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obsproject / obs-studio

OBS Studio - Free and open source software for live streaming and screen recording
https://obsproject.com
GNU General Public License v2.0
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A/V desync only when using projector mode #11145

Open SamSnacBar opened 3 weeks ago

SamSnacBar commented 3 weeks ago

Operating System Info

Ubuntu 22.04

Other OS

Ubuntu Studio 22.04LTS (real time / low latency kernel)

OBS Studio Version

Other

OBS Studio Version (Other)

30.2.3

OBS Studio Log URL

https://obsproject.com/logs/WhWl3JtuFOnoQfwO

OBS Studio Crash Log URL

No response

Expected Behavior

When using the projector mode of OBS displaying in fullscreen the captured video game console using a (Decklink) Blackmagic design Intensity pro 4K, the video and audio should stay synchronized whatever the duration of the stream/capture/recording

Current Behavior

When using the projector mode of OBS displaying in fullscreen the captured video game console using a (Decklink) Blackmagic design Intensity pro 4K, the audio is notably delayed after dozens of minutes (v30.2.3, or around 5min with v30.2.2). The v30.2.3 update get positive impact on the audio delay but not fix it. Note that as mentioned previsouly, the A/V desync occurs ONLY WHEN PROJECTOR mode is used. There is no A/V desync otherwise. Because I did not capture video game console since a while, I assume this bug was introduced with one of the version 30 of OBS (my last console capture using projector was with v29, no A/V desync occurred)

Steps to Reproduce

  1. Run OBS, select the scene including the capture card
  2. Use the projector to project the capture card (or the full scene) in the second screen
  3. play the game, and audio will desync after 10-15 minutes (v30.2.3) or less (around 5min with v30.2.2) ...

Anything else we should know?

HW configuration: CPU Ryzen 3700X stock frequency, 64Go DDR4 RAM, OS disc SSD Samsung 980pro 512 Gb, GPU RTX 3060 12Gb Decklink Blackmagic design Intensity pro 4K PCIe 4x installed on a 16x port Video recording on a 6Tb HDD 7200rpm Seagate hard drive Audio card: internal built in with ASRock Phantom 4 pro gaming, and USB Audio DJ 8 (no effect on the A/V desync) 2 gamer screens 144Hz compliant (Asus VG248 and MSI G2712) 1080p working in native resolution using both DP inputs

SW configuration: Ubuntu Studio 22.04 LTS (low latency 5.15.0-118) OBS 30.2.2 or 30.2.3, NVenc, Deckling Blackmagic design Intensity pro 4K, no buffering, downscale output 720p at 2200kbps @60fps, AAC 160kbps audio encoding Decklink low audio latency mode tested On or Off (no effect on the A/V desync) pulseaudio / pipewire

No A/V desync when projection is not used, even after 3h of stream/capture/recording

SamSnacBar commented 3 weeks ago

I forgot to mention than NVidia drivers are 535.183.01 (from APT). Decklink drivers are in version 14.2 (latest drivers to date). During my stream of yesterday, I got audio delay even w/o the use of projector. This was not huge, but noticable after 30-45 minutes.

SamSnacBar commented 3 weeks ago

Hum... I am lost. During my stream of yesterday, the Audio was 100% sync with the video passthrough of my capture card. Nevertheless the video rendering in real time or in projector mode was severely delayed... (something like 1 seconde late or more, as soon as OBS was running). Continuing my investigation but this is quite unclear...