Best lossless codec for b/w ?

Venom wrote on 9/11/2005, 6:34 AM
My workflow (film restoration) usually includes several intermediates, since I apply Vegas, VirtualDub and AfterFX filters. I use lossless codices like Huffyuv, MSU and Alparysoft. Often I work on b/w projects. With my bits of video knowledge I have some questions that I cannot answer:
1a) Is a DV codec (4-1-1) lossless as long as it is used for b/w (the important luminance information being saved for every pixel)? WRT compression ratio & speed DV is certainly far superior over the other codices mentioned above.
1b) Apart from speed is there any difference in DV codices? Why are MainConcept or Canopus DV codices "better" than MS DV?
If the answer to 1a) is "no":
2. For b/w, can I check YUV color space conversion in Huffyuv or Alparysoft and still going back lossless ?
3. Are there any b/w optimized codices to use?
Thanks a lot!

Comments

Chienworks wrote on 9/11/2005, 8:44 AM
DV is never lossless. However, you are correct that the luminence information is preserved better than the color information. In addition to colorspace compression, DV also uses a JPEG type compression. Fortunately, JPEG is very kind to B&W, so there should be very little loss at all.

There are huge differences between different DV codecs. While the method for storing the compressed image is the same in all cases, the algorithm by which the data is compressed varies greatly. Canopus, Main Concept, and SONY compress the information very well. Microsoft does it very poorly. For an analogy ... both my wife and i can both cook spaghetti. Both of us will achieve the result of tomato sauce with meatballs over pasta. Anyone else looking at our respective offerings would have no problem declaring both to be spaghetti. However, once you taste them, you'll realize that there is a vast difference in how well we made it.* Likewise, all DV codecs make a DV file that is interchangeable with other DV codecs. Some do the job better and preserve the original image better while doing it.

* If you have to ask, yes, it is my wife's version that is far superior. At least my version didn't kill me while i was a bachelor though. ;)
B_JM wrote on 9/11/2005, 12:20 PM
the msu codec is very slow to compress or decompress ..

for film work - i would stay with frames, as in compressed targa frames .. no need to have huge avi files .. plus your timecode, frame and shot info stays perfectly in sync ..

if you want to use avi - watch out for color space conversions and i suggest huffyuv
riredale wrote on 9/11/2005, 6:19 PM
I have read somewhere that the M/S codec is much better now than it has been in the past. Don't know if anyone has done any recent tests on this claim, though.

Leave it to Microsoft to eventually get things right--who was it who once said, "Version 1.0 of anything from M/S is terrible, but watch out for v3.0..."
Chienworks wrote on 9/11/2005, 6:31 PM
I think just about every computer technology reporter has said that at one time or another. I first read it in PC Magazine's review of Windows 3. Oddly enough, even though they praised Windows 3's functionality, they pretty much ended up the article with a comment about it being nifty, but so what? There really wasn't much to do with Windows except use it as a menu system for all your MS-DOS software. I loved the last line: "Killer solitaire program though."
Venom wrote on 9/12/2005, 11:53 AM
The spaghetti analogy is quite illuminative. Of course, for the intermediates I need haute cuisine spaghettis from the Italian shop 'round the corner. :). But ff I stick to hufyuv to stay on the "safe side", can I check YUV conversion or better not?
Venom wrote on 9/12/2005, 11:58 AM
Yes, MSU is indeed extremely slow, and I use rather Hufyuv or Alparysoft, the latter also offering a very fast "realtime" mode. I didn't get exactly what you mean by "stay with frames".
And when you warn of color space conversion, does this apply to b/w footage, too?
B_JM wrote on 9/13/2005, 5:41 PM
with huffyuv and vegas - stay with RGB and always check suggest RGB for output ..