[Kdenlive-devel] more merges

[Jason Wood]

On Monday 15 Sep 2003 12:41 pm, Rolf Dubitzky wrote:
> Hi,
>
> I merged more stuff into the CVS HEAD.  You can now enjoy all choppy and
> crappy wav/au/aiff/etc. (libsndfile) and Ogg/Vorbis (libvorbisfile) sound.
>
> Try   './utils/pplay xyz.ogg'
> To play video and seperate audio, look at 'examples/mix_audio.veml'

will do.

> I can probably hack the player to play the sound non-choppy, but the Right
> Thing is to toss the player into the junk bin and write a half decent
> player class with a seperate audio thread.
>
> Oh, then there is a filter plugin which can do audio resampling
> (libsamplerate). As soon as it is working, it would be possible to insert
> the external audio track into the raw DV file. (This is already possible if
> the external audio has one of the few support sample rates in DV)
>
> The other option is to keep the original samplerate and put it into an
> seperate audio track in the .avi file. Actually I would rather use .ogg
> instead of .avi, but both should be working in a while.

For video editing, would not a seperate .wav be better? The size of the audio 
compared to the size of the video is tiny, so the compression of ogg does not 
buy us very much, wavs are non-lossy, and an advantage (that holds for ogg as 
well, but not really avi) is that you can open up the file in a dedicated 
sound editor to tweak it.

> We need to think about how to modify VEML to handle all this. Probably by
> using as much SMIL as possible. It is straight forward to replace
> <scenelist> with <seq> which directly maps to the SeqContainer class in
> piave and <scene> with <par> I guess, but there are some issues with
> effects. The <par> tag does not directly map to any piave class since it
> allows many inputs as far as I see it. A piave BNode does only have two
> tracks and has also different boundary conditions. Of course my definition
> makes more sense ;-)  but since I agree to the Charles' and Dan's
> arguments, I will propose something that is close to SMIL. That way we can
> replace my simple parser with Dan's full SMIL timing parser in the future.

I think that we should map those bits of SMIL that fit for the moment, and 
leave those bits that don't. So - replacing <scenelist> with <seq> I can live 
with, but I need to understand more about <par> before I start implementing 
it :-)

> Do you think you could support the mixing/replacing of audio in kdenlive
> any time soon, or is this far away? I guess this would require too many
> changes, doesn't it?

There is some work already in place for supporting separate audio tracks - at 
the least, the timeline can display tracks of different types, and there is a 
sound track class. However, they were put in place very early on so may need 
some work to get up to speed - my main thought is that there is probably no 
detection as to whether a clip can be placed in a video track or an audio 
track.

So yes, it will require some work, but probably not as much as if it had not 
been anticipated in the first place.

I am working on refactoring the Kdenlive document model at the moment - I 
realized that the current model only allows AV clips in the project list - 
when what is really needed is av clips, project clips, template clips, etc. 
etc. etc. It's a necessary refactor to keep the code clean later on, but I am 
making slow progress on it.

I am doing these changes on my local machine. Cvs HEAD is still what I hope to 
become the Kdenlive 0.2.3 version. I have sorted out the issue with Kdenlive 
firing too many scenelists at piave ;-) (committed to CVS now) and I am happy 
with what Kdenlive is at the moment for a tarball release. What would you say 
is the best plan of action? I think with a lot of the changes going into 
Piave now, it is going to take some time before Kdenlive catches up, and a 
stable release now is a good idea before starting. What do you think?

>
> Cheers, Rolf
>
> BTW, did I mention that pgrab is in the CVS HEAD? You can use it to capture
> DV from your DV-Cam if it's supported by avc1395.

I noticed it but have not really played around with it yet - I'll give it a 
go.

Cheers,
Jason

-- 
Jason Wood
Homepage : www.uchian.pwp.blueyonder.co.uk