diff --git a/tests/checkasm/sw_scale.c b/tests/checkasm/sw_scale.c index 86d266fb3e..3b8dd310ec 100644 --- a/tests/checkasm/sw_scale.c +++ b/tests/checkasm/sw_scale.c @@ -187,7 +187,6 @@ static void check_yuv2yuvX(int accurate) uint8_t d_val = rnd(); memset(dither, d_val, LARGEST_INPUT_SIZE); randomize_buffers((uint8_t*)src_pixels, LARGEST_FILTER * LARGEST_INPUT_SIZE * sizeof(int16_t)); - randomize_buffers((uint8_t*)filter_coeff, LARGEST_FILTER * sizeof(int16_t)); ctx = sws_alloc_context(); if (accurate) ctx->flags |= SWS_ACCURATE_RND; @@ -201,6 +200,21 @@ static void check_yuv2yuvX(int accurate) if (dstW <= osi) continue; for (fsi = 0; fsi < FILTER_SIZES; ++fsi) { + // Generate filter coefficients for the given filter size, + // with some properties: + // - The coefficients add up to the intended sum (4096, 1<<12) + // - The coefficients contain negative values + // - The filter intermediates don't overflow for worst case + // inputs (all positive coefficients are coupled with + // input_max and all negative coefficients with input_min, + // or vice versa). + // Produce a filter with all coefficients set to + // -((1<<12)/(filter_size-1)) except for one (randomly chosen) + // which is set to ((1<<13)-1). + for (i = 0; i < filter_sizes[fsi]; ++i) + filter_coeff[i] = -((1 << 12) / (filter_sizes[fsi] - 1)); + filter_coeff[rnd() % filter_sizes[fsi]] = (1 << 13) - 1; + src = av_malloc(sizeof(int16_t*) * filter_sizes[fsi]); vFilterData = av_malloc((filter_sizes[fsi] + 2) * sizeof(union VFilterData)); memset(vFilterData, 0, (filter_sizes[fsi] + 2) * sizeof(union VFilterData));