LVPE: Rendering and Exporting Video & Audio from Cinelerra
(this post is part of the Linux Video Production Experience series, which chronicles my experiences with creating a high-quality home movie almost entirely in open source software.)
To be honest, I’ve always had no end of trouble getting my final audio and video to come out of Cinelerra. I’ve tried rendering DV files, MPEG files, and AVI & QuickTime files with various codecs, trying to happen upon the best combination of container & codec that my final encoding tool of choice, Avidemux, can easily handle, and that doesn’t take up 100s of gigabytes of disk space and days of rendering time.
After several Cinelerra projects, I decided to start using the following formats for exporting my final audio/video:
- For video: an AVI container with Motion JPEG A video codec at 100% quality
- For audio: a 16 bit WAV
Now, one thing about exporting AVIs: Cinelerra will fail when trying to write an AVI file that’s greater than 2GB in size (2GB being a magic file size for AVI files). To get around this, I will insert labels at every 2 minute mark along the timeline. I had written a small Ruby script to create the XML to do this before, but I found it’s just as easy to use the Selection Start Time field and the [L] key to enter labels every two minutes:
Be sure that all of your effects that you want enabled are, um, enabled, especially the RGB-601 effect if this render is destined for DVD encoding. Save your project and open the Render window ([Shift]-[R]). Let’s set up the AVI video export first:
(Note: I’m working on creating a Tango theme for Cinelerra 2.1, hence the Tango-y buttons and color scheme in some of the dialogs. It’s not done yet.)
And now set up the video export settings for AVI files:
When naming the file, be sure to place two 00s (zero zero) toward the end of the filename, maybe right before the extension:
FinalRender/FamilyVideo-00.avi
With the “Create new file at each label” option checked, the 00 will be replaced with the index of the current segment:
FinalRender/FamilyVideo-01.avi
FinalRender/ FamilyVideo-02.avi
…
FinalRender/ FamilyVideo-24.avi
FinalRender/ FamilyVideo-25.avi
Click the Go button and go to work or sleep. When you return to your computer, it might be done, or it might not. Just be patient. 
Now do the same for audio. Set up the export settings as such:
And for the codec:
Choose a new filename with the right extension (.wav) and click Go. This one won’t take nearly as long. Once this is done, you have your audio and video ready to be encoded to DVD or whatever format you want. I’ll talk next time about using Avidemux to do this.
Another reason you might want to export video is to preview your video with all of its edits, and not have to worry about Background Render rendering each frame. For this, I’ll use Ogg Vorbis/Theora with a fairly high video bitrate. The resulting file plays fine in VLC or Kaffeine.