BitJazz Is SheerVideo more accurate than DV or DV25? Is SheerVideo more accurate than Photo JPEG? Yes. SheerVideo is a perfectfidelity codec, while Photo JPEG is a DCTbased approximating codec. For realworld 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. Is SheerVideo more accurate than Motion JPEG? Yes. SheerVideo is a perfectfidelity codec, whereas Motion JPEG is a DCTbased approximating codec. For realworld 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, MJPEG A and B have an RMS error of 0.38 b/S, compared to SheerVideo's error of 0.00 b/S. Is SheerVideo more accurate than DigiBeta? Yes. SheerVideo is a perfectfidelity codec, while Sony's Digital Betacam is a DCTbased 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. Is SheerVideo more accurate than DV50? Yes. DV50, also known as D9, DigitalS, or DVCPRO50, is an approximating codec, while SheerVideo is a perfectfidelity codec. No DV50 codec is currently available in software, so error statistics are unavailable. But DV50 definitely has a nonzero error rate, whereas SheerVideo's error rate is zero. Is SheerVideo more accurate than DV or DV25? Yes. In contrast to SheerVideo, a perfectfidelity codec with an error of 0.00 b/S (bits per sample), DV25 is a DCTbased approximating codec that compresses by throwing away (hopefully) lessimportant 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. Is SheerVideo more accurate than MPEG or DivX? Yes, but this isn't a fair question. SheerVideo, as a perfectfidelity 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. Is SheerVideo more accurate than Sorenson? Yes, but this isn't a very meaningful question. SheerVideo is a perfectfidelity 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 lowbandwidth 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 realworld RGB 8b content.
