[vorbis-dev] Digital Radio Monial www.drm.org

[Robert Michel]

On Friday 11 October 2002 18:12, Tor-Einar Jarnbjo wrote:

> Your question is answered by DRM here
> http://www.drm.org/newsevents/faqs/faq- 037.htm,  and I agree with them
> completely.

Thank you Tor-Eimar, 
here the statment from DRM:

If a better audio coding system is developed after DRM transmissions have 
started will it be possible to upgrade the receivers.

 There has been much discussion about whether it would be advisable to allow 
for the possibility of improved audio techniques being available in the 
future. Such improvements in audio coding, if obtainable, will probably not 
provide backwards compatibility with existing coding and decoding processes. 
Such an incompatibility exists between the current MPGEG4 AAC and the older 
MPEG2 (Layers I, II and III). In order to allow for such a possible upgrade, 
it would be necessary to download completely new audio decoder software into 
the receiver. This would preclude manufacturers from achieving the maximum 
economy of chip design and power consumption that tends to come from using a 
dedicated receiver chip set. Also it would require foreknowledge of the 
processing power and memory that the receiver would require for any such new 
audio decoder. For this reason it was not felt to be desirable or possible to 
change the basic receiver functions after they had been delivered to 
consumers.
---------------------------------------
Ok, here argue against this statment step by step:

>Such improvements in audio coding, if obtainable, will probably not provide 
>backwards compatibility with existing coding and decoding processes.
This is why a flashable reciever is needed.

>In order to allow for such a possible upgrade, it would be necessary to 
>download completely new audio decoder software into the receiver. 
DRM can transmitt data, too. So an new codec could be tranmitted one in
5-60 Minutes to flash the receivers.

>This would preclude manufacturers from achieving the maximum economy of chip 
>design and power consumption that tends to come from using a dedicated 
>receiver chip set. 
80% dsp power is needed for the general transmission lawer,
20% dsp power for the audiocodec. 
If the audiocodec is 1/3 less efficient must the dsp 7% more powerfull.

>Also it would require foreknowledge of the processing power and memory that 
>the receiver would require for any such new audio decoder. 
How much power does a flash ROM need? 50% ?
How much % is this form the whole system? 0.01% ?
So this would consume 0.005% more power?

>lso it would require foreknowledge of the processing power and memory that 
>the receiver would require for any such new audio decoder. 
:-)  once a year :-)

I would only fear non public broadcastings, but you could also sell recivers
with build in un-public codecs.

Handys are flashable, too. This feature reduce developing and productionscost.
You can add new features for new products to an old chip layout.
I beleave this arguments are only given to avoid conccurence to MP4.

As I told you, if you broadcast via DRM with MP4 you will produce in MP4, too.
So which codec will DRM-broadcaster use for internet-streaming?

rob

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