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BitJazz
SheerVideo FAQ
Formats: Component Ranges
Does SheerVideo support full-range data?
Does SheerVideo support unbiassed-range data?
Does SheerVideo support video-range data?
Does SheerVideo support wide-range data?
 Does SheerVideo support video-range data?
Yes, SheerVideo supports real-time lossless encoding and decoding of BT.601-4 video-range data:
Y'CbCr[A] 10bv 4:4:4[:4], Y'CbCr[A] 8bv 4:4:4[:4], Y'CbCr[A] 10bv 4:2:2[:4], and Y'CbCr[A] 8bv 4:2:2[:4] data,
both progressive and interlaced, at all resolutions and frame rates, on both Mac and Windows.
SheerVideo supports the video-range RGB[A] 10bv pixel formats
'R10k' and
'r210';
the video-range RGB[A] 8bf pixel format
'VRGB';
SheerVideo supports the video-range Y'CbCr[A] 10+bv 4:4:4[:4] pixel formats
'V416' and
'v410';
the video-range Y'CbCr[A] 8bv 4:4:4[:4] pixel formats
'v408' and
'VUYA';
the video-range Y'CbCr[A] 10bv 4:2:2[:4] pixel formats
'v210',
'v216', and
'Y216';
and the video-range Y'CbCr[A] 8bv 4:2:2[:4] pixel formats
'2vuy'
'yuvs', and
'UYVY':
In SheerVideo codec and format names, the v designation following the precision designation
indicates that the data is video-range:
- Sheer Y'CbCr[A] 10bv 4:4:4[:4]
- Sheer Y'CbCr[A] 8bv 4:4:4[:4]
- Sheer Y'CbCr[A] 10bv 4:2:2[:4]
- Sheer Y'CbCr[A] 8bv 4:2:2[:4]
In 8-bit video-range video data,
the luma and alpha components have a nominal range of 220 unsigned integer values,
and both chroma components have nominal ranges of 225 offset binary integer values.
The chroma range of [16..240]->[-1/2..1/2] allows some play on both ends for out-of-range colors.
Similarly, the luma and alpha components' range of [16..235]->[0..1]
leaves both footroom for subblack and subtransparent colors and headroom for superwhite and superopaque colors.
This format is compliant with the International Telecommunication Union's Recommendation BT.601-4.
In 10-bit ITU-R BT.601-4 video-range data,
red, green, blue, alpha, and luma components
have a nominal range of 877 unsigned integer values, mapping [64..940]->[0..1];
while chroma (Cb, Cr) components have a nominal range of 897 offset binary integer values,
mapping [64..960]->[-1/2..1/2].
Video-range is used in standard uncompressed Y'CBCR 4:2:2 digital video tape (SMPTE D-1),
standard uncompressed digital video links (SMPTE 259M), and professional video equipment.
The specific Sheer codec corresponding to video-range Y'CbCr[A] 10bv 4:4:4[:4] pixel formats is
- Sheer Y'CbCr[A] 10bv 4:4:4[:4]
which encodes from and decodes to Y'CbCr[A] 10bv 4:4:4[:4] pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 8bv 4:4:4[:4] codec also encodes from and decodes to Y'CbCr[A] 10bv 4:4:4[:4] pixel formats in real time, but only to 8 bits of precision.
The Sheer RGB[A] 10bf, Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] codecs
also encode from and decode to Y'CbCr[A] 10bv 4:4:4[:4] pixel formats, but not losslessly, and not always in real time.
The generic Sheer codec encodes Y'CbCr[A] 10bv 4:4:4[:4] as Sheer Y'CbCr[A] 10bv 4:4:4[:4].
The specific Sheer codec corresponding to video-range Y'CbCr[A] 8bv 4:4:4[:4] pixel formats is
- Sheer Y'CbCr[A] 8bv 4:4:4[:4]
which encodes from and decodes to Y'CbCr[A] 8bv 4:4:4[:4] pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 10bv 4:4:4[:4] codec also encodes from and decodes to Y'CbCr[A] 8bv 4:4:4[:4] pixel formats losslessly in real time.
The Sheer RGB[A] 10bf also encodes from and decodes back to Y'CbCr[A] 8bv 4:4:4[:4] pixel formats losslessly (except for out-of-range colors) using Synchromy,
though not always in real time.
The Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] also encode from and decode to Y'CbCr[A] 8bv 4:4:4[:4] pixel formats,
though not losslessly and not always in real time.
The generic Sheer codec encodes Y'CbCr[A] 8bv 4:4:4[:4] as Sheer Y'CbCr[A] 8bv 4:4:4[:4].
The specific Sheer codec corresponding to video-range Y'CbCr[A] 10bv 4:2:2[:4] pixel formats is
- Sheer Y'CbCr[A] 10bv 4:2:2[:4]
which encodes from and decodes to Y'CbCr[A] 10bv 4:4:4[:4] pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 8bv 4:2:2[:4] codec also encodes from and decodes to Y'CbCr[A] 10bv 4:2:2[:4] pixel formats in real time, but only to 8 bits of precision.
The Sheer RGB[A] 10bf, Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:4:4[:4], and Sheer Y'CbCr[A] 8bv 4:4:4[:4] codecs also encode from and decode to Y'CbCr[A] 10bv 4:2:2[:4] pixel formats,
though not losslessly and not always in real time.
The generic Sheer codec encodes Y'CbCr[A] 10bv 4:2:2[:4] as Sheer Y'CbCr[A] 10bv 4:2:2[:4].
The specific Sheer codec corresponding to video-range Y'CbCr[A] 8bv 4:2:2[:4] is
- Sheer Y'CbCr[A] 8bv 4:2:2[:4]
which encodes from and decodes to Y'CbCr[A] 8bv 4:4:4[:4] pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 10bv 4:2:2[:4] codec also encodes Y'CbCr[A] 8bv 4:2:2[:4] pixel formats losslessly in real time.
The Sheer RGB[A] 10bf, Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:4:4[:4], and Sheer Y'CbCr[A] 8bv 4:4:4[:4] codecs also encode from and decode to Y'CbCr[A] 8bv 4:2:2[:4] pixel formats,
though not losslessly and not always in real time.
The generic Sheer codec encodes Y'CbCr[A] 8bv 4:2:2[:4] as Sheer Y'CbCr[A] 8bv 4:2:2[:4].
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Does SheerVideo support wide-range data?
Yes, SheerVideo supports real-time lossless encoding and decoding of wide-range data:
Y'CbCr 8bw 4:2:2,
both progressive and interlaced, at all resolutions and frame rates, on both Mac and Windows.
The wide-range Y'CbCr 8bw 4:2:2 pixel format supported by SheerVideo is
known as 'yuvu' or 'yuv2'.
In SheerVideo codec and format names, the w designation following the precision designation
indicates that the data is wide-range:
In 8-bit wide-range video data,
the chroma components have a wide range of 255 possible values,
represented as two's-complement signed integers [-127..127]->[-1/2..1/2],
while the luma and alpha components use the full range of 256 unsigned integer values
in the range [0..255]->[0..1].
While this format leaves no play for filter slop,
it can represent significantly more displayable colors than the corresponding 601-compliant format,
making it more useful for storage of video from higher-precision sources.
The specific pixel format directly supported by the Sheer Y'CbCr 8bw 4:2:2 codec is known as 'yuv2' or 'yuvu',
corresponding to Apple's Component Video codec.
The specific Sheer codec corresponding to wide-range Y'CbCr 8bw 4:2:2 is
which encodes from and decodes to Y'CbCr 8bw 4:2:2 pixel formats losslessly in real time.
The generic Sheer codec encodes wide-range Y'CbCr 8bw 4:2:2 as Sheer Y'CbCr 8bw 4:2:2.
Wide-range video data is obsolete; modern video-editing systems all abide by the ITU-R BT.601.4 video-range specification.
Thus the Sheer Y'CbCr 8bw 4:2:2 codec is included only for legacy data,
and the Y'CbCr 8bw 4:2:2 format is not supported by any other specific Sheer codecs.
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Does SheerVideo support full-range data?
Yes, SheerVideo supports real-time lossless encoding and decoding of full-range data:
RGB[A] 10bf and RGB[A] 8bf,
both progressive and interlaced, at all resolutions and frame rates, on both Mac and Windows.
SheerVideo supports the full-range RGB[A] 10+bf pixel formats
'b64a',
'L64A',
'b48r',
'R10k', and
'r210';
and the full-range RGB[A] 8bf pixel formats
'ARGB',
'ABGR',
'RGBA',
'BGRA',
'RGB ', and
'BGR ':
In SheerVideo codec and format names, full-range data is indicated
by the absence of a u (unbiassed), v (video), or w (wide)
following the precision designation:
- Sheer RGB[A] 10bf
- Sheer RGB[A] 8bf
In 8-bit full-range data, the components utilize the full range of 256 possible values,
interpreted as unsigned integers [0..255]->[0..1] for red (R), green (G), blue (B), luma (Y'), and alpha (A);
and as two's-complement signed integers [-128..127]->[-1/2..1/2) for chroma (Cb, Cr).
Note that the chroma range is unsymmetrical, with no representation for +1/2,
so that negating chroma can produce out-of-range values.
While this format leaves no play for filter slop,
it can represent significantly more displayable colors than the corresponding 601-compliant format,
making it more useful for storage of video from higher-precision sources.
In 10-bit full-range data, the components use the full range of 1024 possible values,
interpreted as unsigned integers [0..1023]->[0..1] for red (R), green (G), blue (B), luma (Y'), and alpha (A);
and as two's-complement signed integers [-512..511]->[-1/2..1/2) for chroma (Cb, Cr).
Note that the chroma range is unsymmetrical, with no representation for +1/2,
so that negating chroma can produce out-of-range values.
The full-range RGB[A] 8-b pixel formats correspond to Apple's None codec, also known as 'raw '.
The specific Sheer codec corresponding to full-range RGB[A] 10bf is
which encodes from and decodes to RGB[A] 10bf pixel formats losslessly in real time.
The Sheer RGB[A] 8bf codec also encodes from and decodes to RGB[A] 10bf pixel formats in real time, but only to 8 bits of precision.
The Sheer Y'CbCr[A] 10bv 4:4:4[:4], Sheer Y'CbCr[A] 8bv 4:4:4[:4], Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] codecs
also encode from and decode to RGB[A] 10bf pixel formats, but not losslessly, and not always in real time.
The generic Sheer codec encodes RGB[A] 10bf pixel formats as Sheer RGB[A] 10bf.
The specific Sheer codec corresponding to full-range RGB[A] 8bf is
which encodes from and decodes to RGB[A] 8bf pixel formats losslessly in real time.
The Sheer RGB[A] 10bf codec also encodes from and decodes to RGB[A] 10bf pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 10bv 4:4:4[:4] codec also encodes from and decodes to RGB[A] 8bf pixel formats losslessly using Synchromy, though not always in real time.
The Sheer Y'CbCr[A] 8bv 4:4:4[:4], Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] codecs also encode from and decode to RGB[A] 8bf pixel formats,
though not losslessly and not always in real time.
The generic Sheer codec encodes RGB[A] 8bf as Sheer RGB[A] 8bf.
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Does SheerVideo support unbiassed-range data?
Yes, SheerVideo supports real-time lossless encoding and decoding of unbiassed-range data:
Y'CbCr[A] 8bu 4:4:4[:4],
both progressive and interlaced, at all resolutions and frame rates, on both Mac and Windows.
SheerVideo supports the unbiassed-range Y'CbCr[A] 10+bu 4:4:4[:4] pixel format
'r4fl'
and the unbiassed-range Y'CbCr[A] 8bu 4:4:4[:4] pixel format
'r408':
| Y'CbCr[A] 10+bu 4:4:4[:4] |
|
'r4fl'
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| Y'CbCr[A] 8bu 4:4:4[:4] |
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'r408'
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In SheerVideo codec and format names, unbiassed-range data is indicated by a u following the precision designation:
- Sheer Y'CbCr[A] 8bu 4:4:4[:4]
In 8-bit unbiassed-range Y'CbCr[A] video data,
which Apple designed as a compromise between RGBA 8b software and Y'CbCr 8bv data,
the chroma components are 601-compliant video-range,
but the luma component has an unbiassed range of [0..219],
leaving more headroom but no footroom,
and the alpha alpha component has a full range of [0..255]->[0..1].
The specific Sheer codec corresponding to unbiassed-range Y'CbCr[A] 8bu 4:4:4[:4] pixel formats is
- Sheer Y'CbCr[A] 8bu 4:4:4[:4]
an unbiassed variant of the Sheer Y'CbCr[A] 8bv 4:4:4[:4] codec,
which encodes from and decodes to Y'CbCr[A] 8bu 4:4:4[:4] pixel formats losslessly in real time.
The Sheer Y'CbCr[A] 10bv 4:4:4[:4] codec also encodes from and decodes to this data format losslessly (except for out-of-range colors) in real time.
The Sheer RGB[A] 10bf codec also encodes from and decodes to Y'CbCr[A] 8bu 4:4:4[:4] pixel formats losslessly (except for out-of-range colors) using Synchromy, but not always in real time.
The Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] codecs also encode from and decode to Y'CbCr[A] 8bu 4:4:4[:4] pixel formats, but not losslessly and not always in real time.
The generic Sheer encoder and the Sheer Y'CbCr[A] 8bv 4:4:4[:4] encoder encode Y'CbCr[A] 8bu 4:4:4[:4] as Sheer Y'CbCr[A] 8bu 4:4:4[:4].
The Sheer RGB[A] 10bf codec also encodes from and decodes to Y'CbCr[A] 8bu 4:4:4[:4] pixel formats losslessly (except for out-of-range colors) using Synchromy, though not always in real time.
The Sheer RGB[A] 8bf, Sheer Y'CbCr[A] 10bv 4:2:2[:4], and Sheer Y'CbCr[A] 8bv 4:2:2[:4] codecs also encode from and decode to Y'CbCr[A] 8bu 4:4:4[:4] pixel formats,
though not losslessly and not always in real time.
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