The simplest way to decide which Sheer codec to use is to just use the generic Sheer codec, which decides for you on the basis of the format of the data it receives from QuickTime. However, sometimes QuickTime will convert your video from its native format to a different format before handing it to Sheer. Many such format conversions are impossible to accomplish with perfect fidelity, so QuickTime may degrade the image in the process. Unfortunately, SheerVideo has no way of finding out what the original video format was. To reduce the chance that QuickTime covertly converts the format, you can find out what your video format is, and manually choose the appropriate specific Sheer codec. To find out what video format your movie has,

• Select Window > Show Movie Properties… in QuickTime Player's menu bar to bring up the Movie Properties window for the movie.
  




• Select the Video Track in the track list in the Movie Properties window.
  
• Look at the Format column to discover the format of the video tracks, and choose the appropriate Sheer codec according to this table:
  

Format	Sheer Codec
2Vuy	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
2vuy	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
4:4:4:4 CbYCrA	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
4:4:4:4	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
ABGR	Sheer RGB[A] 8bf
ARGB	Sheer RGB[A] 8bf
b48r	Sheer RGB[A] 10bf
b64a	Sheer RGB[A] 10bf
BGR	Sheer RGB[A] 8bf
BGRA	Sheer RGB[A] 8bf
Blackmagic 10 Bit	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Blackmagic 10 bit v210	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Blackmagic 2Vuy 8 Bit	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
Component Video	Sheer Y'CbCr 8bw 4:2:2
Component Video - CCIR-106 uyvy	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
Component Video - CCIR-106 yuyv	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
L64A	Sheer RGB[A] 10bf
None	Sheer RGB[A] 8bf
PNG	Sheer RGB[A] 8bf
R10k	Sheer RGB[A] 10bf
r210	Sheer RGB[A] 10bf
r408	Sheer Y'CbCr[A] 8bu 4:4:4[:4]
r4fl	Sheer Y'CbCr[A] 10bv 4:4:4[:4]
raw	Sheer RGB[A] 8bf
RGB 8b	Sheer RGB[A] 8bf
RGB 10b	Sheer RGB[A] 10bf
RGBA 8b	Sheer RGB[A] 8bf
RGBA 10b	Sheer RGB[A] 10bf
TARGA Ciné YUV	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
TARGA Ciné YUV16	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
TARGA Ciné YUV8	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
TIFF	Sheer RGB[A] 8bf
Uncompressed 10-bit 4:2:2	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Uncompressed 8-bit 4:2:2	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
UYVY	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
v210	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
v216	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
v408	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
v410	Sheer Y'CbCr[A] 10bv 4:4:4[:4]
V416	Sheer Y'CbCr[A] 10bv 4:4:4[:4]
VUYA	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
Y216	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Y'CbCr 10bv 4:2:2	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Y'CbCr 10bv 4:4:4	Sheer Y'CbCr[A] 10bv 4:4:4[:4]
Y'CbCr 8bv 4:2:2	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
Y'CbCr 8bv 4:4:4	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
Y'CbCrA 10bv 4:2:2:4	Sheer Y'CbCr[A] 10bv 4:2:2[:4]
Y'CbCrA 10bv 4:4:4:4	Sheer Y'CbCr[A] 10bv 4:4:4[:4]
Y'CbCrA 8bv 4:2:2:4	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
Y'CbCrA 8bv 4:4:4:4	Sheer Y'CbCr[A] 8bv 4:4:4[:4]
YUV2	Sheer Y'CbCr 8bv 4:2:2
yuv2	Sheer Y'CbCr 8bw 4:2:2 (in generic Sheer codec)
yuvs	Sheer Y'CbCr[A] 8bv 4:2:2[:4]
yuvu	Sheer Y'CbCr 8bw 4:2:2

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Alpha

QuickTime Player 7.0 no longer provides a mechanism for determining whether an individual video track contains an alpha channel. However, to find out whether your movie as a whole contains an alpha channel,

• Select Window > Show Movie Info… in QuickTime Player's menu bar to bring up the Movie Info palette.
  




• Look at the Format field.
  • If the Format field ends with Millions (or anything less), the movie does not have an alpha channel.
    
  • If the Format field ends with Millions+, the movie does have an alpha channel.