Esempio n. 1
0
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;
}
Esempio n. 2
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 = 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;
}
Esempio n. 3
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;
}