[FFmpeg-devel] [PATCH] avcodec/proresdec_lgpl: make use of BlockDSP

[James Almer]

On 6/26/2017 2:34 PM, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavcodec/proresdec_lgpl.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/proresdec_lgpl.c b/libavcodec/proresdec_lgpl.c
> index bc5bdb5..e91abaf 100644
> --- a/libavcodec/proresdec_lgpl.c
> +++ b/libavcodec/proresdec_lgpl.c
> @@ -34,6 +34,7 @@
>  
>  #include "libavutil/intmath.h"
>  #include "avcodec.h"
> +#include "blockdsp.h"
>  #include "idctdsp.h"
>  #include "internal.h"
>  #include "proresdata.h"
> @@ -52,6 +53,7 @@ typedef struct ProresThreadData {
>  } ProresThreadData;
>  
>  typedef struct ProresContext {
> +    BlockDSPContext bdsp;
>      ProresDSPContext dsp;
>      AVFrame    *frame;
>      ScanTable  scantable;
> @@ -86,6 +88,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
>      ctx->slice_data       = NULL;
>  
>      avctx->bits_per_raw_sample = PRORES_BITS_PER_SAMPLE;
> +    ff_blockdsp_init(&ctx->bdsp, avctx);
>      ff_proresdsp_init(&ctx->dsp, avctx);
>  
>      ctx->scantable_type = -1;   // set scantable type to uninitialized
> @@ -431,11 +434,12 @@ static int decode_slice_plane(ProresContext *ctx, ProresThreadData *td,
>  {
>      GetBitContext gb;
>      int16_t *block_ptr;
> -    int mb_num, blocks_per_slice, ret;
> +    int i, mb_num, blocks_per_slice, ret;
>  
>      blocks_per_slice = mbs_per_slice * blocks_per_mb;
>  
> -    memset(td->blocks, 0, 8 * 4 * 64 * sizeof(*td->blocks));
> +    for (i = 0; i < blocks_per_slice; i++)
> +        ctx->bdsp.clear_block(td->blocks + (i << 6));

Is this intended for speed, or to actually clear all blocks instead of
just a few? Because I'm not sure this is going to be faster, especially
if you're not using clear_blocks.
Any relatively recent libc will use AVX internally on new x86 CPUs that
will most likely be faster than calling SSE clear_block in a loop.

>  
>      init_get_bits(&gb, buf, data_size << 3);
>  
>