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Source file is smooth, preview and render is choppy…
I have a strange problem.
On one of my videos, source file playback is perfectly smooth, but for a few seconds in different parts of the video, the rendered video will be choppy (looks like it has a frame rate of 15 fps instead of 30 fps). The same sections of choppiness also occur in the Sony Vegas preview, so I doubt it’s related to bit rate.
I have disabled resampling and also tried turning off GPU acceleration, it did not help.
Project settings:
1920 x 1080
Field order: none (progressive)
PAR: 1.0000
Frame rate: 29.970
Pixel format: 8-bit
Full-resolution rendering quality: best
Motion blur type: gaussian
Deinterlace method: noneSource
Streams
Video: 00:14:19.035, 29.994 fps progressive, 1920x1080x12, AVC
Audio: 00:14:19.052, 48,000 Hz, Stereo, AACI thought maybe it was because the frame rates of project & file were off by 0.024, but that wasn’t the case.
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5 Replies
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Hi Ren,
First of all, which build of Sony Vegas are you using and where did your source footage come from?
When you say that the source video was choppy, does this happen when it’s played on software media players (e.g. VLC)? Any signs of blocking/image tearing up, random lines or similar artifacts?If you could upload the affected file, other users on the forum and I can trial it to see if we get the same problem. I’m new to the forums myself and we’re just trying to help.
RickAVC
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Hi, thanks for responding.
I am using Vegas 12. Source footage is screen capture from PC with Nvidia’s “Shadowplay” program. The sections that are choppy in Vegas are fine in VLC, no artifacts of any kind. It’s a large file and I do not wish to upload it, though I have transferred it to another computer and it also plays fine on that, so it should not be a system problem.
Specs:
i7 4770k
8GB DDR1600
Nvidia GTX 760 2GB -
Ren,
Have you installed any codec pack like K-Lite on your system? Codec packs have been known on the forums to mess with Vegas, not so much for Vegas 12 though some users wouldn’t recommend installing them. Not all H264 encoded videos work with Vegas, you might need some conversion – try converting affected segments of the source footage to an editing format such as DV AVI or MJPEG with Avidemux.RickAVC
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I converted the source using Handbrake to another .mp4, still h264.
Using the new file (same bitrate as source), there is no choppiness in Vegas, which is really strange. Having an intermediate compression step isn’t ideal though.
Thanks for the help.
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Glad you found a way around it, AVC(H264) is a delivery/capture format (e.g. delivering on Youtube, recording footage on digital camcorders nowadays), simply said it only records differences in movement and not full frames, Vegas will have to take more time to decode the file in order to regenerate the frames from the source AVC video, but I’ve think compatibility has improved in Vegas 12 in handling such files.
Shadowplay may have used a variant of AVC(H264) that was optimised for capturing, though Vegas could open the MP4s it makes, it may not behave properly because it’s not entirely compatible with it.
Happy editing,
RickAVC
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