Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #156861 > unrolled thread

Re: new laptop: DVD or Blu-ray

Back to article view | Back to linux.debian.user

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 09:10 +0200
    Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-27 10:30 +0200
      Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 11:50 +0200
        Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-27 12:30 +0200
          Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 13:10 +0200
            Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-27 13:40 +0200
              Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 15:40 +0200
          Re: new laptop: DVD or Blu-ray ken <gebser@mousecar.com> - 2015-08-27 16:30 +0200
            Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 18:10 +0200
          Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-27 18:30 +0200
            Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-27 19:50 +0200
              Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 20:20 +0200
                Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-28 04:10 +0200
        Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-27 18:10 +0200
          Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 19:30 +0200
          Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-27 21:50 +0200
            Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-28 04:20 +0200
              Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-28 09:30 +0200
    Re: new laptop: DVD or Blu-ray Nicolas George <george@nsup.org> - 2015-08-27 17:00 +0200
      Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 18:10 +0200
        Re: new laptop: DVD or Blu-ray Seeker <seeker5528@comcast.net> - 2015-08-27 20:40 +0200
          Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-27 21:50 +0200
            Re: new laptop: DVD or Blu-ray Ric Moore <wayward4now@gmail.com> - 2015-08-28 03:00 +0200
            Re: new laptop: DVD or Blu-ray Seeker <seeker5528@comcast.net> - 2015-08-28 07:30 +0200
              Re: new laptop: DVD or Blu-ray Lisi Reisz <lisi.reisz@gmail.com> - 2015-08-28 09:40 +0200
                Re: new laptop: DVD or Blu-ray Seeker <seeker5528@comcast.net> - 2015-08-29 08:10 +0200
          Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 22:20 +0200
            Re: new laptop: DVD or Blu-ray "T.J. Duchene" <t.j.duchene@gmail.com> - 2015-08-28 00:20 +0200
              Re: new laptop: DVD or Blu-ray "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-28 11:00 +0200
                Re: new laptop: DVD or Blu-ray "T.J. Duchene" <t.j.duchene@gmail.com> - 2015-08-29 01:40 +0200
            Re: new laptop: DVD or Blu-ray Gene Heskett <gheskett@wdtv.com> - 2015-08-28 04:20 +0200
            Re: new laptop: DVD or Blu-ray Seeker <seeker5528@comcast.net> - 2015-08-28 07:50 +0200
    Hh "T.J. Duchene" <t.j.duchene@gmail.com> - 2015-08-27 23:50 +0200

Page 2 of 2 — ← Prev page 1 [2]

#156908

On 8/27/2015 9:04 AM, Thomas Schmitt wrote:
> Hi,
>
> Nicolas George wrote:
>> There were the DVD drives by Matsushita, usually found on laptops, that did
>> refuse to return the encrypted contents if the region did not match.
> This sounds plausible, although i would heavily complain
> towards the seller if i ever found out. There is few chance
> i would step into this puddle when recording and reading
> own data.
>
> Any good keywords to search for ?
> All tries bring me to Macbook drives where it is hard to
> distinguish between hardware and software. Of course if Apple
> orders a shipload of drives with custom firmware add-ons,
> then Matsushita will probably produce them.
>
> There are whole online communities which have chosen
> DVD cheating as their favorite sport. Something about:
> "Matshita Flasher", a software without visible authorship,
> and "RPC-1 good, RPC-2 bad".
>
>
I don't know what this "DVD cheating" stuff is about.

RPC-1, it was intended that all playback software be licensed, licensed 
software had to honor the
region code. It was left up to the software to honor the region code or not.

RPC-2, commonly accessible software is available that does not care 
about region code settings.
Initialization was changed so software does not have access to the 
decryption functions if the
region code does not match taking the decision out of the hand of the 
player software.

People who only watch DVDs for their region will never notice the change.

On the one hand, maybe it sounds perfectly reasonable that the big movie 
producers should
be able to prevent playback of the larger percentage of DVD releases 
that people might want to
watch that do not and will never have a release for their region based 
on their desire to prevent
access to the smaller percentage of titles those big movie producers 
want to prevent access to before
those movies have been released for a region.

On the other hand, DVD drives are cheap these days, as far as I know you 
can still by a second drive
and set it to a different region code. One you have your backup copy 
region is no longer an issue
so you can make a DVD that will play from your media center, copy to 
your tablet, copy to a flash
stick and plug into the USB port on your TV or hardware based player, 
etc.... so in effect all the
change really accomplishes is to be an annoyance to those of us who 
really only care about being
able to play a DVD we actually paid for.

The people that produce a DVD and don't care about controlling access 
based on region*could* release
a DVD in unecrypted form, in which case region does not come into play, 
or set the disc as playable in
all regions.

I expect there are many DVD titles that are region restricted not 
because the producers of those
titles want to prevent playback in other regions, but because the 
producers had no plans on releasing
in another region and just never occurred them to think about the people 
who through the internet
or other means purchase DVDs from sources not in their region.

I had an Australian show I was watching and the final season did not air 
in the US, so it was purchased
on DVD, no mention of region restrictions, but turns out it was not set 
for playback in region 1.

On a marginally related but not relevant note, that was at a time when 
hooking a computer to a TV
was not so common, so a Windows desktop, a Linux desktop, and finally a 
laptop or 2 later I was able to
find a combination that would put out a refresh rate the TV would 
accept. Grrrr. ;)

Later, Seeker

[toc] | [prev] | [next] | [standalone]

#156918

On Thursday 27 August 2015 19:30:48 Seeker wrote:
> On a marginally related but not relevant note, that was at a time when
> hooking a computer to a TV
> was not so common,

My, we have some youngsters on this list now. ;-)

Connecting home computers to TVs came _before_ connecting them to monitors.  
The circle has merely come back to the beginning.

Lisi

[toc] | [prev] | [next] | [standalone]

#156927

On 08/27/2015 03:48 PM, Lisi Reisz wrote:
> On Thursday 27 August 2015 19:30:48 Seeker wrote:
>> On a marginally related but not relevant note, that was at a time when
>> hooking a computer to a TV
>> was not so common,
>
> My, we have some youngsters on this list now. ;-)
>
> Connecting home computers to TVs came _before_ connecting them to monitors.
> The circle has merely come back to the beginning.

I actually had an B/W Hatachi monitor hooked to my 1978 Apple][. But for 
games it was connected to a TV.


-- 
My father, Victor Moore (Vic) used to say:
"There are two Great Sins in the world...
..the Sin of Ignorance, and the Sin of Stupidity.
Only the former may be overcome." R.I.P. Dad.
http://linuxcounter.net/user/44256.html

[toc] | [prev] | [next] | [standalone]

#156935

On 8/27/2015 12:48 PM, Lisi Reisz wrote:
> On Thursday 27 August 2015 19:30:48 Seeker wrote:
>> On a marginally related but not relevant note, that was at a time when
>> hooking a computer to a TV
>> was not so common,
> My, we have some youngsters on this list now. ;-)
LOL
>
> Connecting home computers to TVs came _before_ connecting them to monitors.
> The circle has merely come back to the beginning.
>
> Lisi
>
I had a Commodor 64, but did not have the accessories to actually use it 
like a computer
so it was just a game system to me.

It was probably 2007-2008 so it wasn't *that* long ago, but the TV we 
had was a few years old
at the time.

We did have another smaller TV in a back bedroom that was specifically 
designed to also
work as a computer monitor, but we didn't really want to gather the 
family around in the
back bedroom to watch the show.

Later, Seeker

[toc] | [prev] | [next] | [standalone]

#156940

On Friday 28 August 2015 06:24:33 Seeker wrote:
> On 8/27/2015 12:48 PM, Lisi Reisz wrote:
> > On Thursday 27 August 2015 19:30:48 Seeker wrote:
> >> On a marginally related but not relevant note, that was at a time when
> >> hooking a computer to a TV
> >> was not so common,
> >
> > My, we have some youngsters on this list now. ;-)
>
> LOL
>
> > Connecting home computers to TVs came _before_ connecting them to
> > monitors. The circle has merely come back to the beginning.
> >
> > Lisi
>
> I had a Commodor 64, but did not have the accessories to actually use it
> like a computer
> so it was just a game system to me.
>
> It was probably 2007-2008 so it wasn't *that* long ago,

No - I was referring to c. 1981 when Sinclair launched the ZX81 and Atari 
launched its home computer (or was that in 1982?).  We used TVs for display.  
2007 is really recent.

Lisi

> but the TV we 
> had was a few years old
> at the time.
>
> We did have another smaller TV in a back bedroom that was specifically
> designed to also
> work as a computer monitor, but we didn't really want to gather the
> family around in the
> back bedroom to watch the show.
>
> Later, Seeker

[toc] | [prev] | [next] | [standalone]

#157021

On 8/28/2015 12:38 AM, Lisi Reisz wrote:
> On Friday 28 August 2015 06:24:33 Seeker wrote:
>> On 8/27/2015 12:48 PM, Lisi Reisz wrote:
>>
>>> Connecting home computers to TVs came _before_ connecting them to
>>> monitors. The circle has merely come back to the beginning.
>>>
>>> Lisi
>> I had a Commodor 64, but did not have the accessories to actually use it
>> like a computer
>> so it was just a game system to me.
>>
>> It was probably 2007-2008 so it wasn't *that* long ago,
> No - I was referring to c. 1981 when Sinclair launched the ZX81 and Atari
> launched its home computer (or was that in 1982?).  We used TVs for display.
> 2007 is really recent.
>
> Lisi
>
>
Guess I jumped gears there without giving a clear indication. :-\

2007-2008 was when I started messing around with getting a computer to 
work with the TV so we
could watch the Australian show.

The Commodore 64 was earlier.

www.computerhistory.org seems a bit US centric 
http://www.computerhistory.org/timeline/?category=cmptr
  and missing some of the European computers, their timeline lists Atari 
Model 400 and 800 in
1979, Commodore 64 in 1982. Wikipedia shows Sinclair ZX81 in 1981.
https://en.wikipedia.org/wiki/ZX81

All I really remember of the Commodore was Jumpman Jr. 
https://en.wikipedia.org/wiki/Jumpman
I didn't have the monitor or floppy drive, we hooked it to the TV.

Jumping back to 2007

I see some places on the net that list US NTSC as being 60 on the 
refresh rate, but it is actually slightly less.
The slightly less seemed to be the issue, with the video cards giving a 
59 or 60 or maybe only 60 as an
option.

Currently.

Don't know if the better compatibility these days is in the video 
hardware or the TV hardware, but I
suspect it's on the TV side of the equation, maybe a little of both with 
more people wanting to do
the media center thing, computer gaming on the TV, etc...

About 3 years ago I did play around with Blu-ray, the drive was old, the 
software that came with it
stopped being updated in 2010. Had 2 movies both released after 2010, 
initially neither would play,
after poking around on the net and finding a firmware update, I could 
get one of the movies to play.
Same result with the included software and VLC.

Since then I have seen another solution mentioned in the MythTV mailing 
list a few times. I think it
doesn't allow just watching a movie directly though because they talk 
about a delay while starting
the movie decoding and building up a buffer then watching the buffered 
content.

DVD is only slightly screwed up. With Blu-ray it seems like they did 
every thing they could to screw it
up. Even if you don't care about playing commercial video discs, there 
is some question of whether you
want to spend money supporting a technology that has that much baggage.

Later, Seeker

[toc] | [prev] | [next] | [standalone]

#156920

Hi,

Seeker wrote:
> I don't know what this "DVD cheating" stuff is about.

I mean people who buy stuff of which they know that
the deal is unfair and then take much effort to make
it possible to use it despite.
That's the legal fiction.

In practice i doubt that they paid properly for the deal.
So effectively its cheating on unfair businesses.
Cheaters cheating cheaters.


> RPC-1 [...] It was left up to the software to honor
> the region code or not.
> RPC-2, commonly accessible software is available that does not care about
> region code settings.
> Initialization was changed so software does not have access to the
> decryption functions if the region code does not match taking the
> decision out of the hand of the player software.

I read two narrations in the web:
"RPC-1 has no region code in drive but in software,
 RPC-2 has region code in drive and enforces region
 code match in hardware."
versus
"RPC-1 allows to change region code as often as wanted,
 RPC-2 allows only 5 changes. Special software will read
 and display videos from non-matching regions anyway."

The valid intersection of those is probably sketched
by this warning of program "AnyDVD" (another authorless
one):
  "3. -Your drive is a region locked RPC2 drive, which does not
       allow reading of scrambled sectors from a different
       region and you try to read a DVD from a different region.
       Known drives having this problem are RICOH/PHILIPS DVD
       Writers and Matshita/Panasonic DVD readers and writers.
       You can try to find a RPC1 patched firmware at http://www.rpc1.com"

So some old or manipulated ones will perform the decryption
(which is said to be weak), some new ones will deliver
undecrypted data, and "RICOH/PHILIPS/Matshita/Panasonic"
will not give anything.

This sounds like a clear warning not to buy hardware from
said manufacturers.
Regrettably many manufacturers share their produce in
a shameless way. You never know whose firmware you encounter.

For own data recordings it should not matter, anyway.


Have a nice day :)

Thomas
 

[toc] | [prev] | [next] | [standalone]

#156924

On Thu, 2015-08-27 at 22:19 +0200, Thomas Schmitt wrote:

> 
> For own data recordings it should not matter, anyway.

Correct.  RPC codes only apply to the playback of DVD media that
contains data in DVD organized format designed for a player.

As a side note, RPC-1 drives have not been manufactured in 15 years. All
drives licensed after 2000 are required to use RPC-2.  Many DVD players
(even with RPC-2) have Region 0 as an option, meaning that they will
play any disc, regardless of Region spec. Since PCs never use Region 0,
you generally need a player that tends to ignore the Region
specification, regardless of how it is set.  

VLC in particular ignores Region codes.

[toc] | [prev] | [next] | [standalone]

#156943

Hi,

T.J. Duchene wroye:
> Whether you believe me or not, think me paranoid, 

I got mistrusting, too.


> makemkv forum why they
> get key revocation warnings even when using Linux

Trying to grok their complaints and proposals ...
(well, yes kids, a medium error is indeed bad) ...

They talk of keydb.cfg (clearly a disk file) and quote
the program "most likely current AACS host certificate
is revoked by your drive". Also its about "vid", "vuk".
(whut ?)

Since this all stays a bit obscure, how about this
summary statement:

  Be aware that inserting a commercial Blu-ray video disc
  into the drive can have undesired effects on the overall
  video decoding and display system.
  (This does not affect the use of the BD drive with
   self-burned BD media.)

---------------------------------------------------------
I tried to get a grip on the math:

AACS can target an individual player not by modifying its
firmware but rather by invalidating its decryption keys for
all newly produced BD-ROM media.
(Now wondering how many players they can blacklist
 by cutting off their access path to the actual decryption
 key ... and whether one can steal that key, when found.)

The used player keys cannot but identify themselves in
the video output stream by decrypting slightly different
versions of the video. (Well, one could postprocess the
video in order to deceive Sony's recognizer.)

So if a cracked video shows up, Sony can revoke the player
key, and the newly released videos are safe from it.

At some number of revoked keys, i'd expect that more and
more collateral damage is done to valid uncompromised
player keys. That's because the number of possible
combinations of revoked keys grows very rapidly if the
number of revoked keys grows.
Dirichlet's socks drawer (or somebody else's pigeon holes)
tells that there must be collisions as soon as the number
of combinations exceeds the number of media keys. Well,
actually already at the square root of that number,
according to the birthday paradox.

So this protection depends on the assumption that it is
quite hard to crack a player. Somebody who can crack many
players and release a video from each could topple the
global revocation system.
A million suicidal BD players could suffice, crying
"Kill me, Sony. Kill me." while Sony runs out of bullets.

According to
  https://en.wikipedia.org/wiki/Advanced_Access_Content_System
AACS is even weaker than this contraint, because the number
of collaterally affected keys would depend on the depth of
the common ancestor of the compromised ones in the key tree:
  "to revoke a given device key, the MKB needs only be
   encrypted with that device key's parent key."
The higher parents have lots of innocent children.

So each key revocation grows the sub tree of player keys
which are excluded from viewing new video Blu-rays.
The individual remedy for an innocent victim would then
be to get a new firmware for the drive with a new key
which is not in the affected sub tree.
If the global system is flexible, then one would probably
get a reshuffled key tree where the compromised ones are
consolidated in a small sub tree. But it already has to be
cryptic. So many reshufflings will not uphold the property
that a key cannot learn about its ancestors in the tree.

In this theory, players like AnyDVD and makemkv keep compromised
keys (e.g in file keydb.cfg) and their warnings tell that the
currently used compromised key is not of use with the given video.
I.e. one needs to get new compromised player keys, which were
harvested after the given video disc was pressed.

---------------------------------------------------------

Have a nice day :)

Thomas

[toc] | [prev] | [next] | [standalone]

#157007

On 08/28/2015 03:55 AM, Thomas Schmitt wrote:
> Since this all stays a bit obscure, how about this summary statement: 
> Be aware that inserting a commercial Blu-ray video disc into the drive 
> can have undesired effects on the overall video decoding and display 
> system. (This does not affect the use of the BD drive with self-burned 
> BD media.) 
As I said in an earlier post, that sums it up, yes.

With one last proviso, in that let's hope they never put out a update 
that triggers an existing bug in your firmware that bricks the drive.  
Unlikely to the point of nil, but not entirely impossible.   It is the 
unforeseen consequences of a "self annealing" DRM that concern me.  
Since they clearly have not tested every forced update on every model of 
player/drive, the results cannot be predicted with 100% certainty.

>
> AACS can target an individual player not by modifying its
> firmware but rather by invalidating its decryption keys for
> all newly produced BD-ROM media.
It is correct in that it does not modify the firmware that operates 
equipment specifically, ie the controller.  However, BD devices 
themselves  retain disc keys in the form of flash storage in the 
player/drive's electronics.  If the studios revoke a decryption key, the 
player is essentially "bricked" for  playback of anything that uses that 
key.



>
>
> In this theory, players like AnyDVD and makemkv keep compromised
> keys (e.g in file keydb.cfg) and their warnings tell that the
> currently used compromised key is not of use with the given video.
> I.e. one needs to get new compromised player keys, which were
> harvested after the given video disc was pressed.
Yes, that is why there are no "end all" solutions to BD playback with 
unsanctioned players.  Developers of things like makemkv are playing a 
tug of war with the studios.  Pointless, really.  BD was deliberately 
designed for this outcome.  If you want proper BD on Linux, you will 
have to buy a license and develop a sanctioned player - which means it 
would not be FOSS.

[toc] | [prev] | [next] | [standalone]

#156931

On Thursday 27 August 2015 16:19:11 Thomas Schmitt wrote:

> Hi,
>
> Seeker wrote:
> > I don't know what this "DVD cheating" stuff is about.
>
> I mean people who buy stuff of which they know that
> the deal is unfair and then take much effort to make
> it possible to use it despite.
> That's the legal fiction.
>
> In practice i doubt that they paid properly for the deal.
> So effectively its cheating on unfair businesses.
> Cheaters cheating cheaters.

He gets it!

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

[toc] | [prev] | [next] | [standalone]

#156937

On 8/27/2015 1:19 PM, Thomas Schmitt wrote:
> Hi,
>
> Seeker wrote:
>> RPC-1 [...] It was left up to the software to honor
>> the region code or not.
>> RPC-2, commonly accessible software is available that does not care about
>> region code settings.
>> Initialization was changed so software does not have access to the
>> decryption functions if the region code does not match taking the
>> decision out of the hand of the player software.
> I read two narrations in the web:
> "RPC-1 has no region code in drive but in software,
>   RPC-2 has region code in drive and enforces region
>   code match in hardware."
> versus
> "RPC-1 allows to change region code as often as wanted,
>   RPC-2 allows only 5 changes. Special software will read
>   and display videos from non-matching regions anyway."
>
>
Early drives typically shipped with the region code unset and commonly 
you would
be asked to choose a region when you ran the playback software the first 
time.

Could be that some drives did not limit the number of times you could 
change the
region code. If there were such drives, the information available 
indicated you only
had a limited number of changes going all the way back to the days of 
needing a
special card that only did mpeg acceleration in order to play a DVD.

https://en.wikipedia.org/wiki/RealMagic

Fun times. :-)

Later, Seeker

[toc] | [prev] | [next] | [standalone]

#156923 — Hh

On Thu, 2015-08-27 at 09:03 +0200, Thomas Schmitt wrote:
> Hi,
> 
> the reason why i am insisiting in getting facts is that
> i want to know whether drive firmware can get altered
> by just inserting and reading a commercial Blu-ray disc.

Yes, it can - if you consider that the firmware on a BD drive contains
more than just the controller, but secondary chips.  It is important to
remember that the feature is normally only used on AACS encoded discs,
that is movies that you watch.  BD's used for backup will probably not
be a concern.  

That is not why I posted  to the list, though.  I just wanted you to be
aware that BD is not everything that it is made out to be. In my
experience, the changes to the drive's chips do not usually tamper with
the controller in normal operation, but my point is that there are no
guarantees here - it is flash, after all. BD hardware is designed
specifically to be beholden to whatever controls the Blu-Ray Consortium
or the OEM want to exert over its use through frequent updates in order
to use media.  Any update at all could potentially render the drive
useless to your work.  It's something that you should simply be aware
of.

Whether you believe me or not, think me paranoid, or do with that
knowledge, is as I have said, entirely your own affair. 


> I sincerely doubt that the drive firmware will do this,
> but rather believe it is about software on the level
> of operating system and application software.
> (Both of kinds which i would not touch with fire tongs.)


If you don't want to believe me after I said I have seen my drive's
firmware be belligerent, that's perfectly okay by me. I am absolutely
not offended.

Go digging around on Internet.  There are plenty of instances. If you
think that then why don't you ask people on the makemkv forum why they
get key revocation warnings even when using Linux.  I found that after a
mere 5 minutes of searches. The majority of Makemkv users are Linux btw,
so perhaps you will consider the forum posts as proof that OS does not
matter.
  

> But WinDVD 8 is MS-Windows software, not drive firmware.

True, but BD discs update the drive whenever a new disc is inserted.
This is hardware based, not software.


> 
> One BD spares you four exchanges of the DVD in the drive
> when you make a large backup.

True.

> A BD allows to make incremental backups up to 23 GiB whereas
> DVD+R DL allows only 8 GiB of poor reliablilty.

Says who?  I have not had a DVD write fail for some time.


> With reliable DVD media you are restricted to 4.4 GiB.

Any disc: BD, DVD, or otherwise really depend on the age of your drive,
whether it is properly maintained (the lens kept clean and firmware
updated) and the quality of the media that you buy.  If you buy cheap,
uncertified blanks, then yes you will have problems and some of them
will be bad.  That's just physics and capitalism.  Cheap discs means
less care is taken in making them.



> Of course, hard disks are cheaper per GB. But they have other
> needs when it comes to long term storage or rough transport.
> Further they are large and non divisible.

I don't see what "divisible" has to do with it, since you can easily
partition a drive for any number of uses.  If durability during
transport is a concern then yes BD might be a consideration, but at the
rate that flash discs are dropping in price, it won't be for much
longer. 

> 
> I would commercially compare BD media to USB sticks.
> The sellers of BD-RE take care to stay cheaper than the
> sellers of 16 or 32 GiB sticks.

Only for the present.  BD's days are numbered outside of the film
industry.  There are new forms of flash that will eventually render that
moot.

> 
> One big problem is that the burners deteriorate with time.
> The begin to fail recording readable data. But this affects
> only new recordings. The old recorded media do not die with
> the burner that wrote them. 

True, but I have found that burned discs can be unreadable in other
drives of a different make and model, especially multi-session media.
That is why I prefer to use a different media for backups as overall,
they do not have that quirk.


> I believe no BD problem is so sincere as the problem of
> USB sticks which can be programmed to emulate a keyboard.
>   http://www.zdnet.com/article/usb-flash-drives-masquerading-as-keyboards-mean-more-byod-security-headaches/


USB has been and always will be a security issue.  It was never designed
with security in mind.  That is one of the reasons I do not like Linux
automounters running with elevated permissions.  As for Windows, if you
use that OS, and swap USB drives with your friends like candy, you
deserve what you get.




> Have a nice day :)
And you as well, Thomas!  Do take care.

t.j.

[toc] | [prev] | [standalone]

Page 2 of 2 — ← Prev page 1 [2]

Back to top | Article view | linux.debian.user

csiph-web