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

Brad O'Hearne brado at bighillsoftware.com
Wed May 15 17:43:20 CEST 2013

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. 


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