[Libav-user] Using the libav* libraries in a thread-safe manner?

[Brad O'Hearne]

On May 15, 2013, at 8:19 AM, Joe Flowers <joe.flowers at nofreewill.com> wrote:

> Does anyone know how to make (enable) the libav* APIs to be thread-safe?

This may sound a little ridiculous, but in general with any third-party library, make a thread-safe wrapper around it. I would guess that your dilemma centers on wanting to reuse resources like codecs / contexts, output formats / contexts, to keep the memory footprint low. But for whatever its worth, in throwing my FFmpeg processing on Instruments (Xcode profiling tool) that footprint is likely going to be a blip on the radar compared to the resources used when processing each frame (not because these consume a lot of memory, but because this processing will be executed many times a second). 

So if the motivation for multithreading is to reuse resources, I wouldn't worry about that. If you truly need more than one object accessing the same processing resources, then put a wrapper around it that makes multiple threads play nice. Without knowing exactly what you are trying to do, can't say what is the best route, but that's my best guess. 

Brad