This week was a bit of varied work.

I did this week:

• Cleaned up, refactored, and commented code. This took a day
• Hunting down a memory leak. This took two days. It ended up being leaving opening a video stream without closing it before looping.
• Worked on getting loops to work properly. This took the better part of a day, as there’s various things that need to be manipulated in between loops for proper playback.
• Did various experiments with sound. My current attempt has been disastrous.

What I’m trying to do right now, is work with SDL_mixer. This goes on behind another file, lowering the dependency between SDL_mixer and my module, to make it easier and more portable to other sound systems in the future. One method I tried is to give the sdl_mixer adapter code a reference to a Condition variable, and to send a signal through the Condition variable when it needs more samples to play, whereupon my audio thread would pass it an already allocated buffer, which would then be added into a Mix_Chunk struct, and played via the SDL_mixer api. After doing this, my audio_thread would work on allocating another bunch of samples to pass it when necessary. This… didn’t work. Mainly because the sdl_mixer adapter code would send a signal back to the audio thread, but the audio thread wouldn’t catch the signal(I was using SDL_cond and associated functions to do this) for some reason. Add in as well the issues of deadlocking, which were quite literally textbook, where thread A grabs the GIL and tries to grab a mutex, while thread B grabs the mutex, and tries to grab the GIL. I fixed that.

I’ve also tried building a queue of buffers, which the adapter code will pull out and play when the current buffer is finished. Whenever the audio thread calls playBuffer, it copies that buffer to a newly allocated buffer of the same length, and then that new buffer is stored on the queue.  This isn’t really quite debugged as apparently I need to brush up on pointer manipulation and memory allocation. I think I’m on the right path, by building a queue of buffers, I just need to do it right.

If anyone has any suggestions on how to do this, I will gladly welcome any help!

At the moment, the module will load pretty much any type of movie that ffmpeg supports, play it(infinite amount of times, or a specified amount of times), with pause, and stop working. Seeking does not work yet. Only video works. I’ve also added a few basic parameters to get, like the width and height of the movie itself. Next week, I will work on adding the ability to specify the height and width of the video file. As well, I think I could probably alter the repr a bit to get the current time-stamp. In fact I’ll do that right now. I should also add docs like the other pygame modules.