Mark Kent wrote:
> Roy Schestowitz <newsgroups@xxxxxxxxxxxxxxx> espoused:
>> __/ [ BearItAll ] on Tuesday 08 May 2007 08:29 \__
>>
>>> Roy Schestowitz wrote:
>>>
>>>> Pachter: PS3 Will Win Via Blu-Ray
>>>>
>>>> ,----[ Quote ]
>>>> | It takes a special kind of guy to want to write 207 page
>>>> | reports for a living. A man of vision. A man of honor.
>>>> `----
>>>>
>>>>
>>>
>>
http://kotaku.com/gaming/the-pachter-factor/pachter-ps3-will-win-via-blu+ray-258309.php
>>>>
>>>
>>> That wouldn't really be a reason for Xbox360 fall further into the
>>> doldrums. The Xbox can link to users computers, so they only would need
>>> the one blu-ray device. Alternatively, if I remember right the xbox360
>>> had a USB connector, I suspect a lot of first time buyers of blu-ray
>>> will go for an external device anyway.
>>>
>>> Thinks: It just crossed my mind that a firewire connector might be
>>> needed for blu-ray rather than USB, I should think that unless the
>>> device was given a huge system buffer USB may not be able to keep up.
>>
>> Microsoft said it would support Blut-ray if this media type won the
>> so-called 'race' or 'war'.
>>
>
> A huge system buffer cannot make up for insufficient bandwidth, though.
> At least, not unless you do the download /before/ you watch anything,
> but this is not streaming, this is, well, a forward/store and then watch
> model, which is not the same.
>
The CPU doesn't need to play a large part in the actual transfer, just dma
updates. Processing of audio isn't really an intensive task for the CPU, it
just needs a buffer large enough that as it finishes each block the next
block will be already available. Similar for video but the buffer is just a
bit larger.
For blu-ray where the actual data per frame is greater plus what ever the
algorithm for decoding it, then a USB with a reasonably large buffer might
do the job. I don't know the actual details of blu-ray, just the odd bits
and pieces that are available on the Internet, so I don't really know how
CPU intensive it is.
Streaming isn't really that different from this sort of buffering. The
primary difference is that processing can not look behind, so what is
passing through filtering or processing is not dependant on what is yet to
come and has no more than knockon effect from what has already been
processed. Of cause the streaming process can make use of controls codes
for the streaming system itself, which in itself can change the processing
of data that follows. But it is still a steam, like a fast river, it flows
in one direction, it wears trenches from the river bed that affects the
water following, that water might be carrying rocks that changes the flow
of the water that follows.
The first of the true streaming systems was on the 68xxx serial devices,
they could filter on the fly in the communications device. But to maintain
streaming rates it had to be on a word by word basis, no sub processing
that might affect the flow. An example might be xoring with a comms key.
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