static int adts_parse(aac_buffer *b, int *bitrate, float *length)
{
    int frames, frame_length;
    int t_framelength = 0;
    int samplerate;
    float frames_per_sec, bytes_per_frame;

    /* Read all frames to ensure correct time and bitrate */
    for (frames = 0; /* */; frames++)
    {
        fill_buffer(b);

        if (b->bytes_into_buffer > 7)
        {
            /* check syncword */
            if (!((b->buffer[0] == 0xFF)&&((b->buffer[1] & 0xF6) == 0xF0)))
                break;

            if (frames == 0)
                samplerate = adts_sample_rates[(b->buffer[2]&0x3c)>>2];

            frame_length = ((((unsigned int)b->buffer[3] & 0x3)) << 11)
                | (((unsigned int)b->buffer[4]) << 3) | (b->buffer[5] >> 5);

            t_framelength += frame_length;

            if (frame_length > b->bytes_into_buffer)
                break;

            advance_buffer(b, frame_length);
        } else {
            break;
        }
    }

    frames_per_sec = (float)samplerate/1024.0f;
    if (frames != 0)
        bytes_per_frame = (float)t_framelength/(float)(frames*1000);
    else
        bytes_per_frame = 0;
    *bitrate = (int)(8. * bytes_per_frame * frames_per_sec + 0.5);
    if (frames_per_sec != 0)
        *length = (float)frames/frames_per_sec;
    else
        *length = 1;

    return 1;
}
Unknown