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/*
* HEVC MP4 to Annex B byte stream format filter
* copyright (c) 2015 Anton Khirnov
*
* 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/intreadwrite.h"
#include "libavutil/mem.h"
#include "bsf.h"
#include "bsf_internal.h"
#include "bytestream.h"
#include "defs.h"
#include "hevc.h"
#define MIN_HEVCC_LENGTH 23
typedef struct HEVCBSFContext {
uint8_t length_size;
int extradata_parsed;
} HEVCBSFContext;
static int hevc_extradata_to_annexb(AVBSFContext *ctx)
{
GetByteContext gb;
int length_size, num_arrays, i, j;
int ret = 0;
uint8_t *new_extradata = NULL;
size_t new_extradata_size = 0;
bytestream2_init(&gb, ctx->par_in->extradata, ctx->par_in->extradata_size);
bytestream2_skip(&gb, 21);
length_size = (bytestream2_get_byte(&gb) & 3) + 1;
num_arrays = bytestream2_get_byte(&gb);
for (i = 0; i < num_arrays; i++) {
int type = bytestream2_get_byte(&gb) & 0x3f;
int cnt = bytestream2_get_be16(&gb);
if (!(type == HEVC_NAL_VPS || type == HEVC_NAL_SPS || type == HEVC_NAL_PPS ||
type == HEVC_NAL_SEI_PREFIX || type == HEVC_NAL_SEI_SUFFIX)) {
av_log(ctx, AV_LOG_ERROR, "Invalid NAL unit type in extradata: %d\n",
type);
ret = AVERROR_INVALIDDATA;
goto fail;
}
for (j = 0; j < cnt; j++) {
int nalu_len = bytestream2_get_be16(&gb);
if (4 + AV_INPUT_BUFFER_PADDING_SIZE + nalu_len > SIZE_MAX - new_extradata_size) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
ret = av_reallocp(&new_extradata, new_extradata_size + nalu_len + 4 + AV_INPUT_BUFFER_PADDING_SIZE);
if (ret < 0)
goto fail;
AV_WB32(new_extradata + new_extradata_size, 1); // add the startcode
bytestream2_get_buffer(&gb, new_extradata + new_extradata_size + 4, nalu_len);
new_extradata_size += 4 + nalu_len;
memset(new_extradata + new_extradata_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
}
}
av_freep(&ctx->par_out->extradata);
ctx->par_out->extradata = new_extradata;
ctx->par_out->extradata_size = new_extradata_size;
if (!new_extradata_size)
av_log(ctx, AV_LOG_WARNING, "No parameter sets in the extradata\n");
return length_size;
fail:
av_freep(&new_extradata);
return ret;
}
static int hevc_mp4toannexb_init(AVBSFContext *ctx)
{
HEVCBSFContext *s = ctx->priv_data;
int ret;
if (ctx->par_in->extradata_size < MIN_HEVCC_LENGTH ||
AV_RB24(ctx->par_in->extradata) == 1 ||
AV_RB32(ctx->par_in->extradata) == 1) {
av_log(ctx, AV_LOG_VERBOSE,
"The input looks like it is Annex B already\n");
} else {
ret = hevc_extradata_to_annexb(ctx);
if (ret < 0)
return ret;
s->length_size = ret;
s->extradata_parsed = 1;
}
return 0;
}
static int hevc_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
{
HEVCBSFContext *s = ctx->priv_data;
AVPacket *in;
GetByteContext gb;
int got_irap = 0;
int i, ret = 0;
ret = ff_bsf_get_packet(ctx, &in);
if (ret < 0)
return ret;
if (!s->extradata_parsed) {
av_packet_move_ref(out, in);
av_packet_free(&in);
return 0;
}
bytestream2_init(&gb, in->data, in->size);
while (bytestream2_get_bytes_left(&gb)) {
uint32_t nalu_size = 0;
int nalu_type;
int is_irap, add_extradata, extra_size, prev_size;
if (bytestream2_get_bytes_left(&gb) < s->length_size) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
for (i = 0; i < s->length_size; i++)
nalu_size = (nalu_size << 8) | bytestream2_get_byte(&gb);
if (nalu_size < 2 || nalu_size > bytestream2_get_bytes_left(&gb)) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
nalu_type = (bytestream2_peek_byte(&gb) >> 1) & 0x3f;
/* prepend extradata to IRAP frames */
is_irap = nalu_type >= HEVC_NAL_BLA_W_LP &&
nalu_type <= HEVC_NAL_RSV_IRAP_VCL23;
add_extradata = is_irap && !got_irap;
extra_size = add_extradata * ctx->par_out->extradata_size;
got_irap |= is_irap;
if (FFMIN(INT_MAX, SIZE_MAX) < 4ULL + nalu_size + extra_size) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
prev_size = out->size;
ret = av_grow_packet(out, 4 + nalu_size + extra_size);
if (ret < 0)
goto fail;
if (extra_size)
memcpy(out->data + prev_size, ctx->par_out->extradata, extra_size);
AV_WB32(out->data + prev_size + extra_size, 1);
bytestream2_get_buffer(&gb, out->data + prev_size + 4 + extra_size, nalu_size);
}
ret = av_packet_copy_props(out, in);
if (ret < 0)
goto fail;
fail:
if (ret < 0)
av_packet_unref(out);
av_packet_free(&in);
return ret;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_HEVC, AV_CODEC_ID_NONE,
};
const FFBitStreamFilter ff_hevc_mp4toannexb_bsf = {
.p.name = "hevc_mp4toannexb",
.p.codec_ids = codec_ids,
.priv_data_size = sizeof(HEVCBSFContext),
.init = hevc_mp4toannexb_init,
.filter = hevc_mp4toannexb_filter,
};
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