static int mov_read_esds(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
{
    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
    int tag, len;

    get_be32(pb); /* version + flags */
    len = mp4_read_descr(c, pb, &tag);
    if (tag == MP4ESDescrTag) {
        get_be16(pb); /* ID */
        get_byte(pb); /* priority */
    } else
        get_be16(pb); /* ID */

    len = mp4_read_descr(c, pb, &tag);
    if (tag == MP4DecConfigDescrTag) {
        int object_type_id = get_byte(pb);
        get_byte(pb); /* stream type */
        get_be24(pb); /* buffer size db */
        get_be32(pb); /* max bitrate */
        get_be32(pb); /* avg bitrate */

        st->codec->codec_id= codec_get_id(ff_mp4_obj_type, object_type_id);
        dprintf(c->fc, "esds object type id %d\n", object_type_id);
        len = mp4_read_descr(c, pb, &tag);
        if (tag == MP4DecSpecificDescrTag) {
            dprintf(c->fc, "Specific MPEG4 header len=%d\n", len);
            st->codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!st->codec->extradata)
                return AVERROR(ENOMEM);
            get_buffer(pb, st->codec->extradata, len);
            st->codec->extradata_size = len;
            /* from mplayer */
            if ((*st->codec->extradata >> 3) == 29) {
                st->codec->codec_id = CODEC_ID_MP3ON4;
            }
        }
    }
    return 0;
}