Today we released another upgrade to the SheerVideo Pro Preview for Mac. We expect this to be the last preview version before the first commercial release of the product. So if you find that any essential features are missing, please speak up now! You can download the free preview from
The new version, 0.9.8, introduces the following changes and new features:
We've added a new SheerVideo codec for Y'CbCr 8bv 4:4:4. In contrast to the broadcast-quality Y'CbCr 4:2:2 formats, which omit the chroma information at half of the pixels, the studio-quality Y'CbCr 4:4:4 formats store the chroma components (Cb, Cr) at every pixel. Thus whereas 4:2:2 formats are most useful for archival, recording, and broadcasting, Y'CbCr 4:4:4 formats are ideal during the video production process, although they take up 50% more space. Note that RGB formats, which are used mostly for film and CGI material, are always 4:4:4.
The new codec supports the two most popular Y'CbCr 8b 4:4:4 pixel formats: 'v408' and 'r408'. In the 'v408' pixel format, all the components adhere to the ITU-R BT.601 standard. In the 'r408' pixel format, luma has the same range, but is zero-based, while alpha is full-range. The two pixel formats also differ in byte order.
To encode Y'CbCr[A] 8bv 4:4:4[:4] video, select
The Sheer RGB 8b and Y'CbCr 8bv 4:4:4 codecs can now store an alpha channel,
denoting opacity/transparency or coverage, for use in compositing applications.
Accordingly, they have been renamed as
To compress alpha in addition to the color information, select
The interlaced versions for all SheerVideo codecs now work purely intrafield, making them more robust in the presence of extreme interfield motion. As a bonus, the interlaced codecs are now generally faster than their progressive-scan counterparts.
To use the interlaced version of a SheerVideo codec, select
It's okay to use the Interlaced codec for progressive-scan video, or the Progressive codec for interlaced video. In fact, the "wrong" codec may actually compress some source material better. And you may prefer to use the Interlaced codec just for the extra speed. However, note that SheerVideo labels the video as such. Please let us know if this is a problem.
Videos created with earlier versions of SheerVideo are still supported with free readers.
An interlaced option has been added for Sheer RGB[A] 8b. This is useful for interlaced Y'CbCr[A] video that has been converted to RGB[A] for postproduction; for computer-generated imagery that is preinterlaced for broadcast; and for video cameras that output raw interlaced RGB.
The SheerVideo decoders have been sped up by up to 10%. In particular, the RGB[A] 8b and Y'CbCr[A] 8bv 4:4:4[:4] decoders are now nearly as fast as the encoders. For current speed statistics, see the page
This improvement necessitated a slight change in coding format. In most cases, the compression power has also increased slightly. Free decoders are available for videos encoded with previous versions of SheerVideo.
When decompressing to Y'CbCrA 8bu 4:4:4:4, the Sheer Y'CbCr 8bu 4:4:4 codec now sets the alpha component to 255/255 (opaque) instead of 219/255, since alpha uses the full range in 'r408'.
In version 0.9.7, the Y'CbCr encoders misinterpreted the expiration date. This has been fixed.
The Sheer settings summary displayed in the Compression Settings dialog has been augmented and simplified. It now includes the name of the selected Sheer codec. The scan mode, when known, is now simply indicated by a p (progressive) or i (interlaced) after the codec name (i.e. RGB 8bp versus RGB 8bi). If alpha output is to be included, that is now indicated by an A after the color space name (i.e. RGBA or Y'CbCrA).
This release of SheerVideo expires on 30 May 2003.
No further preview releases are planned, so please evaluate this version thoroughly and let us know immediately if it lacks anything essential for your application!
The PC/Windows edition has been delayed by changes to the Sheer Engine code, but it's still coming soon. We've also had numerous requests for a Linux/PC edition. Do you need support for any other platforms? Please let us know!
To stop receiving this newsletter, just reply to this e-mail with the word ‘Remove’.