Merge commit '52c9b0a6c0d02cff6caebcf6989e565e05b55200'

[ffmpeg] / libavcodec / wmv2dec.c

diff --git a/libavcodec/wmv2dec.c b/libavcodec/wmv2dec.c
index 4f97d9227ce1e032d9951e8eb23180ad6b95fedb..92daa1639e5e9b7a2572b891d5d1c964f4213af2 100644 (file)
--- a/libavcodec/wmv2dec.c
+++ b/libavcodec/wmv2dec.c
@@ -181,6 +181,14 @@ int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s)
             }
 
             s->dc_table_index = get_bits1(&s->gb);
+
+            // at minimum one bit per macroblock is required at least in a valid frame,
+            // we discard frames much smaller than this. Frames smaller than 1/8 of the
+            // smallest "black/skip" frame generally contain not much recoverable content
+            // while at the same time they have the highest computational requirements
+            // per byte
+            if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16))
+                return AVERROR_INVALIDDATA;
         }
         s->inter_intra_pred = 0;
         s->no_rounding      = 1;