Go Back   Cockos Incorporated Forums > REAPER Forums > REAPER for Video Editing/Mangling

Reply
 
Thread Tools Display Modes
Old 10-02-2020, 04:32 AM   #1
Sekkleman
Human being with feelings
 
Join Date: Mar 2017
Posts: 36
Default When rendering video an additional frame is added at 29sec and 03 frames

Hey guys,

I've noticed an issue when rendering video from Reaper.

I've installed the latest ffmpeg-4.3.1-win64-shared DLL's and the video I'm using in Reaper is a mov with the following specs -

Video: 1920x1080, h264, 25.00fps Audio: 48000hz, 16bps, 2ch, s16l

When I select more than 30 seconds of the video to render with audio and then reimport the video file to check, it always has an additional frame added onto the video at 29 seconds and 03 frames. This means that the audio is then out of synch with the video by a frame for the remainder of the video clip. This is true for mov/MKV/AVI and H264+MJPEG, but I stopped testing after trying all those formats.

I only noticed it because I work with burnt in timecode on the video and when I reimported it I could clearly see this issue as the burn-in TC went out of synch by a frame from the Reaper TC display.

Have any of you guys come across this issue before?
Sekkleman is offline   Reply With Quote
Old 10-03-2020, 01:00 AM   #2
Sekkleman
Human being with feelings
 
Join Date: Mar 2017
Posts: 36
Default

Just posted a bug report.

After further investigation it turns out this bug happen only when rendering video with an audio sample rate of 48K. Having a sample rate of 44.1K doesn't trigger the issue and Reaper doesn't add an additional frame at 29 seconds and 03 frames.
Sekkleman is offline   Reply With Quote
Old 11-12-2020, 10:06 PM   #3
vudymanuj
Human being with feelings
 
Join Date: Dec 2019
Posts: 1
Default

Sekkleman, thank you for this post. I have the same problem and I couldn't figure out what it was. I made the sound for a full-meter film in Surround 5.1 and then had to adjust the frames that were out of sync in the video editor - it's just a nightmare. If this is a bug DAW Reaper, then where to write to fix it somehow? Because the audio standard for video is 48 kHz and not 44.1kHz. Please share your experience if anyone else has met. Thanks.
vudymanuj is offline   Reply With Quote
Old 11-12-2020, 11:32 PM   #4
Sekkleman
Human being with feelings
 
Join Date: Mar 2017
Posts: 36
Default

Hi vudymanuj,

There is a work around to fix this issue - you need to go into preferences/rendering and change 'Block size to use when rendering' to 256 instead of the default blank. Hit apply and then render and it fixes the bug. The thing to remember is to always change it back to the recommended blank setting before continuing to work and glue/freeze/render as apparently it's best practice to leave the setting blank.

I also made a bug report and provided a project to Justin so he could replicate the bug. Hopefully it'll be fixed at some point.

https://forum.cockos.com/showthread....DOlZLDHa44g6MY

Hope that helps!
Sekkleman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 01:26 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.