News Slysoft's AnyDVD HD ignores copy protection

Completely different - pirate bay offers a tracking service that enables the unauthorised download of content protected by copyright. Okay, they don't actually host the content, but the principle stands.

Allofmp3 does directly host content that (the RIAA claims) it is not authorised to offer for download.

In both cases, pirate bay and allofmp3 are offering users unauthorised copies of protected content. In total contrast, Slysoft (as I understand) has only made a tool which enables someone to strip the DRM from protected HD discs. If you only used it to back up your own discs to your media centre for streaming around your home, would you be doing anything wrong? Morally, I'd argue that the answer is clearly no, and in many countries (including the US - if we ignore laws precluding the circumvention of DRM, personal copies for fair use are legitimate), the legal answer is also no.

Let's take an analogy. Allofmp3 is selling copies of old skool analogue music tapes at a dodgy car boot sale. The pirate bay is an organisation that puts people in touch with other people who have copied tapes for swaps. Slysoft is just making tape recorders.

My understanding of the DCMA is quite limited, but I believe it prohibits the reverse engineering of software in order to strip out DRM. The DCMA is an enactment of the US legislature, the jurisdiction of which stops (regardless of what they may think) at American borders. As such, unless you live in a country bound by the DCMA or a similar law, you can reverse engineer software to your heart's content, as Slysoft has done. On the other hand, most countries do have laws preventing direct infringement of copyright, so setting up a pirate bay / allofmp3 type service is a lot more controversial.

 

Look up 12 posts dude. You're late to the party!

Okay, I'm sure H.264 rips will look better with HD source than with DVD, but my point stands. My point was that you won't get ANY lossless compression out of an even half-way decently encoded video file of any format (kenco_uk was suggesting that you could losslessly compress an HD movie to half its size).

If we're talking lossy compression, then of course the newer, more advanced codecs will likely produce better results than the older ones. However, to compress an HD movie lossily and maintain the HD resolution and acceptable quality, we need to face the fact that file sizes are still going to be pretty big. 50% might be realistic, I don't know, but that's still way above the 10GB mark for a 2 hour movie. You will have to compress quite aggressively, with some pretty horrendous artefacts, I suspect, to make a full HD movie (i.e. ~2 hours in 1080p), recompressed but retaining the HD res, fit on even a DL DVD.

Let's not forget that almost all HD-DVDs and most of the newer Blu-Ray discs are not encoded in MPEG-2 - they are using VC-1, which, though generally held in lower regard than H.264, is considerably more efficient than MPEG-2. As such, to retain most of the fidelity, you're not going to save a lot of space by re-encoding to H.264.

Even allowing for the fact that decent quality HD rips are still going to be on the >10GB scale, I predict mass torrenting of HD content within a couple of years. Definitely within 5 years it will be as trivial to download an HD movie as it is to download an SD movie now.

 

Hrm. I'm not sure how feasible that would be. The only frame of reference I have is that you can losslessly compress CD-quality audio to 50% its size, but to the best of my (limited) knowledge that's the result of a. a lot of work over a long period of time, and b. the inherent nature of audio. So yeah, I guess expecting 50% lossless compression is a bit much at this point.

Mmm. Let's put it this way: re-encoding it to a 700 MB or even 10 GB H.264 would be better than re-encoding it to a 700 MB or 10 GB XviD. Am I far enough away from the original point of the thread yet?

 

You are right - good lossless audio codecs can make ~50% file size reduction. However, that is a result of the fact that CD / WAV audio files are not at all compressed, so can easily be losslessly compressed. Think about it, if you were writing a lossy video codec, and you found your output could be losslessly compressed, you'd realise your codec wasn't producing the smallest file sizes and you'd either improve the algorithm (most likely) or add a final step that losslessly compressed the lossily encoded output.

It may be that there are codecs that produce more efficient lossy encoding than what is used on HD discs, but the very nature of lossy encoding means that you will ALWAYS lose some quality if you decode the original HD content and re-encode it with your superior encoder. So unless you can get hold of the original, uncompressed, HD source (on the order of 1TB for a 1080p24 2 hour movie) you won't get a video file of equal quality to the HD disc with a smaller file size.

 

What I was on about was the fact that, even on DVD's, you can leave out 5.1 DTS soundtracks for languages you're never going to want. I would imagine, with HD-DVD having that much more available room, you're going to get even more DTS foreign language sound stuffed on it. And with DTS 5.1 taking up a fair chunk of space on a standard DVD, I'd imagine they'd take even more room up on a HD-DVD. Thus you could drop them and save a lot of storage space.

Imo, 'lossless' was probably the wrong word. I used it in the same context as people call .ogg 'lossless' compared to mp3. As mcclean007 mentioned, a h264 rip would keep enough integrity of the picture and sound.

 

Maybe, but as a percentage of the storage space of the disc, the audio tracks will probably be a lot less than on a DVD. I wouldn't expect the savings, percentage-wise, to be as good as with DVD, especially if you want your rip to include the highest quality audio on the disc (PCM multi-channel or Dolby TrueHD). I guess if you binned that and took the standard DTS/DD 5.1 track, you'd probably save a lot more space, but that sort of defeats the point a bit.

Fair enough. I guess the thing is, DVD used a pretty inefficient codec by modern standards (MPEG-2), so it was quite easy to rip and encode DVDs to much smaller file sizes while retaining the majority of the detail of the original, simply by using a better codec. Both the HD formats are capable of using MPEG-4 derived better codecs themselves, and (with the exception of some early blu-ray titles, which inexplicably used MPEG-2) seem to have settled on VC-1, which, while perhaps not quite up there with H.264, is not nearly so inferior as MPEG-2 is to, say, XVID.

Obviously, H.264 doesn't touch the sound, so the integrity of the sound is down to whether you keep the original lossless TrueHD/PCM, the original lossy 5.1, the original stereo (eugh, that's if they even still put 2-channel on the new discs) or a recode of one of the above.

I've never heard of Vorbis (I presume this is what you mean by .ogg) being called 'lossless' compared to mp3. As I see it, something either is lossless or it isn't, so the concept of 'comparatively lossless' is meaningless. You could say that Vorbis achieves transparency (where you can't tell the difference between the encoded version and the original) at a lower bit-rate than mp3 for most people and on most equipment. I guess also that some people can still tell well encoded 320kb/sec MP3 (think lame --alt-preset insane) from the original with certain source audio - my ears aren't that good - whereas they might accept q9/q10 Vorbis as transparent. I don't know. On my stereo, with my ears, q6 is perfectly transparent, as is MP3 at --alt-preset standard.

 

Whilst I wholeheartedly agree with what you're saying (and I sit down, corrected, for the most part) you're missing the point of what I'm trying to say. Uncompressed or HD audio takes up a fair amount of space (even if it is the only audio stream on the disc, there'll be more than one language) and as you say, audio 'transparency' means you could get away with at least some compression. Tie that together with the fact that it won't just be in English, but Italian, Spanish, German, etc.. all you'd need would be the language you want to hear, so you could drop the other languages and save a fair amount of space.

Granted, I may have exaggerated saying you could save about half the space, but do you want me quoting exact figures? I'm not disagreeing with you at all, I'm just trying to get my point across.

 

Totally, you could definitely save some space with no loss of quality by stripping out the superfluous features, languages, subs etc., and by trimming the credits if you like that kind of thing. My point was that, based on the assumption that audio bitrates won't increase as much from DVD to HD as video bitrates as a rule, the percentage saving of stripping out the unwanted sound tracks will not be as great. Now, if you're just directly ripping from (say) a 30GB movie, saving 1-2 GB of sound is no big deal. If, however, you plan to accept some loss of quality by re-encoding at lower bitrate, that 1-2GB starts to look like a much bigger saving in the face of, say, a 10GB file. Take it to the logical conclusion, i.e. rips to dual layer DVD or two single layer DVDs, and saving a bit on sound will, I agree, make sense as it allows you to keep the video bitrate (and hence quality) as high as possible.

I think we're preaching from the same bible!

Anyway, personally I'm not bothered about the availability of pirate copies for download / purchase from my local friendly Chinese mafia. The reason I'd want to be able to rip HD discs is to archive them on my (future) media server, in their full, untained HD glory (i.e. no re-encoding). I will obviously tear out the unwanted languages, subs, features (I've never watched the extras on 99% of my discs, and I'll still have all the originals, so I'll be happy to put the disc in if I ever fancy a bit of behind the scenes action) and lesser quality audio streams (retaining the PCM/TrueHD/DD+ whichever is the best available on the disc). Terabytes of storage are getting pretty reasonable these days, so a RAID-5 server with ~3TB (mmm - 100+ HD films) will be quite affordable in a couple of years, when I plan to make this a reality - hopefully the ripper technology will be flawless and easy to use by then!

 

lol

I've just had a wiki on hd-dvd and there's a few more audio streams that are apparantly mandatory, i.e. Linear PCM, True-HD(2-ch)+, DD+, DD, DTS and MPEG Audio.

Am I reading this right?
The Maximum Data Transfer rate is 36.55 Mb/s on a HD-DVD, of which a maximum of 29.4 Mb/s is used for Video. This leaves 7.15 Mb/s used for audio which sounds fair enough.

Compare this to 10.08 Mb/s maximum bandwidth on a DVD and 9.8 Mb/s for video, this leaves 0.28 Mb/s used for audio on DVD!

This is what's confusing me into thinking that, you could have a lossless VC-1 video track with just your preferred audio stream and save shed loads of storage space, as the audio bandwidth on HD-DVD jumps way above that of DVD, which translates to me that audio takes up a crap-load more room in comparison (I.e. the 7.15 Mb/s for an hour and a half takes up a lot more room percentage-wise on a hd-dvd disc than a 0.28 Mb/s for an hour and a half movie on a dvd disc).

Please put me right

 

Yes, you're quite right. I'm afraid I don't really have anything else to say after that large quote.

 

kind of - 'mandatory' is a reference to the fact that all players have to support these streams, not that they must be on every disc.

Well, that's assuming the full 29.4 Mb/s is used for video. I guess in principle you could use almost the entire bandwidth for audio and have a crappy 300kb/s video stream, though that kind of defeats the point!

If you look in the wikipedia entry for Dolby Digital, you'll see that HD-DVD specifies 18 Mb/s maximum data rate for a single TrueHD stream.

Again, that's assuming the full 9.8 Mb/s is used for video, leaving only 280 kb/s for audio. In practice, I think DVD soundtracks generally use more bandwidth - the Dolby Digital article on wikipedia suggests that DVD supports AC-3 Dolby Digital tracks with bitrates up to 448 kb/s per track - if you have a few of these plus a couple of lesser quality soundtracks for director's commentary, secondary languages etc., it soon adds up.

I'd be surprised if any discs are using 7.15 Mb/s average for their audio streams. But yes, if you had a disc that featured multiple high bitrate lossless streams for multiple languates / director's commentary etc., then you could in principle save a fair amount while keeping a perfect copy of the video stream and your chosen audio stream. In practice, however, I expect most discs to ship with a high bitrate lossless English soundtrack, up to one or two other lower rate English tracks, and a number of lower quality soundtracks for other languages. So if you want to keep the best quality English track, you will be keeping the highest bitrate soundtrack, and while you might save a decent amount of space by getting rid of the others, it won't be THAT much.