#cinelerra-cv: navigating the codec maze

Bottom line up front

Use DV files for importing and exporting to/from Cinelerra, transcoding with ffmpeg where necessary. MP3 files are good for sound-only tracks. Other formats are often problematical, and you’ll save yourself a lot of grief if you just stick with the tried and true.

The melange

Cinelerra has its own internal version of ffmpeg, meaning that both the standalone version of ffmpeg and vlc support a much wider range of containers and codecs.

Not all containers support all codecs. MP4 does not support the pcm_s16le audio codec, for example. pcm_s16le works perfectly in Cinelerra, and is used in DV files. But the fact that MP4 doesn’t support the codec means that you probably don’t want to work with MP4.

Cinelerra support of audio codecs seems patchy, making many containers/codecs unusable. What I have found is that sometimes the video will work fine, but I have problems with the sound, like it cutting out if I move the slider over Cinelerra’s viewer window.

The upshot is: just use DV, and Cinelerra should work smoothly.

DV is a space hog

An hour of DV will take up about 13GB – which is obviously a huge amount. Compare that with, say, a WTV (Window’s TV) file, which will use about 718MB.

DV is relatively quick to transcode, and is smooth for Cinelerra. So there’s that.

If I have a lot of footage at your disposal, but only want to use sparse sections of it, my current approach is to start with the footage in MOV format. I can select chunks of footage from the MOV file using ffmpeg, which I save in DV format. Here’s an example command:

ffmpeg -ss 01:02:30  -i reel01.mov -t 00:01:00 \
-vf scale=720x576 chunk01-01.dv

The ss flag specifies the start point for the chunk (1 hr, 2 min, 30 sec in my example), whilst the t flag  sets the duration of the clip (in this case 1 min).

MOV file

MOV files have the advantage over DV files in that they are much more compact, and have similar quality. They are slower to transcode, though.

Cinelerra seems to get “close” to importing MOV files.Often the sound will work if I play a clip from the beginning, but then run into problems if I want to start a clip at random points. MOV files that use the mp3 audio codec play in vlc flawlessly, but Cinelerra doesn’t like them.

Cinelerra’s rendering of MOV files are bad, and a no-go.

libvorbis is bad

I could not get either vlc or Cinelerra to play audio encoded in this codec.

Other ffmpeg audio codecs which work in vlc, but not in Cinelerra: ac3, libmp3lame

Audio codecs with were reported as unknown: libfaac, wav

An interesting audio codec is aac. This seems to be “the wave of the future”. It is designed to be a successor to MP3, and it used by YouTube, amongst others. Unfortunately, ffmpeg reported that aac support was experimental, requiring an over-ride flag to use it. I didn’t want to use an experimental feature, especially since the chances of Cinelerra supporting it were slim.

WTV format

WTV is an abbreviation for “Windows Recorded TV Show”. Vlc can play these files, but it stutters frequently. Cinelerra does not understand them at all.

Fortunately, you can use ffmpeg to convert them into a friendlier format. The quality will be just as good.


About mcturra2000

Computer programmer living in Scotland.
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