Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
Now, more than five years later, and with the advent of HDTV, it's time for a new generation of DVB devices.
Here's a list of the features such a device should have:
http://www.cadsoft.de/vdr/hdtv-dream.htm
Ok, this is a dream I have - I don't know if any manufacturer will ever come up with such a device. But then again, in the mid-nineties the DVB cards we have now were a dream as well...
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
Klaus
On Mon, Oct 10, 2005 at 06:33:57PM +0200, Klaus Schmidinger wrote:
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
Now, more than five years later, and with the advent of HDTV, it's time for a new generation of DVB devices.
Here's a list of the features such a device should have:
Just have a look to
http://www.vdrportal.de/board/thread.php?threadid=34730
Ok, this is a dream I have - I don't know if any manufacturer will ever come up with such a device. But then again, in the mid-nineties the DVB cards we have now were a dream as well...
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
The problem right management introduced by the film industry ... this will stop manufacturers selling such hardware.
Werner
Klaus Schmidinger a écrit :
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
Now, more than five years later, and with the advent of HDTV, it's time for a new generation of DVB devices.
Here's a list of the features such a device should have:
http://www.cadsoft.de/vdr/hdtv-dream.htm
Ok, this is a dream I have - I don't know if any manufacturer will ever come up with such a device. But then again, in the mid-nineties the DVB cards we have now were a dream as well...
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
I do not fully agree with the "Full Featured vs. Budget" concept.
There are plenty of non-DVB chips, cards and motherboards that are able to decode MPEG2, and MPEG4 in the near future. I envision a budget-only DVB card world, where the MPEG[24] decoding is delegated to another card, maybe onboard (on-mobo). Each card can be optimized for cost by the manufacturer. MPEG2 can already be decoded by many chipsets, on motherboards with slow and silent processors. MPEG4 will soon be (I think about VIA CLE266 -> CN400, but nVidia is on the way, and others too).
The current problem is lack of completely open-source drivers : there is either a binary lib, or a binary firmware, or a complete binary driver. That's what really limit possibilities.
When softdevice will be able to use the onboard hardware decoder of graphic cards, we will have achieved that part of the deal, for current DVB programs.
En/na Klaus Schmidinger ha escrit:
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
quoting from the page
"Some people claim that today's CPUs are fast enough to decode HDTV data in real time, and therefore there is no need for hardware MPEG decoders any more. Well, this may be true, but it requires a 3GHz machine to get a decent result, and that's something nobody really wants to have in their living room. There are hardware MPEG decoder chips, so let's use them!"
not that I'm really interested in hdtv now (maybe in a couple of decades ;-) but the 3GHz requirement still stands for hardware accelerated mpeg decoding? This is present in epia motherboards and a low end nvidia card capable of xvmc is considerably cheaper than a full featured, low resolution, card.
Bye
Nicolas Huillard wrote:
Klaus Schmidinger a écrit :
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
Now, more than five years later, and with the advent of HDTV, it's time for a new generation of DVB devices.
Here's a list of the features such a device should have:
http://www.cadsoft.de/vdr/hdtv-dream.htm
Ok, this is a dream I have - I don't know if any manufacturer will ever come up with such a device. But then again, in the mid-nineties the DVB cards we have now were a dream as well...
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
I do not fully agree with the "Full Featured vs. Budget" concept.
There are plenty of non-DVB chips, cards and motherboards that are able to decode MPEG2, and MPEG4 in the near future. I envision a budget-only DVB card world, where the MPEG[24] decoding is delegated to another card, maybe onboard (on-mobo). Each card can be optimized for cost by the manufacturer. MPEG2 can already be decoded by many chipsets, on motherboards with slow and silent processors. MPEG4 will soon be (I think about VIA CLE266 -> CN400, but nVidia is on the way, and others too).
The current problem is lack of completely open-source drivers : there is either a binary lib, or a binary firmware, or a complete binary driver. That's what really limit possibilities.
When softdevice will be able to use the onboard hardware decoder of graphic cards, we will have achieved that part of the deal, for current DVB programs.
Well, a "full featured" card is certainly the most user friendly way of doing it, because it could provide both video _and_ audio, and there wouldn't be problems with keeping audio and video in sync, because all this would be done on the FF DVB card. Also, I would expect that switching between channels should be faster with a FF card than with a budget/softdevice combo.
Nevertheless, if there were a card that can decode MPEG2/4/HDTV video _and_ normal/AC3 audio, and a "budget" card that can receive DVB-S2 and has CAM support, I'd go for that, too. But my dream continues to be a real FF card ;-)
Klaus
Dr. Werner Fink wrote:
On Mon, Oct 10, 2005 at 06:33:57PM +0200, Klaus Schmidinger wrote:
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
Now, more than five years later, and with the advent of HDTV, it's time for a new generation of DVB devices.
Here's a list of the features such a device should have:
Just have a look to
http://www.vdrportal.de/board/thread.php?threadid=34730
Well, it's been rather quiet about this lately. On 2005-09-06 "randy" wrote
"aber nicht verzagen - oktober. linux stb. ide. hdtv. offenes sdk."
Ok, there are still a few weeks in october...
Ok, this is a dream I have - I don't know if any manufacturer will ever come up with such a device. But then again, in the mid-nineties the DVB cards we have now were a dream as well...
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
The problem right management introduced by the film industry ... this will stop manufacturers selling such hardware.
Werner
Well, in an "ideal" world we would probably all just send our money to the movie industry without getting anything in return. That would be the most secure way of handling things.
Klaus
Nicolas Huillard schrieb:
There are plenty of non-DVB chips, cards and motherboards that are able to decode MPEG2, and MPEG4 in the near future.
Yes. But manufacturers save on hardware design for their TV-outs. Today's Nvidia and ATI cards may be great graphics cards, but their TV-outs still suck after all those years of development.
And fully digital TV without any signal degradation maybe just around the corner, but it will still be just around the corner for a few years to come.
I'm glad that I have my DVB-C full-featured card with a TV-out that offers the quality of a stand-alone DVD player.
Regards,
Hanno
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
Klaus
I would add a seperate layer for subtitle. I'm working with DVD decoders and they provide seperate layers for OSD and subtitle. This would remove the concurrent access to OSD for DVB and DVD subtitle generation.
regards Peter
Klaus Schmidinger schrieb:
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
I think the situation is different with the new display technology than it was before with out 50/100 Hz TV PAL sets.
If you say that the new full featured hardware should implement DVI output etc. - what will be responsible e.g. for things like scaling and deinterlacing?
To be honest: If you look at latest (flat-)TV sets and their way to deinterlace and scale the picture, I would prefer to get this done by software e.g. by using spline resize algorithms (see e.g. http://audio.rightmark.org/lukin/graphics/resampling.htm) and advanced deinterlacing options (see e.g. http://home.knuut.de/MWieser_/vf_raw_ntv_8) known from xine and mplayer. Unfortunately, those algorithms need processing power, processing power is expensive, and this will make this hardware really expensive.
In the end, the price will make the market again, and so we might get lower quality as we really want, and a budget card with an apropriate software solution will then be the better choice.
Don´t get me wrong, I like my FF, the quality I get on my 50 Hz TV and the fact, that nothing (not even heaviest hard disc access) can interrupt the decoding process. But I know: 50 Hz, real interlace display and sharp image quality even on fastest movements will soon be history - if it isn´t already. Maybe this will change in the near future, but as I said, you will first pay a lot for it.
With kind regards
Joerg
There are three main aspects regarding TV reception: Receiving, decoding, and output.
In the past, the most critical part was imho output, and it still is: Only very few solutions exist that allow to create interlaced PAL TV output without scaling and messing up the field order.
For the HDTV future, this will be different. In the past, a TV output was some kind of attachment to the graphics card. Now, since HDMI is compatible to DVI, a primary DVI output is the best solution to connect a HDTV display. Its just a matter of time until modern graphics cards will be able to produce fully HDTV compatible output for TV sets, including audio.
Next thing is decoding. HDTV will soon be directly related to MPEG4/AVC, to keep bandwidth in an acceptable range. For the main CPU, this is still a difficult task, so hardware accelerated decoding should be the path. My guess is that most next generation graphics cards will have MPEG4/AVC and VC-1 decoders built in. Getting this on Linux will take some time, but its not impossible.
Finally, reception. This sounds like the easiest part, but I fear that this will be the one that stops us. With the current attitude of the movie and TV industry, we'll probably get HDTV only in DRM'ed versions, so they can force their no-recording dreams on us. I don't see that they allow open source software to access the video streams, just like they never allowed open source software for CSS protected DVDs. And my guess is that this time it wont be that easy to get around it.
Basically, I think the future lies in budget cards combined with hardware accelerated graphics cards for output. However, there's no point in wasting time on this topic until we know for sure that there will be open access to the video stream, and it doesn't look like that in the moment.
Cheers,
Udo
Peter Dittmann wrote:
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
Klaus
I would add a seperate layer for subtitle. I'm working with DVD decoders and they provide seperate layers for OSD and subtitle. This would remove the concurrent access to OSD for DVB and DVD subtitle generation.
Is it really necessary to have both subtitles and OSD menus at the same time? After all, you can only reasonably use one at a time ;-)
Klaus
Joerg Knitter wrote:
Klaus Schmidinger schrieb:
Several years ago, when VDR was first developed, it was based upon a then all new DVB card, which implemented a complete device with tuner, MPEG decoder and optional CI adapter.
I think the situation is different with the new display technology than it was before with out 50/100 Hz TV PAL sets.
If you say that the new full featured hardware should implement DVI output etc. - what will be responsible e.g. for things like scaling and deinterlacing?
I would expect a good tv set to do that. But then again I have no personal experience with these things. So far I only had a regular PAL tv set...
Klaus
Udo Richter wrote:
... Basically, I think the future lies in budget cards combined with hardware accelerated graphics cards for output. However, there's no point in wasting time on this topic until we know for sure that there will be open access to the video stream, and it doesn't look like that in the moment.
Assuming there will be broadcasts that prevent us from accessing the data stream, the only way to have a chance of watching such a broadcast live in a Linux STB would be a full featured HDTV DVB card. Such a card could receive and decode the signal, without making the data externally available, except on the HDCP protected output. Even if it wouldn't be possible to record such a broadcast, we could at least watch it live with the STB of our choice. A solution with separate budget DVB card and hardware accelerated graphics card could never do that, because there the data stream would have to be allowed to run through the PC's CPU - and I don't think they would allow that.
Klaus
On Fri, Oct 14, 2005 at 03:27:35PM +0200, Klaus Schmidinger wrote:
Peter Dittmann wrote:
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
Klaus
I would add a seperate layer for subtitle. I'm working with DVD decoders and they provide seperate layers for OSD and subtitle. This would remove the concurrent access to OSD for DVB and DVD subtitle generation.
Is it really necessary to have both subtitles and OSD menus at the same time?
Yes. I have missed the subtitles while using OSD menus.
After all, you can only reasonably use one at a time ;-)
Both layers (OSD and subtitles) are mostly transparent or translucent, and the subtitles typically cover only a small area on the screen. I would say you can reasonably use both. At least I routinely simultaneously access the OSD menus and read subtitles on channels that burn the subtitles on the MPEG video stream.
Marko
Marko Mäkelä wrote:
I would add a seperate layer for subtitle. I'm working with DVD decoders and they provide seperate layers for OSD and subtitle. This would remove the concurrent access to OSD for DVB and DVD subtitle generation.
With a reasonable OSD, it should be possible to merge both in one, shouldn't it? The current OSD is too restricted in memory, but with fullscreen 256-color OSD or higher, it should be possible to merge several OSD clients into one.
Cheers,
Udo
Marko Mäkelä wrote:
On Fri, Oct 14, 2005 at 03:27:35PM +0200, Klaus Schmidinger wrote:
Peter Dittmann wrote:
Please let me know what you think about this, and if I have forgotten anything or got something wrong.
Klaus
I would add a seperate layer for subtitle. I'm working with DVD decoders and they provide seperate layers for OSD and subtitle. This would remove the concurrent access to OSD for DVB and DVD subtitle generation.
Is it really necessary to have both subtitles and OSD menus at the same time?
Yes. I have missed the subtitles while using OSD menus.
After all, you can only reasonably use one at a time ;-)
Both layers (OSD and subtitles) are mostly transparent or translucent, and the subtitles typically cover only a small area on the screen. I would say you can reasonably use both. At least I routinely simultaneously access the OSD menus and read subtitles on channels that burn the subtitles on the MPEG video stream.
Marko
Well, ok, of course I wouldn't mind if my "dream device" would allow for several layers of OSD.
Personally I find subtitles rather irritating. The other day I watched "Star Wreck - In the Pirkinning" (see http://www.starwreck.com). This is a pretty funny scifi spoof, with CGI sequences that in part are even better than what's in regular scifi shows. Unfortunately they produced it in Finnish (I believe - I'm afraid I can't tell these nordic languages apart), so I had to watch the subtitled version. However, while the subtitles allow me to understand what the actors say, I miss a lot of what's going on in the video, so I frequently have to rewind.
Klaus
Klaus Schmidinger wrote:
Assuming there will be broadcasts that prevent us from accessing the data stream,
on a funny side note, read this: Microsoft aktualisiert Media Center Edition http://www.heise.de/newsticker/meldung/64919
"Während sich die erweiterten DRM-Funktionen hierzulande scheinbar nicht auswirken, berichten Teilnehmer amerikanischer Foren, dass sie nun einige Sendungen von Pay-TV-Sendern nicht mehr aufzeichnen können, weil die MCE gewisse Broadcast Flags auswerte und die Aufnahme untersage."
Thats the kind of feature that convinces me that MCE is better than VDR :D
the only way to have a chance of watching such a broadcast live in a Linux STB would be a full featured HDTV DVB card. Such a card could receive and decode the signal, without making the data externally available, except on the HDCP protected output.
Good point. On the other hand, VDR would then be limited to be a channel switch tool, something that every simple diskless receiver can do either.
The budget cards may be able to do more, on a TCPA-nailed system. But all the data streams would probably be restricted to trusted mode, and I don't see that happening in an open source OS ever.
Cheers,
Udo
Klaus Schmidinger wrote:
live in a Linux STB would be a full featured HDTV DVB card. Such a card could receive and decode the signal, without making the data externally available, except on the HDCP protected output. Even if it wouldn't be possible to record such a broadcast, we could at least watch it live
Such a card might even allow the encrypted stream to be dumped to the disk and replayed back through the HDMI at a later date (provided the DRM flagged that such time shifting was permissible).
It might even be possible to support time-limited replay if the card is willing to trust the timestamps that it receives from the incoming aerial signal at the time of replay.
Jon
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Dr. Werner Fink -
Hanno Mueller -
Joerg Knitter -
Jon Burgess -
Klaus Schmidinger -
Luca Olivetti -
Marko Mäkelä -
Nicolas Huillard -
Peter Dittmann -
Udo Richter