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ffmpeg/libavcodec/bsf/h264_mp4toannexb.c

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/*
* H.264 MP4 to Annex B byte stream format filter
* Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
*
* 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 "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "bsf.h"
#include "bsf_internal.h"
#include "bytestream.h"
#include "defs.h"
#include "h264.h"
typedef struct H264BSFContext {
uint8_t *sps;
uint8_t *pps;
int sps_size;
int pps_size;
unsigned sps_buf_size;
unsigned pps_buf_size;
uint8_t length_size;
uint8_t new_idr;
uint8_t idr_sps_seen;
uint8_t idr_pps_seen;
int extradata_parsed;
} H264BSFContext;
enum PsSource {
PS_OUT_OF_BAND = -1,
PS_NONE = 0,
PS_IN_BAND = 1,
};
static void count_or_copy(uint8_t **out, uint64_t *out_size,
const uint8_t *in, int in_size, enum PsSource ps, int copy)
{
uint8_t start_code_size;
if (ps == PS_OUT_OF_BAND)
/* start code already present in out-of-band ps data, so don't need to
* add it manually again
*/
start_code_size = 0;
else if (ps == PS_IN_BAND || *out_size == 0)
start_code_size = 4;
else
start_code_size = 3;
if (copy) {
memcpy(*out + start_code_size, in, in_size);
if (start_code_size == 4) {
AV_WB32(*out, 1);
} else if (start_code_size) {
(*out)[0] =
(*out)[1] = 0;
(*out)[2] = 1;
}
*out += start_code_size + in_size;
}
*out_size += start_code_size + in_size;
}
static int h264_extradata_to_annexb(AVBSFContext *ctx,
uint8_t *extradata, int extradata_size)
{
H264BSFContext *s = ctx->priv_data;
GetByteContext ogb, *gb = &ogb;
uint16_t unit_size;
uint32_t total_size = 0;
uint8_t *out = NULL, unit_nb, sps_done = 0;
static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
const int padding = AV_INPUT_BUFFER_PADDING_SIZE;
int length_size, pps_offset = 0;
bytestream2_init(gb, extradata, extradata_size);
bytestream2_skipu(gb, 4);
/* retrieve length coded size */
length_size = (bytestream2_get_byteu(gb) & 0x3) + 1;
/* retrieve sps and pps unit(s) */
unit_nb = bytestream2_get_byteu(gb) & 0x1f; /* number of sps unit(s) */
if (!unit_nb) {
goto pps;
}
while (unit_nb--) {
int err;
/* possible overread ok due to padding */
unit_size = bytestream2_get_be16u(gb);
total_size += unit_size + 4;
av_assert1(total_size <= INT_MAX - padding);
if (bytestream2_get_bytes_left(gb) < unit_size + !sps_done) {
av_log(ctx, AV_LOG_ERROR, "Global extradata truncated, "
"corrupted stream or invalid MP4/AVCC bitstream\n");
av_free(out);
return AVERROR_INVALIDDATA;
}
if ((err = av_reallocp(&out, total_size + padding)) < 0)
return err;
memcpy(out + total_size - unit_size - 4, nalu_header, 4);
bytestream2_get_bufferu(gb, out + total_size - unit_size, unit_size);
pps:
if (!unit_nb && !sps_done++) {
unit_nb = bytestream2_get_byteu(gb); /* number of pps unit(s) */
pps_offset = total_size;
}
}
if (out)
memset(out + total_size, 0, padding);
if (pps_offset) {
uint8_t *sps;
s->sps_size = pps_offset;
sps = av_fast_realloc(s->sps, &s->sps_buf_size, s->sps_size);
if (!sps) {
av_free(out);
return AVERROR(ENOMEM);
}
s->sps = sps;
memcpy(s->sps, out, s->sps_size);
} else {
av_log(ctx, AV_LOG_WARNING,
"Warning: SPS NALU missing or invalid. "
"The resulting stream may not play.\n");
}
if (pps_offset < total_size) {
uint8_t *pps;
s->pps_size = total_size - pps_offset;
pps = av_fast_realloc(s->pps, &s->pps_buf_size, s->pps_size);
if (!pps) {
av_freep(&s->sps);
av_free(out);
return AVERROR(ENOMEM);
}
s->pps = pps;
memcpy(s->pps, out + pps_offset, s->pps_size);
} else {
av_log(ctx, AV_LOG_WARNING,
"Warning: PPS NALU missing or invalid. "
"The resulting stream may not play.\n");
}
av_freep(&ctx->par_out->extradata);
ctx->par_out->extradata = out;
ctx->par_out->extradata_size = total_size;
s->length_size = length_size;
s->new_idr = 1;
s->idr_sps_seen = 0;
s->idr_pps_seen = 0;
s->extradata_parsed = 1;
return 0;
}
static int h264_mp4toannexb_save_ps(uint8_t **dst, int *dst_size,
unsigned *dst_buf_size,
const uint8_t *nal, uint32_t nal_size,
int first)
{
static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
const int start_code_size = sizeof(nalu_header);
uint8_t *ptr;
uint32_t size;
if (first)
size = 0;
else
size = *dst_size;
ptr = av_fast_realloc(*dst, dst_buf_size, size + nal_size + start_code_size);
if (!ptr)
return AVERROR(ENOMEM);
memcpy(ptr + size, nalu_header, start_code_size);
size += start_code_size;
memcpy(ptr + size, nal, nal_size);
size += nal_size;
*dst = ptr;
*dst_size = size;
return 0;
}
static int h264_mp4toannexb_filter_ps(H264BSFContext *s,
const uint8_t *buf,
const uint8_t *buf_end)
{
int sps_count = 0;
int pps_count = 0;
uint8_t unit_type;
do {
uint32_t nal_size = 0;
/* possible overread ok due to padding */
for (int i = 0; i < s->length_size; i++)
nal_size = (nal_size << 8) | buf[i];
buf += s->length_size;
/* This check requires the cast as the right side might
* otherwise be promoted to an unsigned value. */
if ((int64_t)nal_size > buf_end - buf)
return AVERROR_INVALIDDATA;
if (!nal_size)
continue;
unit_type = *buf & 0x1f;
if (unit_type == H264_NAL_SPS) {
h264_mp4toannexb_save_ps(&s->sps, &s->sps_size, &s->sps_buf_size, buf,
nal_size, !sps_count);
sps_count++;
} else if (unit_type == H264_NAL_PPS) {
h264_mp4toannexb_save_ps(&s->pps, &s->pps_size, &s->pps_buf_size, buf,
nal_size, !pps_count);
pps_count++;
}
buf += nal_size;
} while (buf < buf_end);
return 0;
}
static int h264_mp4toannexb_init(AVBSFContext *ctx)
{
int extra_size = ctx->par_in->extradata_size;
/* retrieve sps and pps NAL units from extradata */
if (!extra_size ||
(extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
(extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
av_log(ctx, AV_LOG_VERBOSE,
"The input looks like it is Annex B already\n");
} else if (extra_size >= 7) {
return h264_extradata_to_annexb(ctx,
ctx->par_in->extradata,
ctx->par_in->extradata_size);
} else {
av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
return AVERROR_INVALIDDATA;
}
return 0;
}
static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt)
{
H264BSFContext *s = ctx->priv_data;
AVPacket *in;
uint8_t unit_type, new_idr, sps_seen, pps_seen;
const uint8_t *buf;
const uint8_t *buf_end;
uint8_t *out;
uint64_t out_size;
int ret;
size_t extradata_size;
uint8_t *extradata;
ret = ff_bsf_get_packet(ctx, &in);
if (ret < 0)
return ret;
extradata = av_packet_get_side_data(in, AV_PKT_DATA_NEW_EXTRADATA,
&extradata_size);
if (extradata) {
ret = h264_extradata_to_annexb(ctx, extradata, extradata_size);
if (ret < 0)
goto fail;
}
/* nothing to filter */
if (!s->extradata_parsed) {
av_packet_move_ref(opkt, in);
av_packet_free(&in);
return 0;
}
buf_end = in->data + in->size;
ret = h264_mp4toannexb_filter_ps(s, in->data, buf_end);
if (ret < 0)
goto fail;
#define LOG_ONCE(...) \
if (j) \
av_log(__VA_ARGS__)
for (int j = 0; j < 2; j++) {
buf = in->data;
new_idr = s->new_idr;
sps_seen = s->idr_sps_seen;
pps_seen = s->idr_pps_seen;
out_size = 0;
do {
uint32_t nal_size = 0;
enum PsSource ps;
/* possible overread ok due to padding */
for (int i = 0; i < s->length_size; i++)
nal_size = (nal_size << 8) | buf[i];
buf += s->length_size;
/* This check requires the cast as the right side might
* otherwise be promoted to an unsigned value. */
if ((int64_t)nal_size > buf_end - buf) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (!nal_size)
continue;
unit_type = *buf & 0x1f;
if (unit_type == H264_NAL_SPS) {
sps_seen = new_idr = 1;
} else if (unit_type == H264_NAL_PPS) {
pps_seen = new_idr = 1;
/* if SPS has not been seen yet, prepend the AVCC one to PPS */
if (!sps_seen) {
if (!s->sps_size) {
LOG_ONCE(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
} else {
count_or_copy(&out, &out_size, s->sps, s->sps_size, PS_OUT_OF_BAND, j);
sps_seen = 1;
}
}
}
/* If this is a new IDR picture following an IDR picture, reset the idr flag.
* Just check first_mb_in_slice to be 0 as this is the simplest solution.
* This could be checking idr_pic_id instead, but would complexify the parsing. */
if (!new_idr && unit_type == H264_NAL_IDR_SLICE && (buf[1] & 0x80))
new_idr = 1;
/* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
if (new_idr && unit_type == H264_NAL_IDR_SLICE && !sps_seen && !pps_seen) {
if (s->sps_size)
count_or_copy(&out, &out_size, s->sps, s->sps_size, PS_OUT_OF_BAND, j);
if (s->pps_size)
count_or_copy(&out, &out_size, s->pps, s->pps_size, PS_OUT_OF_BAND, j);
new_idr = 0;
/* if only SPS has been seen, also insert PPS */
} else if (new_idr && unit_type == H264_NAL_IDR_SLICE && sps_seen && !pps_seen) {
if (!s->pps_size) {
LOG_ONCE(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
} else {
count_or_copy(&out, &out_size, s->pps, s->pps_size, PS_OUT_OF_BAND, j);
}
}
if (unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS)
ps = PS_IN_BAND;
else
ps = PS_NONE;
count_or_copy(&out, &out_size, buf, nal_size, ps, j);
if (unit_type == H264_NAL_SLICE) {
new_idr = 1;
sps_seen = 0;
pps_seen = 0;
}
buf += nal_size;
} while (buf < buf_end);
if (!j) {
if (out_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
ret = av_new_packet(opkt, out_size);
if (ret < 0)
goto fail;
out = opkt->data;
}
}
#undef LOG_ONCE
av_assert1(out_size == opkt->size);
s->new_idr = new_idr;
s->idr_sps_seen = sps_seen;
s->idr_pps_seen = pps_seen;
ret = av_packet_copy_props(opkt, in);
if (ret < 0)
goto fail;
fail:
if (ret < 0)
av_packet_unref(opkt);
av_packet_free(&in);
return ret;
}
static void h264_mp4toannexb_close(AVBSFContext *ctx)
{
H264BSFContext *s = ctx->priv_data;
av_freep(&s->sps);
av_freep(&s->pps);
}
static void h264_mp4toannexb_flush(AVBSFContext *ctx)
{
H264BSFContext *s = ctx->priv_data;
s->idr_sps_seen = 0;
s->idr_pps_seen = 0;
s->new_idr = s->extradata_parsed;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
};
const FFBitStreamFilter ff_h264_mp4toannexb_bsf = {
.p.name = "h264_mp4toannexb",
.p.codec_ids = codec_ids,
.priv_data_size = sizeof(H264BSFContext),
.init = h264_mp4toannexb_init,
.filter = h264_mp4toannexb_filter,
.close = h264_mp4toannexb_close,
.flush = h264_mp4toannexb_flush,
};
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