Demise of HD-DVD recorders

[johnb]

A lot of the material I have consists of off-air recordings and I really need to get these transferred to CD before the whole lot is rendered worthless. This happened to my video tapes and piles of valuable material had to be skipped. The audio material is actually worth more to me than the video element. DVD RAM discs are still available so doubt if the technology is going to be obsolete any time soon but the OP's experience is a warning!

Petrushka, to transfer the audio to CD there are a number of steps to go through:

1) Extract the audio from the DVD-RAM discs. If the audio is part of a video recording this is relatively straight forward with software such as VideoReDo Suite, which I have used a great deal (though other software options are available). You would open the files on the disc and save as elementary streams. This writes separate files for the video and the audio.

2) The audio from the Panasonic will either be LPCM, which is fine, or AC3 which will need to be converted to wave format.

3) The audio will have a sample rate of 48kHz. This needs to be resampled to 44.1kHz.

4) Edit the audio as necessary - trimming it and splitting into tracks, as required.

5) Burning to CD.

None if this is particularly difficult, but it gives you an idea of the process.

[Stunsworth]

My issue isn`t so much about dvd-ram discs but as the simple matter of archiving material on dvd disc. I do wonder whether the entire industry is moving towards a point where you simply can`t keep things for posterity because there are no machines on which to burn discs!

I've never used DVD-Ram, but I assume that physically they are the same size as standard DVDs. If so you could use this to copy the DVD as a file to your hard drive (using something like the free Handbrake), and then create a new 'normal' DVD from the file you've created...

http://www.amazon.co.uk/DVD-Writer-Drive-external-Slim-DVD±RW/dp/B001BJDUQ0/ref=sr_1_15?&ie=UTF8&qid=1438552144&sr=8-15&keywords=dvd+ram

Personally I store my video files on a hard drive that's backed up. I find that more convenient that using DVDs.

[Stunsworth]

...highly regarded VideoReDo video editor (though I am sure there must be free alternatives).

VideoReDo is one of the few pieces of software that I've missed since moving to a Mac a few years ago.

[Dave2002]

I've never used DVD-Ram, but I assume that physically they are the same size as standard DVDs. If so you could use this to copy the DVD as a file to your hard drive (using something like the free Handbrake), and then create a new 'normal' DVD from the file you've created...

http://www.amazon.co.uk/DVD-Writer-Drive-external-Slim-DVD±RW/dp/B001BJDUQ0/ref=sr_1_15?&ie=UTF8&qid=1438552144&sr=8-15&keywords=dvd+ram

Personally I store my video files on a hard drive that's backed up. I find that more convenient that using DVDs.

Can Handbrake be used to copy a video file with no loss? Actually that's a non trivial question, as I have files which in the original (no loss version) won't play very well on some hardware, yet a very small amount of lossy compression using Handbrake (presumably would give a slight theoretical quality loss) can sometimes work wonders. I figure that this is because sometimes moving the data from the storage device to memory during playback makes a difference, and smaller source files can be moved to memory faster, allowing the hardware more time per frame to do other video related tasks.

I'd rather watch a video with almost imperceptible loss on each frame but with smooth flow, rather than a "perfect" frame by frame performance with frequent stuttering. I've seen this several times over, and also seen situations where exactly the same video file gives different performance on exactly the same hardwre if it's viewed in Windows or viewed in Mac OS X.

I generally like to keep one copy of the original - absolutely not compressed source - as future developments may make it playable - and it's nearly always possible to do the Handbrake trick to make the video playable on the hardware one has. Once some loss has been introduced that's permanent. Also depends how important the video content is, of course.

[Dave2002]

I've never used DVD-Ram, but I assume that physically they are the same size as standard DVDs. If so you could use this to copy the DVD as a file to your hard drive (using something like the free Handbrake), and then create a new 'normal' DVD from the file you've created...

DVD-RAMS are physically the same size I think (though some come in a caddy IIRC) but not all DVD readers will cope with them. Whether that's a hardware or software thing I can't say.

[johnb]

DVD-RAM discs are the same size as DVDs. As Dave says, some come in "caddies" which require special drives, but it is a simple matter to remove the disc from the caddy. I think many DVD drives these days can "play" DVD-RAM discs. I put play in quotes because, of course, they can hold other data besides video. They were particularly useful with the old Panasonic recorders as data could be transferred to them with no loss of quality, whereas burning to DVD-R necessitated de-coding and re-encoding.

[David-G]

They were particularly useful with the old Panasonic recorders as data could be transferred to them with no loss of quality, whereas burning to DVD-R necessitated de-coding and re-encoding.

Why does decoding and re-encoding entail a loss of quality in a digital system?

[Dave2002]

Why does decoding and re-encoding entail a loss of quality in a digital system?

it depends whether or not both the decoding and the encoding processes are lossy. There are lossless enccoding and decoding methods for video, but presumably the methods referred to for older recorders such as we are discussing are lossy. The lossless methods don't give enough compression for small capacity media.

Another very unlikely possibility is that the encoding process is idempotent, with the decoding process being non lossy. In that case there would be no further loss providing the same encoder was used for the reencoding at the end of the recovery process. In practice there could be degradation with any lossy encoding and decoding processes, though whether it would be significant would depend on a lot of factors. It would probably never be a good idea for master recordings, or for any important content. Sometimes practical considerations might favour a reencoding process and the loss may be considered acceptsble, and introduce few artefacts - but there would be a loss.