Set the callback function and user data that will be called with the oldest buffer when all pads have been collected, or null on EOS. If a buffer is passed, the callback owns a reference and must unref it.
MT safe.
the function to set
Set the callback function and user data that will be called with the oldest buffer when all pads have been collected, or null on EOS. If a buffer is passed, the callback owns a reference and must unref it.
MT safe.