Cineform Prefs settings for HVX

S

sodotoguwangus

Well-known member
Couple questions regarding Cineform Connect HD and the HVX200.

Under the prefs menu under CINEFORM ENCODER OPTIONS should set the HD file size to small, medium, or large? Whats the difference ... does this affect the final product' quality, or does is it just to help the computers performance during editing?

under FRAME RATE CHANGE (ADVANCED) should I check remove 3:2 pulldown, or not?

And what should I select under RESIZE VIDEO: resize to 1280x720 or 1440x1080? Does this depend on what I shoot at? If it does, I'm assuming that for 720p footage I would use 1280x720 and for 1080p footage I would use 1440x1080. Correct?

Thanks.
 
There are no adsolute settings, that's why we give you all the options. Small, medium, Large impact quality mostly, and performance a little. Medium in fine for industrial, Large is preferred for anything using effects or film projects. When in doubt use Large.

If you have shot in either 1080p24 or 1080pa24 then the "remove 3:2 pulldown", will extract the true 24p signal. This option is ignored for all 720p sources. When using 1080p24 from P2 media use remove pulldown (only exception is for Canon XL-H1 users.)

You don't need to select resize, however I recommend 1280x720 all only HVX200 progressive shoots (even the 1080 modes.) The HVX doesn't produce much more resolution in the 1080 modes than the 720p modes, so the 1280x720 is a good normallized middle ground. Resize to 1440x1080 (not leave it as 1280x1080) for interlaced projects. If you using a tool like Sony Vegas, or any other NLE that doesn't have a 1.5:1 pixel ratio (many don't) you will need to resize, as the DVCPRO-HD's 1280x1080 will not be supported, whereas 1440x1080 and 1280x720 will be.
 
I played around with some of those settings but wasn't able to bring the quality over average. The final clip always has a lot of compression artifacts, noise and halos/strokes around contrasty edges, almost like a weird sharpening effect. Is it just the codec limitations of Cineform, or do you think I'm doing something wrong?

Thanks,
-onur
 
It is NOT the CineForm codec -- we have too many years in this for you to be seeing bad artifacts. It is more likely to be the source camera issue. "noise and halos/strokes around contrasty edges" are camera artifacts not compression. All compressors actually suppress high frequency noise, although DCT compressor can add mosquito noise (DV, DVCPRO, etc), a wavelet compressor like CineForm has no mosquito noise. "halos/strokes" are normally a fault of camera sharpening -- it is not a common compression artifact of any known compression.

If you provide your source MXF data (link in a private message) I can prove all of this.
 
I did my own testing of the Small/Medium/Large quality so that I could discover the pros and cons first hand. I was particularly curious to find out the file size differences. For the particular clip I was using (camera locked off, not much movement, bright highlights and some shadows) the LARGE option yielded a converted file that was slightly smaller in size than the original DVCPro HD file. The SMALL file was less than half the size of the original, and the MEDIUM was roughly in between the SMALL and LARGE file size. Makes sense.

While I'm no expert in compression artifacts, I've had some experience picking up on those things. I shot a 960x720 24pn image, and converted via HDLink to Small, Medium, and Large. For all 3 I resized to 1280x720.

The results? Playing the short clips one after another at full speed at native resolution, I was not able to see quality difference between the 3 of them.

Only when I isolated the same frame on each version, zoomed in to the image to 200% (on playback, premiere pro 2) and A/B/C compared the 3 frames was I able to identify which was small, medium and large quality. It was mostly noticeable in the noisy shadows (the native DVCPro-HD clip had shadow noise/artifacts to begin with. While I didn't do a mathematical comparison between them, I would agree with Cineform's line "Visually Lossless." It really is an amazing codec.

I would only use SMALL if I'm really, really pressed for HD space. Otherwise I'll normally be using MEDIUM, or occasionally LARGE if I know there's a lot of manipulation to be done.

For the work I'm doing, 10 bit just isn't necesary so I'll stick with Aspect (that is, once my trial period is over).
 
ThePhage,

Thank you, that was an excellent write-up, and a recommend testing procedure for anyone looking to select a compression level. Regarding Large being smaller then the source DVCPRO-HD file, that commonly happens because of the improved efficiency of wavelet, however some images come out a little bigger as the CineForm is a Variable Bit Rate (VBR) to maintain quality, not Constant Bit Rate (CBR) like the DVCPRO-HD source to maintain tape compliance.
 
David Newman said:
The HVX doesn't produce much more resolution in the 1080 modes than the 720p modes, so the 1280x720 is a good normallized middle ground.
Click to expand...

What does it mean?

are you saying that is almost the same shot in 720p than 1080 ?????

I'm making a movie and have shot 1080 24pA with many many difficulties in storage, palyback speed, etc.

Please tell me: did I lost my time and effort?

:crybaby: :( :Drogar-Sick(DBG):
 
1080p24 gets you a little more horizontal resolution, not much more vertical definition -- this has bveen concluded in many places on the site (and others.) So there is a benefit to 1080 modes, but not has much as the increase in bit-rate would imply. I have recommended to 1080 mode but down-res'ing them to 1280x720 CineForm is the best combination of quality, disk space and performance.
 
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