s->sample_rate = sample_rate;
static int decode_header(MPADecodeContext *s, UINT32 header){    int sample_rate, frame_size, mpeg25, padding;    int sample_rate_index, bitrate_index;    if (header & (1<<20)) {        s->lsf = (header & (1<<19)) ? 0 : 1;        mpeg25 = 0;    } else {        s->lsf = 1;        mpeg25 = 1;    }        s->layer = 4 - ((header >> 17) & 3);    /* extract frequency */    sample_rate_index = (header >> 10) & 3;    sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);    if (sample_rate == 0)        return 1;    sample_rate_index += 3 * (s->lsf + mpeg25);    s->sample_rate_index = sample_rate_index;    s->error_protection = ((header >> 16) & 1) ^ 1;    bitrate_index = (header >> 12) & 0xf;    padding = (header >> 9) & 1;    //extension = (header >> 8) & 1;    s->mode = (header >> 6) & 3;    s->mode_ext = (header >> 4) & 3;    //copyright = (header >> 3) & 1;    //original = (header >> 2) & 1;    //emphasis = header & 3;    if (s->mode == MPA_MONO)        s->nb_channels = 1;    else        s->nb_channels = 2;        if (bitrate_index != 0) {        frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];        s->bit_rate = frame_size * 1000;        switch(s->layer) {        case 1:            frame_size = (frame_size * 12000) / sample_rate;            frame_size = (frame_size + padding) * 4;            break;        case 2:            frame_size = (frame_size * 144000) / sample_rate;            frame_size += padding;            break;        default:        case 3:            frame_size = (frame_size * 144000) / (sample_rate << s->lsf);            frame_size += padding;            break;        }        s->frame_size = frame_size;    } else {        /* if no frame size computed, signal it */        if (!s->free_format_frame_size)            return 1;        /* free format: compute bitrate and real frame size from the           frame size we extracted by reading the bitstream */        s->frame_size = s->free_format_frame_size;        switch(s->layer) {        case 1:            s->frame_size += padding  * 4;            s->bit_rate = (s->frame_size * sample_rate) / 48000;            break;        case 2:            s->frame_size += padding;            s->bit_rate = (s->frame_size * sample_rate) / 144000;            break;        default:        case 3:            s->frame_size += padding;            s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;            break;        }    }    s->sample_rate = sample_rate;    #if defined(DEBUG)    printf("layer%d, %d Hz, %d kbits/s, ",           s->layer, s->sample_rate, s->bit_rate);    if (s->nb_channels == 2) {        if (s->layer == 3) {            if (s->mode_ext & MODE_EXT_MS_STEREO)                printf("ms-");            if (s->mode_ext & MODE_EXT_I_STEREO)                printf("i-");        }        printf("stereo");    } else {        printf("mono");    }    printf("\n");#endif    return 0;}