Audio does not sync when doing conversion from VHS

[GuyinOhio]

I recently started using Digitnow! Video capture card BR119-US-S.
Windows 10 laptop.
OBS Studio v 31.0.0

I'm trying to convert old VHS tapes to digital but as the recording goes on, the audio and video get out of sync. It gets worse as time goes on. This is not happenning when I play the tape in my VCR (on my tv), just when I'm using the software with the converter card.

I'm guessing there is some adjustments I have to make in the settings but I'm lost as to where to start.
Any help would be appreciated.
Thanks

 

[Suslik V]

Please post a log with your issue! Here's how...

OBS Studio creates a log file each time you run it which contains very useful diagnostic information. Without a log file, it's much harder for any support volunteers to figure out problems and your post may be ignored. To upload a log file, go to the Help menu > Log Files > Upload Last Log...

obsproject.com

 

[GuyinOhio]

Log file you requested

https://obsproject.com/logs/XOy2OcZvf9KCP1gb

 

[Suslik V]

What you tried to achieve with these settings?

13:03:36.574:     base resolution:   1920x1080
13:03:36.574:     output resolution: 1280x720
13:03:36.574:     fps:               30/1
...
13:03:36.943:         - filter: 'Render Delay' (gpu_delay)
...
13:03:37.352: [DShow Device: 'Video Capture Device'] settings updated:
13:03:37.352:     resolution: 720x576
13:03:37.352:     fps: 25.00 (interval: 400000)

1. "Render Delay" filter (as most of the OBS filters) useful for real-time streaming, i.e. when you cannot edit footage. It is better to remove it.
2. OBS output (30 fps) doesn't match your main source (25 fps). Your main source is the capture card which output (25 fps) may depend on the device connected to it or even on type (film) that is playing back. It is better to set OBS Settings > Video > Common FPS Values to match the input source (your capture card).
3. OBS Settings > Video > Output (Scaled) Resolution is better to set to match Base (Canvas) Resolution and better to set it to match the source (in this log it is 720x576) or keep close to source (in case image is squashed by your capture card --> OBS outputs only square pixels, thus old 1.067 pixels results in 768x576 at 4:3 image ratio).

Unfortunately, there is no recording attempt in your log. Try to record something for test purposes - if issue is present then attach OBS log from this session (find it by time and date).

Anyway,
You usually capturing raw video at max possible quality for your equipment and then making adjustments in post production. If audio delay is monotonically increasing then sound track can easily be adjusted with audio editors.

 

[GuyinOhio]

What you tried to achieve with these settings?

13:03:36.574:     base resolution:   1920x1080
13:03:36.574:     output resolution: 1280x720
13:03:36.574:     fps:               30/1
...
13:03:36.943:         - filter: 'Render Delay' (gpu_delay)
...
13:03:37.352: [DShow Device: 'Video Capture Device'] settings updated:
13:03:37.352:     resolution: 720x576
13:03:37.352:     fps: 25.00 (interval: 400000)

1. "Render Delay" filter (as most of the OBS filters) useful for real-time streaming, i.e. when you cannot edit footage. It is better to remove it.
2. OBS output (30 fps) doesn't match your main source (25 fps). Your main source is the capture card which output (25 fps) may depend on the device connected to it or even on type (film) that is playing back. It is better to set OBS Settings > Video > Common FPS Values to match the input source (your capture card).
3. OBS Settings > Video > Output (Scaled) Resolution is better to set to match Base (Canvas) Resolution and better to set it to match the source (in this log it is 720x576) or keep close to source (in case image is squashed by your capture card --> OBS outputs only square pixels, thus old 1.067 pixels results in 768x576 at 4:3 image ratio).

Unfortunately, there is no recording attempt in your log. Try to record something for test purposes - if issue is preset then attach OBS log from this session (find it by time and date).

Anyway,
You usually capturing raw video at max possible quality for your equipment and then making adjustments in post production. If audio delay is monotonically increasing then sound track can easily be adjusted with audio editors.

Thanks for your reply. Unfortunately I don't understand most of it. I'm not an expert at this; I'm just trying to convert some old VHS tapes to digital.

I did submit the log file from the recording I did right before I submitted my original post. I don't know what else I can do, but I followed the directions exactly as they were given to me above. If I didn't submit what I was supposed to, how were you able to give me corrections to make? I'm confused here.

I will try to figure out the steps you outlined above but I will probably need a simpler explanation of what I'm supposed to be doing. For instance, how do I remove render delay? You're telling me what to do but not how to do it.

Again, thanks for your reply.

 

[GuyinOhio]

Thanks for your reply. Unfortunately I don't understand most of it. I'm not an expert at this; I'm just trying to convert some old VHS tapes to digital.

I did submit the log file from the recording I did right before I submitted my original post. I don't know what else I can do, but I followed the directions exactly as they were given to me above. If I didn't submit what I was supposed to, how were you able to give me corrections to make? I'm confused here.

I will try to figure out the steps you outlined above but I will probably need a simpler explanation of what I'm supposed to be doing. For instance, how do I remove render delay? You're telling me what to do but not how to do it.

Again, thanks for your reply.

Ok,
I changed the settings you outlined above in steps 2 and 3 (the closest I could find was 768x432). I can't find "render delay" in the settings anywhere. Please tell me where that is and how to remove it. Thanks.

 

[Suslik V]

Posted log-file has no recording attempt in it. You forgot to: remember the date and time, click Start Recording button, wait for few minutes, click Stop Recording button, close OBS, check if recorded media file has de-synchronization (use "mpv player" or VLC player), if the mentioned de-sync issue is present - open OBS main menu Help > Log Files > Show Log Files - select (by remembered earlier time and date) the log-file and attach it to your post here, on the forum. Log-file (with logged recording session in it) has important data of how well process of encoding (compressing) and rendering (drawing of raw data) preformed by your hardware. Capturing in real-time is resource demanding task, so your issue may come from miss-configuration.

Digitizing of tapes is not simple task. There are different standards for video signals stored on tapes. You need to know source (tape) original resolution, fps, color space, color range, interlaced or not (when interlaced if top field goes first), is there any audio (and how many tracks) etc. You may wish to read about it online.

OBS itself is not easy tool for newbies. To be more comfortable with OBS you can read guides, books, tutorials (including video).

Guides (OBS Studio)

Guides for OBS Studio

obsproject.com

Knowledge Base | OBS

OBS (Open Broadcaster Software) is free and open source software for video recording and live streaming. Stream to Twitch, YouTube and many other providers or record your own videos with high quality H264 / AAC encoding.

obsproject.com

and many more resources.

1. Filters for the source can be added/removed in the Filters window. When you right-click over the "Video Capture Device" source in the list (pane) of the Sources - you will find Filters menu entry --> it opens the Filters window.
2. The Output (Scaled) Resolution and Base (Canvas) Resolution fields in OBS are interactive - you can type in these fields in format: WIDTHxHEIGHT (the "x" letter is separator) - just click in the field! General rules: output size is not less than 32x32 px or sizes dividable by 32, 16, 4, 2 (values of dividers depends on selected encoder and color format). Likely, you need to type: 768x576 in the both fields. Then you can resize the capturing source by right-click over the "Video Capture Device" source and selecting Transform > Stretch to screen (720x576 video will be stretched to fill up the 768x576 canvas and circles in the video becomes circles again).

 

[GuyinOhio]

While I appreciate your help, I do not have the time to go through all of that work. I had a video converter a few years ago that worked perfectly for this purpose but unfortunately it doesn't work anymore, so I bought this unit. There is simply not enough time in my day to do all of this. Again, thanks for your help. I have already made arrangements to return the converter.