN64(src + i) - 0x0100010001000101ULL)) &
0x8000800080008080ULL))
continue;
FIND_FIRST_ZERO;
STARTCODE_TEST;
i -= 7;
}
#else
for (i = 0; i + 1 < length; i += 5) {
if (!((~AV_RN32(src + i) &
(AV_RN32(src + i) - 0x01000101U)) &
0x80008080U))
continue;
FIND_FIRST_ZERO;
STARTCODE_TEST;
i -= 3;
}
#endif /* HAVE_FAST_64BIT */
#else
for (i = 0; i + 1 < length; i += 2) {
if (src[i])
continue;
if (i > 0 && src[i - 1] == 0)
i--;
STARTCODE_TEST;
}
#endif /* HAVE_FAST_UNALIGNED */
if (i >= length - 1 && small_padding) { // no escaped 0
nal->data =
nal->raw_data = src;
nal->size =
nal->raw_size = length;
return length;
} else if (i > length)
i = length;
nal->rbsp_buffer = &rbsp->rbsp_buffer[rbsp->rbsp_buffer_size];
dst = nal->rbsp_buffer;
memcpy(dst, src, i);
si = di = i;
while (si + 2 < length) {
// remove escapes (very rare 1:2^22)
if (src[si + 2] > 3) {
dst[di++] = src[si++];
dst[di++] = src[si++];
} else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
if (src[si + 2] == 3) { // escape
dst[di++] = 0;
dst[di++] = 0;
si += 3;
if (nal->skipped_bytes_pos) {
nal->skipped_bytes++;
if (nal->skipped_bytes_pos_size < nal->skipped_bytes) {
nal->skipped_bytes_pos_size *= 2;
av_assert0(nal->skipped_bytes_pos_size >= nal->skipped_bytes);
av_reallocp_array(&nal->skipped_bytes_pos,
nal->skipped_bytes_pos_size,
sizeof(*nal->skipped_bytes_pos));
if (!nal->skipped_bytes_pos) {
nal->skipped_bytes_pos_size = 0;
return AVERROR(ENOMEM);
}
}
if (nal->skipped_bytes_pos)
nal->skipped_bytes_pos[nal->skipped_bytes-1] = di - 1;
}
continue;
} else // next start code
goto nsc;
}
dst[di++] = src[si++];
}
while (si < length)
dst[di++] = src[si++];
nsc:
memset(dst + di, 0, AV_INPUT_BUFFER_PADDING_SIZE);
nal->data = dst;
nal->size = di;
nal->raw_data = src;
nal->raw_size = si;
rbsp->rbsp_buffer_size += si;
return si;
}
static const char *hevc_nal_type_name[64] = {
"TRAIL_N", // HEVC_NAL_TRAIL_N
"TRAIL_R", // HEVC_NAL_TRAIL_R
"TSA_N", // HEVC_NAL_TSA_N
"TSA_R", // HEVC_NAL_TSA_R
"STSA_N", // HEVC_NAL_STSA_N
"STSA_R", // HEVC_NAL_STSA_R
"RADL_N", // HEVC_NAL_RADL_N
"RADL_R", // HEVC_NAL_RADL_R
"RASL_N", // HEVC_NAL_RASL_N
"RASL_R", // HEVC_NAL_RASL_R
"RSV_VCL_N10", // HEVC_NAL_VCL_N10
"RSV_VCL_R11", // HEVC_NAL_VCL_R11
"RSV_VCL_N12", // HEVC_NAL_VCL_N12
"RSV_VLC_R13", // HEVC_NAL_VCL_R13
"RSV_VCL_N14", // HEVC_NAL_VCL_N14
"RSV_VCL_R15", // HEVC_NAL_VCL_R15
"BLA_W_LP", // HEVC_NAL_BLA_W_LP
"BLA_W_RADL", // HEVC_NAL_BLA_W_RADL
"BLA_N_LP", // HEVC_NAL_BLA_N_LP
"IDR_W_RADL", // HEVC_NAL_IDR_W_RADL
"IDR_N_LP", // HEVC_NAL_IDR_N_LP
"CRA_NUT", // HEVC_NAL_CRA_NUT
"IRAP_IRAP_VCL22", // HEVC_NAL_IRAP_VCL22
"IRAP_IRAP_VCL23", // HEVC_NAL_IRAP_VCL23
"RSV_VCL24", // HEVC_NAL_RSV_VCL24
"RSV_VCL25", // HEVC_NAL_RSV_VCL25
"RSV_VCL26", // HEVC_NAL_RSV_VCL26
"RSV_VCL27", // HEVC_NAL_RSV_VCL27
"RSV_VCL28", // HEVC_NAL_RSV_VCL28
"RSV_VCL29", // HEVC_NAL_RSV_VCL29
"RSV_VCL30", // HEVC_NAL_RSV_VCL30
"RSV_VCL31", // HEVC_NAL_RSV_VCL31
"VPS", // HEVC_NAL_VPS
"SPS", // HEVC_NAL_SPS
"PPS", // HEVC_NAL_PPS
"AUD", // HEVC_NAL_AUD
"EOS_NUT", // HEVC_NAL_EOS_NUT
"EOB_NUT", // HEVC_NAL_EOB_NUT
"FD_NUT", // HEVC_NAL_FD_NUT
"SEI_PREFIX", // HEVC_NAL_SEI_PREFIX
"SEI_SUFFIX", // HEVC_NAL_SEI_SUFFIX
"RSV_NVCL41", // HEVC_NAL_RSV_NVCL41
"RSV_NVCL42", // HEVC_NAL_RSV_NVCL42
"RSV_NVCL43", // HEVC_NAL_RSV_NVCL43
"RSV_NVCL44", // HEVC_NAL_RSV_NVCL44
"RSV_NVCL45", // HEVC_NAL_RSV_NVCL45
"RSV_NVCL46", // HEVC_NAL_RSV_NVCL46
"RSV_NVCL47", // HEVC_NAL_RSV_NVCL47
"UNSPEC48", // HEVC_NAL_UNSPEC48
"UNSPEC49", // HEVC_NAL_UNSPEC49
"UNSPEC50", // HEVC_NAL_UNSPEC50
"UNSPEC51", // HEVC_NAL_UNSPEC51
"UNSPEC52", // HEVC_NAL_UNSPEC52
"UNSPEC53", // HEVC_NAL_UNSPEC53
"UNSPEC54", // HEVC_NAL_UNSPEC54
"UNSPEC55", // HEVC_NAL_UNSPEC55
"UNSPEC56", // HEVC_NAL_UNSPEC56
"UNSPEC57", // HEVC_NAL_UNSPEC57
"UNSPEC58", // HEVC_NAL_UNSPEC58
"UNSPEC59", // HEVC_NAL_UNSPEC59
"UNSPEC60", // HEVC_NAL_UNSPEC60
"UNSPEC61", // HEVC_NAL_UNSPEC61
"UNSPEC62", // HEVC_NAL_UNSPEC62
"UNSPEC63", // HEVC_NAL_UNSPEC63
};
static const char *hevc_nal_unit_name(int nal_type)
{
av_assert0(nal_type >= 0 && nal_type < 64);
return hevc_nal_type_name[nal_type];
}
static const char *h264_nal_type_name[32] = {
"Unspecified 0", //H264_NAL_UNSPECIFIED
"Coded slice of a non-IDR picture", // H264_NAL_SLICE
"Coded slice data partition A", // H264_NAL_DPA
"Coded slice data partition B", // H264_NAL_DPB
"Coded slice data partition C", // H264_NAL_DPC
"IDR", // H264_NAL_IDR_SLICE
"SEI", // H264_NAL_SEI
"SPS", // H264_NAL_SPS
"PPS", // H264_NAL_PPS
"AUD", // H264_NAL_AUD
"End of sequence", // H264_NAL_END_SEQUENCE
"End of stream", // H264_NAL_END_STREAM
"Filler data", // H264_NAL_FILLER_DATA
"SPS extension", // H264_NAL_SPS_EXT
"Prefix", // H264_NAL_PREFIX
"Subset SPS", // H264_NAL_SUB_SPS
"Depth parameter set", // H264_NAL_DPS
"Reserved 17", // H264_NAL_RESERVED17
"Reserved 18", // H264_NAL_RESERVED18
"Auxiliary coded picture without partitioning", // H264_NAL_AUXILIARY_SLICE
"Slice extension", // H264_NAL_EXTEN_SLICE
"Slice extension for a depth view or a 3D-AVC texture view", // H264_NAL_DEPTH_EXTEN_SLICE
"Reserved 22", // H264_NAL_RESERVED22
"Reserved 23", // H264_NAL_RESERVED23
"Unspecified 24", // H264_NAL_UNSPECIFIED24
"Unspecified 25", // H264_NAL_UNSPECIFIED25
"Unspecified 26", // H264_NAL_UNSPECIFIED26
"Unspecified 27", // H264_NAL_UNSPECIFIED27
"Unspecified 28", // H264_NAL_UNSPECIFIED28
"Unspecified 29", // H264_NAL_UNSPECIFIED29
"Unspecified 30", // H264_NAL_UNSPECIFIED30
"Unspecified 31", // H264_NAL_UNSPECIFIED31
};
static const char *h264_nal_unit_name(int nal_type)
{
av_assert0(nal_type >= 0 && nal_type < 32);
return h264_nal_type_name[nal_type];
}
static int get_bit_length(H2645NAL *nal, int skip_trailing_zeros)
{
int size = nal->size;
int v;
while (skip_trailing_zeros && size > 0 && nal->data[size - 1] == 0)
size--;
if (!size)
return 0;
v = nal->data[size - 1];
if (size > INT_MAX / 8)
return AVERROR(ERANGE);
size *= 8;
/* remove the stop bit and following trailing zeros,
* or nothing for damaged bitstreams */
if (v)
size -= ff_ctz(v) + 1;
return size;
}
/**
* @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
* 0 if the unit should be skipped, 1 otherwise
*/
static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
{
GetBitContext *gb = &nal->gb;
if (get_bits1(gb) != 0)
return AVERROR_INVALIDDATA;
nal->type = get_bits(gb, 6);
nal->nuh_layer_id = get_bits(gb, 6);
nal->temporal_id = get_bits(gb, 3) - 1;
if (nal->temporal_id < 0)
return AVERROR_INVALIDDATA;
av_log(logctx, AV_LOG_DEBUG,
"nal_unit_type: %d(%s), nuh_layer_id: %d, temporal_id: %d\n",
nal->type, hevc_nal_unit_name(nal->type), nal->nuh_layer_id, nal->temporal_id);
return 1;
}
static int h264_parse_nal_header(H2645NAL *nal, void *logctx)
{
GetBitContext *gb = &nal->gb;
if (get_bits1(gb) != 0)
return AVERROR_INVALIDDATA;
nal->ref_idc = get_bits(gb, 2);
nal->type = get_bits(gb, 5);
av_log(logctx, AV_LOG_DEBUG,
"nal_unit_type: %d(%s), nal_ref_idc: %d\n",
nal->type, h264_nal_unit_name(nal->type), nal->ref_idc);
return 1;
}
static int find_next_start_code(const uint8_t *buf, const uint8_t *next_avc)
{
int i = 0;
if (buf + 3 >= next_avc)
return next_avc - buf;
while (buf + i + 3 < next_avc) {
if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1)
break;
i++;
}
return i + 3;
}
static void alloc_rbsp_buffer(H2645RBSP *rbsp, unsigned int size, int use_ref)
{
int min_size = size;
if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
goto fail;
size += AV_INPUT_BUFFER_PADDING_SIZE;
if (rbsp->rbsp_buffer_alloc_size >= size &&
(!rbsp->rbsp_buffer_ref || av_buffer_is_writable(rbsp->rbsp_buffer_ref))) {
av_assert0(rbsp->rbsp_buffer);
memset(rbsp->rbsp_buffer + min_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
return;
}
size = FFMIN(size + size / 16 + 32, INT_MAX);
if (rbsp->rbsp_buffer_ref)
av_buffer_unref(&rbsp->rbsp_buffer_ref);
else
av_free(rbsp->rbsp_buffer);
rbsp->rbsp_buffer = av_mallocz(size);
if (!rbsp->rbsp_buffer)
goto fail;
rbsp->rbsp_buffer_alloc_size = size;
if (use_ref) {
rbsp->rbsp_buffer_ref = av_buffer_create(rbsp->rbsp_buffer, size,
NULL, NULL, 0);
if (!rbsp->rbsp_buffer_ref)
goto fail;
}
return;
fail:
rbsp->rbsp_buffer_alloc_size = 0;
if (rbsp->rbsp_buffer_ref) {
av_buffer_unref(&rbsp->rbsp_buffer_ref);
rbsp->rbsp_buffer = NULL;
} else
av_freep(&rbsp->rbsp_buffer);
return;
}
int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
void *logctx, int is_nalff, int nal_length_size,
enum AVCodecID codec_id, int small_padding, int use_ref)
{
GetByteContext bc;
int consumed, ret = 0;
int next_avc = is_nalff ? 0 : length;
int64_t padding = small_padding ? 0 : MAX_MBPAIR_SIZE;
bytestream2_init(&bc, buf, length);
alloc_rbsp_buffer(&pkt->rbsp, length + padding, use_ref);
if (!pkt->rbsp.rbsp_buffer)
return AVERROR(ENOMEM);
pkt->rbsp.rbsp_buffer_size = 0;
pkt->nb_nals = 0;
while (bytestream2_get_bytes_left(&bc) >= 4) {
H2645NAL *nal;
int extract_length = 0;
int skip_trailing_zeros = 1;
if (bytestream2_tell(&bc) == next_avc) {
int i = 0;
extract_length = get_nalsize(nal_length_size,
bc.buffer, bytestream2_get_bytes_left(&bc), &i, logctx);
if (extract_length < 0)
return extract_length;
bytestream2_skip(&bc, nal_length_size);
next_avc = bytestream2_tell(&bc) + extract_length;
} else {
int buf_index;
if (bytestream2_tell(&bc) > next_avc)
av_log(logctx, AV_LOG_WARNING, "Exceeded next NALFF position, re-syncing.\n");
/* search start code */
buf_index = find_next_start_code(bc.buffer, buf + next_avc);
bytestream2_skip(&bc, buf_index);
if (!bytestream2_get_bytes_left(&bc)) {
if (pkt->nb_nals > 0) {
// No more start codes: we discarded some irrelevant
// bytes at the end of the packet.
return 0;
} else {
av_log(logctx, AV_LOG_ERROR, "No start code is found.\n");
return AVERROR_INVALIDDATA;
}
}
extract_length = FFMIN(bytestream2_get_bytes_left(&bc), next_avc - bytestream2_tell(&bc));
if (bytestream2_tell(&bc) >= next_avc) {
/* skip to the start of the next NAL */
bytestream2_skip(&bc, next_avc - bytestream2_tell(&bc));
continue;
}
}
if (pkt->nals_allocated < pkt->nb_nals + 1) {
int new_size = pkt->nals_allocated + 1;
void *tmp;
if (new_size >= INT_MAX / sizeof(*pkt->nals))
return AVERROR(ENOMEM);
tmp = av_fast_realloc(pkt->nals, &pkt->nal_buffer_size, new_size * sizeof(*pkt->nals));
if (!tmp)
return AVERROR(ENOMEM);
pkt->nals = tmp;
memset(pkt->nals + pkt->nals_allocated, 0, sizeof(*pkt->nals));
nal = &pkt->nals[pkt->nb_nals];
nal->skipped_bytes_pos_size = 1024; // initial buffer size
nal->skipped_bytes_pos = av_malloc_array(nal->skipped_bytes_pos_size, sizeof(*nal->skipped_bytes_pos));
if (!nal->skipped_bytes_pos)
return AVERROR(ENOMEM);
pkt->nals_allocated = new_size;
}
nal = &pkt->nals[pkt->nb_nals];
consumed = ff_h2645_extract_rbsp(bc.buffer, extract_length, &pkt->rbsp, nal, small_padding);
if (consumed < 0)
return consumed;
if (is_nalff && (extract_length != consumed) && extract_length)
av_log(logctx, AV_LOG_DEBUG,
"NALFF: Consumed only %d bytes instead of %d\n",
consumed, extract_length);
pkt->nb_nals++;
bytestream2_skip(&bc, consumed);
/* see commit 3566042a0 */
if (bytestream2_get_bytes_left(&bc) >= 4 &&
bytestream2_peek_be32(&bc) == 0x000001E0)
skip_trailing_zeros = 0;
nal->size_bits = get_bit_length(nal, skip_trailing_zeros);
ret = init_get_bits(&nal->gb, nal->data, nal->size_bits);
if (ret < 0)
return ret;
if (codec_id == AV_CODEC_ID_HEVC)
ret = hevc_parse_nal_header(nal, logctx);
else
ret = h264_parse_nal_header(nal, logctx);
if (ret <= 0 || nal->size <= 0 || nal->size_bits <= 0) {
if (ret < 0) {
av_log(logctx, AV_LOG_WARNING, "Invalid NAL unit %d, skipping.\n",
nal->type);
}
pkt->nb_nals--;
}
}
return 0;
}
void ff_h2645_packet_uninit(H2645Packet *pkt)
{
int i;
for (i = 0; i < pkt->nals_allocated; i++) {
av_freep(&pkt->nals[i].skipped_bytes_pos);
}
av_freep(&pkt->nals);
pkt->nals_allocated = pkt->nal_buffer_size = 0;
if (pkt->rbsp.rbsp_buffer_ref) {
av_buffer_unref(&pkt->rbsp.rbsp_buffer_ref);
pkt->rbsp.rbsp_buffer = NULL;
} else
av_freep(&pkt->rbsp.rbsp_buffer);
pkt->rbsp.rbsp_buffer_alloc_size = pkt->rbsp.rbsp_buffer_size = 0;
}
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