dont randomly disallow intr4v in adaptive quant

some PSNR/bitrate gain if adaptive quant is used
initalize qscale_table correctly (it was pretty much random since the qp->lambda change)
  this probably has not much effect as the table isnt used currently IIRC

Originally committed as revision 7342 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h263.c

@@ -486,6 +486,20 @@ static inline void restore_ac_coeffs(MpegEncContext * s, DCTELEM block[6][64], i
     }
 }
 
+/**
+ * init s->current_picture.qscale_table from s->lambda_table
+ */
+static void ff_init_qscale_tab(MpegEncContext *s){
+    int8_t * const qscale_table= s->current_picture.qscale_table;
+    int i;
+
+    for(i=0; i<s->mb_num; i++){
+        unsigned int lam= s->lambda_table[ s->mb_index2xy[i] ];
+        int qp= (lam*139 + FF_LAMBDA_SCALE*64) >> (FF_LAMBDA_SHIFT + 7);
+        qscale_table[ s->mb_index2xy[i] ]= clip(qp, s->avctx->qmin, s->avctx->qmax);
+    }
+}
+
 /**
  * modify qscale so that encoding is acually possible in h263 (limit difference to -2..2)
  */
@@ -493,6 +507,8 @@ void ff_clean_h263_qscales(MpegEncContext *s){
     int i;
     int8_t * const qscale_table= s->current_picture.qscale_table;
 
+    ff_init_qscale_tab(s);
+
     for(i=1; i<s->mb_num; i++){
         if(qscale_table[ s->mb_index2xy[i] ] - qscale_table[ s->mb_index2xy[i-1] ] >2)
             qscale_table[ s->mb_index2xy[i] ]= qscale_table[ s->mb_index2xy[i-1] ]+2;
@@ -507,7 +523,6 @@ void ff_clean_h263_qscales(MpegEncContext *s){
             int mb_xy= s->mb_index2xy[i];
 
             if(qscale_table[mb_xy] != qscale_table[s->mb_index2xy[i-1]] && (s->mb_type[mb_xy]&CANDIDATE_MB_TYPE_INTER4V)){
-                s->mb_type[mb_xy]&= ~CANDIDATE_MB_TYPE_INTER4V;
                 s->mb_type[mb_xy]|= CANDIDATE_MB_TYPE_INTER;
             }
         }

tests/ffmpeg.regression.ref

@@ -79,10 +79,10 @@ stddev: 10.25 PSNR:27.91 bytes:7602176
 657582 ./data/a-mpeg4-qprd.avi
 5b620f592a795b1caad323ab3fab0859 *./data/out.yuv
 stddev: 12.12 PSNR:26.45 bytes:7602176
-b41b9915af65da1c03f17f59a1806d0e *./data/a-mpeg4-adap.avi
-400192 ./data/a-mpeg4-adap.avi
-9dffb8079a1666c054514ab02d9d4871 *./data/out.yuv
-stddev: 14.68 PSNR:24.78 bytes:7602176
+94c5a5e14f51e04b173d72eb0648b206 *./data/a-mpeg4-adap.avi
+400190 ./data/a-mpeg4-adap.avi
+8e5842fc2b92afa362bfcf17f339d47f *./data/out.yuv
+stddev: 14.67 PSNR:24.79 bytes:7602176
 5fff534f0b958547dfdb811d4f289931 *./data/a-mpeg4-thread.avi
 761170 ./data/a-mpeg4-thread.avi
 fe1d119938f8a26174b38eeaa18dff85 *./data/out.yuv

tests/rotozoom.regression.ref

@@ -79,10 +79,10 @@ stddev:  4.84 PSNR:34.41 bytes:7602176
 235016 ./data/a-mpeg4-qprd.avi
 224969c07440a23b376521c484936e75 *./data/out.yuv
 stddev:  4.24 PSNR:35.56 bytes:7602176
-62c7e87076d4741eb99d76e3ec424db0 *./data/a-mpeg4-adap.avi
-205456 ./data/a-mpeg4-adap.avi
-fe20d6bd1aa019196fb6426fdd0f4779 *./data/out.yuv
-stddev:  4.08 PSNR:35.91 bytes:7602176
+7ecfbb848740d316e2fcf573b32cb848 *./data/a-mpeg4-adap.avi
+205454 ./data/a-mpeg4-adap.avi
+c9225addf2e620e0094d26e805693af1 *./data/out.yuv
+stddev:  4.05 PSNR:35.96 bytes:7602176
 8cd8940d7451925784536fe9b2f2a5e3 *./data/a-mpeg4-thread.avi
 254260 ./data/a-mpeg4-thread.avi
 d160a4224ea1af66c85178912f8d3a7c *./data/out.yuv