Use free formats by default

[Kẏra]

A free format should be used as the default format.

WebM could be used as the default Youtube upload format.

Dirac Lossless and FLAC could be used as the lossless recording format.

[Andrew (and471)]

Neither of these formats are suitable for the default recording format, as they are both lossy - this is why we use lossless h264.

We could however use WebM as the default format for the youtube upload, or dirac lossless and flac as the default format, however I would need to experiment with the encoding speed of both of these.

I shall therefore change this bug to be using free formats by default.

[Kẏra (thekyriarchy)]

Are you using the lossless option for h.264? I feel as though the output files would be much bigger if they were indeed raw video files...

[Andrew (and471)]

Yes I am

[Kẏra (thekyriarchy)]

I see. Well, this may interest you: https://groups.google.com/a/webmproject.org/group/webm-discuss/browse_thread/thread/15472be8933f4022

Perhaps WebM could be provided as the default, but still have lossless h.264 as an option? Using h.264 by default is that support for it probably prevents Kazam from being shipped with any major distro-- dream big!

[Andrew (and471)]

Yes I saw that, however the whole reason we are using lossless is so that changes are non-destructive (i.e. the screencast doesn't need to be re-recorded) but also it means that not a lot of CPU power is needed for encoding on the fly.

I appreciate that h264 prevents it being shipped with many distros, but I don't want to make it use a lossless codec for the first recording, I feel we need to find a lossless free codec, not make sacrifices elsewhere.

[Alan Pope 🍺🐧🐱 🦄 (popey)]

Have you tried huffyuv?

It's also lossless and licensed under the GPL :)

Worth a punt.

http://en.wikipedia.org/wiki/Huffyuv

[Wayne (waynedpj)]

also, Dirac supports lossless encoding:

http://en.wikipedia.org/wiki/Dirac_%28codec%29

so i imagine that combined with FLAC in a MKV, that would cover a FLOSS lossless video solution.

hope it helps.

peace.

[David Klasinc (bigwhale)]

Alan,

I did _a lot_ and I really mean a lot of testing of codecs and different compression levels and other stuff too. The end findigs were that the only real 'lossless' (none of them are actually completely lossless) format is Huffyuv and even then, the videos that are replayed have to be replayed with mplayer -vo x11 and the video will be exact copy of what was on the screen. Huffyuv is something that Kdenlive for example will not recognize and you won't be able to edit it.

The biggest problem is with colors. Screens are RGB and most movie formats are YUV. YUV444 is a pixel format that performs almost no conversion and is the closest representation of RGB. The problem? Most movie players (mplayer, ffmpeg, vlc, and totem included) support only YUV420 and will refuse to play anything else.

Previously mentioned Huffyuv also supports RGB pixels which is great, but when you edit your footage you will end up converting it to YUV again, so you don't gain much.

Anyway, VP8/WebM is now a default and for now the only format supported.

[Kẏra (thekyriarchy)]

This is great, can't tell you how much I appreciate this work!