Skip to main content

Topic: WavPack hybrid mode verification file (Read 712 times) previous topic - next topic

0 Members and 1 Guest are viewing this topic.
  • bryant
  • [*][*][*][*][*]
  • Developer (Donating)
WavPack hybrid mode verification file
A question that sometimes comes up with WavPack hybrid files is whether or not a given player is actually decoding the "correction" file, especially at higher bitrates where this is virtually impossible to tell by ear. I was running into some similar
situations myself this week, so I created a test file to make it easy and obvious.

If this 10-second file is played in lossless mode (with the correction file) then it sounds like a solid 1 kHz tone with a little very high frequency hiss (which might not even be audible at lower volumes or higher ages).

On the other hand, lossy playback (without the correction file) sounds completely different. The 1 kHz tone is still audible, but there's also a loud, pulsating noise that sounds a little like a washing machine. No ambiguity.

  • Faelix
  • [*][*]
Re: WavPack hybrid mode verification file
Reply #1
Thanks a lot! I've downloaded and tested the files. They'll be quite useful. I suggest that you put them on the Wavpack site.

  • kode54
  • [*][*][*][*][*]
  • Administrator
Re: WavPack hybrid mode verification file
Reply #2
This reminded me to look at the WavPack support in my fork of Cog. Apparently, it only supported lossy/lossless, not hybrid with correction file. This has been corrected somewhat. I may extend it in the future to use Spotlight, if possible, to search existing file indexes for a matching filename if one is not found in the same path as the .wv file.

  • bryant
  • [*][*][*][*][*]
  • Developer (Donating)
Re: WavPack hybrid mode verification file
Reply #3
That would be great to have full hybrid support in Cog, although I've always considered correction file support optional because in some cases it's just not practical (like Gstreamer or Rockbox). The idea is that you're supposed to pick a lossy bitrate that you're willing to listen to...  :)

I am sometimes lazy and use filenames like Track01.wv, so just matching filenames might not always be ideal. At one point I considered putting a GUID in matching hybrid files so there would never be an ambiguity, but it seemed like a lot of trouble for a situation that would not come up too often (and they would have to be opened up to check the GUIDs anyway).

  • DARcode
  • [*][*][*][*][*]
  • Members (Donating)
Re: WavPack hybrid mode verification file
Reply #4
Brilliant, thanks a bunch David.
WavPack 5.00.0 -b384hx6cmv / qaac 2.61 -V 100