avcodec/elbg: Add persistent ELBGContext

It will be used in future commits to avoid having to allocate and free
all the buffers used.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/libavcodec/msvideo1enc.c b/libavcodec/msvideo1enc.c
index fa65a2fbc4..d43013ba5f 100644
--- a/libavcodec/msvideo1enc.c
+++ b/libavcodec/msvideo1enc.c
@@ -36,6 +36,7 @@
  */
 typedef struct Msvideo1EncContext {
     AVCodecContext *avctx;
+    struct ELBGContext *elbg;
     AVLFG rnd;
     uint8_t *prev;
 
@@ -117,7 +118,8 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
             }
             // try to find optimal value to fill whole 4x4 block
             score = 0;
-            avpriv_do_elbg  (c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
+            avpriv_elbg_do(&c->elbg, c->block, 3, 16, c->avg,
+                           1, 1, c->output, &c->rnd);
             if(c->avg[0] == 1) // red component = 1 will be written as skip code
                 c->avg[0] = 0;
             for(j = 0; j < 4; j++){
@@ -136,7 +138,8 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
             }
             // search for optimal filling of 2-color block
             score = 0;
-            avpriv_do_elbg  (c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
+            avpriv_elbg_do(&c->elbg, c->block, 3, 16, c->codebook,
+                           2, 1, c->output, &c->rnd);
             // last output value should be always 1, swap codebooks if needed
             if(!c->output[15]){
                 for(i = 0; i < 3; i++)
@@ -161,7 +164,9 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
             // search for optimal filling of 2-color 2x2 subblocks
             score = 0;
             for(i = 0; i < 4; i++){
-                avpriv_do_elbg  (c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
+                avpriv_elbg_do(&c->elbg, c->block2 + i * 4 * 3, 3, 4,
+                               c->codebook2 + i * 2 * 3, 2, 1,
+                               c->output2 + i*4, &c->rnd);
             }
             // last value should be always 1, swap codebooks if needed
             if(!c->output2[15]){
@@ -286,6 +291,7 @@ static av_cold int encode_end(AVCodecContext *avctx)
     Msvideo1EncContext * const c = avctx->priv_data;
 
     av_freep(&c->prev);
+    avpriv_elbg_free(&c->elbg);
 
     return 0;
 }