So much for dd'ing video DVD

On Wed, 04 Jan 2006 21:03:15 -0500, Fred staggered into the Black Sun and said:

Um... what's a CD+RW? I buttume you meant a CD-RW.

Is this movie that's been copied to a CD-RW an SVCD, a VCD, or what? dd used in this manner only works on the first track of data CDs and will fail miserably on audio CDs, multisession CDs, or VCDs. If you need to copy a CD exactly, you use "cdrdao copy" or possibly vcdimager if the thing's a VCD of some sort.

Also, in earlier posts, like the one in Message-ID but said you were copying from a DVD to another DVD. Using CDs instead of DVDs makes things different. When you are dealing with technology, Details Count. Video on CD-R is usually in VCD or SVCD or ... something with "DV" in it IIRC. The first 2 formats use multiple tracks and dispense with some error correction data. The last format is something newer, DiVX;-) encoded data, either on an ISO9660 fs or some weird VCD-like thing. May require a computer to play that, not a typical DVD player.

snip similar errors

I'd guess the first data track on this CD is about that size. The variation you saw may be due to the runout at the end of the data track not being reproducibly readable.

Using sync cuts performance drastically, usually for little gain. Did you remember the "bs=32k"? If you leave the bs= off, dd will read and write in 512-byte blocks, which is inefficient for large volumes of data.

The problem may be that you're using the wrong tool--see what cdrdao says about this CD that's in an unnamed format. HTH,

-- Matt GThere is no Darkness in Eternity-But only Light too dim for us to see Brainbench MVP for Linux Admin mail: TRAP + SPAN don't belong ----------------------------- penguins, is Tux." --MegaHAL