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Re: Digital video recording software



On Wed, Dec 25, 2002 at 03:46:00PM +0100, Richard Atterer wrote:

> What I'd like to do with my machine:
> 
>   - record full-resolution TV. Possible with "streamer" (without dropped
>     frames if you do it right!), except that rgb15 format eats 1.3 GB per
>     minute. There's a nice fast GPLd lossless compression codec called
>     "huffyuv", but apparently there's no way to use it for encoding under
>     Linux. Hopefully mencoder will be able to use it at some point.

keep in mind that huffyuv only gets about 2:1 or so compression:

http://math.berkeley.edu/~benrg/huffyuv.html#Benchmarks

so the output is still huge.  There is some support in ffmpeg CVS for
huffyuv now, I believe, but it is really not usable for everyday recording,
only for situations where a short-term lossless copy is desirable (and will
fit in available storage).

>   - Watch TV while recording. Apparently, this is impossible at full
>     resolution because the PCI bus is too slow to transmit the data twice,
>     but just a small preview window would be enough. I haven't found any
>     app which can do that, though...

Eh?  I do this all the time with MythTV; PCI is not usually the bottleneck,
but CPU and main memory bandwidth, and these requirements can be reduced in
exchange for lower quality.

>   - Cut out the commercials, remove black borders, deinterlace.  
>     avidemux looks OK for that, except I think it can't read huffyuv.

You can do some basic manual editing in MythTV (cutting out segments).  For
more complex tasks, you'll want to use a more featureful editing program
like avidemux.

>   - Encode to fit 700MB, or 2x700MB in two separate files. Possible with 
>     avidemux.
> 
> Everything gets much easier if you only record at half of the TV 
> resolution, for example you can watch while recording, or use a more 
> processor-intensive encoder.

What you want is MythTV: www.mythtv.org
Here's a blurb from the package description:

 MythTV implements the following PVR features, and more, with a
 unified graphical interface:
 .
  - Basic 'live-tv' functionality. Pause/Fast Forward/Rewind "live" TV.
  - Video compression using RTjpeg or MPEG-4
  - Program listing retrieval using XMLTV
  - Themable, semi-transparent on-screen display
  - Electronic program guide
  - Scheduled recording of TV programs
  - Resolution of conflicts between scheduled recordings
  - Basic video editing

It's licensed under the GPL; feel free to subscribe to the mailing list and 
get involved.

-- 
 - mdz



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