Audio and video slowly get out of sync over time

Hello, first time linux user on the forums.

Note: I am new to the world of advanced video editing. My previous experience involves windows movie maker, so I don’t know about b-frames, i-frames, etc. My problem lies in the preview, not after exporting. An attempt at exporting just creates a video with the same problem.

I seem to be having a problem with a single clip, and not a series of clips and audio files. Over time, the single clip loses sync with the audio and video in the shotcut preview. If you pause it, and play it again, it regains its sync; however, it slowly loses it again. The audio gets ahead of the video. It cannot be my computer, because my old weak computer could run shotcut just fine. I have also tried muting the audio, and making it a separate audio file below the video file, but the same thing happens.

I have played the video in other video players, and the clip plays just fine. The only difference is that the framerate is at 29.9365 in shotcut, but 30 fps in other video players. Because of that, I have tried tinkering with the settings to see if it would improve. In the video mode, I have tried creating a custom framerate of 30 fps, and nothing. I have tried turning off frame dropping, I have updated everything on my computer, I have tried converting the video to be edit friendly, and I seem defeated here. How can shotcut perform worse after I virtually doubled what I had to work with?

What are your computer specifications? What version of Shotcut do you have?

Specs:

  • Linux Mint 18.3
  • 8gb DDR4 RAM
  • AMD A12-9720P Radeon R7 Quad Core Processor 64 bit
  • Running shotcut 18.05.08

It’s all that System Info gave me on Linux mint.

I’m not an expert on here, but I’ve tried Googling the 29.9365 frame rate, but can’t figure out what it would be used for. What does Shotcut say about your file in Properties?
Properties

Properties audio

And what are your export settings?
export settings

Audio Sample Rate 1

“The original frame rate of NTSC video was exactly 30 fps. When color was added, the rate had to be changed slightly, to the rate of 29.97 fps. The field rate of NTSC video is 59.94 fields per second. … Note: The actual NTSC video frame rate is 29.97 fps”

For computer use and modern TV’s it’s of little to zero consequence.

1 Like

It seems more people are now editing video from video games and such. I think the video games are using modified codecs, perhaps with variable frame rate, and they do not lend themselves to video editing. If your source files have unusual codecs then it is advised to first convert them to a “standard” and editable video format first, perhaps even using an intermediate codec. Handbrake is the most often mentioned tool for doing these types of conversions. Good luck.

-=Ken=-

The export settings are irrelevant unless they affect the preview in shotcut. Nevertheless, here they are.

Properties:

snip1

snip2

snip3

And the export settings:

snip4

snip5

snip6

Note that this is a different file (with the same frames, resolution, etc), so the problem is the same. These are clips that I have recorded from my xbox one with the built in recording feature.

Possibly. Check out this post on b-frames.

I’m guessing you’re trying to publish to YouTube. Select the YouTube preset for Export. The GOP frame settings seem a bit high. If it is for YouTube, B frames need to be at 2, according to YouTube. And YouTube does require 30 or 60 fps.

The more knowledge the better, especially with the XBox. I was thinking you were like importing old VHS tapes, lol. I’m thinking the more experienced folk here know about how to with XBox files.

Just to verify, did you try to use the newly created file? In case it is not obvious, you have to manually switch to using it - Shotcut does not automatically replace your current file with the new one.

Yes, I have tried using the newly created file. The problem with the newly created file is that the file plays out of sync on both shotcut, and a regular video player. That is opposed to the original recording playing regularly in a regular video player, but out of sync on shotcut. I want to figure out how I can make the shotcut playback the same as the playback in any other video editor.