static int
flac_header (AVFormatContext * s, int idx)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    AVStream *st = s->streams[idx];
    GetBitContext gb;
    int mdt;

    if (os->buf[os->pstart] == 0xff)
        return 0;

    init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
    get_bits(&gb, 1); /* metadata_last */
    mdt = get_bits(&gb, 7);

    if (mdt == 0x7f) {
        skip_bits(&gb, 4*8); /* "FLAC" */
        if(get_bits(&gb, 8) != 1) /* unsupported major version */
            return -1;
        skip_bits(&gb, 8 + 16);      /* minor version + header count */
        skip_bits(&gb, 4*8); /* "fLaC" */

        /* METADATA_BLOCK_HEADER */
        if (get_bits_long(&gb, 32) != FLAC_STREAMINFO_SIZE)
            return -1;

        skip_bits(&gb, 16*2+24*2);

        st->codec->sample_rate = get_bits_long(&gb, 20);
        st->codec->channels = get_bits(&gb, 3) + 1;

        st->codec->codec_type = CODEC_TYPE_AUDIO;
        st->codec->codec_id = CODEC_ID_FLAC;

        st->codec->extradata =
            av_malloc(FLAC_STREAMINFO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
        memcpy (st->codec->extradata, os->buf + os->pstart + 5 + 4 + 4 + 4,
                FLAC_STREAMINFO_SIZE);
        st->codec->extradata_size = FLAC_STREAMINFO_SIZE;

        st->time_base.num = 1;
        st->time_base.den = st->codec->sample_rate;
    } else if (mdt == 4) {
        vorbis_comment (s, os->buf + os->pstart + 4, os->psize - 4);
    }

    return 1;
}
Exemple #2
0
static int flac_read_header(AVFormatContext *s,
                             AVFormatParameters *ap)
{
    uint8_t buf[ID3v2_HEADER_SIZE];
    int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
    uint8_t header[4];
    uint8_t *buffer=NULL;
    AVStream *st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->codec_type = CODEC_TYPE_AUDIO;
    st->codec->codec_id = CODEC_ID_FLAC;
    st->need_parsing = AVSTREAM_PARSE_FULL;
    /* the parameters will be extracted from the compressed bitstream */

    /* skip ID3v2 header if found */
    ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
    if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) {
        int len = ff_id3v2_tag_len(buf);
        url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR);
    } else {
        url_fseek(s->pb, 0, SEEK_SET);
    }

    /* if fLaC marker is not found, assume there is no header */
    if (get_le32(s->pb) != MKTAG('f','L','a','C'))
        return 0;

    /* process metadata blocks */
    while (!url_feof(s->pb) && !metadata_last) {
        get_buffer(s->pb, header, 4);
        ff_flac_parse_block_header(header, &metadata_last, &metadata_type,
                                   &metadata_size);
        switch (metadata_type) {
        /* allocate and read metadata block for supported types */
        case FLAC_METADATA_TYPE_STREAMINFO:
        case FLAC_METADATA_TYPE_VORBIS_COMMENT:
            buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!buffer) {
                return AVERROR_NOMEM;
            }
            if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) {
                av_freep(&buffer);
                return AVERROR_IO;
            }
            break;
        /* skip metadata block for unsupported types */
        default:
            ret = url_fseek(s->pb, metadata_size, SEEK_CUR);
            if (ret < 0)
                return ret;
        }

        if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
            FLACStreaminfo si;
            /* STREAMINFO can only occur once */
            if (found_streaminfo) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            if (metadata_size != FLAC_STREAMINFO_SIZE) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            found_streaminfo = 1;
            st->codec->extradata      = buffer;
            st->codec->extradata_size = metadata_size;
            buffer = NULL;

            /* get codec params from STREAMINFO header */
            ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);

            /* set time base and duration */
            if (si.samplerate > 0) {
                av_set_pts_info(st, 64, 1, si.samplerate);
                if (si.samples > 0)
                    st->duration = si.samples;
            }
        } else {
            /* STREAMINFO must be the first block */
            if (!found_streaminfo) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            /* process supported blocks other than STREAMINFO */
            if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
                if (vorbis_comment(s, buffer, metadata_size)) {
                    av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
                }
            }
            av_freep(&buffer);
        }
    }

    return 0;
}