document some dsp alignments

[ffmpeg] / libavcodec / zmbvenc.c

diff --git a/libavcodec/zmbvenc.c b/libavcodec/zmbvenc.c
index 2feeb66605715cb9f1c875292b9d6c0d51fa0d63..a6b51ba306bb51d89a05114df57cd907f99e26b9 100644 (file)
--- a/libavcodec/zmbvenc.c
+++ b/libavcodec/zmbvenc.c
@@ -54,6 +54,8 @@ typedef struct ZmbvEncContext {
     z_stream zstream;
 } ZmbvEncContext;
 
+static int score_tab[256];
+
 /** Block comparing function
  * XXX should be optimized and moved to DSPContext
  * TODO handle out of edge ME
@@ -62,13 +64,18 @@ static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2
 {
     int sum = 0;
     int i, j;
+    uint8_t histogram[256]={0};
 
     for(j = 0; j < bh; j++){
         for(i = 0; i < bw; i++)
-            sum += src[i] ^ src2[i];
+            histogram[src[i] ^ src2[i]]++;
         src += stride;
         src2 += stride2;
     }
+
+    for(i=1; i<256; i++)
+        sum+= score_tab[histogram[i]];
+
     return sum;
 }
 
@@ -235,8 +242,12 @@ static av_cold int encode_init(AVCodecContext *avctx)
 {
     ZmbvEncContext * const c = avctx->priv_data;
     int zret; // Zlib return code
+    int i;
     int lvl = 9;
 
+    for(i=1; i<256; i++)
+        score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
+
     c->avctx = avctx;
 
     c->pic.data[0] = NULL;
@@ -318,6 +329,6 @@ AVCodec zmbv_encoder = {
     encode_init,
     encode_frame,
     encode_end,
-    .pix_fmts = (enum PixelFormat[]){PIX_FMT_PAL8, -1},
-    .long_name = "Zip Motion Blocks Video",
+    .pix_fmts = (enum PixelFormat[]){PIX_FMT_PAL8, PIX_FMT_NONE},
+    .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
 };