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BitJazz
SheerVideo FAQ
Formats: Scan Orders

Does SheerVideo support interlaced?

Does SheerVideo support progressive?

SheerVideoDoes SheerVideo support interlaced?

Yes, SheerVideo currently supports real-time lossless encoding and decoding of interlaced RGB[A] 8b, Y'CbCr[A] 8bv 4:4:4[:4], Y'CbCr[A] 8bu 4:4:4[:4], Y'CbCr[A] 8bv 4:2:2[:4], and Y'CbCr 8bw 4:2:2 data, at all resolutions and frame rates, on both Mac and Windows.

Every Sheer codec comes in two flavors, called interlaced and progressive. The interlaced SheerVideo codecs operate entirely within a field, so that their compression performance is robust is in the face of even the most extreme interfield motion. In general, they are somewhat faster than their progressive-scan counterparts, but their compression power is somewhat lower for frames with little or no interfield motion. However, SheerVideo's interlaced scan mode can also be used for progressive-scan images.

To use the interlaced flavor of a Sheer codec, click on the Interlaced radio button in the Sheer Settings dialog box before encoding.

Whenever the SheerVideo scan mode is known to be interlaced, this is indicated by an i (interlaced) at the end of the codec name:

  • Sheer RGB[A] 10bf i
  • Sheer RGB[A] 8bf i
  • Sheer Y'CbCr[A] 10bv 4:4:4[:4] i
  • Sheer Y'CbCr[A] 8bv 4:4:4[:4] i
  • Sheer Y'CbCr[A] 8bu 4:4:4[:4] i
  • Sheer Y'CbCr[A] 10bv 4:2:2[:4] i
  • Sheer Y'CbCr[A] 8bv 4:2:2[:4] i
  • Sheer Y'CbCr 8bw 4:2:2 i

In interlaced (as opposed to progressive-scan) video, each frame is divided into two fields, with alternate horizontal scanlines belonging to opposite fields. Thus all the even lines belong to the even field, and all the odd lines belong to the odd field. When interlaced video is recorded or displayed, it is captured or displayed one field at a time at a steady rate, so that it takes two sweeps to update an entire frame. As a result, if you freeze a single interlaced frame during fast camera or scene motion, you see a horrible zig-zag pattern. But when played at normal speed, the fact that interlaced video updates fields at twice the frame rate tricks the human eye into seeing more continuous motion. In NSTC video, which has a frame rate of just under 30 frames per second, the field rate is 60 per second. PAL and SECAM video, which have 25 frames per second, update 50 fields per second.

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SheerVideoDoes SheerVideo support progressive?

Yes, SheerVideo currently supports real-time lossless encoding and decoding of progressive-scan RGB[A] 8b, Y'CbCr[A] 8bv 4:4:4[:4], Y'CbCr[A] 8bu 4:4:4[:4], Y'CbCr[A] 8bv 4:2:2[:4], and Y'CbCr 8bw 4:2:2 data, at all resolutions and frame rates, on both Mac and Windows.

Every Sheer codec comes in two flavors, called interlaced and progressive. The progressive SheerVideo codecs take advantage of patterns between fields, usually resulting in a higher compression power than their interlaced counterparts for images with little or no interfield motion. In general, they are also slightly slower than their interlaced counterparts. However, SheerVideo's progressive scan mode can also be used for interlaced images.

To use the progressive-scan flavor of a Sheer codec, click on the Progressive radio button in the Sheer Settings dialog box before encoding.

Whenever the SheerVideo scan mode is known to be progressive-scan, this is indicated by a p (progressive) at the end of the codec name:

  • Sheer RGB[A] 10bf p
  • Sheer RGB[A] 8bf p
  • Sheer Y'CbCr[A] 10bv 4:4:4[:4] p
  • Sheer Y'CbCr[A] 8bv 4:4:4[:4] p
  • Sheer Y'CbCr[A] 8bu 4:4:4[:4] p
  • Sheer Y'CbCr[A] 10bv 4:2:2[:4] p
  • Sheer Y'CbCr[A] 8bv 4:2:2[:4] p
  • Sheer Y'CbCr 8bw 4:2:2 p

In progressive (as opposed to interlaced) scanning, each frame is captured and displayed one complete frame at a time in a single sweep. Film and computer-generated imagery is ordinarily progressive-scan.

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