Use avcodec_check_dimensions instead of custom hack

Originally committed as revision 3836 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/8bps.c

@@ -160,8 +160,7 @@ static int decode_init(AVCodecContext *avctx)
 
 	c->pic.data[0] = NULL;
 
-    // FIXME: find a better way to prevent integer overflow
+    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
-    if (((unsigned int)avctx->width > 32000) || ((unsigned int)avctx->height > 32000)) {
         av_log(avctx, AV_LOG_ERROR, "Bad image size (w = %d, h = %d).\n", avctx->width, avctx->height);
         return 1;
     }

libavcodec/lcl.c

@@ -640,9 +640,7 @@ static int decode_init(AVCodecContext *avctx)
         return 1;
     }
 
-    // FIXME: find a better way to prevent integer overflow
+    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
-    if (((unsigned int)avctx->width > 32000) || ((unsigned int)avctx->height > 32000)) {
-        av_log(avctx, AV_LOG_ERROR, "Bad image size (w = %d, h = %d).\n", avctx->width, avctx->height);
         return 1;
     }