Tag Archives: Prores

Mastering codecs revisited

A lot of folks were excited by the release of the Windows ProRes 422 decoders for QuickTime last week. It does solve a workflow issue for editors needing to get ProRes material into third party Windows applications, but it doesn’t allow for roundtripping.

The lack of a Windows encoder is only part of the problem with ProRes. Its lack of alpha channel support remains a dealbreaker for many editors and motion graphics pros.

Looking for a reasonable bandwidth, all I-frame mastering codec? DNxHD remains the best cross-platform mastering solution.

ProRes 422 – After Effects gotcha

Previous testing of the ProRes codec comparing it the Avid DNxHD codec yielded some unexpected results when Adobe After Effects was used to generate test media. While the Avid codec made the round trip from Media Composer 2.7 to After Effects and back without issue, the ProRes codec showed what appears to be an YUV to RGB conversion issue.

Further testing reveals that the issue is not consistent between a recent beta release of Adobe After Effects 8/CS3 and After Effects 7.

ProRes 422 through After EffectsPictured (click to enlarge) are the waveform and vectorscope images when the original ProRes 422 HQ material is placed on V1 of a Final Cut Pro 6 timeline and the same image placed on V2 after being run through After Effects with no changes made to the image – the clip was placed in an AE timeline and simply re-rendered with ProRes 422 HQ.

For the time being I don’t recommend using Adobe After Effects to render ProRes 422 material. While we can be confident this issue will be addressed shortly, this is exactly the kind of gotcha that can be expected when a new codec is released in the latter phases of a beta cycle. I’ve been transcoding clips to the Animation codec with Final Cut’s Media Manager before going to After Effects. Allowing FCP to handle the YUV-RGB conversions seems to work well.

The bigger lesson is that whenever a new codec is introduced to your workflow it should be tested in the applications it will be used in.

Looking down the road, color space, codec, and file format, and frame rate conversions will be with us for a long time. Make hardware and software decisions with eye towards the future and compatibility.

DNxHD vs. ProRes 422 redux

In a previous post on another blog I did a quick and dirty comparison of Avid’s DNxHD and Apple’s ProRes 422 codecs. The test was somewhat flawed in that I compared the codecs within Adobe After Effects CS3. This forced a YUV to RGB conversion. In that test, DNxHD outperformed ProRes. In essence all I was comparing was color space conversion capabilities.

In real world usage – ProRes within Final Cut Pro 6 and DNxHD within Avid Media Composer, the two codecs both performed very similarly. In other words, no one’s clients are going to complain about either codec.

So that means the codecs are pretty much the same? Yes and no. There are still real differences that pros in the trenches need to take into consideration.

Avid DNxHD colorspace options

Obviously my test proved that if you plan on doing anything in RGB space, such as After Effects or Photoshop work, you’re better off with DNxHD since the codec allows you to select the correct colorspace for rendering.

Just as Apple made a big deal about QuickTime being fully MPEG-4 compliant, Avid is working closely with SMPTE to make DNxHD fully VC-3 compliant.

In addition, Avid DNxHD is compliant with SMPTE draft standard VC-3, an HD video compression format in development that enables open media exchange. VC-3 is making excellent progress toward becoming a SMPTE Standard (to be identified as SMPTE 2019) and the effort is nearing completion. Pending VC-3 standardization by SMPTE, Avid DNxHD will be the world’s first codec fully compliant with VC-3 compression technology, and any manufacturer that licenses Avid DNxHD will have confidence knowing that it is working with a SMPTE standard.

That last line is interesting. Avid licenses DNxHD. Word on the street is that many developers don’t like the terms and pricing, but that’s still a step forward from closed and proprietary.

I can’t be talking about ProRes being closed and proprietary, can I? It’s in QuickTime, isn’t it? Yes, it is. But it’s only available on systems with Final Cut Studio installed, making it a $1,300 codec available only in Mac OS X. And that’s where working in ProRes can get ugly. No ability compress ProRes video on Windows workstation for FLV, WMV, MPEG-2, or 3gp. That’s a problem. Compressor 3 is very good, but it’s not the perfect solution for a lot of common compression tasks.

At the end of the day image quality it the most important feature a codec brings to the table, but it’s just one of several factors to consider when choosing a professional post workflow. For a good amount of the work I do, ProRes meets my needs. For a good amount more, DNxHD is the ideal codec.

Wouldn’t it just plain rock if AJA or Blackmagic would license DNxHD for Final Cut Pro capture hardware? Then I could choose an editing system based on the merits of the editor, instead of the codec’s required workflows.

%d bloggers like this: