swscale/utils: Fix intermediate format for cascaded alpha downscaling

Fixes Ticket4926

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2015-12-24 21:46:15 +01:00
parent 4bec36f98c
commit b83d8be6bf
1 changed files with 3 additions and 0 deletions

View File

@ -1803,6 +1803,9 @@ fail: // FIXME replace things by appropriate error codes
int tmpH = sqrt(srcH * (int64_t)dstH);
enum AVPixelFormat tmpFormat = AV_PIX_FMT_YUV420P;
if (isALPHA(srcFormat))
tmpFormat = AV_PIX_FMT_YUVA420P;
if (srcW*(int64_t)srcH <= 4LL*dstW*dstH)
return AVERROR(EINVAL);