On Sun, Oct 23, 2011 at 3:38 PM, jb <j...@kdenlive.org> wrote: > On Friday 14 October 2011 13:31:24 Dan Dennedy wrote: > >> I was thinking to do something like that in mlt_multitrack where I am >> currenty setting that value, but I had not yet decided on whether to >> add a constant or use double the track count or other. >> >> > Mikko, I would be interested to know if these changes have an influence >> > on the crashes you experienced. >> >> I was really curious about that huge stack of invalid clip dialogs. >> What do you think is going on there? > > Using MLT in debug mode, I discovered several cases where FFmpeg did show a > warning about insufficient thread locking around avcodec open / close.
I have seen these messages before as well, but there are global mutex locks around all calls to avcodec_open/close. > After several of this warnings, the avformat producer became corrupted and > unable to load any clip, or simply crashed, which might be the reason for > those clips becoming invalid. > > These problems were caused by concurrent uses of producers in Kdenlive, and > also by a "weakness" in the sdl preview consumer that caused such corruption > when doing the following steps very fast several times: > > stop the consumer > delete the producer > connect a new producer to the consumer > start the consumer > > Looks like when looping, sometimes the consumer was stopped while starting, Were you calling consumer.is_stopped() before trying to start it? I do not criticize you if you were not; it is not exactly obvious you should need to, but I am wondering if that would help. > which caused avformat locking issues. I now inserted an event wait to make > sure the consumer is correctly started before attempting a stop which fixed > the issue. Did you learn about an improvement that can be made in mlt in the process of this? > I managed to fix almost all cases that showed up on my 4 cores CPU, so > Kdenlive should hopefully be more stable than ever now. > > regards > jb ------------------------------------------------------------------------------ The demand for IT networking professionals continues to grow, and the demand for specialized networking skills is growing even more rapidly. Take a complimentary Learning@Cisco Self-Assessment and learn about Cisco certifications, training, and career opportunities. http://p.sf.net/sfu/cisco-dev2dev _______________________________________________ Kdenlive-devel mailing list Kdenlive-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kdenlive-devel
