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/*
* Copyright (C) 2017 foo86
*
* 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "spdif.h"
#define MARKER_16LE 0x72F81F4E
#define MARKER_20LE 0x20876FF0E154
#define MARKER_24LE 0x72F8961F4EA5
#define IS_16LE_MARKER(state) ((state & 0xFFFFFFFF) == MARKER_16LE)
#define IS_20LE_MARKER(state) ((state & 0xF0FFFFF0FFFF) == MARKER_20LE)
#define IS_24LE_MARKER(state) ((state & 0xFFFFFFFFFFFF) == MARKER_24LE)
#define IS_LE_MARKER(state) (IS_16LE_MARKER(state) || IS_20LE_MARKER(state) || IS_24LE_MARKER(state))
static int s337m_get_offset_and_codec(void *avc,
uint64_t state,
int data_type, int data_size,
int *offset, enum AVCodecID *codec)
{
int word_bits;
if (IS_16LE_MARKER(state)) {
word_bits = 16;
} else if (IS_20LE_MARKER(state)) {
data_type >>= 8;
data_size >>= 4;
word_bits = 20;
} else {
data_type >>= 8;
word_bits = 24;
}
if ((data_type & 0x1F) != 0x1C) {
if (avc)
avpriv_report_missing_feature(avc, "Data type %#x in SMPTE 337M", data_type & 0x1F);
return AVERROR_PATCHWELCOME;
}
if (codec)
*codec = AV_CODEC_ID_DOLBY_E;
switch (data_size / word_bits) {
case 3648:
*offset = 1920;
break;
case 3644:
*offset = 2002;
break;
case 3640:
*offset = 2000;
break;
case 3040:
*offset = 1601;
break;
default:
if (avc)
avpriv_report_missing_feature(avc, "Dolby E data size %d in SMPTE 337M", data_size);
return AVERROR_PATCHWELCOME;
}
*offset -= 4;
*offset *= (word_bits + 7 >> 3) * 2;
return 0;
}
static int s337m_probe(const AVProbeData *p)
{
uint64_t state = 0;
int markers[3] = { 0 };
int i, pos, sum, max, data_type, data_size, offset;
uint8_t *buf;
for (pos = 0; pos < p->buf_size; pos++) {
state = (state << 8) | p->buf[pos];
if (!IS_LE_MARKER(state))
continue;
buf = p->buf + pos + 1;
if (IS_16LE_MARKER(state)) {
data_type = AV_RL16(buf );
data_size = AV_RL16(buf + 2);
} else {
data_type = AV_RL24(buf );
data_size = AV_RL24(buf + 3);
}
if (s337m_get_offset_and_codec(NULL, state, data_type, data_size, &offset, NULL))
continue;
i = IS_16LE_MARKER(state) ? 0 : IS_20LE_MARKER(state) ? 1 : 2;
markers[i]++;
pos += IS_16LE_MARKER(state) ? 4 : 6;
pos += offset;
state = 0;
}
sum = max = 0;
for (i = 0; i < FF_ARRAY_ELEMS(markers); i++) {
sum += markers[i];
if (markers[max] < markers[i])
max = i;
}
if (markers[max] > 3 && markers[max] * 4 > sum * 3)
return AVPROBE_SCORE_EXTENSION + 1;
return 0;
}
static int s337m_read_header(AVFormatContext *s)
{
s->ctx_flags |= AVFMTCTX_NOHEADER;
return 0;
}
static void bswap_buf24(uint8_t *data, int size)
{
int i;
for (i = 0; i < size / 3; i++, data += 3)
FFSWAP(uint8_t, data[0], data[2]);
}
static int s337m_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
uint64_t state = 0;
int ret, data_type, data_size, offset;
enum AVCodecID codec;
while (!IS_LE_MARKER(state)) {
state = (state << 8) | avio_r8(pb);
if (avio_feof(pb))
return AVERROR_EOF;
}
if (IS_16LE_MARKER(state)) {
data_type = avio_rl16(pb);
data_size = avio_rl16(pb);
} else {
data_type = avio_rl24(pb);
data_size = avio_rl24(pb);
}
if ((ret = s337m_get_offset_and_codec(s, state, data_type, data_size, &offset, &codec)) < 0)
return ret;
if ((ret = av_get_packet(pb, pkt, offset)) != offset)
return ret < 0 ? ret : AVERROR_EOF;
if (IS_16LE_MARKER(state))
ff_spdif_bswap_buf16((uint16_t *)pkt->data, (uint16_t *)pkt->data, pkt->size >> 1);
else
bswap_buf24(pkt->data, pkt->size);
if (!s->nb_streams) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st) {
return AVERROR(ENOMEM);
}
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = codec;
st->need_parsing = AVSTREAM_PARSE_HEADERS;
}
return 0;
}
AVInputFormat ff_s337m_demuxer = {
.name = "s337m",
.long_name = NULL_IF_CONFIG_SMALL("SMPTE 337M"),
.read_probe = s337m_probe,
.read_header = s337m_read_header,
.read_packet = s337m_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};
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