wmv1 slice_height != mb_height support

encoding of slice_height != mb_height
1bit shorter wmv1 headers if bit_rate<50 !? ROTFL M$ is even more stupid than i thought
using dc of non intra blocks for dc prediction of wmv1 if bitrate < 129 && res < 320x240

Originally committed as revision 723 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpegvideo.h

@@ -392,6 +392,7 @@ typedef struct MpegEncContext {
     UINT8 *intra_h_scantable;
     /* [mb_intra][isChroma][level][run][last] */
     int ac_stats[2][2][MAX_LEVEL+1][MAX_RUN+1][2];
+    int inter_intra_pred;
     
 
     /* decompression specific */

libavcodec/msmpeg4data.h

@@ -1867,3 +1867,7 @@ static UINT8 *wmv1_scantable[WMV1_SCANTABLE_COUNT+1]={
     wmv1_scantable03,
 };
 
+static UINT8 table_inter_intra[4][2]={
+    {0,1},{2,2},{6,3},{7,3}
+};
+