avcodec/rv30: put the rpr check back in init with the max vs bits bug fixed

Its usefull to know immediatly if extradata is wrong and not just when later
the decoder tries to use it.

This check was removed by: a6a2282c25
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/rv30.c

@@ -267,6 +267,10 @@ static av_cold int rv30_decode_init(AVCodecContext *avctx)
     }
 
     r->max_rpr = avctx->extradata[1] & 7;
+    if(avctx->extradata_size < 2*r->max_rpr + 8){
+        av_log(avctx, AV_LOG_WARNING, "Insufficient extradata - need at least %d bytes, got %d\n",
+               2*r->max_rpr + 8, avctx->extradata_size);
+    }
 
     r->parse_slice_header = rv30_parse_slice_header;
     r->decode_intra_types = rv30_decode_intra_types;