[linux-dvb] Re: AW: Re: Timing recording

[Chris Pitchford <nova-t@intrepid.cx>]

Ive just updated my scripts and stuck them on a website..

http://dvb.intrepid.cx/

Here's how I record stuff:
in Crontab:

55 19 * * * stream -t 40m -d /myrecordings 8

that makes a file in /myrecordings for 40minutes of video called

Channel4-20021211-1955+40m.ts

Since 8 refers to channel 4 in my channel config file

That part is easy.. however..

For space saving I transcode (using transcode) into FFMPEG DivX avis.
250meg for half an hour is better than 1.1gig!

However I have a neat trick that I use to detect the start and stop points
of program (program start/stop, commercials start/stop)

First I convert the .ts file into a .mpg (vob?) file using dvb-mplex

mplex -t MPEG2 -i TS_STREAM -o Chan4.mpg \
	Channel4-20021211-1955+40m.ts

I use transcode to convert frames to ppm files as follows:
transcode -V -Q 0,0 -k -x mpeg2,null -y im,null -F ppm -o OUT-From$START
	-c $START-$END	-i Chan4.mpg

We can assume that Chan4.mpg looks like this

--adverts--->|<---part1--->|<--adverts-->|<---part2--->|<--adverts--

Now, when transcode gets to a transitional point (going from advert to
program or program to advert) it, and you wont believe this, segfaults!

I get this in the output
OUT-From1-05531.ppm     size 1 Meg ish
OUT-From1-05532.ppm	size 0bytes

This is assuming START=1 and END=100000000 (big number.. )

If I then look at frame number 5532 it is, conincidentally the start frame
of the program!! amazing! incrementing START to 5534 and starting the
command again will keep running till the end of part1. start can keep
being incremented until the end of part2 has been determined!

If I could figure out HOW this happens and actually make a tool to do
this, I would as its is quite possibly the most useful thing Ive seen in a
long while!

Note I only capture from Channel4 at the moment so maybe its something
quirky they do..


I have a number of encoding scripts that take start and stop frame numbers
and can be used to "edit" recordings into mpeg and divx files. Let me tidy
these up and I'll put them on the above site also

I know this is not what you were looking for, but it is a freaky
obnormality none the less

cp


On Thu, 12 Dec 2002, Alexandre CONRAD wrote:

>
>
> > what about vdr, with the build-in cut function you should be able to
> > get your clean video, or you convert it to *.mpg and cut it with
> > something else
>
> Yeah, that's okay. The recording it not really a problem, the cutting
> neither. The thing is that I want to do that everyday, and I want to
> automate it... so I don't have to care about it. I set it up once, and
> we're done. I'm not looking for cutting tools, or recording tools,
> really, I'm looking for a technic to make that happend automaticly.
>
> Any ideas ?
>
> --
> Alexandre CONRAD
> Research & Development
> tel : +33 1 30 80 55 00
> fax : +33 1 30 56 50 20
> TLV
> 6, rue de la plaine
> 78860 - SAINT NOM LA BRETECHE
> FRANCE
>
>



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