[Windows 10] OBS-VirtualCam: Black screen if you use different fps

If I use OBS-VirtualCam and set frames per second (fps) at 61 Jami only displays a black screen. No issues if I use OBS-VirtualCam (SAME settings) together with Element.

OBS-VirtualCam: If I set 10,25,48, 60 or even 80 fps there are no issues (Jami can show you the video of the virtual webcam (Audio and Video settings) ).

However - some framerates for example 61 fps (but also issues if the framerate of OBS-VirtualCam is set at 23,29.97 and 59,94 fps) don't work and Jami only shows a black screen.

If I use Element (https://element.io/ ) I never had any issues - SAME settings!

here are the logs (OBS-VirtualCam 61 fps - just a black video):

[1627332246.081|14948|video_input.cpp   :521  ] MRL: 'camera://video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B}'
[1627332246.083|14948|audio_input.cpp   :274  ] Switching audio source to match 'camera://video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B}'
[1627332246.084| 8316|video_input.cpp   :170  ] VideoInput ready to capture
[1627332246.085| 9204|audio_input.cpp   :78   ] Switching audio input to 'video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B}'
[1627332246.086| 8316|media_decoder.cpp :133  ] Trying to open device video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B} with format dshow, pixel format , size 1360x768, rate 61.000159
[1627332246.087|10780|portaudiolayer.cpp:620  ] Starting PortAudio Input Stream
[dshow @ 0000016193875780] Could not set video options
[1627332246.098| 8316|media_decoder.cpp :143  ] avformat_open_input failed: I/O error
[1627332246.099| 8316|video_input.cpp   :294  ] Could not open input "video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B}" with status -5
[1627332246.100| 8316|video_input.cpp   :209  ] VideoInput closed
[1627332246.105| 9204|audio_input.cpp   :78   ] Switching audio input to 'video=@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{A3FCE0F5-3493-419F-958A-ABA1250EC20B}'

mentioned in issue #514 (closed)

mentioned in issue jami-project#1294 (closed)

@atraczyk If you are using Windows 10 can you also check this issue / if this issue still exists?

Jami shows "no video". (61 fps) If you stop the virtualcam you also see "no video" instead of the blue OBS-VirtualCam preview (Url:https://www.bandicam.com/blog/wp-content/uploads/2021/08/zoom-obs-virtual-camera-1.jpg )

@Mehdighayour @atraczyk Any chance the team can fix this issue? (Just reproduced again)

mentioned in issue jami-daemon#735 (closed)

added BacklogMedium label

mentioned in issue #747 (closed)

assigned to @agsantos

added SprintIn progress label and removed BacklogMedium label

marked this issue as related to #747 (closed)

@agsantos I just reproduced the following issue:

Steps to reproduce: (I always disabled hardware acceleration in Jami)

Issue a:

1. Start Jami (OBS-VirtualCam is NOT launched)
2. Jami: Open settings > Audio / Video the resolution is 1360x768 and 30fps (Since OBS-VirtualCam is NOT launched you can only view the blue camera preview: Url: https://www.kiloview.com/en/wp-content/uploads/2021/08/obs-virtual-camera-image-cover-600.jpg )
3. Now open OBS and launch OBS-VirtualCam
4. Now stop OBS-VirtualCam
5. Just OBS-Studio: Change the fps to 61 fps.(Integer fps value: 61) Click apply and ok
6. Jami won't update the fps; even if you change the device (in Jami) you will still get 30 fps
7. OBS: Click "Start OBS-VirtualCam"
8. Now Jami shows the video preview (30 fps) although the fps value is 61 fps. Every second you get a short video lag (Does Jami try to show 61 fps using 30 fps?)
9. Now click "Stop OBS-VirtualCam"
10. Jami: Select another device (example ManyCam Virtual Webcam) and return again / select OBS-VirtualCam again; Still just 30 fps but this time you only view "no video"
11. Now exit Jami
12. Now enter Jami again. You will still get "no video" but this time you can select 30 fps AND 61 fps. However, even if you select 61 fps you will get a "no video" message instead of the blue camera preview (Url: https://www.kiloview.com/en/wp-content/uploads/2021/08/obs-virtual-camera-image-cover-600.jpg )
13. OBS Studio: Now click "Start virtual camera"
14. Jami will still display "no video" but you are not able to select 30 fps or anything else; just 61 fps; Note: although I never used such a resultion I can still select "1920x1080" and 30 fps in Jami?
15. OBS: Now click: "Stop virtual cam"
16. Now exit Jami

If I enter Jami again I can still just select "1920x1080" and 30 fps (??) and 1360x768 and 61 fps; I always just get "no video"

Issue b (after these steps)

1. Exit Jami
2. Just OBS-Studio: change the fps to common fps value "30", click "Apply" and "OK" (I never exit OBS-Studio)
3. Now open Jami
4. Jami will still show 61 fps and "no video". And you can only select "61 fps"
5. Jami: select another device (example "ManyCam virtual webcam"); Select "OBS VirtualCam" again - Nothing changes (As mentioned: "I can still just select "1920x1080" and 30 fps (??) and 1360x768 and 61 fps; I always just get "no video"")
6. OBS-Studio: Now start the virtual cam (Jami still shows "no video")
7. OBS-Studio: Now stop the virtual cam (Jami still shows "no video")
8. Now exit Jami (NOT OBS-Studio!; but you stopped the virtual cam)
9. Now open Jami again
10. Suddenly Jami allows you to select 61 fps AND 30 fps and you can see this preview (Url: https://www.kiloview.com/en/wp-content/uploads/2021/08/obs-virtual-camera-image-cover-600.jpg )
11. If you leave 61 fps (although OBS now uses 30 fps) and start the virtual cam you get a video
12. Now stop the virtual cam
13. Jami: now select 30 fps
14. OBS: Now start the virtual cam
15. OBS: Stop the virtual cam
16. Jami: Now you are only able to select 30 fps (and again?? 1920x1080 and 30 fps; although I never used this resolution)

Just one comment for issue b:

If you exit Jami, change the fps to common fps value "30" using just OBS-Studio, and then launch Jami (again) you start from start 10 (issue b)

changed title from OBS-VirtualCam: Black screen if you use different fps to [Windows 10] OBS-VirtualCam: Black screen if you use different fps

https://review.jami.net/c/jami-daemon/+/22234

added SprintTo review label and removed SprintIn progress label

mentioned in commit jami-daemon@5df9251e

added SprintDone label and removed SprintTo review label

I guess we can close, there will be a new beta/release in the following days for windows

I actually wanted to close this issue but I have one question left: Did you (Linux-Distro user?) also reproduced this bug (I was using Windows 10)?

Because if yes, can you also check if everything works if you use fractual fps values? Does Jami support values like 59,9 fps or 48,7 fps etc. if OBS-VirtualCam does? (OBS:Studio: File-Settings-Video-Fractual FPS value)

If Jami allows users to use a frame rate like 47,6 etc. can you (if you reproduced the black screen) or another developer try Fractional FPS Values using OBS-Studio?

we round up the fps anyway and to be honest what's the real use case to get a video-conference to 59.8fps comparing to 60fps?

also on linux we use what v4l2 will give, so if it's usable by v4l2, the rest of the system will follow.

So it should not matter if you set OBS-VirtualCam to 29 fps, 33,4 etc. - using the newest beta version of Jami you should never get a black screen again?

What does round up mean when it comes to Jami? If you have 30,1 fps or even 30,001 fps will Jami use 30 fps (and round DOWN) or 31 fps (and therefore will always round up)?

indeed for the black screen

30.4999=>30/30.511111=>31

closed

removed SprintDone label