5 ms·

How lossy is transcoding at the RF level of an already lossy medium?

actionfromafar 3y ago
It's much better than any other existing technology to capture VHS. It bypasses all analog processing of the signal by the VHS player and captures the video signal directly from the tape head. All further processing is then done in software. If any improvements in software processing is made, the "raw" capture can then be reprocessed with better results.
- bitwize 3y ago
  So it's like a Kryoflux for VHS tapes? That is cool.
  - actionfromafar 3y ago
    Ha, adding that to my parlance! It's exactly like Kryoflux for VHS tapes. An example - S-VHS tapes can not be played back in regular VHS players. They can't handle the format. But with vhs-decode, it doesn't matter. A regular cheap VHS player can "rip" an S-VHS tape. And decode the HiFi FM-stereo signal, too.
  - rainbowzootsuit 3y ago
    Or Domesday Duplicator for LaserDisc Preservation.
    - gofixurcode 3y ago
      It’s actually a fork of that project!
- iisan7 3y ago
  Best at capture/preservation, but only theoretically best at playback someday. Currently the best software processing algorithms are imo not on par with video playback quality from the best hardware of the era, especially for damaged tapes. It's hard, although certainly not impossible, to imagine that changing. I'm 100% glad it exists though.
  - actionfromafar 3y ago
    You could always take the best hardware of the era, and capture from that. If you were talking about decks. I'm not sure about playback - the output from vhs-decode looks pretty darn good to me, but I'm not an expert at all in composite video gear.
    - iisan7 3y ago
      Right, my language was sloppy but I meant two things-- the quality will still be dependent on the hardware chain, and I should expect that a 'bit perfect' capture of a VHS tape will usually be inferior to one captured from a vintage pro deck. And then regarding processing, I'm not a professional, but I've done several successful restorations using virtualdub and avisynth, and on some degraded tapes I couldn't do nearly as well as whatever magic was going on in the vhs to dvd section of the JVC SR-MV50.
    - xattt 3y ago
      Even the best VHS decks from the 80s/90s, which would have been used in production environments and thus “well worn”, would have wear-related quality issues.
      - actionfromafar 3y ago
        But that’s the beauty of vhs-decode. The transport mechanism needs to be stable and the head clean. The rest of the player doesn’t matter.
        xattt 3y ago
        My impression was that the transport mechanism would have seen the most wear.
  - Solvency 3y ago
    I'm not following why would software still be inferior playback to now ancient hardware? Isn't that sort of like suggesting digital can't replay a vinyl record transcoded to digital as well?
- kmoser 3y ago
  Yes, but still don't throw away the original tapes, because if a better (read: more accurate/sensitive) tape head ever becomes available, you'll want to use it to upgrade your capture device and then re-scan the original tapes with even better fidelity.

It's much better than any other existing technology to capture VHS. It bypasses all analog processing of the signal by the VHS player and captures the video signal directly from the tape head. All further processing is then done in software. If any improvements in software processing is made, the "raw" capture can then be reprocessed with better results.

bitwize 3y ago
So it's like a Kryoflux for VHS tapes? That is cool.
- actionfromafar 3y ago
  Ha, adding that to my parlance! It's exactly like Kryoflux for VHS tapes. An example - S-VHS tapes can not be played back in regular VHS players. They can't handle the format. But with vhs-decode, it doesn't matter. A regular cheap VHS player can "rip" an S-VHS tape. And decode the HiFi FM-stereo signal, too.
- rainbowzootsuit 3y ago
  Or Domesday Duplicator for LaserDisc Preservation.
  - gofixurcode 3y ago
    It’s actually a fork of that project!
iisan7 3y ago
Best at capture/preservation, but only theoretically best at playback someday. Currently the best software processing algorithms are imo not on par with video playback quality from the best hardware of the era, especially for damaged tapes. It's hard, although certainly not impossible, to imagine that changing. I'm 100% glad it exists though.
- actionfromafar 3y ago
  You could always take the best hardware of the era, and capture from that. If you were talking about decks. I'm not sure about playback - the output from vhs-decode looks pretty darn good to me, but I'm not an expert at all in composite video gear.
  - iisan7 3y ago
    Right, my language was sloppy but I meant two things-- the quality will still be dependent on the hardware chain, and I should expect that a 'bit perfect' capture of a VHS tape will usually be inferior to one captured from a vintage pro deck. And then regarding processing, I'm not a professional, but I've done several successful restorations using virtualdub and avisynth, and on some degraded tapes I couldn't do nearly as well as whatever magic was going on in the vhs to dvd section of the JVC SR-MV50.
  - xattt 3y ago
    Even the best VHS decks from the 80s/90s, which would have been used in production environments and thus “well worn”, would have wear-related quality issues.
    - actionfromafar 3y ago
      But that’s the beauty of vhs-decode. The transport mechanism needs to be stable and the head clean. The rest of the player doesn’t matter.
      - xattt 3y ago
        My impression was that the transport mechanism would have seen the most wear.
- Solvency 3y ago
  I'm not following why would software still be inferior playback to now ancient hardware? Isn't that sort of like suggesting digital can't replay a vinyl record transcoded to digital as well?
kmoser 3y ago
Yes, but still don't throw away the original tapes, because if a better (read: more accurate/sensitive) tape head ever becomes available, you'll want to use it to upgrade your capture device and then re-scan the original tapes with even better fidelity.