ffmpeg/libavcodec/eac3_core_bsf.c

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/*
* Copyright (c) 2018 Paul B Mahol
*
* 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 "bsf.h"
#include "bsf_internal.h"
#include "get_bits.h"
#include "ac3_parser_internal.h"
static int eac3_core_filter(AVBSFContext *ctx, AVPacket *pkt)
{
AC3HeaderInfo hdr;
GetBitContext gbc;
int ret;
ret = ff_bsf_get_packet_ref(ctx, pkt);
if (ret < 0)
return ret;
ret = init_get_bits8(&gbc, pkt->data, pkt->size);
if (ret < 0)
goto fail;
ret = ff_ac3_parse_header(&gbc, &hdr);
if (ret < 0) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (hdr.frame_type == EAC3_FRAME_TYPE_INDEPENDENT ||
hdr.frame_type == EAC3_FRAME_TYPE_AC3_CONVERT) {
pkt->size = FFMIN(hdr.frame_size, pkt->size);
} else if (hdr.frame_type == EAC3_FRAME_TYPE_DEPENDENT && pkt->size > hdr.frame_size) {
AC3HeaderInfo hdr2;
ret = init_get_bits8(&gbc, pkt->data + hdr.frame_size, pkt->size - hdr.frame_size);
if (ret < 0)
goto fail;
ret = ff_ac3_parse_header(&gbc, &hdr2);
if (ret < 0) {
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (hdr2.frame_type == EAC3_FRAME_TYPE_INDEPENDENT ||
hdr2.frame_type == EAC3_FRAME_TYPE_AC3_CONVERT) {
pkt->size -= hdr.frame_size;
pkt->data += hdr.frame_size;
} else {
pkt->size = 0;
}
} else {
pkt->size = 0;
}
return 0;
fail:
av_packet_unref(pkt);
return ret;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_EAC3, AV_CODEC_ID_NONE,
};
const FFBitStreamFilter ff_eac3_core_bsf = {
.p.name = "eac3_core",
.p.codec_ids = codec_ids,
.filter = eac3_core_filter,
};