vertical sync

I thought that the fact that I can’t display any subtitles in my player while playing a Blue-ray m2ts-file was fairly trivial to fix. Surely there must be a filter that can generate a picture with the subtitles that I can then merge with the actual video in the renderer. Or so I thought.

It seems that the ubiquitous DirectVobSub filter that handles various subtitle formats doesn’t handle the Blue-ray format. An error message is displayed when I turn on the subtitles in the Haali Media Splitter. Some posts on the Internet even claim that the subtitle format of Blue-ray isn’t published. Others claim that it is a bitmapped format, i.e. that the subtitles come out as (presumably) small images. I still have to verify (or reject) those and a number of other claims.

Anyway, it looks like I’ve got myself a new hobby project: to try to add Blue-ray subtitle support to GothPlayer. The planned approach is to get the subtitles in whatever format they come from the subtitle pin of the Haali filter, do any necessary processing to create a picture with the subtitles on it, input that frame into one of the pins of the SyncVMR9 renderer (my custom renderer) and compose the output picture using the renderer’s built in mixer. Many things may go wrong: The Haali splitter may actually not output anything on its subtitle pin when playing Blue-ray m2ts or it may be encrypted in some shrewd way. But I’ll give it a try and keep you posted…

My Blue-ray drive and a bunch of movies including a couple on Blue-ray arrived one day after I put the orders. Swedish Mail has got their act together!

It turned out that Windows XP can’t read the Blue-ray discs out of the box at all. It lacks a driver for the UDF 2.5 file format used on Blue-ray discs. There aren’t many drivers around unfortunately. The general wisdom out there on the net seems to be that Toshiba’s driver is good. As it is not intended for other than Toshiba computers, it is a bit tricky to install – but not impossible (see [1]). Once installed, you can browse the Blue-ray volume just like a DVD.

The files are encrypted though, as I mentioned in my previous post. Enter Slysoft AnyDVD HD. I still need to figure out how to display subtitles etc with my player. But that’s for later…

One possible filter graph for playing Blue-ray.

Links

[1] How to add UDF 2.5 support to Windows XP.

I was starting to look forward to upgrading my HTPC with a Blue-ray drive and to upgrade my media player, the Gothplayer, so that it would play Blue-ray discs. The commercial players still lack the framelock feature of GothPlayer so I prefer my own player. Should be a no-brainer I thought. GothPlayer does after all play DVDs, full HD AVCHD movies from my camcorder and a whole bunch of different file types. But it turned out that Microsoft does not provide support for Blu-ray in the DirectShow library in the same way they do for DVD menu navigation and playback. I can only speculate as to why but my guess is that it has something to do with licensing of the Blue-ray decryption solution [1]. So what does history tell us?

The DVD encryption was cracked by a bunch of Norwegian hackers back in 1999 and several open source codecs that could decode DVD video appeared. In addition, Microsoft’s DirectShow library supported the navigation of DVD menus so that it was relatively straightforward to design a mediaplayer that was able to play DVDs.

A similar attempt to protect music with DRM has all but disappeared on the market place. Many download sites such as ITunes and the Swedish cdon.se today offer unprotected music. Because people demand it.

It seems that the Blue-ray encryption is destined to face the same fate as the two example above [2]. This was in fact predicted many years ago in IEEE Spectrum [3]. The decryption keys are all over the Internet and you can actually play a Blue-ray movie with an open source Linux movie player with some effort. There is also a Blue-ray “driver”for Windows that supposedly presents the Blue-ray disc as a non-encrypted volume for copy and playback [4].

The (at least until now) always backward-looking media industry has thus lost again. I believe that unencrypted high-definition movies will eventually become legally downloadable or “streamable” over the Internet, just like DRM-free music is today. Both the physical discs and the encryption will be things of the past. But before that the motion-picture industry will no doubt fight the inevitable through yet a few court cases.

I’m betting on that some of the solutions out there, perhaps AnyDVD [4] will function well enough so that I can upgrade my player to Blue-ray. Or that I can “borrow” the required DirectShow filters from one of the commercial players (that have paid their dues). I have anyhow placed an order for a Blue-ray drive and will start experimenting as soon as it arrives. To be continued…

Links

[1] Advanced Access Content System
[2] Restricted formats in Ubuntu. Ubuntu community documentation
[3] Loser: DVD Copy Protection, Take 2
[4] Slysoft: Home of AnyDVD

It was no good then; it is no good now.

Watching an AVCHD file from my Sony SR11 HandyCam with my HTPC is a rather pleasant experience (as long as the cinematographer’s hand has been reasonably steady). The camcorder records in a 1080i format which means that you get 50 fields per second of video. It turns out that the PowerDVD8 H.264 decoder cranks out 50 different full frames per second meaning that it does some kind of intelligent / adaptive deinterlacing. This produces a very fluid motion, very different from what you get if you for instance render the AVCHD video into a 25 fps WMV file. (The PowerDVD / CyberLink decoder seems to fall back to 25 fps if it can not use the DXVA interface (Windows) of the VMR9 renderer, e.g. when an extra filter is inserted between the decoder and the VMR9. This happens for instance when using the Haali splitter which insists on rendering subtitles even if none exist. With my filter set, a DirectVobSub filter is inserted between the decoder and the VMR9 to render the subtitles. This breaks the DXVA interface between the decoder and the VMR9.)

According to the Swedish version of Wikipedia, the “1080p” format is supposed to produce superior quality as compared to “1080i”, especially when “depicting motion”. I would agree of course if we are talking about full HD, i.e. 1080p/50 (or 60), which produces 50 (60) full frames per second; frames are always better than fields, as long as you get them in equal numbers. I would take issue with the suggestion that 1080p/25 produces better video than 1080i. At least in the case of my camcorder, I definitely prefer the original interlaced format before any 25 fps rendering of this format, as long as I have a good deinterlacer. Most of my movies contain show jumping competitions so there is definitely a lot of motion in them. And I would claim that it is exactly when there is a lot of motion that the 1080i format is superior to any 25 fps format.

The 24 fps movie film standard was once upon a time set as low as possible to save film but just about high enough to render reasonable audio. As I already claimed in an earlier post it is an arcane standard that is long overdue for an upgrade to either 50 fps (as the EU would probably prefer) or 60 fps (the American way). There is an interesting article at Projector Central about the problems with 24 fps video that is used in Blue-ray and some technologies used to mitigate these problems.