[Matroska-devel] Re: Variable Framerate, plugin based video editing tool

Cyrius suiryc at yahoo.com
Mon Jan 26 21:18:38 CET 2004


--- Christian HJ Wiesner <chris at matroska.org> wrote:
> Hi,
> i have the pleasure to tell you that there is a good chance that Mosu
> and Cyrius will work together on a new video editing tool. The new
> tool 
> should not be based on any existing programs, but be more or less 
> started from scratch. Mosu and Cyrius are currently in the process to
> agree on basic structure, and the matroska-devel ML will be used for 
> these initial steps.
> A first draft of the scope of the program could look like that :
> - Variable Framerate ( VFR ) capable
> - Extendable via plugins, for both input/output containers
> - Standard editing Format is MKV ( matroska )
> - Can handle at least one video stream, plus several audio and
> subtitles 
> streams
> - X-platform, GUI made with wxwindows for improved portability
> - Possibility to extend to handling of multiple video streams for NLE
> ( 
> Non-Linear Editing )
> A possible road map could look like
> 1. Define basic structure, including the internal scripting
> 2. Define API for input/output modules
> 3. Allow muxing of MKV files, using different source formats

I agree that Matroska may be one of the first output formats supported.
But I think we should try to also support an 'easy' format from the
beginning too (thinking of AVI or OGM).
>From my point of view when you design the code you need to try and
prepare it for its future purpose (i.e. generally more advanced
features). When testing the code it may be better to have both
'basic'/'limited', and 'advanced' cases to test.
In other words it's good to test it to produce Matroska files which
support various things such as Variable FrameRate and exotic codec
combinations. But it may also be good to test it on more limited
formats such as AVI (I mean Constant FrameRate video, preferably CBR
audio, or VBR with a few workarounds in the specs ;); but e.g. no
Vorbis allowed :p).
Since I may be wrong, I invite people to tell here what they think
about it :)

> 4. Implement simple cutting/editing based on frame number / timestamp
> ----- note : at this step mkvmerge becomes redundant
> 5. Add Preview for the most used and free formats ( via libavcodec ? 
> licensing problems ? )
> 6. Implement enhanced one step editing, similar to Virtualdub ( mark 
> areas to be deleted / copied )
> 7. Define a codec plugin API
> 8. Realize re-encoding of audio and video streams, using de/encoder
> plugins
> ----- note : at this step vdubmod becomes redundant
> 9. Adding NLE, with fades etc.

That would indeed be a good roadmap to replace mkvmerge and
virtualdubmod step by step ...
However I'm not sure you can separate that easily steps 4 and 6.
Maybe it's only me, but I think that if you start only doing too simple
editing features then it might be quite hard to then implement more
advanced ones.
For other parts of the program (such as handling codec plugins, etc)
you can somewhat add them later (by taking into account what it will
need in the code), but upgrading a framework from too basic editing
capabilities to complex editing features may need to rewrite the code.

> As you all might be aware, this is a huge task and can not be
> completed 
> by the two alone. It must be the goal of the complete matroska team
> to 
> contribute to this project, mainly by adding usable input modules, so
> that step 4. could be achieved in reasonable time, so that the full 
> scope of mkvmerge is matched by the new editor. After that, the 
> definition of a codec plugin API and the creation of codecs based on 
> this should be the mian goal, so we could finally lift matroska to a 
> level where it can truely overcome AVI and VfW, and will get a
> general 
> standard status for the future of video and audio encoding.
> I expect Mosu will have something to say here now, and i suppose he
> will 
> get a lot more technical than i did, and also will answer with a lot
> of  
> 'BUT's :-) . So please, before you reply to this email to tell us
> your 
> opinion about it, wait for his email first. After all, i might have
> seen 
> things too optimistic, as always ;-) ....

Sorry for not waiting for his mail ;)
And yes you are always too optimistic (I'm still waiting a good
x-platform media api ;)) :p

Best regards

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