First Blu-ray test disc shot on RED

[Stacey Spears]

Sorry, could not resist the "first" in the title. I am not sure if this is the first Blu-ray test disc with RED footage or not. The disc was released in March.
It is also included with the new OPPO BDP-83 Blu-ray player. There is a 3-minute montage shot on the RED.

The disc was finished in October because that is when the OPPO was originally going to ship. I received my camera in Mid to late August,
so I had very little time to learn the camera, shoot footage, edit, grade, encode and author.

Along with the montage are a series of static test patterns to help you setup your display. They also allow you to evaluate your player,
video processor or display. All patterns were generated in their native color space. By this I mean many of our patterns were created directly
in 8-bit 4:2:0. This ensures the highest chroma bandwidth. Its a real stress test for some devices. I also hand encoded the entire disc.
(with the excecption of the DTS trailer, that came pre-encoded) These are the most accurate patterns on disc to date.

You can also evaluate deinterlacing. This will help you figure out if your player, or display, is best at dealing with interlaced sources.
This includes progressive content with a telecine pattern, like the new Season 1 of CSI on Blu-ray.

I previously worked on Digital Video Essentials HD DVDs and Blu-ray as well as the pro version of the DVD. Mainly encoding the HD content.

More information on the disc, including menu screen shots, is here: http://www.spearsandmunsil.com/hdbenchmark.html

A PDF of the user guide. This information is available at the press of a button when viewing the specific pattern, includes a good/bad example.
http://www.spearsandmunsil.com/pdf/UG_SM_HD_Benchmark.pdf

We are publishing a series of articles on how to use the disc. First are the basic "how to" set picture controls. Once those are done we have
an article on how to select the best color space from a player. (4:2:2, 4:4:4 or RGB) Not one selection will work best with all displays or processors.
http://www.spearsandmunsil.com/articles.html

Below is a frame from the montage. You can download the original 4k TIFF exported from SCRATCH. The other two frames are a before and after encode.
The first is the source fed into the encoder and the second is a decoded frame so you can see the quality of the compression.

Original 4k TIFF: (48 MB) http://www.spearsandmunsil.com/images/SM_Montage_Frame_00800_Original_4k.tif

Source:

Encoded/Decoded:

 

[jonnycom]

Very cool, can you get this disc without the Oppo player? What did you use to encode?

 

[Stacey Spears]

There is a link on my site that lets you order the disc by itself.

I used PEP. (branded as Sonic Cinevision PSE) PEP is the primary VC-1 encoder used for Blu-ray. I was hoping to offer the montage in AVC using all of the available AVC encoders, but two major AVC vendors did not want to participate. They did not want their implementation compared to another using the same content.

For the MPEG-2 SD versions of the deinterlacing tests, I used an open source MPEG-2 encoder.

 

[jbeale]

> They did not want their implementation compared to another using the same content.

Wow... that's a pretty telling comment about their software!

 

[Stacey Spears]

The sad part is one of them has the best AVC encoder. It could be they did not want their compeition to know what they are doing.

I know some people like details, so here is how the montage was done. The footage was shot on build 16 and 17. Most of it was with the 18-50mm. In some shots I also used a 2x extender. I always had a tiffen hot mirror on the lens. I also used a screw on pola for many of the shots.

The offline was done on my MacBook Pro using FCP. An EDL was exported and the final work was done in SCRATCH. I did very little color grading. I exported 16-bit TIFFs from SCRATCH. I then used my own stuff to convert to 8-bit 4:2:0. It uses noise shaping + random dither to convert to the lower bitdepth. The resizing was also done in linear light vs. gamma corrected.

The following posts will be a repost of what I have posted on another forum. This is to show the type of processing and scaling done.

I am starting a new thread to discuss pre-processing of video. In this context, I am talking about converting from a higher bitdepth down to a lower bitdepth. In the case of BD and HD DVD, it is often 10-bit 4:2:2 to 8-bit 4:2:0.

Below are two examples taken from the Elephants Dream project. You can download the publically available 8-bit uncompressed PNG files from their website. http://media.xiph.org/ED/1080-png/ Sorry, I don’t recall the exact frame number. I am not sure the process they used to create their 8-bit PNGs. Elephants Dream does have some pretty severe banding throughout.

I was able to obtain the original 16-bit OpenEXR files from them. In my two examples, the same path was used.
1. Open EXR file in After Effects CS3
2. Disable all processing
3. Export as 16-bit TIFF
4. Use xScaler (name of tool) to convert from 16-bit TIFF (48-bit RGB) into 8-bit RGB (24-bit RGB)
5. The images were also converted from PC to Video levels.

In the top image I used one of the xScaler dither modes. In the bpttom I used the xScaler rounding mode. There are a lot of different techniques to dither an image, this is simply our favorite. Don and I spent a lot of time working on this technology. It was originally written about six years ago.

The area to see the banding is on the light gradient to the right of the image.

It is simple to maintain this level of detail on a static image. The problem comes when there is motion. In this particular part of Elephants Dream, the image pans to the right. The dither does make compression more difficult in this example. I have other examples, like Coral Reef, where it actually becomes easier to compress.

 

[Stacey Spears]

Dither

Round

 

[Stacey Spears]

Here is another clip. In the ED example, I converted from 16-bit RGB to 8-bit RGB. In this next example, I will convert from 10-bit 4:2:2 down to 2-bit RGB. OK, perhaps 2.5 bit.
There are 5 levels used in the 2-bit examples. You can open in your favorite app and look at the RGB histogram if you don't believe it.

First up is the 10-bit to 8-bit reference image.

 

[Stacey Spears]

This is the 10-bit to 2-bit using rounding. If you look real close, you might be able to see some banding in the image.

 

[Stacey Spears]

This is the 10-bit to 2-bit using random noise dither. Its using an R250 random number generator. Its a bit noisy, but the banding has been reduced.
I had to use a full quantization of random noise to reduce the banding.

 

[Stacey Spears]

This is 10-bit to 2-bit using error diffusion with the random number generator. This is using half a quantization of random noise to remove banding.
This is our favorite and is what was used in the Elephants Dream example above.

 

[Stacey Spears]

So we have looked at dither, now I will post some image reszing samples using the same tool.

One of the ideas that we have been pushing is to perform all processing in linear light. The video you watch today has a gamma curve. Linear light involves removing the gamma curve,
perform processing and then re-applying the gamma curve. When working with linear light, you need extra bits for processing. An 8-bit gamma corrected image would need 12-14 bits
if working in linear light. Personally, I would not do it in less that 16-bit floating point.

The first sample is a zone plate that cycles from 5 MHz to 20 MHz. This is the original image, which is 1080p.

 

[Stacey Spears]

This image is the 1080p zone plate resized to 720p using linear light. The filter kernel is a bicubic algorithm.

 

[Stacey Spears]

This image is the 1080p zone plate resized to 720p like everyone else does it, ie with gamma correction. The same bicubic algorithm was used.

There are a couple of things to point out. First, the edges are darker. This is the highest frequency portion of the zone plate. Second, the moire is more pronounced. If you look closely at the linear version, the moire is present, just more difficult to see because the high frequency detail is not pulled towards black.

The linear zone plate looks more like the orignal. Again, same tool was used to resize, I simply turned linear processing on and off.

 

[Stacey Spears]

This next sample shows what happens on think diagonal lines as well as on strong colors. Pay attention to the thickness of the text and diagonal lines. Also look at the edges of the text on the red and blue backgrounds in the resized samples.

 

[Stacey Spears]

The image on the left was resized in linear light. The image on the right was done with gamma correction.

You will notice that the "Here is some white text" has become thin on the right image. You should also notice that the green text on the red background has dark spots around the edges.
You can also look at the thickness of the diagonal lines.