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BitJazz
SheerVideo
Usage FAQ
Answers to Frequently Asked Questions
About Using SheerVideo
How do I export ATI 4:2:2 video to SheerVideo?
What does error code -2034 mean?
What does error code -5000 mean?
What does error code -8969 mean?
What does error code -8972 mean?
What does error code -8978 mean?
Why are my DeckLink-captured Sheer videos the wrong resolution?
Why can't I export MPEG to SheerVideo?
Why can't I export RGB[A] to Sheer Y'CbCr[A] in Perfect mode?
Why can't I launch the installer or registration application?
Why did SheerVideo make my DV | H.264 | HDV | MJPEG | MPEG files bigger?
Why does QuickTime Player 7.1.3+ display Sheer Y'CbCr 8bw 4:2:2 as solid white?
Why does QuickTime hang when displaying SheerVideo on my hyperthreading PC?
Why does QuickTime's Movie Settings dialog for SheerVideo say "Medium Quality"?
Why don't my SheerVideo movies don't play back smoothly?
Why is it safe to archive in SheerVideo, a proprietary format?
Why is my video displayed slightly lighter|darker with Sheer?
 What does error code -8978 mean?
Error code -8978 means "Codec disabled itself."
SheerVideo Pro has a time-limited tryout period during which it is fully functional without a license.
When the preview period of twenty days is up, playback continues to work, but encoding is disabled.
To continue using the encoding capabilities of SheerVideo Pro, you need to purchase a SheerVideo Pro license.
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What does error code -8972 mean? Error code -8972 means "Codec condition error."
This means that SheerVideo cannot encode or decode the data as requested.
The most common cause of a -8972 error is asking a Sheer codec to perfectly encode data which cannot possibly be encoded perfectly,
because the specific Sheer codec has a lower precision or different chroma sampling scheme.
For example, when outputting an Adobe After Effects Pro 16-bit project,
the Sheer RGB[A] 10bf codec cannot store the lower 6 bits, so you must set 'Pixel Format Conversion' to 'Best', instead of 'Perfect' in the Sheer Settings dialog box.
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What does error code -8969 mean? Error code -8969 means "Codec bad data error."
This means that, in a Sheer codec's self-check mode, the reconstituted image does not exactly match the original image.
A -8969 error occurs when a Sheer codec is asked to self-check the encoding of data which cannot possibly be encoded perfectly,
because the specific Sheer codec has a lower precision or different chroma sampling scheme than the input data.
For example, since Adobe After Effects Pro always works in RGB[A],
if you try to export from an 8-bit AE project to Sheer Y'CbCr 10bv 4:2:2[:4] with the Self-Check Sheer Setting turned on,
the Sheer Y'CbCr 10bv 4:2:2[:4] codec will issue a -8978 error,
warning you that a 4:2:2[:4] codec cannot losslessly encode RGB[A], which is always 4:4:4[:4],
because 4:2:2[:4] formats only store half the chroma information.
To encode to a Sheer codec with lower precision or different chroma-sampling, you must turn off 'Self-Check' mode in the Sheer Settings dialog box.
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What does error code -5000 mean? Error code -5000 means "Insufficient access privileges for operation."
The SheerVideo Installers for Mac OS X give you a choice between installing the SheerVideo QT codecs system-wide (in /Library/QuickTime),
and just for the current user (in /Users/username/Library/QuickTime).
In order to install system-wide, you have to have administrator privileges.
To avoid this error, either log on as administrator, or install in the user directory.
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What does error code -2034 mean? Error code -2034 means "Internal QuickTime Error."
When converting to or from the 'v210' (Y'CbCr 10bv 4:2:2) pixel format,
QuickTime 6.5 and earlier computed the row width incorrectly and allocated too little memory for the image.
This problem was corrected in QuickTime 7.0.
To avoid crashes in earlier versions of QuickTime, SheerVideo detects this condition and returns error code -2034.
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Why does QuickTime Player 7.1.3+ display Sheer Y'CbCr 8bw 4:2:2 as solid white? The "Sheer Y'CbCr 8bw 4:2:2" codec is included in SheerVideo only for backward support
for customers using the obsolete wide-range 'yuv2' or 'yuvu' pixel format,
and has not been upddated to include Synchromy support.
Apple has been warning for years that users should switch to the video-range '2vuy' or 'yuvs' pixel format.
QuickTime 7.1.3 apparently no longer supports direct display of the 'yuv2' or 'yuvu' pixel format,
although BTVPro and some other applications still do.
If you have a particular need for Y'CbCr 8-bit wide-range 4:2:2 data,
please let us know, and we will consider adding Synchromy support to the "Sheer Y'CbCr 8bw 4:2:2" codec
for display and other pixel-format conversion purposes.
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Why can't I export RGB[A] to Sheer Y'CbCr[A] in Perfect mode? If you set the Pixel Format Conversion in the Sheer Settings dialog box to 'Perfect',
the Sheer encoder will only accept pixel formats which it can nondestructively encode.
For unfortunate historical reasons, most QuickTime applications require a video compressor to accept RGB[A] 8bf input,
even for compressing pure Y'CbCr material.
For example, the preview image in the QuickTime Compression Settings dialog box only accepts RGB 8b input,
even for Y'CbCr sources going to Y'CbCr formats.
However, it is theoretically impossible, even with SheerVideo's Synchromy technology,
to losslessly convert from RGB[A] 8bf to Y'CbCr[A] 8b or from 4:4:4[:4] to 4:2:2[:4].
The only Sheer Y'CbCr[A] encoder which nondestructively encodes RGB[A] 8bf is Sheer Y'CbCr[A] 10bv 4:4:4[:4].
All other Sheer Y'CbCr[A] encoders refuse to accept RGB[A] 8bf input in Perfect mode,
so all QuickTime applications which require the encoder to accept RGB[A] input will fail.
Therefore, unfortunately, you must use Best Conversion for all Sheer Y'CbCr[A] encoders except Sheer Y'CbCr[A] 10bv 4:4:4[:4],
even when encoding Y'CbCr.
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Why did SheerVideo make my DV | H.264 | HDV | MJPEG | MPEG files bigger? DV, H.264, HDV, MJPEG, and MPEG are destructive, or "lossy" codecs, which "compress" the video by throwing a lot of the image information away.
SheerVideo, in contrast, is a nondestructive, or "lossless" codec, which truly compresses the video,
by packing the image information more efficiently without throwing any of it away.
Whereas a nondestructive codec such as SheerVideo cannot compress video beyond its intrinsic entropy,
there is no theoretical limit to the "compression" power of destructive codecs;
in fact, a destructive codec could easily attain infinite "compression" power by throwing away all the information
- although the "restored" video would then no longer have anything to do with the original.
SheerVideo is designed for professional video and film production and archival, where quality cannot be compromised.
DV and HDV are designed for consumer and prosumer video acquisition, where compactness and cost are more important than quality.
Similar priorities hold for MJPEG, which is designed for proxy editing; and for H.264 and MPEG, which are designed for distribution.
For professional editors who use uncompressed video, SheerVideo saves both space and time while maintaining perfect fidelity.
But compared to editing in DV or other highly destructive formats, SheerVideo generally takes more space.
And although the SheerVideo codec itself runs faster than DV and other lossy codecs,
editing with SheerVideo can be slower in workflows in which storage speed is the bottleneck.
However, unlike SheerVideo, destructive codecs such as DV degrade the image further each time they decompress and recompress the video.
Even if you are editing your DV with a professional editing application that uses nondestructive edit decision lists,
this means that every time you do a resize, speed change, color correction, filter, or any effect even as simple as a fade or dissolve,
your image quality will worsen further, eventually turning to mud from the cumulative loss of information.
So for serious editing, it is essential to use a nondestructive codec.
The only nondestructive video codecs fast enough for real-time editing are uncompressed codecs and SheerVideo.
Since uncompressed codecs require more than double the number, speed, and cost of disks and busses than SheerVideo,
SheerVideo saves huge amounts of time, space, and money.
How do lossy codecs destroy information?
To begin with, DV-25 and MPEG-2 use a 4:1:1 or 4:2:0 pixel representation,
meaning that they throw away 3 out of every 4 chroma samples compared to a full 4:4:4 pixel representation.
Then they chop up the image into square tiles,
and throw away most of the detail by approximating each tile with a few coarsely gradated sinusoidal waves
to compress the 4:1:1 or 4:2:0 video by a factor of 5 (for DV-25),
and typically by factor of 10 to 100 for MPEG-2.
Due to roundoff errors, lossy codecs actually degrade the image further each time it is decompressed and recompressed.
In comparison, the lowest-quality pixel representation currently supported by SheerVideo is 4:2:2,
which is equivalent to standard broadcast television.
SheerVideo is exact, and always reproduces the image with perfect fidelity
no matter how often it is decompressed and recompressed.
For real-world 4:2:2 footage, SheerVideo's compression power averages 2.43.
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Why does QuickTime's Movie Settings dialog for SheerVideo say "Medium Quality"? The QuickTime compression user interface ordinarily displays a Quality slider.
All SheerVideo encoders have exactly one quality setting: perfect, so the Quality slider has no effect on SheerVideo.
Displaying the Quality slider would mislead users into thinking they can choose different encoding qualities, and thus perhaps waste their time trying out different quality settings.
Eventually, QuickTime introduced a mechanism for encoders to remove the slider.
Unfortunately, when the slider is removed, QuickTime assumes that the quality is Medium, even if the encoder specifies that it is lossless by setting the 'codecInfoDoesLossless' flag for the format.
Presumably, the programmers at the time were only thinking of the DV-25 format, which is always medium quality, and have just never bothered to fix it,
although BitJazz filed a bug report about the issue years ago.
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Why are my DeckLink-captured Sheer videos the wrong resolution? As reported by Blackmagic Design, Final Cut fails to call 'VDSetPreferredImageDimensions()'
to inform the DeckLink 'VDIG' driver of the image resolution,
so the driver has to infer the image dimensions from the size of the capture window.
However, Final Cut sizes the capture window to half-size when recording high definition,
which is indistinguishable from setting the capture dimensions to 960x540.
Blackmagic Design handles HD codecs as special cases, and always records these at full HD frame size even if the capture window is half-sized.
The Sheer codecs were added to this list by August of 2006, fixing the problem.
So if your DeckLink-captured Sheer videos have the wrong resolution, you need to update your drivers.
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Why can't I launch the installer or registration application? In Mac OS X, if you unzip the SheerVideo download with an older version of StuffIt,
you may get a corrupted installation package.
One telltale sign is that the names of the files in the installation package read "SheerVideo, Nc …" instead of "SheerVideo™ …".
Another is that the installer and registration applications do not have their proper icons:
Install SheerVideo™ HD Pro X |
Register SheerVideo™ HD Pro X |
Install SheerVideo™ HD Reader X |
Register SheerVideo™ HD Reader X |
If you are using Mac OS X 10.4+ (Tiger), then the solution is to use the BOMArchiveHelper.app built in to CoreServices:
- Select the SheerVideo Zip archive ("sheervideo_pro_osx.zip" or "sheervideo_reader_osx.zip").
- Select 'File > Open With > BOMArchiveHelper.app'.
If you are using an earlier version of Mac OS X, download the latest version of StuffIt Expander.
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Why is my video displayed slightly lighter|darker with Sheer? The brightness is related to a parameter called "gamma",
which measures how quickly the spacing between brightness levels grows.
DV and other standard-definition video formats have a fixed gamma level of 2.2,
corresponding to the brightness of television.
The Mac display has a gamma of 1.8; and on a PC, display gamma is usually 2.5.
When DV and other fixed-gamma formats are displayed,
the DV or other codec adjusts the gamma to that of the display.
In contrast, when DV and other video formats are exported to a variable-gamma format such as SheerVideo,
the gamma remains at 2.2,
so that any processing of the Sheer-encoded video will happen at the correct gamma of 2.2,
just as it would for the original DV or other video format.
The Sheer codecs themselves never alter the gamma level of the pixels,
since doing so would destroy image information.
When Sheer-encoded video is displayed,
the Sheer decoders let QuickTime know that the source gamma level is 2.2.
QuickTime then either adjusts the gamma level of the pixels in software,
or asks the hardware display card do the adjustment.
Unfortunately, DV and other video codecs, graphics cards, and QuickTime do not yield identical gamma-correction results.
Note that gamma support was added to SheerVideo in v1.2.8.
Earlier versions of SheerVideo did not keep track of gamma.
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Why don't my SheerVideo movies don't play back smoothly? In QuickTime 6.5 and earlier, attempting to export from MPEG to SheerVideo elicits the error message:
"Couldn't export the movie "filename" because the required compressor could not be opened."
This problem is due to QuickTime wiring bugs that were fixed in QuickTime 7.0.
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Why can't I export MPEG to SheerVideo? There were two problems here, one with captured video, and one with the dual G5.
Both problems were fixed in QuickTime 6.5.
Make sure you have the latest release of QuickTime
and the latest release of SheerVideo.
During video capture, QuickTime groups frames into chunks in a way that is optimal
when all frames are encoded to the same size, such as for uncompressed video or for DV,
or, apparently, when the codec is slow enough.
In earlier versions of QuickTime, QuickTime's chunking method worked poorly when the encoded frames have a variable data rate,
and, apparently, when the codec is too fast, as for SheerVideo.
To play back captured video smoothly with earlier versions of QuickTime,
re-export the SheerVideo movie to the same SheerVideo format,
and QuickTime will rechunk the video data optimally for smooth playback.
QuickTime 6.5 can play back such mischunked data smoothly.
In a separate problem, earlier versions of QuickTime did not play back any SheerVideo smoothly on the dual G5.
This problem too has been fixed in QuickTime 6.5.
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How do I export ATI 4:2:2 video to SheerVideo? The easiest way is to use QuickTime 6+.
ATI's "best or 4:2:2" codec incorrectly sets the pixel depth to 16 instead of 24.
QuickTime 6 ignores this error, permitting you to export it to SheerVideo Y'CbCr 8bw 4:2:2.
QuickTime 5 ignores the error for playback, but not for export.
If you need to use QuickTime 5, you can correct the depth setting yourself with Apple's Dumpster utility.
Open the ATI-captured movie with Dumpster, and look for a 'trak' Track whose 'stsd' Sample Description
(under 'mdia':'minf':'stbl':) has a "dataFormat" of type 'yuv2' and "name" "ATI Video 4:2:2".
In the "depth" field, replace the number 16 with 24.
Finish by choosing File>Save and File>Quit.
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Why is it safe to archive in SheerVideo, a proprietary format?
- The SheerVideo decoder is free, and you can archive it along with your footage.
- SheerVideo is a QuickTime codec, and QuickTime and Apple have an excellent track record for maintaining compatibility across versions and platforms.
- SheerVideo is from BitJazz, who has been around since 1997 and also has an excellent track record for maintaining compatibility across versions and platforms.
- For perspective, consider the fact that MPEG, JPEG, GIF, LZW, Animation, Graphics, and just about all other codecs except PNG are likewise proprietary.
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Why does QuickTime hang when displaying SheerVideo on my hyperthreading PC? You need to install the latest version of SheerVideo.
This problem was fixed in SheerVideo v1.9.9.
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