What happens when DVD+RW disks go bad?

[cityboy-stl]

I have DVD recorder to record TV shows from cable. Lately I've been having a problem where for several minutes on the recorded show the video just goes completely blank. The sound is fine, just no picture. I'm trying to determine if its a problem with the recorder or with the disks. The RW disks are fairly old with a lot of use and I'm thinking the disks. Do disks fail randomly like this? Has anyone had this happen?

 

[andysayshi]

Why not buy yourself a new disk to clarify the problem? Do the disks play okay on another DVD player? Is your TV reception reliable?

DVD recorders record a multiplexed audio/video stream to disc, so it seems strange that a faulty disc might contain audio and no video. Typically it would be all or nothing. I think it's more likely a problem with the Recorder, possibly a problem with the MPEG2 encoder.

 

[storm-0]

It may NOT be your recorder. Some cable stations (TMC, HBO, ect...) can block your DVD recorders ability to record copyright protected movies -- mostly new release or blockbusters. If the program you're recording doesn't have the stations call letters on the lower right corner of the screen you will not be able to record the program. The major networks do this to prevent new releases from being copied and sold on eBay and other online auction houses. Hope this helps!

 

[Corny]

DVD recorders record a multiplexed audio/video stream to disc, so it seems strange that a faulty disc might contain audio and no video. Typically it would be all or nothing.

On the contrary - it is quite often the case that while the video has problems ( that does not mean that nothing got recorded) the audio continues.

 

[andysayshi]

^ If the disk is faulty, ie failing to properly store data, then it would be very unlikely for audio or video to fail independently. The data on a Video DVD is multiplexed: the audio and video information are combined in the same data packets. If a packet fails to be read during playback, both audio and video information are lost. Hence, my suggestion that an issue with the player is a more likely cause.

storm-0's suggestion is a great one - I hadn't considered the possibility that copy protection (such as Macrovision) may be blocking the recorder. You can purchase video stabilizers that will strip out copy protection systems from an analog video signal, if that's the issue.

 

[Corny]

^ see it this way: small error in the disc, drive reads from the disc, recognizes the error, error correction kicks in, the amount of audio data on the damaged pits is small and quickly reconstruct, you may hear a jitter and audio continues. however the decoder doesn't come along fast enough for the video. in some players that leads to massive artifacts and "scrambled" screens (due to missing b-frames) others just show a blank. eventually the damaged region is over, and normal play continues.
I am of course assuming a read error here, while I believe you are talking about write errors. But imho write errors should be detected at recording time, not when watching the video later.

 

[cityboy-stl]

It isn't a copyright thing. I'm just recording network shows like Reaper or Desperate Housewives. 85% of the show will be just fine but at some point the video goes completely blank while the sound continues. It has happened too often for too long to be a cable problem and never happens if I'm just watching TV. I hadn't thought of it until someone suggested but I did just now try playing back one of the disks on my computer DVD drive and it did the same thing; the video went blank at exactly the same spot. That still doesn't prove anything though.

 

[trawler69]

I suggest that the first thing you should do is to try a new disk. RW discs only have a finite life. As corny says, audio is more resilient to errors than video.

 

[cityboy-stl]

This is happening on several disks that I bought in a package at the same and have all had about the same amount of usage; but not all of those disks from that same package experience the video dropout.

However, I reformatted the disk in the computer and ran a surface check with Nero which did not show any bad spots. So I've completely erased the disk and I'll put it back in the DVD and try to record something and see what happens. Maybe it just needed to be reformatted.

I am really hoping the last two weeks of Smallville and Supernatural that I haven't watched yet do not have a problem.

 

[trawler69]

From what you say it all points to the discs having gone bad. They cost next to nothing now so you might as well buy some new ones to nail the problem once and for all.

 

[pinolian]

I had the same thing happen when I bought Frys house brand, each dvd would go to blank and just audio and it did the same thing in another player. So I started buying Fuji and have never had a problem since then.....

 

[Edward Twinkletoes]

My DVD recorder does OK with RW discs but I don't have a lot of use on them. I would replace them once in a while just to say I did. You can get a small pack of them for about $10. No need to be that tight about it.