[mythtv-users] S-video again

faginbagin mythtv at hbuus.com
Thu May 20 05:55:47 UTC 2010


Hi Ted,

A couple of suggestions:

You don't have to use MythTV to capture S-video input from the HVR-1600. You can use v4l2-ctl to configure the analog side of the card to capture S-video. I think what you would need is:
$ v4l2-ctl -i 1
$ cat /dev/video0 > file.mpg &

You can monitor the recording using:
mplayer file.mpg

Then kill the cat process when the recording is complete.

v4l2-ctl --help will display all the options. For example: v4l2-ctl -n will list the inputs available on the analog side of the card.

However, capturing recordings from your PVR using s-video will produce recording that are worse quality than the originals. Why? Because you are converting a digital recording to analog (s-video from the PVR) and then back to digital (s-video into HVR-1600 through its MPEG2 encoder). If there's a way to copy the PVR's original recordings, you'll be able to preserve the original recording's quality. That's why Mike Perkins suggested pulling the hard drive and mounting it. But who knows what the file system is like and whether it will be something intelligible to Linux? The file system could be something proprietary to the PVR manufacturer.

If your PVR lets you copy to DVD-video format losslessly, you can then rip the video using a variety of Linux tools, including MythTV. Ideally, you'd want to use DVD-RW or DVD+RW media so you can reuse them.

If your PVR lets you copy to DVD-VR format losslessly, there's a nifty little utility dvd-vr ripper that can read this format. DVD-VR format is a file format common for DVD recorders and is usually the format used for DVD-RAM, as well as DVD+RW. The utility that can read DVD-VR format can be found here:
http://www.pixelbeat.org/programs/dvd-vr/
I have used it to extract recordings made by a Panasonic DVD recorder. It's got a hard drive and a DVD burner which allows me to copy recordings between hard drive and DVD media.

One of these days, I may try to do what Mike Perkins has suggested. I wouldn't be surprised the the Panasonic's hard drive file system looks more like DVD-VR than something more familiar, like VFAT or NTFS or some Linux file system type. So I suspect my best bet will be to transfer a DVD's worth of recordings at a time. I actually hope it is DVD-VR because I can use the dvd-vr ripper, which can read some of the recording metadata, like title and date-time of recording, which I can then use to give meaningful file names to the copied recordings. I suspect the safest bet will be to copy a DVD's worth of recordings at a time, and I plan to use DVD-RAM and the dvd-vr ripper to do the job.

HTH,
Helen


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