Function mpc7_decode_init

libavcodec/mpc7.c:78–123

}

static av_cold int mpc7_decode_init(AVCodecContext * avctx)
{
    static AVOnce init_static_once = AV_ONCE_INIT;
    MPCContext *c = avctx->priv_data;
    GetBitContext gb;
    LOCAL_ALIGNED_16(uint8_t, buf, [16]);

    /* Musepack SV7 is always stereo */
    if (avctx->ch_layout.nb_channels != 2) {
        avpriv_request_sample(avctx, "%d channels", avctx->ch_layout.nb_channels);
        return AVERROR_PATCHWELCOME;
    }

    if(avctx->extradata_size < 16){
        av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
        return AVERROR_INVALIDDATA;
    }
    memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
    av_lfg_init(&c->rnd, 0xDEADBEEF);
    ff_bswapdsp_init(&c->bdsp);
    ff_mpadsp_init(&c->mpadsp);
    c->bdsp.bswap_buf((uint32_t *) buf, (const uint32_t *) avctx->extradata, 4);
    init_get_bits(&gb, buf, 128);

    c->IS = get_bits1(&gb);
    c->MSS = get_bits1(&gb);
    c->maxbands = get_bits(&gb, 6);
    if(c->maxbands >= BANDS){
        av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
        return AVERROR_INVALIDDATA;
    }
    skip_bits_long(&gb, 88);
    c->gapless = get_bits1(&gb);
    c->lastframelen = get_bits(&gb, 11);
    av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
            c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
    c->frames_to_skip = 0;

    avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
    av_channel_layout_uninit(&avctx->ch_layout);
    avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;

    ff_thread_once(&init_static_once, mpc7_init_static);

    return 0;
}

/**
 * Fill samples for given subband