lavc/svq3: Fix regression decoding some files.
authorNikolas Bowe <nbowe@google.com>
Tue, 31 Jul 2018 00:22:02 +0000 (17:22 -0700)
committerMichael Niedermayer <michael@niedermayer.cc>
Sun, 28 Oct 2018 00:22:42 +0000 (02:22 +0200)
Fixes some SVQ3 encoded files which fail to decode correctly after 6d6faa2a2d.
These files exhibit lots of artifacts and logs show "Media key encryption is not implemented".
However they decode without artifacts before 6d6faa2a2d.
The attatched patch allows these files to successfully decode, but also reject media key files.

Tested on the files in #6094 and http://samples.mplayerhq.hu/V-codecs/SVQ3/Vertical400kbit.sorenson3.mov

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 5aeb3b008080d8d4a38f245d557dbc9bd6c36dcf)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/svq3.c

index a937b2f..5d89921 100644 (file)
@@ -1064,16 +1064,15 @@ static int svq3_decode_slice_header(AVCodecContext *avctx)
         av_log(s->avctx, AV_LOG_ERROR, "illegal slice type %u \n", slice_id);
         return -1;
     }
-    if (get_bits1(&s->gb_slice)) {
-        avpriv_report_missing_feature(s->avctx, "Media key encryption");
-        return AVERROR_PATCHWELCOME;
-    }
 
     s->slice_type = ff_h264_golomb_to_pict_type[slice_id];
 
     if ((header & 0x9F) == 2) {
-        i = (s->mb_num < 64) ? 5 : av_log2(s->mb_num - 1);
+        i = (s->mb_num < 64) ? 6 : (1 + av_log2(s->mb_num - 1));
         get_bits(&s->gb_slice, i);
+    } else if (get_bits1(&s->gb_slice)) {
+        avpriv_report_missing_feature(s->avctx, "Media key encryption");
+        return AVERROR_PATCHWELCOME;
     }
 
     s->slice_num      = get_bits(&s->gb_slice, 8);