[FFmpeg-devel] [PATCH] avcodec thread safety fix

[Andreas Öman]

Baptiste Coudurier wrote:
> Hi,
> 
> Andreas ?man wrote:
>> Art Clarke wrote:
>>> So I take back my recommendation :)  Ship it.
>> Ok, I've applied the patch now. And i've also tested it with my
>> own mediaplayer and it seems to work fine.
>>
> 
> Your own ? What is it ? :)

http://www.lonelycoder.com/hts

It uses FFmpeg not only for playing media, but also for loading
all images/icons, etc in the UI using lots of threads so it's
quite thread intensive.

> Btw, it may be nice to have an example of its utilization, it would help
> users for sure.

Sure, a typical callback would look like this (for pthreads).
Perhaps add this to APIChanges?

static int
lockmgr(void **mtx, enum AVLockOp op)
{
  switch(op) {
  case AV_LOCK_CREATE:
    *mtx = malloc(sizeof(pthread_mutex_t));
    if(!*mtx)
      return 1;
    return !!pthread_mutex_init(*mtx, NULL);
  case AV_LOCK_OBTAIN:
    return !!pthread_mutex_lock(*mtx);
  case AV_LOCK_RELEASE:
    return !!pthread_mutex_unlock(*mtx);
  case AV_LOCK_DESTROY:
    pthread_mutex_destroy(*mtx);
    free(*mtx);
    return 0;
  }
  return 1;
}



// During application startup.

if(av_lockmgr_register(lockmgr)) {
  // Failure
}

// During application shutdown.

av_lockmgr_register(NULL);