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_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 = av_new_stream(s, 0);
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;
}
int my_spdif_read_packet(AVFormatContext *s, AVPacket *pkt,
uint8_t * garbagebuffer, int garbagebuffersize, int * garbagebufferfilled)
{
AVIOContext *pb = s->pb;
enum IEC61937DataType data_type;
enum AVCodecID codec_id;
uint32_t state = 0;
int pkt_size_bits, offset, ret;
*garbagebufferfilled = 0;
while (state != (AV_BSWAP16C(SYNCWORD1) << 16 | AV_BSWAP16C(SYNCWORD2))) {
if(*garbagebufferfilled < garbagebuffersize){
*garbagebuffer = avio_r8(pb);
(*garbagebufferfilled)++;
state = (state << 8) | *garbagebuffer;
garbagebuffer++;
if (avio_feof(pb)){
return AVERROR_EOF;
}
}else{
return AVERROR_STREAM_NOT_FOUND;
}
}
*garbagebufferfilled -= 4;
data_type = avio_rl16(pb);
pkt_size_bits = avio_rl16(pb);
if (pkt_size_bits % 16)
avpriv_request_sample(s, "Packet not ending at 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;
}
my_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) {
avpriv_report_missing_feature(s, "Codec change in IEC 61937");
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;
}
