MP4 output file corrupts when over 4GB

[PhilPreston3072]

I've been recording live events on OBS (Online Broadcast Streaming) software and the file ends up being about 11GB in size. Strangely when I edit and output the file in VideoStudio 2019 using smartrender and use output settings same as first clip, the resultant file plays fine at the start but then will freeze at around the 36min mark, which is where I think is the 4GB mark of the file. Even though the picture is frozen and sound has stopped in VLC player playback, the time counter keeps going.

If I compress the OBS file in handbrake down to less than 4GB, then Videostudio will output the mp4 file that plays no problem to the end.

I tried rendering the file with the preset mp4 1920x1080 profile in VS without smartrender and that played fine from the start too, but still ended with ongoing freeze frames at about the 8GB mark into the file.

My work around has been to output the project in smaller segments of less than 4GB and then join them back together with a separate free mp4 joining software, but it's quite a hassle which I thought surely Video editing software should be able to take care of. If I join the clips in VS, the problem happens again.

Just wondering if anyone has a solution for this? I also did try rendering videos from my camera which are m2ts files and they rendered fine even when the output file was over 4GB.

[tletter]

MP4 output file corrupts when over 4GB

Perhaps you're trying to render to a FAT32 formatted storage device with its 4GB file size limit.

tletter
https://www.youtube.com/user/tletter

[Ken Berry]

That was also my first thought. Can you tell us whether the video with the problem is being stored on your PC's hard drive or stored on a connected USB hard disk or stick drive which may be formatted as FAT32. As tletter has already said, FAT32 cannot deal with files over 4 GB...

[PhilPreston3072]

I'm using a 4TB drive that is NTFS formatted.

Perhaps it's simplest if I share 1 recording of the OBS file and see if others here can render it. If you can get it to render entirely and playback near the end smoothly I'd be happy to know. A clue to the problem is after rendering the mp4 file, when you playback the file and jump to near the end of the timeline in VLC mediaplayer, the sound plays but the picture is freezeframe for a few seconds before the sound catches up to sync up with the freezeframe. When uploaded to youtube it results in continuous freezeframes towards the end, making it irritating to watch. Apologies that the file is nearly 11GB, but it needs to be that long for the glitches to appear.

Below is the file you can test out.
https://drive.google.com/file/d/1Zz-vWO ... sp=sharing

[canuck]

I'm using a 4TB drive that is NTFS formatted.

Perhaps it's simplest if I share 1 recording of the OBS file and see if others here can render it. If you can get it to render entirely and playback near the end smoothly I'd be happy to know. A clue to the problem is after rendering the mp4 file, when you playback the file and jump to near the end of the timeline in VLC mediaplayer, the sound plays but the picture is freezeframe for a few seconds before the sound catches up to sync up with the freezeframe. When uploaded to youtube it results in continuous freezeframes towards the end, making it irritating to watch. Apologies that the file is nearly 11GB, but it needs to be that long for the glitches to appear.

Below is the file you can test out.
https://drive.google.com/file/d/1Zz-vWO ... sp=sharing

The downloaded file is only 1.1GB/ Is that a typo in your posts?

[PhilPreston3072]

The downloaded file is only 1.1GB/ Is that a typo in your posts?

No typo. In my Google drive it says 10GB so I was off by 1GB so apologies for that. That is strange if your download is only 1.1GB. Does your video run for 1hr 27mins 39secs?

[Ken Berry]

Mine also shows 10.2 GB, though I don't have time right now to do any experiments. Will report back later.

[Ken Berry]

I'm a little confused now. That video is obviously already edited and rendered. That being said, I don't get any freeze frames anywhere, and there are only a few minor flickery bits which I suspect are part of the original camera work rather than anything going wrong in the subsequent render. Nothing untoward occurred around the 35 - 40 minutes area, nor at around the 70 - 80 minute area. Everything in fact seemed to play quite smoothly from beginning to end.

What I did notice at the very beginning was that the voice did not quite match the lips of the man. It was out by probably less than half a second, but noticeable. This out of sync audio continued throughout the video in all parts, whoever was speaking or singing. But it was consistently half a second behind from beginning to end, never getting any worse. Whether this slight fault would drive an audience crazy after nearly 90 minutes, I couldn't say, though I think most people could probably live with it.

However, as I say, the video played smoothly throughout -- no freeze frames or audio loss anywhere...

Re-rendering the video is not going to prove anything, I fear. The out of sync problem is not going to miraculously be cured. That would required extracting the audio and trying to realign it by half a second to the video. I suppose it could be done with a bit of patience, and at least the out of sync effect is constant in its length throughout the whole video.

[PhilPreston3072]

I'm a little confused now. That video is obviously already edited and rendered. That being said, I don't get any freeze frames anywhere, and there are only a few minor flickery bits which I suspect are part of the original camera work rather than anything going wrong in the subsequent render. Nothing untoward occurred around the 35 - 40 minutes area, nor at around the 70 - 80 minute area. Everything in fact seemed to play quite smoothly from beginning to end.

This video file wasn't edited or rendered in Videostudio. It is a straight out mp4 recording through OBS software which is for online broadcast productions. Title overlays and scene crossfades were all done live in OBS and our Blackmagic video mixer. So this video file plays fine, and I do concur that there are some lipsync issues but that I know how to fix so not the issue here.

The problem for me is when I want to edit the file in Videostudio 2019 for any mistakes or awkward long breaks, then I need to render in Videostudio and then the glitches happen, particularly after 1hr 18mins. Even if I don't do any edits in Videostudio and simply render the entire file in Videostudio the glitches still happen which shows that it's not being caused by any editing effect. So I want to know if there's something I can do to correct this glitching after 1hr 18mins. It would be even better if smartrender could work so I can get the output file faster.

[Ken Berry]

Thanks for the explanation. It would have been useful to have that information from the beginning as I have never heard of the OBS software before.

Since writing the above, in fact I did what I suggested and extracted the audio. I realize you now say you could correct that. But FWIW I found that moving the entire audio stream to the right by 10 frames i.e. 1/3 of a second, the audio and video were in perfect sync, and that remained the case throughout the video to the very end.

However, I then rendered using SmartRender. This took a while, and got particularly slow when I reached 92%, which is about where all the written sequences appear in the video. But in the end I got a "Successfully rendered" message. The sync now appears perfect in the rendered video...

That being said, so far, when I start playing the new video in VLC, Windows Media Player or even Win 10's Movie & TV player, and try to jump ahead, all I get is black screen though the audio continues to play. This happens in all players. Jumping ahead in much smaller increments appears to work fine, but when I reach exactly 35'09" the video stops and remains static on screen while the audio continues. That is in VLC player. Neither WMP nor Movies & TV will allow me to jump ahead at all in either small or large increments.

[PhilPreston3072]

Thanks very much Ken for your efforts in replicating the issue and my apologies for not explaining the situation fully with OBS which led to confusion. Really appreciate you having a go.
I needed to know if the problem was on my side (user error, PC error), or is it a problem in general for all.
I get the same problem with Smartrender where the video ends up freezing in VLC at around the same 35min mark.
Comparing the video header parameters between the source video clip and the output video clip shows a couple of discrepancies that could be the problem but I'm not sure. I'll bring them up probably tomorrow as I don't have time now.

But it would seem at this stage that the output of the OBS files are incompatible for outputting with VS, unless the output files are under 4GB.

[Ken Berry]

Well, I'm back again. I had another go at it, and this time rendered Same As Project Settings but without SmartRender. It was very much slower, taking close to an hour. Mind you, one hour to render a 1 hour 27 minute video is probably not too bad when all is said and done.

And I have to say that this time it appears to have worked! It is all there, and all in sync. Moreover, I can jump forward in increments through the whole video.

If you want, I will try uploading it to Dropbox tomorrow (Sunday) but right now I have to go to bed as it is already 1:30 a.m. Saturday night!

[PhilPreston3072]

If you want, I will try uploading it to Dropbox tomorrow (Sunday) but right now I have to go to bed as it is already 1:30 a.m. Saturday night!

That would be great. Thanks very much Ken

[Ken Berry]

Ok, I've uploaded it to Dropbox. It's the only video there. I don't normally share online, so let me know if there is any problem accessing it... Click on Open in the top right of screen and choose Download:

https://www.dropbox.com/s/gwsw80cqxhgph ... 2.mp4?dl=0

[RobertOZ]

Hi Ken,
Can confirm that the video plays without any apparent freezing, no problem moving backwards/forwards in VLC, audio seems to be in sync