Function sonic_encode_init

libavcodec/sonic.c:170–278

}

static av_cold int sonic_encode_init(AVCodecContext *avctx)
{
    SonicContext *s = avctx->priv_data;
    int *coded_samples;
    PutBitContext pb;
    int i;

    s->version = 2;

    if (avctx->ch_layout.nb_channels > MAX_CHANNELS)
    {
        av_log(avctx, AV_LOG_ERROR, "Only mono and stereo streams are supported by now\n");
        return AVERROR(EINVAL); /* only stereo or mono for now */
    }

    if (avctx->ch_layout.nb_channels == 2)
        s->decorrelation = MID_SIDE;
    else
        s->decorrelation = 3;

    if (avctx->codec->id == AV_CODEC_ID_SONIC_LS)
    {
        s->lossless = 1;
        s->num_taps = 32;
        s->downsampling = 1;
        s->quantization = 0.0;
    }
    else
    {
        s->num_taps = 128;
        s->downsampling = 2;
        s->quantization = 1.0;
    }

    // max tap 2048
    if (s->num_taps < 32 || s->num_taps > 1024 || s->num_taps % 32) {
        av_log(avctx, AV_LOG_ERROR, "Invalid number of taps\n");
        return AVERROR_INVALIDDATA;
    }

    // generate taps
    s->tap_quant = av_calloc(s->num_taps, sizeof(*s->tap_quant));
    if (!s->tap_quant)
        return AVERROR(ENOMEM);

    for (i = 0; i < s->num_taps; i++)
        s->tap_quant[i] = ff_sqrt(i+1);

    s->channels = avctx->ch_layout.nb_channels;
    s->samplerate = avctx->sample_rate;

    s->block_align = 2048LL*s->samplerate/(44100*s->downsampling);
    s->frame_size = s->channels*s->block_align*s->downsampling;

    s->tail_size = s->num_taps*s->channels;
    s->tail = av_calloc(s->tail_size, sizeof(*s->tail));
    if (!s->tail)
        return AVERROR(ENOMEM);