On Mon, Sep 19, 2022 at 11:27:49PM +0200, Andreas Rheinhardt wrote:
> Only used there and by x86 snow asm code as fallback.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
> ---
>  libavcodec/snow.c     | 33 ---------------------------------
>  libavcodec/snow.h     |  3 ---
>  libavcodec/snow_dwt.c | 32 ++++++++++++++++++++++++++++++++
>  libavcodec/snow_dwt.h |  3 +++
>  4 files changed, 35 insertions(+), 36 deletions(-)
> 
> diff --git a/libavcodec/snow.c b/libavcodec/snow.c
> index aa15fccc42..85ad6d10a1 100644
> --- a/libavcodec/snow.c
> +++ b/libavcodec/snow.c
> @@ -29,39 +29,6 @@
>  #include "snowdata.h"
>  
>  
> -void ff_snow_inner_add_yblock(const uint8_t *obmc, const int obmc_stride, uint8_t * * block, int b_w, int b_h,
> -                              int src_x, int src_y, int src_stride, slice_buffer * sb, int add, uint8_t * dst8){
> -    int y, x;
> -    IDWTELEM * dst;
> -    for(y=0; y<b_h; y++){
> -        //FIXME ugly misuse of obmc_stride
> -        const uint8_t *obmc1= obmc + y*obmc_stride;
> -        const uint8_t *obmc2= obmc1+ (obmc_stride>>1);
> -        const uint8_t *obmc3= obmc1+ obmc_stride*(obmc_stride>>1);
> -        const uint8_t *obmc4= obmc3+ (obmc_stride>>1);
> -        dst = slice_buffer_get_line(sb, src_y + y);
> -        for(x=0; x<b_w; x++){
> -            int v=   obmc1[x] * block[3][x + y*src_stride]
> -                    +obmc2[x] * block[2][x + y*src_stride]
> -                    +obmc3[x] * block[1][x + y*src_stride]
> -                    +obmc4[x] * block[0][x + y*src_stride];
> -
> -            v <<= 8 - LOG2_OBMC_MAX;
> -            if(FRAC_BITS != 8){
> -                v >>= 8 - FRAC_BITS;
> -            }
> -            if(add){
> -                v += dst[x + src_x];
> -                v = (v + (1<<(FRAC_BITS-1))) >> FRAC_BITS;
> -                if(v&(~255)) v= ~(v>>31);
> -                dst8[x + y*src_stride] = v;
> -            }else{
> -                dst[x + src_x] -= v;
> -            }
> -        }
> -    }
> -}
> -
>  int ff_snow_get_buffer(SnowContext *s, AVFrame *frame)
>  {
>      int ret, i;
> diff --git a/libavcodec/snow.h b/libavcodec/snow.h
> index ed0f9abb42..1c976b9ba7 100644
> --- a/libavcodec/snow.h
> +++ b/libavcodec/snow.h
> @@ -45,11 +45,8 @@
>  #define QSHIFT 5
>  #define QROOT (1<<QSHIFT)
>  #define LOSSLESS_QLOG -128
> -#define FRAC_BITS 4
>  #define MAX_REF_FRAMES 8
>  
> -#define LOG2_OBMC_MAX 8
> -#define OBMC_MAX (1<<(LOG2_OBMC_MAX))
>  typedef struct BlockNode{
>      int16_t mx;                 ///< Motion vector component X, see mv_scale
>      int16_t my;                 ///< Motion vector component Y, see mv_scale
> diff --git a/libavcodec/snow_dwt.c b/libavcodec/snow_dwt.c
> index 18b315ef66..9401d119d0 100644
> --- a/libavcodec/snow_dwt.c
> +++ b/libavcodec/snow_dwt.c
> @@ -25,6 +25,38 @@
>  #include "me_cmp.h"
>  #include "snow_dwt.h"
>  
> +void ff_snow_inner_add_yblock(const uint8_t *obmc, const int obmc_stride,
> +                              uint8_t **block, int b_w, int b_h,
> +                              int src_x, int src_y, int src_stride,
> +                              slice_buffer * sb, int add, uint8_t * dst8)
> +{
> +    for (int y = 0; y < b_h; y++) {
> +        //FIXME ugly misuse of obmc_stride
> +        const uint8_t *obmc1 = obmc  + y * obmc_stride;
> +        const uint8_t *obmc2 = obmc1 + (obmc_stride >> 1);
> +        const uint8_t *obmc3 = obmc1 + obmc_stride * (obmc_stride >> 1);
> +        const uint8_t *obmc4 = obmc3 + (obmc_stride >> 1);
> +        IDWTELEM *dst = slice_buffer_get_line(sb, src_y + y);
> +        for (int x = 0; x < b_w; x++) {
> +            int v = obmc1[x] * block[3][x + y*src_stride]
> +                  + obmc2[x] * block[2][x + y*src_stride]
> +                  + obmc3[x] * block[1][x + y*src_stride]
> +                  + obmc4[x] * block[0][x + y*src_stride];
> +
> +            v <<= 8 - LOG2_OBMC_MAX;
> +            if (FRAC_BITS != 8)
> +                v >>= 8 - FRAC_BITS;
> +            if (add) {
> +                v += dst[x + src_x];
> +                v = (v + (1 << (FRAC_BITS - 1))) >> FRAC_BITS;
> +                if (v & (~255)) v= ~(v>>31);
> +                dst8[x + y*src_stride] = v;
> +            } else
> +                dst[x + src_x] -= v;
> +        }
> +    }
> +}
> +

putting this in snow_dwt may be convenient but it is not part of the dwt so
this feels semantically wrong

thx

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct answer.