Just Out of Curiosity

[lubczyk]

You know how Monkey's Audio can just be a compressed wav file that can be restored to original quality. Also tools being around like RatDVD that can compress a DVD and then decompress it to it's original form. Is there enough data on that so-called Digital Versitile Disc (DVD) to reconstruct the original frames prior to mpeg-2 compression? Could this be possible disregarding the mpeg-2 compression artefacts and the telecine process?

Just curious. I know that if one could actually decompress a so called mpeg-2 it would probably take up gigs upon gigs of data.

Sorry if this doesn't belong in the Avisynth Usage Forum.

[stickboy]

This has nothing to do with AviSynth.

Anyhow, Monkey's Audio is a lossless compressor. MPEG2 is lossy, which, by definition, loses data during compression. Once they're gone, it's impossible to reconstruct the original bits exactly (the pigeonhole principle). (If it were possible, there'd be no such thing as MPEG artifacts!)

[Wilbert]

Use an appropriate title please. Moved to a more appropriate forum.

[Mug Funky]

the reconstruction you speak of (you say "disregarding mpeg-2 artefacts") happens already... it's called decoding :)

and yeah, uncompressed yuv takes up more than a few gigs. but to get what was originally on the tape you'd need 10-bit 4:2:2 storage. this has a slightly higher data rate, but still only about 200 gigs per movie (including 4 channels of 20 bit audio). of course, for lord of the rings or kenneth branagh's hamlet, you'll need way more than 200 gigs...

there's hope though - the source of this 10 bit yuv is usually lossy. digital betacam is a (very very slightly) lossy DCT compression, stored at 90 megabits per second. to contrast that with something, consumer level DV is a measly 25 megabits, including audio.

[lubczyk]

What you're talking about Mug Funky might be possible if the Holographic Versatile Disc (HVD) ever gets released: http://en.wikipedia.org/wiki/Holographic_Versatile_Disc.

What the article is saying that HVD technology could allow storage capacity of 3.9 Terabytes with the average transfer speed of about 1 Gigabyte a second. Wouldn't that be amazing?

[Teegedeck]

[Just a rant because I got a free minute... ;))
Now that seems like video enthusiasts would soon experience a similar 'clash of civilizations' as the audio freaks.

Among music fans you have one camp which regards themselves 'audiophile' and claim that the music from a CD sounds more 'relaxed' after the CD has spent some time in the freezer. (They also typically refuse the concept of double-blindtests...) They wouldn't touch an MP3 player for their lives. For that camp, the frequency spectrum can't be wide enough and filesize can't be large enough. The result is SACD, the audio format catering to the superior ears of bats.

Strangely, the movie industry goes along with that line of thought. They seem rather desperate for innovations, so they just increase the number of audio channels and the bitrate per channel every few years. First there was DTS which is actually a rather backward format but at least it uses higher bitrates... Now Dolby's latest feat is 13.1-channel lossless audio...

The other camp test whether they can distinguish the compressed audio from the uncompressed original and when they can't that's alright then. The encoder that reaches the lowest filesize and is still indistinguishable from the original is regarded best, efficiency's the word.

Now, when it comes to video it's largely the same. Some people are satisfied with MPEG-4 (not mentioning those indiscriminate folks who actually watch VCDs), others ask for uncompressed video - not realizing that being uncompressed doesn't mean it looks better. Now MPEG-2 might have its deficiencies but one thing is for sure - it looks better than Laserdisc, although Laserdiscs featured uncompressed video (every single frame an uncompressed picture!) if we leave colorspace-inherent compression aside. Simply because MPEG-2 reaches up to 576 lines horizontal res while Laserdisc could only reach up to 440 (and was prone to scratches that resulted in visible 'dropouts'). And the difference in 'size' between the two formats was rather obvious...

If I were to spent more money for a new storage format I'd like a _visible_ advantage from that. IMHO holographic storage would be better used to store some 'ultra-HDTV' resolution of the future some day than to be wasted on lossless video. Apart from the needs of professional video editors in studios of course. :)

[dragongodz]

Teegedeck - :goodpost: or should that be "good rant" ? :D

[Revgen]

Among music fans you have one camp which regards themselves 'audiophile' and claim that the music from a CD sounds more 'relaxed' after the CD has spent some time in the freezer.

These "audiophiles" typically play CD's in modified CD players that use vacuum tubes instead of solid state circuits for producing sound. The problem with tubes is that they can get very hot. This can be problematic for these CD players and CD discs that were originally designed to work with cooler solid state electronics.

Frozen or Cryo'd CD's and CD players allow the equipment to run without heat problems posed by the tubes.

However I do agree that there are members of the "audiophile" community who do definitely do have weird ideas. One guy said that his CD player sounded better after he rubbed petroleum jelly on his power cord and his A/V cables. I wish I remembered where it was posted but I forgot.