Sony's Latest Blu-ray Encoder Software Lets You Dial in Grain Preservation

When the 20th Century Fox classic film Patton came out on Blu-ray, almost everyone was delighted to see a vivid, high-definition version of the movie gain new life on home video. Almost everyone. A small but vocal cadre of visually astute film buffs – led by Robert A. Harris, whose extensive experience with high-end film restoration has made him a guru among Web-connected videophiles – started an Internet campaign condemning the release for its lack of film grain. Patton was originally shot in 65mm, but Harris argued in a column at TheDigitalBits.com that the large-gauge film’s grain structure, along with the fine detail that grain reveals in a film image, should still be evident in the transfer. It was not. “Blu-ray,” he declared, “as a system, failed the acid test.”
Some viewers suspect studios try to minimize film grain on Blu-ray releases because consumers don’t understand that the visibility of grain means a picture is more detailed, rather than less. (There are anecdotes, perhaps apocryphal, about consumers buying HD DVD copies of the notoriously grainy 300 last year and returning their equipment to the store because of the “fuzzy” picture.) Well, it may be too late for Patton, but film grain seems to have been recognized as an endangered species by Blu-ray technologists, who are doing their best to keep grain alive.

As one example, Sony’s new BAE-VX1000 Blu-code Encoder software includes a number of preset “scaling lists,” which determine exactly how the system’s H.264/AVC encoder treats fine detail in the frame. Set to one of two “grain preservation” modes (one for interlaced video and one for progressive), the system will maintain film grain in the image that would otherwise be ignored during the encoding process to maximize the codec’s efficiency. Encoding presets are also available that tell the system how to approach different content genres, including “film,” “CG anime” and “sports” settings.

The Blu-code system also has a timeline-based function that allows a compressionist to scrub through an encoded file and make fine adjustments to parameters like bit-rate, noise reduction, and I/B/P -frame placement on a shot-by-shot or even a frame-by-frame basis. The system then re-encodes only the segments of the footage that have been flagged for special attention, saving time and encouraging some degree of experimentation with the compression results.

That kind of detail-orientation goes way beyond the needs of many users, who just need to create a high-quality, Blu-ray-compliant stream without obvious compression artifacts or other glitches. (The Blu-code is designed to prevent users from creating non-compliant streams.) But for quality-critical projects like Hollywood movies, the system gives compressionists a great deal of control over encoding parameters on the macro level, as well as an enormous array of options for micro-managing image quality.

The Blu-code is also attractive from a system standpoint – it’s a software-only encoding system that plays nice with an HP xw8600 workstation running a quad-core Xeon 3.2 GHz CPU, with 8 GB of memory, and outfitted with Blackmagic Design HD SDI (Decklink HD Pro 4:4:4 or Decklink HD Extreme) or HDMI (Intensity) I/O cards. (Support for similar boards from Bluefish and AJA is in the works.) Since it runs on standard workstation hardware, you can buy a USB dongle for your main workstation, and then you can build a render farm with multiple machines, dramatically increasing your encode speeds without paying extra licensing fees – the highest-quality AVC encoding takes real-time times 5 on a single system, but if you chain four more systems together, it becomes a real-time operation. (MPEG-2 encoding is faster-than-real-time on a single-workstation system.)

The BAE-VX1000 software runs $40,000; it’s available as a turnkey system for $55,000. For more information: sony.com/blucode