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Subject: Re: Video plugin and tools problems/limitations
From: [IDC]Dragon (idc-dragon_at_gmx.de)
Date: 2004-02-18


Hello Jens et al,

> - Question: Is it possible to set the "repeat" flag in the RVFh
> for long videos that do not fit into the buffer completely and
> the plugin repeats the whole video over and over? (I would do
> this with a hex editor then.)

Yes, the player is using this flag, you can do so. rvf_mux just doesn't yet
offer to set it. But it is used player-internally when playing an old-style
(headerless) video, I generate an internal header then, and if that's shorter
than 1 second I set the loop flag to treat is as a still.

> - Perhaps on the 2 MB recorder it is better to not spin down the
> disk between reads. Could you prepare a modified plugin to
> test this?

Hmm, then I would have to explicitely prevent the disk from falling asleep.
Needs a new plugin function, or I change it to do nothing and you set a long
spindown timer. Currently I spindown immediately when the data portion is
read.

> > I think this can be changed to 4 GB, have to look into it.
>
> It should be possible to read even >4 GB on windows if you use
> NTFS. Don't know about linux here.

It seems the POSIX file functions I use for portability dont support >2 GB.
If I give that up, I can use Windows' 64 bit file addressing.

> >> - "RVF_MUX" has problems multiplexing the video with audio
> >> that uses MPEG2 or MPEG2.5 sample rates ...
>
> > MPEG2 should work. I have not implemented the 2.5 audio
> > formats, but this can be easily changed.
>
> MPEG2 definitely doesn't work most of the time. I did the
> following thorough tests:

May be a bug. I have meanwhile implemented 2.5, without testing it, I send
it to you in a separate email. Maybe it changes the 2 behaviour as well, but I
don't think so.
I have also speeded up halftone.exe by a factor of 3. In there some really
suboptimal code from my first tries was never reworked. Feel free to
redistribute, I can't update my webspace right now.

> > Strange, I only set the volume, because it can be muted when
> > the plugin starts. The others I don't touch. ...
>
> But it definitely does reset these. I tested this with really
> strange setting, e. g. set balance all to the left - as soon as
> you start playing a video, it's back to the center and stays
> there after it, but when you enter sound settings, it still shows
> "all left"! Perhaps this related to another glitch in the
> plugin - there are two rather loud "pops" at the start of any
> video with audio. Do you somehow reset the MAS?

Other people have reported that as well. I set the volume and init the
playback. Maybe there are some side effects. I currently can't compile Rockbox,
while being in Taiwan.

> > I try. I'm (slowly) working on a one-click tool to convert AVI
> > and MPEG. This will be Windows-only, since it uses the
> > DirectShow infrastructure. halftone and rvf_mux are portable.
>
> Don't know if a one-click tool makes much sense since there are
> many special things in the conversion process which require
> manual correction (e. g. I do rigorous clipping of widescreen
> films because the display is so small, encode audio with
> different settings with lame etc).

> Most appreciated would be a
> tool (could be a portable command line tool too) that
>
> - does all steps of AVItoYUV, Halftone and Rvf_mux at once, i. e.
> takes a properly scaled AVI (112x64 RGB24, perhaps also
> YUV/YV2) and an MP2/MP3 and spits out the already multiplexed
> RVF.

Well, not exactly one click. You still will have to set the target frame
rate and check the cropping

> Most appreciated would be a
> tool (could be a portable command line tool too) that
> - can read AVI >2 GB and even >4 GB on NTFS

The portability already stops at AVI, I think.

> This way you don't even need to create the intermediate AVI
> physically - have a look at "AVIsynth" (http://www.avisynth.org).

This is also Windows only, if I read correct.

But yes, with what I have in mind you won't need any intermediate files.

Jörg

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