[Bug] Deadlocks in FLAC codec

Ivanich 306

Hi!

I have UWP app where IMFSourceReader decodes audio stream. Users report that when they rewind FLAC audio it sometimes hangs and it happens only with this codec. I call reader's methods in serialized synchronous way, so calls to Reader->SetCurrentPosition(GUID_NULL, prop) and Reader->ReadSample(MF_SOURCE_READER_FIRST_AUDIO_STREAM, 0, 0, &dwFlags, NULL, &sample) are never called concurrently. In debugger I see that when player hangs, it stucks in ReadSample despite that previous call to SetCurrentPosition completes successfully.

I can send source code to reproduce this bug, but not on the public resource.

Roy Li - MSFT 32,231 Reputation points Microsoft Vendor

2020-10-14T07:24:00.277+00:00

Would you mind to tell if what's the OS version of the device and what's the target version of your app? Also, will this issue happen every time or it happens randomly?
Ivanich 306 Reputation points

2020-10-14T11:52:39.557+00:00

I have tested it on 1903 but can remember that FLAC codec had same or similar problem since introduction. App's min version is Anniversary Update and Target Version is 1809. Issue does not happen every time when you rewind, I had to rewind several times within a short period of time to catch it in the debugger.
Roy Li - MSFT 32,231 Reputation points Microsoft Vendor

2020-10-16T08:39:54.45+00:00

I'm asking other engineers about this. I'll come back when I get response.