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Multithreaded decoding produces different results than single threaded decoding

Open jrmuizel opened this issue 3 years ago • 5 comments

See the list of hashes in: https://github.com/cisco/openh264/blob/ef270363115315a592685967901ebf462ea74dea/test/api/decoder_test.cpp#L91 and https://github.com/cisco/openh264/blob/ef270363115315a592685967901ebf462ea74dea/test/api/thread_decoder_test.cpp#L99 for the files that decode differently.

jrmuizel avatar Aug 31 '22 19:08 jrmuizel

@xiaotiansf

huili2 avatar Nov 30 '22 07:11 huili2

I'll investigate it.

xiaotiansf avatar Nov 30 '22 15:11 xiaotiansf

I have investigated the issue of hash difference between threaded and non-threaded. The the maximum pixel value difference is just 1. I think it is caused by a slight different way when deblocking. especially related to 2676933. So I think there is no concern about the difference.

xiaotiansf avatar Dec 11 '22 05:12 xiaotiansf

Isn't the result of H264 decoding specified exactly? i.e. one of the decodes is correct and one isn't?

jrmuizel avatar Dec 11 '22 18:12 jrmuizel

Let me try to compare the results to that from JM H.264 AVC REFERENCE decoder.

xiaotiansf avatar Dec 11 '22 19:12 xiaotiansf