Logs:
https://gist.github.com/anonymous/7c968c3b901e6625e2958fbbeea53d4e
Hi
I think I've found the root cause of a problem that I've been dealing with for quite a long time. I believe it is due to a bug that causes buffering to remain enabled for audio while being disabled for video, but I will explain the whole situation and let you decide that :)
The problem:
If buffering is disabled on my capture device (Blackmagic design Decklink), and I record for very long times, the audio from the capture device progressively lags behind the video.
Take a look at this example video:
Notice how from 00:55 to 1:42, the audio and video are in perfect sync. However, the sound gets very slowly, but very steadily out of sync with the video. By the time you get to 1:58:00 (almost 2 hours), you'll notice that the sound from the game is about 2 or 3 seconds behind the video.
While it is not done on the sample video, if I add a microphone source, that microphone and the video remain in sync.
If I enable buffering on the capture device, the game's audio and video remain in perfect sync even for very long periods of recording; but the additional microphone will be out of sync: the mic source will be getting progressively ahead of the game. That's why I believe this is a problem related to buffering (maybe exclusive to blackmagic devices?)
Things that I've tried:
-OBS classic does NOT have this problem.
-Adding either "Video capture device" and "blackmagic device". The issue still occurs.
-Mute the capture device's audio and adding a "audio input capture" source with the capture device's audio device. The issue still occurs.
-Redirecting the audio from the capture device to an output device and adding an "audio output capture" on that output device. The issue still occurs.
-Played with all sorts of default vs custom configurations of the encoding plugin (AMD AMF). Nothing seemed to make any diference.
-Tried different versions from 18 up to 20. The issue still occurs.
-Increasing or reducing resolution doesn't seem to have any effect.
-41Khz and 48Khz in audio settings both cause the issue.
-Added different audio and video filters to the capture device, none made any difference
-I don't recall if I tried the h.264 codec alone, I could give it a go if that helps
https://gist.github.com/anonymous/7c968c3b901e6625e2958fbbeea53d4e
Hi
I think I've found the root cause of a problem that I've been dealing with for quite a long time. I believe it is due to a bug that causes buffering to remain enabled for audio while being disabled for video, but I will explain the whole situation and let you decide that :)
The problem:
If buffering is disabled on my capture device (Blackmagic design Decklink), and I record for very long times, the audio from the capture device progressively lags behind the video.
Take a look at this example video:
Notice how from 00:55 to 1:42, the audio and video are in perfect sync. However, the sound gets very slowly, but very steadily out of sync with the video. By the time you get to 1:58:00 (almost 2 hours), you'll notice that the sound from the game is about 2 or 3 seconds behind the video.
While it is not done on the sample video, if I add a microphone source, that microphone and the video remain in sync.
If I enable buffering on the capture device, the game's audio and video remain in perfect sync even for very long periods of recording; but the additional microphone will be out of sync: the mic source will be getting progressively ahead of the game. That's why I believe this is a problem related to buffering (maybe exclusive to blackmagic devices?)
Things that I've tried:
-OBS classic does NOT have this problem.
-Adding either "Video capture device" and "blackmagic device". The issue still occurs.
-Mute the capture device's audio and adding a "audio input capture" source with the capture device's audio device. The issue still occurs.
-Redirecting the audio from the capture device to an output device and adding an "audio output capture" on that output device. The issue still occurs.
-Played with all sorts of default vs custom configurations of the encoding plugin (AMD AMF). Nothing seemed to make any diference.
-Tried different versions from 18 up to 20. The issue still occurs.
-Increasing or reducing resolution doesn't seem to have any effect.
-41Khz and 48Khz in audio settings both cause the issue.
-Added different audio and video filters to the capture device, none made any difference
-I don't recall if I tried the h.264 codec alone, I could give it a go if that helps
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