avcodec/cavsdec: print error messages in case of errors

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/cavsdec.c

@@ -565,8 +565,10 @@ static int decode_residual_block(AVSContext *h, GetBitContext *gb,
         level_code = get_ue_code(gb, r->golomb_order);
         if (level_code >= ESCAPE_CODE) {
             run      = ((level_code - ESCAPE_CODE) >> 1) + 1;
-            if(run > 64)
+            if(run > 64) {
+                av_log(h->avctx, AV_LOG_ERROR, "run %d is too large\n", run);
                 return AVERROR_INVALIDDATA;
+            }
             esc_code = get_ue_code(gb, esc_golomb_order);
             level    = esc_code + (run > r->max_run ? 1 : r->level_add[run]);
             while (level > r->inc_limit)
@@ -892,8 +894,10 @@ static inline int decode_slice_header(AVSContext *h, GetBitContext *gb)
     if (h->stc > 0xAF)
         av_log(h->avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc);
 
-    if (h->stc >= h->mb_height)
+    if (h->stc >= h->mb_height) {
+        av_log(h->avctx, AV_LOG_ERROR, "stc 0x%02x is too large\n", h->stc);
         return AVERROR_INVALIDDATA;
+    }
 
     h->mby   = h->stc;
     h->mbidx = h->mby * h->mb_width;