Advantages of Cineform over .mxf for Canon SX-1 IS

Laurence wrote on 3/8/2010, 7:30 PM
If I convert the .mov files from a Canon SX-1 IS to Cineform codec avi's, Neo Scene does three things that are invaluable while it does the conversion:

1/ Slows down the framerate from 30fps to 29.97 and stretches the audio to fit the new length.
2/ Converts from 1920 x 1088 frame size to 1920 x 1080.
3/ Converts the colorspace from cRGB to sRGB.

Yes I could batch convert all the clips with a script like Proxy Stream or Ultimate-S to .mxf, but it wouldn't do those three really important things during the conversion.

Comments

CClub wrote on 3/10/2010, 5:56 AM
Those are relevant opinions coming from you, Laurence, because aren't you typically an MXF advocate over Cineform?
PerroneFord wrote on 3/10/2010, 6:16 AM
I see #1 and #3 as a disadvantage.

#2 could be some help.
Laurence wrote on 3/10/2010, 6:45 AM
Well the 30fps to 29.97 slowdown is really essential. The SX-1 IS is a secondary camera and if I stick true 30p on a 29.97 timeline I have to choose between frames with double images and jerky looking dropped frames. Neo Scene automatically slows down the audio so it matches the video as well. The slowdown is miniscule so I haven't noticed a pitch change.

One thing you'll notice if you read reviews on this camera or that you'll see if you look up videos from it onYoutube or Vimeo is that people are complaining about the highs being blown out on the auto settings. What I have realized is that the problem is just that it is cRGB instead of sRGB. If you use the AV or HDMI output this is automatically corrected, but if you put it on a Vegas timeline the levels are wrong. The correction that Neo Scene does here is neccessary and rather than changing the footage, it merely matches the levels to what you would see at the camera's HDMI out. In Neo Scene this conversion is done at 10 bits. If you did it in Vegas you would be lowering this to eight bit precision because of VFW. I imagine that Canon DSLRs benefit from this as well. Even when I do an Internet render I never go up past sRGB levels of 235 for the whites because on most monitors it will look blown out.
PerroneFord wrote on 3/10/2010, 7:46 AM
I am not saying that changing these things isn't helpful in some cases. It certainly can be. But I don't want ANYTHING to happen automatically. I want things to happen when I make them happen.

I may WANT my output at 30fps. Especially if I am going to combine footage with the Canon 5D and don't want to work with multiple framerates in one project.

I may WANT the increased luma latitude of cRGB, especially if I am going to the web. If I want to reduce latitude I can easily do it myself in Vegas with a single FX application.

But if this works for you.. that's great. I sure as heck wouldn't want my transcoder making these kinds of decisions for me unless I asked it to.
David Newman wrote on 3/11/2010, 11:34 AM
30-29.97fps change is user controllable, but the default is to do this, even for 5D footage, as this saves a lot of support issues (and end user headaches.) The cgRGB vs vsRGB, CineForm is simply handling this correctly, to few do.

David Newman
CTO, CineForm
LarsHD wrote on 3/11/2010, 2:01 PM
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PerroneFord wrote on 3/11/2010, 4:26 PM
I am glad to hear that the 30 > 29.97 change is user controllable. And I am sure it saves you guys some support calls. But quite frankly, I wouldn't want it, and any pro should be able to handle this easily in post when the decision is made for frame rate.

As to the cRGB > sRGB being "correct", well it may be correct for broadcast, but it darn sure isn't correct for web delivery, film delivery, or prep for grading. Cineform makes GREAT advertising use out of their ability to utilize the 10-bit structure for increase latitude and handling. What's the point if you then compress the latitude in the transcode before the user can even get their hands on it?

Dan, honestly, if you have any say so in this matter, for the sake of people who are NOT going to broadcast, make this user definable as well. Even if it defaults to a position of changing this to broadcast spec. There are those of us who INTENTIONALLY shoot our cameras outside of broadcast spec just so we have more to play with in post, and it would be appreciated by those who do, and who use Cineform, if it didn't arbitrarily undo our careful choices of how we shoot out footage.

For the record, I shoot my EX1 to limit out at what would generally be about 105 IRE. I walk that down for broadcast, but do NOT do that when going out to film or when we are going to project that footage in outdoor daylight scenes. And I don't always walk it down when delivering to the web. I'll set my histogram down to about 245-248 RGB in the whites for the web, because walking it down to the broadcast safe 235 looks dingy and gray on a well calibrated monitor.

Laurence wrote on 3/11/2010, 5:03 PM
Well to me at least, Cineform makes all the difference in the world with Canon footage. Without Cineform, the footage is too contrasty, highlights are blown out, and there are double images and jumps in the motion as Vegas tries to justify the slightly fast frame rate. With Cineform, the footage is absolutely perfect. My only complaint is that if I use as a second camera on a performance, it is slightly stretched. I can fix that though. IMHO Cineform takes the Canon footage that is almost there and takes it the rest of the way home.
PerroneFord wrote on 3/11/2010, 5:26 PM
I'm glad it's working well for you. Cineform wasn't in my Vegas workflow, and wasn't needed *for me*.

There are lots of ways to attack the 30p 5D workflow. Each have their merits and drawbacks. I tried 3 separate workflows before settling on one that I liked.
Laurence wrote on 3/11/2010, 5:29 PM
What is your workflow?
PerroneFord wrote on 3/11/2010, 6:32 PM
These questions are always VERY difficult for me to answer.

My 5D workflow (or any camera workflow) is different depending on needs, and what I am trying to accomplish. I have found "in general" that most users of Vegas are solo flyers. Shooting, editing, coloring, and delivering finals themselves. So if I was doing an end-to-end workflow, I'd consider a few variables:

1. How much native footage is there. 1hr? 10hrs, 30 days of shooting worth?

2. How much time do I have? Is this a SDE (wedding) or a film with 3 months to do post.

3. What is my final? Film? Web? Broadcast?


Each of those answers can vastly change how I approach the workflow. But generally, I look at the delivery spec, and work backwards.

If I have a lot of footage, and a lot of cutting, transitions, effects, etc., then I am going to get that footage into an i-frame format ASAP. If it's straight cuts, or I've got to work in a hurry, I am going to put that footage straight onto a timeline in the 64bit version of Vegas, or take it through the trimmer.

Once I have my in's and outs, I'll assemble a rough cut and a basic 1-light look. I simply this by putting all the footage from a single room/scene on a track and setting the look for that track. I like to set my exposure parameters per clip to make sure everything is in spec before doing color, so I have consistent exposure throughout the piece.

Once the rough is assembled, I'll do a 10 render second test to final output to check the look and quality. From there, I do a final edit, apply whatever looks I want scene by scene, check everything for exposure, and do a low-res comp to check everything end to end. If the lo-res looks good, I do a render to my final delivery format.

Obviously this is GROSSLY oversimplified, but it's a rough idea of how I work. Sometimes there are dailies to be assembled and sent. Sometimes the rough cut can take on a dozen forms before a final is settled on. Sometimes the output test doesn't meet muster, and I have to change something further up in the workflow.

I prefer to work lossless for as long as I can. In big project, this means I may need to render proxies and cut those for speed. These are generally SD files of some kind or DNxHD 36 files if I've got a lot of detail I need to pay attention to.

There can be a lot of variables depending on what I am trying to do.

Laurence wrote on 3/12/2010, 5:58 AM
Well with Cineform Neo Scene, all you have to do is set the camera memory card as your source, a subdirectory on your hard drive as your destination, and run the conversion as your file copy. It's really easy and the conversion doesn't seem much longer than a file copy.

PerroneFord wrote on 3/12/2010, 6:22 AM
LOL ok.

You win. 1-step magic. Awesome.