[FFmpeg-devel] [PATCH 3/4] checkasm/h263dsp: test dct_unquantize_{intra, inter}

[James Almer]

On 6/12/2024 1:47 AM, Rémi Denis-Courmont wrote:
> ---
>   tests/checkasm/h263dsp.c | 47 +++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/checkasm/h263dsp.c b/tests/checkasm/h263dsp.c
> index 2d0957a90b..8a2cdb34df 100644
> --- a/tests/checkasm/h263dsp.c
> +++ b/tests/checkasm/h263dsp.c
> @@ -18,13 +18,55 @@
>    * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
>    */
>   
> +#include <stdbool.h>
>   #include <string.h>
>   
>   #include "checkasm.h"
>   
> -#include "libavcodec/h263dsp.h"
> +#include "libavutil/avassert.h"
>   #include "libavutil/mem.h"
>   #include "libavutil/mem_internal.h"
> +#include "libavcodec/h263dsp.h"
> +#include "libavcodec/mpegvideodata.h"
> +
> +static uint_fast8_t mpeg_qscale_rnd(void)
> +{
> +    int n = rnd(), q = (n >> 1) & 31;
> +
> +    if (n & 1)
> +        return ff_mpeg2_non_linear_qscale[q];
> +    else
> +        return q << 1;
> +}
> +
> +typedef void (*unquantizer)(int16_t *, size_t, int, int);
> +
> +static void check_dct_unquantize(unquantizer func, const char *name)
> +{
> +#define LEN 64
> +    LOCAL_ALIGNED_16(int16_t, block0, [LEN]);
> +    LOCAL_ALIGNED_16(int16_t, block1, [LEN]);

These are not padded, and unless I'm reading this wrong, an asm 
implementation loading say 16 bytes at a time will overread/write in 
dct_unquantize_intra (which offsets block by 1).

> +    size_t len = 1 + (rnd() & (LEN - 1));
> +    const int qscale = mpeg_qscale_rnd();
> +    const int qmul = qscale << 1;
> +    const int qadd = (rnd() & 1) ? (qscale - 1) | 1 : 0;
> +
> +    declare_func(void, int16_t *, size_t, int, int);
> +
> +    for (size_t i = 0; i < LEN; i++)
> +        block1[i] = block0[i] = (rnd() & 1) ? rnd() : 0;
> +
> +    if (check_func(func, "h263dsp.dct_unquantize_%s", name)) {
> +        av_assert0(len <= LEN);
> +        call_ref(block0, len, qmul, qadd);
> +        call_new(block1, len, qmul, qadd);
> +
> +        if (memcmp(block0, block1, len * sizeof (int16_t)))
> +            fail();
> +
> +        bench_new(block1, LEN, qmul, qadd);
> +    }
> +}
>   
>   typedef void (*filter)(uint8_t *src, int stride, int qscale);
>   
> @@ -56,6 +98,9 @@ void checkasm_check_h263dsp(void)
>       H263DSPContext ctx;
>   
>       ff_h263dsp_init(&ctx);
> +    check_dct_unquantize(ctx.h263_dct_unquantize_intra, "intra");
> +    check_dct_unquantize(ctx.h263_dct_unquantize_inter, "inter");
> +    report("dct_unquantize");
>       check_loop_filter('h', ctx.h263_h_loop_filter);
>       check_loop_filter('v', ctx.h263_v_loop_filter);
>       report("loop_filter");