mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-17 04:54:55 +00:00
2e0c360abd
* qatar/master: cosmetics: Align muxer/demuxer declarations mpeg12: Do not change frame_pred_frame_dct flag and demote error into a warning avcodec: remove avcodec_guess_channel_layout() avutil: Add av_get_default_channel_layout() Conflicts: doc/APIchanges libavcodec/mpeg12.c libavformat/cdg.c libavformat/matroskaenc.c libavformat/mpegts.c libavformat/nuv.c libavformat/wav.c libavutil/audioconvert.c libavutil/audioconvert.h libavutil/avutil.h Merged-by: Michael Niedermayer <michaelni@gmx.at>
236 lines
7.2 KiB
C
236 lines
7.2 KiB
C
/*
|
|
* IEC 61937 demuxer
|
|
* Copyright (c) 2010 Anssi Hannula <anssi.hannula at iki.fi>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* IEC 61937 demuxer, used for compressed data in S/PDIF
|
|
* @author Anssi Hannula
|
|
*/
|
|
|
|
#include "avformat.h"
|
|
#include "spdif.h"
|
|
#include "libavcodec/ac3.h"
|
|
#include "libavcodec/aacadtsdec.h"
|
|
|
|
static int spdif_get_offset_and_codec(AVFormatContext *s,
|
|
enum IEC61937DataType data_type,
|
|
const char *buf, int *offset,
|
|
enum CodecID *codec)
|
|
{
|
|
AACADTSHeaderInfo aac_hdr;
|
|
GetBitContext gbc;
|
|
|
|
switch (data_type & 0xff) {
|
|
case IEC61937_AC3:
|
|
*offset = AC3_FRAME_SIZE << 2;
|
|
*codec = CODEC_ID_AC3;
|
|
break;
|
|
case IEC61937_MPEG1_LAYER1:
|
|
*offset = spdif_mpeg_pkt_offset[1][0];
|
|
*codec = CODEC_ID_MP1;
|
|
break;
|
|
case IEC61937_MPEG1_LAYER23:
|
|
*offset = spdif_mpeg_pkt_offset[1][0];
|
|
*codec = CODEC_ID_MP3;
|
|
break;
|
|
case IEC61937_MPEG2_EXT:
|
|
*offset = 4608;
|
|
*codec = CODEC_ID_MP3;
|
|
break;
|
|
case IEC61937_MPEG2_AAC:
|
|
init_get_bits(&gbc, buf, AAC_ADTS_HEADER_SIZE * 8);
|
|
if (avpriv_aac_parse_header(&gbc, &aac_hdr)) {
|
|
if (s) /* be silent during a probe */
|
|
av_log(s, AV_LOG_ERROR, "Invalid AAC packet in IEC 61937\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
*offset = aac_hdr.samples << 2;
|
|
*codec = CODEC_ID_AAC;
|
|
break;
|
|
case IEC61937_MPEG2_LAYER1_LSF:
|
|
*offset = spdif_mpeg_pkt_offset[0][0];
|
|
*codec = CODEC_ID_MP1;
|
|
break;
|
|
case IEC61937_MPEG2_LAYER2_LSF:
|
|
*offset = spdif_mpeg_pkt_offset[0][1];
|
|
*codec = CODEC_ID_MP2;
|
|
break;
|
|
case IEC61937_MPEG2_LAYER3_LSF:
|
|
*offset = spdif_mpeg_pkt_offset[0][2];
|
|
*codec = CODEC_ID_MP3;
|
|
break;
|
|
case IEC61937_DTS1:
|
|
*offset = 2048;
|
|
*codec = CODEC_ID_DTS;
|
|
break;
|
|
case IEC61937_DTS2:
|
|
*offset = 4096;
|
|
*codec = CODEC_ID_DTS;
|
|
break;
|
|
case IEC61937_DTS3:
|
|
*offset = 8192;
|
|
*codec = CODEC_ID_DTS;
|
|
break;
|
|
default:
|
|
if (s) { /* be silent during a probe */
|
|
av_log(s, AV_LOG_WARNING, "Data type 0x%04x", data_type);
|
|
av_log_missing_feature(s, " in IEC 61937 is", 1);
|
|
}
|
|
return AVERROR_PATCHWELCOME;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Largest offset between bursts we currently handle, i.e. AAC with
|
|
aac_hdr.samples = 4096 */
|
|
#define SPDIF_MAX_OFFSET 16384
|
|
|
|
static int spdif_probe(AVProbeData *p)
|
|
{
|
|
const uint8_t *buf = p->buf;
|
|
const uint8_t *probe_end = p->buf + FFMIN(2 * SPDIF_MAX_OFFSET, p->buf_size - 1);
|
|
const uint8_t *expected_code = buf + 7;
|
|
uint32_t state = 0;
|
|
int sync_codes = 0;
|
|
int consecutive_codes = 0;
|
|
int offset;
|
|
enum CodecID codec;
|
|
|
|
for (; buf < probe_end; buf++) {
|
|
state = (state << 8) | *buf;
|
|
|
|
if (state == (AV_BSWAP16C(SYNCWORD1) << 16 | AV_BSWAP16C(SYNCWORD2))
|
|
&& buf[1] < 0x37) {
|
|
sync_codes++;
|
|
|
|
if (buf == expected_code) {
|
|
if (++consecutive_codes >= 2)
|
|
return AVPROBE_SCORE_MAX;
|
|
} else
|
|
consecutive_codes = 0;
|
|
|
|
if (buf + 4 + AAC_ADTS_HEADER_SIZE > p->buf + p->buf_size)
|
|
break;
|
|
|
|
/* continue probing to find more sync codes */
|
|
probe_end = FFMIN(buf + SPDIF_MAX_OFFSET, p->buf + p->buf_size - 1);
|
|
|
|
/* skip directly to the next sync code */
|
|
if (!spdif_get_offset_and_codec(NULL, (buf[2] << 8) | buf[1],
|
|
&buf[5], &offset, &codec)) {
|
|
if (buf + offset >= p->buf + p->buf_size)
|
|
break;
|
|
expected_code = buf + offset;
|
|
buf = expected_code - 7;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!sync_codes)
|
|
return 0;
|
|
|
|
if (sync_codes >= 6)
|
|
/* good amount of sync codes but with unexpected offsets */
|
|
return AVPROBE_SCORE_MAX / 2;
|
|
|
|
/* some sync codes were found */
|
|
return AVPROBE_SCORE_MAX / 8;
|
|
}
|
|
|
|
static int spdif_read_header(AVFormatContext *s)
|
|
{
|
|
s->ctx_flags |= AVFMTCTX_NOHEADER;
|
|
return 0;
|
|
}
|
|
|
|
static int spdif_read_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
AVIOContext *pb = s->pb;
|
|
enum IEC61937DataType data_type;
|
|
enum CodecID codec_id;
|
|
uint32_t state = 0;
|
|
int pkt_size_bits, offset, ret;
|
|
|
|
while (state != (AV_BSWAP16C(SYNCWORD1) << 16 | AV_BSWAP16C(SYNCWORD2))) {
|
|
state = (state << 8) | avio_r8(pb);
|
|
if (url_feof(pb))
|
|
return AVERROR_EOF;
|
|
}
|
|
|
|
data_type = avio_rl16(pb);
|
|
pkt_size_bits = avio_rl16(pb);
|
|
|
|
if (pkt_size_bits % 16)
|
|
av_log_ask_for_sample(s, "Packet does not end to a 16-bit boundary.");
|
|
|
|
ret = av_new_packet(pkt, FFALIGN(pkt_size_bits, 16) >> 3);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pkt->pos = avio_tell(pb) - BURST_HEADER_SIZE;
|
|
|
|
if (avio_read(pb, pkt->data, pkt->size) < pkt->size) {
|
|
av_free_packet(pkt);
|
|
return AVERROR_EOF;
|
|
}
|
|
ff_spdif_bswap_buf16((uint16_t *)pkt->data, (uint16_t *)pkt->data, pkt->size >> 1);
|
|
|
|
ret = spdif_get_offset_and_codec(s, data_type, pkt->data,
|
|
&offset, &codec_id);
|
|
if (ret) {
|
|
av_free_packet(pkt);
|
|
return ret;
|
|
}
|
|
|
|
/* skip over the padding to the beginning of the next frame */
|
|
avio_skip(pb, offset - pkt->size - BURST_HEADER_SIZE);
|
|
|
|
if (!s->nb_streams) {
|
|
/* first packet, create a stream */
|
|
AVStream *st = avformat_new_stream(s, NULL);
|
|
if (!st) {
|
|
av_free_packet(pkt);
|
|
return AVERROR(ENOMEM);
|
|
}
|
|
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
|
|
st->codec->codec_id = codec_id;
|
|
} else if (codec_id != s->streams[0]->codec->codec_id) {
|
|
av_log_missing_feature(s, "codec change in IEC 61937", 0);
|
|
return AVERROR_PATCHWELCOME;
|
|
}
|
|
|
|
if (!s->bit_rate && s->streams[0]->codec->sample_rate)
|
|
/* stream bitrate matches 16-bit stereo PCM bitrate for currently
|
|
supported codecs */
|
|
s->bit_rate = 2 * 16 * s->streams[0]->codec->sample_rate;
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVInputFormat ff_spdif_demuxer = {
|
|
.name = "spdif",
|
|
.long_name = NULL_IF_CONFIG_SMALL("IEC 61937 (compressed data in S/PDIF)"),
|
|
.read_probe = spdif_probe,
|
|
.read_header = spdif_read_header,
|
|
.read_packet = spdif_read_packet,
|
|
.flags = AVFMT_GENERIC_INDEX,
|
|
};
|