[Ffmpeg-devel] vhook contaminating video stream bug when -deinterlace is used on flv streams

[Scott Manley]

OK another bug from me - i Have a video file which I'm told was encoded 
using Sorenson Squeeze using the following parameters

FLV
1500kbpbs
Sorenson Spark codec 1-pass CBR
30fps (also tried 24fps)
400x244 size
Keyframe every 45 & auto keyframe on scene change
Tried with image smoothing on & off
Audio: mp3, 128kbps, 44mhz, mono

You can download it from http://www.bootysatva.com/junior.flv

So when I try to use one of the vhook plugins to do something to the video the change seems to feedback into the next frame if there's motion the text overlay gets smeared along the motion path as if the decoder is taking the post vhook output as part of its input for generating the next frame. Notably, this corruption only happens when 

So, something like this shows the bug

ffmpeg -i junior.flv -deinterlace -vcodec mpeg4 -f flv -acodec copy -vhook "vhook/drawtext.so  -c #ffffff -f resources/VAGRoundedStd-Bold.otf -t crazytext"  junior-watermarked.mov

while this is fine

ffmpeg -i junior.flv  -vcodec mpeg4 -f flv -acodec copy -vhook "vhook/drawtext.so  -c #ffffff -f resources/VAGRoundedStd-Bold.otf -t crazytext"  junior-watermarked.mov