id,summary,reporter,owner,description,type,status,priority,component,version,resolution,keywords,cc,blockedby,blocking,reproduced,analyzed
1639,concat filter frozen,chinshou,,"The concat filter cause ffmpeg frozen.

prepare any mp4 video , rename it to 1.mp4. then copy it to 2.mp4.

finally execute following command to join the two videos

ffmpeg -f lavfi -i ""movie=1.mp4, scale=512:288 [v1] ; amovie=1.mp4 [a1] ;movie=2.mp4, scale=512:288 [v2] ; amovie=2.mp4 [a2] ;[v1] [v2] concat [out0] ; [a1] [a2] concat=v=0:a=1 [out1]"" join.avi

ffmpeg begin to encoding successfully , but frozen at 50% .

I used the ffmpeg 20120810 windows build from 
http://ffmpeg.zeranoe.com/builds/win32/static/ffmpeg-20120810-git-633b90c-win32-static.7z

I investigate the code and found the frozen caused by av_read_frame , the call will be blocked at 50% position.
",defect,closed,normal,avfilter,git-master,fixed,movie,,,,1,1