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FFmpeg/libavcodec/h2645_parse.c
Hendrik Leppkes a9bb4cf87d h2645_parse: support badly muxed mp4 streams
Some streams contain an additional AnnexB NAL inside the mp4/nalff NALU.
This commonly occurs in interlaced streams where both fields are packed
into the same MP4 NAL with an AnnexB startcode in between.

Port handling of this format from the previous h264 nal handling.

Fixes trac #5529
2016-05-17 14:03:21 +02:00

377 lines
12 KiB
C

/*
* 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 "hevc.h"
#include "h2645_parse.h"
int ff_h2645_extract_rbsp(const uint8_t *src, int length,
H2645NAL *nal)
{
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_RN64A(src + i) &
(AV_RN64A(src + i) - 0x0100010001000101ULL)) &
0x8000800080008080ULL))
continue;
FIND_FIRST_ZERO;
STARTCODE_TEST;
i -= 7;
}
#else
for (i = 0; i + 1 < length; i += 5) {
if (!((~AV_RN32A(src + i) &
(AV_RN32A(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) { // no escaped 0
nal->data =
nal->raw_data = src;
nal->size =
nal->raw_size = length;
return length;
}
av_fast_malloc(&nal->rbsp_buffer, &nal->rbsp_buffer_size,
length + AV_INPUT_BUFFER_PADDING_SIZE);
if (!nal->rbsp_buffer)
return AVERROR(ENOMEM);
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;
return si;
}
static const char *nal_unit_name(int nal_type)
{
switch(nal_type) {
case NAL_TRAIL_N : return "TRAIL_N";
case NAL_TRAIL_R : return "TRAIL_R";
case NAL_TSA_N : return "TSA_N";
case NAL_TSA_R : return "TSA_R";
case NAL_STSA_N : return "STSA_N";
case NAL_STSA_R : return "STSA_R";
case NAL_RADL_N : return "RADL_N";
case NAL_RADL_R : return "RADL_R";
case NAL_RASL_N : return "RASL_N";
case NAL_RASL_R : return "RASL_R";
case NAL_BLA_W_LP : return "BLA_W_LP";
case NAL_BLA_W_RADL : return "BLA_W_RADL";
case NAL_BLA_N_LP : return "BLA_N_LP";
case NAL_IDR_W_RADL : return "IDR_W_RADL";
case NAL_IDR_N_LP : return "IDR_N_LP";
case NAL_CRA_NUT : return "CRA_NUT";
case NAL_VPS : return "VPS";
case NAL_SPS : return "SPS";
case NAL_PPS : return "PPS";
case NAL_AUD : return "AUD";
case NAL_EOS_NUT : return "EOS_NUT";
case NAL_EOB_NUT : return "EOB_NUT";
case NAL_FD_NUT : return "FD_NUT";
case NAL_SEI_PREFIX : return "SEI_PREFIX";
case NAL_SEI_SUFFIX : return "SEI_SUFFIX";
default : return "?";
}
}
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;
int nuh_layer_id;
if (get_bits1(gb) != 0)
return AVERROR_INVALIDDATA;
nal->type = get_bits(gb, 6);
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, nal_unit_name(nal->type), nuh_layer_id, nal->temporal_id);
return nuh_layer_id == 0;
}
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, nal_ref_idc: %d\n",
nal->type, nal->ref_idc);
return 1;
}
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 consumed, ret = 0;
const uint8_t *next_avc = is_nalff ? buf : buf + length;
pkt->nb_nals = 0;
while (length >= 4) {
H2645NAL *nal;
int extract_length = 0;
int skip_trailing_zeros = 1;
if (buf >= next_avc) {
int i;
for (i = 0; i < nal_length_size; i++)
extract_length = (extract_length << 8) | buf[i];
buf += nal_length_size;
length -= nal_length_size;
if (extract_length > length) {
av_log(logctx, AV_LOG_ERROR, "Invalid NAL unit size.\n");
return AVERROR_INVALIDDATA;
}
next_avc = buf + extract_length;
} else {
/* search start code */
while (buf[0] != 0 || buf[1] != 0 || buf[2] != 1) {
++buf;
--length;
if (length < 4) {
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;
}
} else if (buf >= (next_avc - 3))
break;
}
buf += 3;
length -= 3;
extract_length = length;
if (buf >= next_avc) {
/* skip to the start of the next NAL */
int offset = next_avc - buf;
buf += offset;
length -= offset;
continue;
}
}
if (pkt->nals_allocated < pkt->nb_nals + 1) {
int new_size = pkt->nals_allocated + 1;
void *tmp = av_realloc_array(pkt->nals, new_size, sizeof(*pkt->nals));
if (!tmp)
return AVERROR(ENOMEM);
pkt->nals = tmp;
memset(pkt->nals + pkt->nals_allocated, 0,
(new_size - pkt->nals_allocated) * 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(buf, extract_length, nal);
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++;
/* see commit 3566042a0 */
if (consumed < length - 3 &&
buf[consumed] == 0x00 && buf[consumed + 1] == 0x00 &&
buf[consumed + 2] == 0x01 && buf[consumed + 3] == 0xE0)
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) {
if (ret < 0) {
av_log(logctx, AV_LOG_ERROR, "Invalid NAL unit %d, skipping.\n",
nal->type);
}
pkt->nb_nals--;
}
buf += consumed;
length -= consumed;
}
return 0;
}
void ff_h2645_packet_uninit(H2645Packet *pkt)
{
int i;
for (i = 0; i < pkt->nals_allocated; i++) {
av_freep(&pkt->nals[i].rbsp_buffer);
av_freep(&pkt->nals[i].skipped_bytes_pos);
}
av_freep(&pkt->nals);
pkt->nals_allocated = 0;
}