[FFmpeg-devel] [PATCH] checkasm: h264dsp: test luma_dc_dequant

[Martin Storsjö]

On Thu, 12 Jun 2025, Tristan Matthews wrote:

> ---
> tests/checkasm/h264dsp.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/tests/checkasm/h264dsp.c b/tests/checkasm/h264dsp.c
> index d1228ed985..5fba31cf69 100644
> --- a/tests/checkasm/h264dsp.c
> +++ b/tests/checkasm/h264dsp.c
> @@ -22,6 +22,7 @@
> #include "checkasm.h"
> #include "libavcodec/h264dsp.h"
> #include "libavcodec/h264data.h"
> +#include "libavcodec/h264idct.h"
> #include "libavcodec/h264_parse.h"
> #include "libavutil/common.h"
> #include "libavutil/intreadwrite.h"
> @@ -324,6 +325,41 @@ static void check_idct_multiple(void)
>     }
> }
>
> +static void check_idct_dequant(void)
> +{
> +    static const int depths[5] = { 8, 9, 10, 12, 14 };
> +    LOCAL_ALIGNED_16(int16_t, src, [16]);
> +    LOCAL_ALIGNED_16(int16_t, dst0, [16 * 16]);
> +    LOCAL_ALIGNED_16(int16_t, dst1, [16 * 16]);
> +    H264DSPContext h;
> +    int bit_depth, i, qmul;
> +    declare_func_emms(AV_CPU_FLAG_MMX | AV_CPU_FLAG_SSE2, void, int16_t *output, int16_t *input, int qmul);
> +
> +    for (int j = 0; j < 16; j++)
> +        src[j] = (rnd() % 512) - 256;
> +
> +    qmul = rnd() % 4096;
> +
> +    memset(dst0, 0, 16 * 16 * sizeof(dst0[0]));
> +    memset(dst1, 0, 16 * 16 * sizeof(dst1[0]));
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(depths); i++) {
> +        bit_depth = depths[i];
> +        ff_h264dsp_init(&h, bit_depth, 1);
> +
> +        if (check_func(h.h264_luma_dc_dequant_idct, "h264_luma_dc_dequant_idct_%d", bit_depth)) {
> +
> +            call_ref(dst0, src, qmul);
> +            call_new(dst1, src, qmul);
> +
> +            if (memcmp(dst0, dst1, 16 * 16 * sizeof(*dst0)))
> +                fail();

If possible, use the checkasm_check_*() helpers for validation for new 
code; this gives you printout of the differing values if you run "checkasm 
-v" and more. In this case, I think checkasm_check(int16_t, dst0, 
16*sizeof(int16_t), dst1, 16*sizeof(int16_t), 16, 16, "dst") would be 
suitable one.

// Martin