[LAU] Successor/replacement for RME HDSP+Multiface?

[Kazakore]

On 30/08/14 16:17, Gene Heskett wrote:
> On Friday 29 August 2014 03:21:27 Kaza Kore did opine
> And Gene did reply:
>>> From: gheskett at wdtv.com
>>> To: linux-audio-user at lists.linuxaudio.org
>>> Date: Thu, 28 Aug 2014 22:45:41 -0400
>>> Subject: Re: [LAU] Successor/replacement for RME HDSP+Multiface?
>>>
>>> On Thursday 28 August 2014 21:14:48 Kaza Kore did opine
>>>
>>> And Gene did reply:
>>>>> From: gheskett at wdtv.com
>>>>> To: linux-audio-user at lists.linuxaudio.org
>>>>> Date: Thu, 28 Aug 2014 20:37:53 -0400
>>>>> Subject: Re: [LAU] Successor/replacement for RME HDSP+Multiface?
>>>>>
>>>>> ...Hi-8 tape...
>>>> I thought we were talking about the future here! The 80s wants its
>>>> property back!!
>>>>
>>>> Also Hi8 is an analogue format so everything in the post is plain
>>>> bollocks! Maybe you meant Digital8?? Still 15 years old and any
>>>> tape format is pretty much dead and definitely not the future!
>>> Not this one, it uses metal tape in the same casette as a Hi-8 would
>>> use, but about a tenner more expensive. and is "digital Hi-8"
>>> format.
>>>
>>> Reasonably sharp too at 720p.  Go look it up, its a Sony HandyCam
>>> DCR- TRV460 NTSC. and about 11 years old IIRC.
>> So not Hi8 then! :p (If you look I did mention Digital8 too.) Not sure
>> where you get the idea it's 720P capable! Specs on website state
>> 640x480 and you even state in the name you provided it's NTSC, which
>> is never 720P, same as PAL and SECAM aren't. They are old, SD
>> standards. 720/1080 P/I are very different beasts really.
>>
>> Anyway it's probably more important to talk about the standardised DV25
>> and DV50 protocol all these commercial/prosumer products use for
>> communication that tape/card formats. There are some Sony and
>> Panasonic camera that do this fine over USB so it's not impossible or
>> a problem with USB itself. I see yours (and apparently many others)
>> claim to have some kind of USB Streaming but for some reason it's not
>> usually full quality, as you would get from Firewire. Wonder why...
> The std says the speed is there.  But on this Asus M2N-SLI Deluxe
> motherboard that cost $287 USD when I bought it, all USB ports claim to be
> USB2.0.  The throughput to/from a hard drive in a self powered usb box
> that I have 2 of, one 40Gb, one 300Gb drive, has a hard time out running a
> floppy disk.  No mistakes ever, but the usable bandwidth simply is not
> there.  My next door neighbor bought one of the 40's the same day I bought
> mine, runs it as a backup on her windows machines.  On her windows boxes,
> it has no problem moving data in either direction at about 50 megabytes a
> second.
>
> A 640x480 USB2.0 camera, plugged into the rear port of a D525MW Atom
> powered board, only make 3 frames a second.
>
> The linux version of USB is a 1 legged dog in comparison.  Why we put up
> with that poor usb performance is beyond me. We had the original USB in
> full usage on linux a good year ahead of the Redmond version, but IMSNHO,
> linux has been sitting on its butt for at least a decade.
>
> What the bloody hell, a copy of the std reference is well within the
> financial reach of both Red Hat and Ubuntu & even SuSe.  But I don't see
> any improvements in the speeds here, and I am currently running a 3.16.0
> kernel on a quad core phenom.
>
> Cheers, Gene Heskett

Which is well more than enough for full bandwidth transfer of many video 
channels from a DV type device (which are very similar to your 
Digital8.) They use DV25, which is 25Mbit/s, or there was the DVCPRO50 
at 50Mbit/s and DVCHD which uses 100Mbit/s. The tape storage media 
stores it at these compression rates so there is no way to get better 
quality from them!

The specs of your camera specifically say that the USB is for WebCam 
output though! So I'm not surprised to head it's lower quality and 
framerate. I just don't understand why!

Sony and Panasonic have both implemented it on a very low number of 
their camcorders and as far as I know it works fine. But they require 
special, propriety software so not really any use for the FLOSS world! I 
honestly don't understand why there isn't a more widespread solution, 
especially as firewire seems so hard to get these days, but answers of 
the type "USB isn't up to it" don't bear up to the facts in my opinion.

Dale.