On 08/04/2017 01:51 PM, Mark Thompson wrote:
+ if (ret)
+ return 0;
+
+ return avpriv_v4l_dequeue(cap_pool, frame, NULL, timeout);
+}
What happens to the decoder if some parameters like resolution change
mid-stream? (Try the stream h264/reinit-large_420_8-to-small_420_8.h264 in the
fate samples.)
yes, it breaks - the player still shows and image but it is corrupted.
I am not sure how to handle this situation to be honest...so need to
look into this.
Also, are the frames returned here actually still used by the decoder
internally as reference frames, or is the reference frame copied somewhere else?
I think once the buffers are dequeued, the v4l2 decoder doesnt keep any
references to it.
(Seems slightly unlikely that they would be copied given the additional
memory requirements, but I know discrete desktop GPUs (which admittedly have
9001x the memory bandwidth and power budget) do do this to hide the possible
issues.) I think, though I'm not entirely sure because I haven't run it, that
the returned buffers will only have the user reference, so will appear to be
writable to following filters - if that ends up writing on reference frames
then the decoder will break.
ack
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