| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | success | Make fate finished |
diff --git a/libavcodec/motionpixels.c b/libavcodec/motionpixels.c index b48200b017..0bf153f883 100644 --- a/libavcodec/motionpixels.c +++ b/libavcodec/motionpixels.c @@ -324,8 +324,7 @@ static int mp_decode_frame(AVCodecContext *avctx, if (sz == 0) goto end; - if (mp->max_codes_bits <= 0) - goto end; + if (mp->codes_count > 1) if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0)) goto end; mp_decode_frame_helper(mp, &gb);
If the Huffman tree consists of only one entry (which has length zero), no tree is used at all for parsing as the VLC API currently can't handle this. So it makes no sense to create a VLC in this case. Commit 41b7389cade702383e59343561776f83bb26e17f added a check for whether creating the VLC should be skipped, but it also skipped decoding the packet and it used the wrong check: It checked max_codes_bits, the maximum length of code; but this value is only updated iff there is more than one Huffman entry. So if there is only one Huffman entry, and there was a previous frame with more than one entry, then a VLC was created unnecessarily; yet if there was no previous frame with more than one entry, then this frame will be skipped which is probably spec-incompliant. I have no sample for the latter. This commit improves the check to create a VLC iff it is going to be used. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavcodec/motionpixels.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)