The original clip, in mpeg4-part2, taken from a Flip video ultra camera was 33MB.

Putting this clip into timeline workarea and selecting Render AVI DV generated output of size 212MB.



Why is the output so much larger than the input?

 

MPEG-2 is a compressed format, while AVI DV is nearly a raw format, with very little compression.

Thanks.



Have googled on AVI and now understand it refers to a way of packaging video and audio data. So, my mpeg4 input was packaged in an AVI container produced by the camera and the totally different output data format AVI DV selected via the Render function was put in an avi container by Kdenlive. This is in no way obvious to the video edit beginner.



I think the most natural output format is the implicit 'what goes in comes out', i.e. the input and output formats as well as the input and output containers should be the same. That is the default behaviour of  most computer editors, e.g. Word, Notepad, Paint and so on.

 

Just another thought...



Since output format is selected by the pair Container and DataFormat, I think the Kdenlive GUI should use two lists for output selection: one for the container showing AVI, MPEG, OGG and so on and the other showing the formats/codecs available for each container.

This would be instructive for the beginner as well as making it easier to use.