Set x264_build so that checks are simpler.

Originally committed as revision 21681 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -873,6 +873,7 @@ av_cold int ff_h264_decode_init(AVCodecContext *avctx){
     h->thread_context[0] = h;
     h->outputed_poc = INT_MIN;
     h->prev_poc_msb= 1<<16;
+    h->x264_build = -1;
     ff_h264_reset_sei(h);
     if(avctx->codec_id == CODEC_ID_H264){
         if(avctx->ticks_per_frame == 1){
@@ -1782,7 +1783,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
 
         if(h->sps.timing_info_present_flag){
             int64_t den= h->sps.time_scale;
-            if(h->x264_build > 0 && h->x264_build < 44)
+            if(h->x264_build < 44U)
                 den *= 2;
             av_reduce(&s->avctx->time_base.num, &s->avctx->time_base.den,
                       h->sps.num_units_in_tick, den, 1<<30);

libavcodec/h264_direct.c

@@ -286,7 +286,7 @@ single_col:
             if(!IS_INTRA(mb_type_col[0]) && !h->ref_list[1][0].long_ref
                && (   (l1ref0[0] == 0 && FFABS(l1mv0[0][0]) <= 1 && FFABS(l1mv0[0][1]) <= 1)
                    || (l1ref0[0]  < 0 && l1ref1[0] == 0 && FFABS(l1mv1[0][0]) <= 1 && FFABS(l1mv1[0][1]) <= 1
-                       && (h->x264_build>33 || !h->x264_build)))){
+                       && h->x264_build>33U))){
                 a=b=0;
                 if(ref[0] > 0)
                     a= pack16to32(mv[0][0],mv[0][1]);
@@ -315,7 +315,7 @@ single_col:
                 /* col_zero_flag */
                 if(!IS_INTRA(mb_type_col[0]) && !h->ref_list[1][0].long_ref && (   l1ref0[x8 + y8*b8_stride] == 0
                                               || (l1ref0[x8 + y8*b8_stride] < 0 && l1ref1[x8 + y8*b8_stride] == 0
-                                                  && (h->x264_build>33 || !h->x264_build)))){
+                                                  && h->x264_build>33U))){
                     const int16_t (*l1mv)[2]= l1ref0[x8 + y8*b8_stride] == 0 ? l1mv0 : l1mv1;
                     if(IS_SUB_8X8(sub_mb_type)){
                         const int16_t *mv_col = l1mv[x8*3 + y8*3*b4_stride];