DVB bandwidth "shredding" possible?

[ginacman]

Hello,

 

I'm recently using a Skystar USB. This piece of hardware is really nice to use but it shows USB throughput limitations with some providers having their bitrate as high as 9 Mb/s, and more, even in SD. As a result, with those services, the datastream congests the USB link on a regular basis.

 

I don't know exactly if such a question is appropriate for this forum/section, but it would be nice in such cases, to "shred" somewhow the DVB datastream so to reduce in turn the USB link bandwidth occupation. I wonder if such a feature could be achieved, eventually by using some sort of plugin in DVBViewer.

Thank you

Edited November 21, 2005 by ginacman

[Griga]

having their bitrate as high as 9 Mb/s

 

Per channel? IMO not possible to receive them properly with USB 1.1, by no means.

 

DVBViewer GE 1.7 provides a low bandwidth checkbox (see hardware tab). This option prevents actions that yield to receiving more than one TV channel at a time (e.g. attempts to switch over to channel B when channel A from the same transponder is recorded). That's all we can do.

[ginacman]

having their bitrate as high as 9 Mb/s

 

Per channel? IMO not possible to receive them properly with USB 1.1, by no means.

 

 

I agree, although the USB 1.1 specs might allow for some 12 Mbps, indeed significant amount less, due to protocol structure and overhead limitations. To this same extent please also note that services around >8 Mb/s are still ok in my actual case, with most of the USB host implementations I have had access to so far.

Even if the USB could not keep up with speed, that's why I was querying about a means of discarding selected data units from the stream. Sorry for not being clear enough on that.

 

DVBViewer GE 1.7 provides a low bandwidth checkbox (see hardware tab). This option prevents actions that yield to receiving more than one TV channel at a time (e.g. attempts to switch over to channel B when channel A from the same transponder is recorded). That's all we can do.

<{POST_SNAPBACK}>

 

In fact, I think more and more that the feature in question has more to do with device driver itself rather than the application. Do you think, perhaps, could that be more properly addressed to the Technisat people for a new feature request in their product eventually? Motivation could be the fact that, after all, their product should be adequate to standard definition digital signals under controllable conditions.

 

The idea of "shreddding" the protocol traffic was started in my mind by simply considering comparable tecnique of reducing the data size of DVD media contents.

Thank you for your reply

[Griga]

could that be more properly addressed to the Technisat people for a new feature request in their product?

 

A simple solution would be to support USB 2.0. I don't understand why they still stick to USB 1.1. Check what other vendors are offering.

 

My USB 2.0 DVB-T device (Terratec Cinergy T2 with BDA driver) delivers the whole transponder (4 TV channels plus EPG plus teletext plus AC3...) without restrictions. I can record it all at the same time.

[Derrick]

The idea of "shreddding" the protocol traffic was started in my mind by simply considering comparable tecnique of reducing the data size of DVD media contents.

For this idea you have to transport the stream first from the card to your pc via the usb1 bus

[ginacman]

The idea of "shreddding" the protocol traffic was started in my mind by simply considering comparable tecnique of reducing the data size of DVD media contents.

For this idea you have to transport the stream first from the card to your pc via the usb1 bus

<{POST_SNAPBACK}>

 

 

Check mate!

Thank you.

 

 

PS: possible castle would be to preventively discard frames from stream at the device level, at the likely cost of loosing control of quality.