/*
* 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 "avcodec.h"
#include "bytestream.h"
#include "hevc.h"
#define MIN_HEVCC_LENGTH 23
typedef struct HEVCBSFContext {
uint8_t length_size;
int extradata_parsed;
int logged_nonmp4_warning;
/* When private_spspps is zero then spspps_buf points to global extradata
and bsf does replace a global extradata to own-allocated version (default
behaviour).
When private_spspps is non-zero the bsf uses a private version of spspps buf.
This mode necessary when bsf uses in decoder, else bsf has issues after
decoder re-initialization. Use the "private_spspps_buf" argument to
activate this mode.
*/
int private_spspps;
uint8_t *spspps_buf;
uint32_t spspps_size;
} HEVCBSFContext;
static int hevc_extradata_to_annexb(HEVCBSFContext* ctx, AVCodecContext *avctx)
{
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, avctx->extradata, avctx->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 == NAL_VPS || type == NAL_SPS || type == NAL_PPS ||
type == NAL_SEI_PREFIX || type == NAL_SEI_SUFFIX)) {
av_log(avctx, 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);
}
}
if (!ctx->private_spspps) {
av_freep(&avctx->extradata);
avctx->extradata = new_extradata;
avctx->extradata_size = new_extradata_size;
}
ctx->spspps_buf = new_extradata;
ctx->spspps_size = new_extradata_size;
if (!new_extradata_size)
av_log(avctx, AV_LOG_WARNING, "No parameter sets in the extradata\n");
return length_size;
fail:
av_freep(&new_extradata);
return ret;
}
static int hevc_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
AVCodecContext *avctx, const char *args,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size,
int keyframe)
{
HEVCBSFContext *ctx = bsfc->priv_data;
GetByteContext gb;
uint8_t *out = NULL;
size_t out_size = 0;
int got_irap = 0;
int i, ret = 0;
if (!ctx->extradata_parsed) {
if (avctx->extradata_size < MIN_HEVCC_LENGTH ||
AV_RB24(avctx->extradata) == 1 ||
AV_RB32(avctx->extradata) == 1) {
if (!ctx->logged_nonmp4_warning) {
av_log(avctx, AV_LOG_VERBOSE,
"The input looks like it is Annex B already\n");
ctx->logged_nonmp4_warning = 1;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return 0;
}
if (args && strstr(args, "private_spspps_buf"))
ctx->private_spspps = 1;
ret = hevc_extradata_to_annexb(ctx, avctx);
if (ret < 0)
return ret;
ctx->length_size = ret;
ctx->extradata_parsed = 1;
}
*poutbuf_size = 0;
*poutbuf = NULL;
bytestream2_init(&gb, buf, buf_size);
while (bytestream2_get_bytes_left(&gb)) {
uint32_t nalu_size = 0;
int nalu_type;
int is_irap, add_extradata, extra_size;
for (i = 0; i < ctx->length_size; i++)
nalu_size = (nalu_size << 8) | bytestream2_get_byte(&gb);
nalu_type = (bytestream2_peek_byte(&gb) >> 1) & 0x3f;
/* prepend extradata to IRAP frames */
is_irap = nalu_type >= 16 && nalu_type <= 23;
add_extradata = is_irap && !got_irap;
extra_size = add_extradata * ctx->spspps_size;
got_irap |= is_irap;
if (SIZE_MAX - out_size < 4 ||
SIZE_MAX - out_size - 4 < nalu_size ||
SIZE_MAX - out_size - 4 - nalu_size < extra_size) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
ret = av_reallocp(&out, out_size + 4 + nalu_size + extra_size);
if (ret < 0)
goto fail;
if (add_extradata)
memcpy(out + out_size, ctx->spspps_buf, extra_size);
AV_WB32(out + out_size + extra_size, 1);
bytestream2_get_buffer(&gb, out + out_size + 4 + extra_size, nalu_size);
out_size += 4 + nalu_size + extra_size;
}
*poutbuf = out;
*poutbuf_size = out_size;
return 1;
fail:
av_freep(&out);
return ret;
}
static void hevc_mp4toannexb_close(AVBitStreamFilterContext *bsfc)
{
HEVCBSFContext *ctx = bsfc->priv_data;
if (ctx->private_spspps)
av_freep(&ctx->spspps_buf);
}
AVBitStreamFilter ff_hevc_mp4toannexb_bsf = {
"hevc_mp4toannexb",
sizeof(HEVCBSFContext),
hevc_mp4toannexb_filter,
hevc_mp4toannexb_close,
};