[MPlayer-users] Blu-Ray Playback/Subtitles

[galenz at zinkconsulting.com]

On Jan 17, 2008, at 1:24 PM, Nan Null wrote:

>
> ----- Original Message ----
>> From: "galenz at zinkconsulting.com" <galenz at zinkconsulting.com>
>> To: "MPlayer usage questions, feature requests, bug reports" <mplayer-users at mplayerhq.hu 
>> >
>> Sent: Thursday, January 17, 2008 2:16:22 PM
>> Subject: Re: [MPlayer-users] Blu-Ray Playback/Subtitles
>>
>>
>> On Jan 17, 2008, at 11:08 AM, Nan Null wrote:
>>
>>>
>>>
>>> ----- Original Message ----
>>>> From: "galenz at zinkconsulting.com"
>>>> In this particular case, I managed to find the subtitles elsewhere
>>>> and
>>>>
>>>
>>>> convert them into a .srt file.
>>>>
>>>> However, this would still be a useful feature to have.
>>>>
>>>> -Galen
>>>> _______________________________________________
>>>
>>>
>>> It would be real nice if you pop the thing in, and it plays,
>>> encrypted or not.
>>
>> There are serious technical/cryptographic issues associated with
>> that!
>>
>
>> In other words, it may never happen, at least not reliably. I don't
>> know if you're making fun of me, or if you're serious, but either
>> way,
>>
>
>> my point stands.
>>
>> Subtitle extraction, given that Blu-Ray uses an MPEG-2 transport
>> stream variant for data storage, does not seem too far-fetched.
>>
>> Parsing text is much easier than cracking encryption and re-
>> implementing a complex application runtime environment.
>>
>> -Galen
>> _______________________________________________
>> MPlayer-users mailing list
>> MPlayer-users at mplayerhq.hu
>> http://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
>>
>
> I didn't mean to make fun of you.  :-)
>
> I actually wish that would happen.  I thought some people already  
> broke the HD DVD, and it's very similar to Blu-ray (besides some  
> advanced DRM feature).
> Legally speaking, DVD encryption was broken and played by Linux, and  
> hasn't be sued yet (or has it?).  If Blu-ray is widespread, it's  
> very likely that it'll need to be run under Linux.
>
> It's very likely that Blu-ray will be widespread in the future.  So,  
> I just hope that we'll have that feature soon.

The encryption used on DVDs was quite trivial - both flawed and easily  
cracked using brute-force. The encryption used on Blu-Ray and HD-DVD  
is crytographically sound and it is unlikely significant flaws will be  
found or that brute-force will prove viable anytime soon.

That said, all DRM (no matter how sound the encryption) is basically a  
game of giving the user both encrypted data and a decryption key, but  
trying to keep them from using the decryption key, except through the  
particular mechanism the media provider chooses.

Therefore, users have found ways to get the decryption keys for Blu- 
ray and HD-DVD discs. However, these keys are quickly revoked, so new  
discs require the extraction of new keys. This means there is not, and  
likely never will be, a simple library for decrypting the high  
definition discs, like exists for regular discs.

Also, the menu system for HD-DVDs and Blu-Ray discs is much more  
complex than DVDs, so will be unlikely a complete menu system for high  
definition discs will emerge.

Do note, in the US, the DMCA forbids the breaking of encryption that  
relates to copy protection.

-Galen