Function wv_get_value

libavcodec/wavpack.c:261–362

}

static int wv_get_value(WavpackContext *ctx, GetBitContext *gb, int channel, int *last)
{
    int t, t2;
    int sign, base, add, ret;
    WvChannel *c = &ctx->ch[channel];

    *last = 0;

    if((ctx->ch[0].median[0] < 2U) && (ctx->ch[1].median[0] < 2U) && !ctx->zero && !ctx->one){
        if(ctx->zeroes){
            ctx->zeroes--;
            if(ctx->zeroes){
                c->slow_level -= LEVEL_DECAY(c->slow_level);
                return 0;
            }
        }else{
            t = get_unary_0_33(gb);
            if(t >= 2) t = get_bits(gb, t - 1) | (1 << (t-1));
            ctx->zeroes = t;
            if(ctx->zeroes){
                memset(ctx->ch[0].median, 0, sizeof(ctx->ch[0].median));
                memset(ctx->ch[1].median, 0, sizeof(ctx->ch[1].median));
                c->slow_level -= LEVEL_DECAY(c->slow_level);
                return 0;
            }
        }
    }

    if(get_bits_count(gb) >= ctx->data_size){
        *last = 1;
        return 0;
    }

    if(ctx->zero){
        t = 0;
        ctx->zero = 0;
    }else{
        t = get_unary_0_33(gb);
        if(get_bits_count(gb) >= ctx->data_size){
            *last = 1;
            return 0;
        }
        if(t == 16) {
            t2 = get_unary_0_33(gb);
            if(t2 < 2) t += t2;
            else t += get_bits(gb, t2 - 1) | (1 << (t2 - 1));
        }

        if(ctx->one){
            ctx->one = t&1;
            t = (t>>1) + 1;
        }else{
            ctx->one = t&1;
            t >>= 1;
        }
        ctx->zero = !ctx->one;
    }