avcodec/snowenc: add intra_penalty AVOption

This allows favoring intra or inter blocks by a user specified amount.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/snow.h

@@ -175,6 +175,7 @@ typedef struct SnowContext{
     slice_buffer sb;
     int memc_only;
     int no_bitstream;
+    int intra_penalty;
 
     MpegEncContext m; // needed for motion estimation, should not be used for anything else, the idea is to eventually make the motion estimation independent of MpegEncContext, so this will be removed then (FIXME/XXX)
 

libavcodec/snowenc.c

@@ -912,7 +912,7 @@ static av_always_inline int check_block(SnowContext *s, int mb_x, int mb_y, int
         block->type &= ~BLOCK_INTRA;
     }
 
-    rd= get_block_rd(s, mb_x, mb_y, 0, obmc_edged);
+    rd= get_block_rd(s, mb_x, mb_y, 0, obmc_edged) + s->intra_penalty * !!intra;
 
 //FIXME chroma
     if(rd < *best_rd){
@@ -1877,6 +1877,7 @@ static const AVOption options[] = {
     FF_MPV_COMMON_OPTS
     { "memc_only",      "Only do ME/MC (I frames -> ref, P frame -> ME+MC).",   OFFSET(memc_only), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
     { "no_bitstream",   "Skip final bitstream writeout.",                    OFFSET(no_bitstream), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
+    { "intra_penalty",  "Penalty for intra blocks in block decission",      OFFSET(intra_penalty), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE },
     { NULL },
 };