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| | BitJazz Is SheerVideo more accurate than DV or DV-25?
Yes. SheerVideo is a perfect-fidelity codec, while Photo JPEG is a DCT-based approximating codec. For real-world RGB 8b imagery, Apple's superb Photo JPEG codec at its Best quality setting has an RMS (root mean square) error of 0.70 b/S (bits per sample), whereas SheerVideo has 0.00 b/S error. For Y'CbCr 8bv, whether 4:4:4 or 4:2:2, Photo JPEG's RMS error is 0.38 b/S, against SheerVideo's 0.00 b/S error.
Yes. SheerVideo is a perfect-fidelity codec, whereas Motion JPEG is a DCT-based approximating codec. For real-world RGB 8b content, Apple's excellent Motion JPEG A and B codecs at their Best quality setting have an RMS (root mean square) error of 1.21 b/S (bits per sample), while SheerVideo has an error of 0.00 b/S. For Y'CbCr 8bv 4:4:4, Motion JPEG A and B's RMS error is 0.80 b/S, against SheerVideo's error of 0.00 b/S. Likewise, for Y'CbCr 8bv 4:2:2, M-JPEG A and B have an RMS error of 0.38 b/S, compared to SheerVideo's error of 0.00 b/S.
Yes. SheerVideo is a perfect-fidelity codec, while Sony's Digital Betacam is a DCT-based approximating codec. The DigiBeta codec is not available in software, so we can't give you error statistics. But though DigiBeta is renowned for its low error rate, its error rate is certainly not zero. SheerVideo's error rate is zero.
Yes. DV-50, also known as D9, Digital-S, or DVCPRO50, is an approximating codec, while SheerVideo is a perfect-fidelity codec. No DV-50 codec is currently available in software, so error statistics are unavailable. But DV-50 definitely has a non-zero error rate, whereas SheerVideo's error rate is zero.
Yes. In contrast to SheerVideo, a perfect-fidelity codec with an error of 0.00 b/S (bits per sample), DV-25 is a DCT-based approximating codec that compresses by throwing away (hopefully) less-important information. Thus Apple's DV codec has an average error of 3.75 b/S (bits per sample) for Y'CbCr 8bv 4:2:2, and 2.48 b/S for RGB 8b.
Yes, but this isn't a fair question. SheerVideo, as a perfect-fidelity codec designed for production, interchange, and archival, has an error of 0.0 b/S (bits per sample). MPEG, which is designed for video distribution over low bandwidth channels, needs far higher compression than can be attained with perfect quality. The error rate for MPEG compression depends both on the degree of compression and on the particular implementation of the MPEG codec, of which there are many.
Yes, but this isn't a very meaningful question. SheerVideo is a perfect-fidelity codec intended for use in production, interchange, and archival, where errors cannot be tolerated, and as such SheerVideo has an error of 0.0 b/S (bits per sample). Sorenson Video, in contrast, is an approximating codec designed for compressing video for low-bandwidth distribution. Sorenson's error rate naturally depends on how much you want to compress the data. At its maximum quality settings, Sorenson 3 has an average error of 1.7 b/S for real-world RGB 8b content.
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