4 simultaneous DVB-T/S stream transcodes + two immediate capture/play

[jalyst]

If I want the ability to transcode 4x DVB-T/S streams at the same time as I'm viewing one or two using the system outlined below...
Could I get away with doing all transcoding in software with minimal performance degradation & quality compromises?

How does one go about calculating for themselves?

Gigabyte GA-P35-DQ6
Antec TruePower 3.0 650w
Intel E6420 2.13Ghz ----------------------- [Core2Duo;Conroe]
Generic 1GB DDR2-800 (PC6400) -------- [Will upgrade to 4GB+]
DNTV Live QuattroS Dual-Hybrid DVB-T/S [This will be replaced with something linux compatible]
Asus EN8600GTS 256MB DDR3 ----------- [HDCP]
The following SATA 1.5/2 drives:
-1x 1TB WD Caviar Black
-1x 250GB Seagate ------------------------ [I think? YTBD]
-1x 150GB WD Raptor
-1x 74GB WD Raptor

Cards that do analogue capture but without on-board encoding sound more ideal:
http://www.mythtv.org/wiki/Video_capture_card#Types_of_cards

If the config. above is too weak then I'll just have to be less ambitious and hope for two simultaneous DVB-T/S + two immediate capture/play.
The PVR componant will move into a VM on a bare-metal hypervisor server later-on anyway, this will be a much more powerful system.

Advice/knowledge greatly appreciated!

Cheers

[jalyst]

Hi All,

could I possibly get some advice/thoughts regarding this?
Thanks heaps in advance! :)

[Guest]

Are you talking about SD or HD?

And transcode to what from what? Using what software and what settings?

Your goal sounds way too optimistic for the machine you specified.

And why do you need our advice? Just try it and see what happens.

[jalyst]

Are you talking about SD or HD?

HD

And transcode to what from what? Using what software and what settings?

Transcode from the standard format used for HD DVB-T transmissions in Oz (think its mpeg-2, I forget the detail, need to check) to whatever the best format for storage/quality is.
Lets say for arguments sake HD mpeg4... (I know that's still a little vague)

Just wanting to work out exactly how taxing this would be so that I can determine if my hardware's suitable.

Night

[Guest]

It's too vague.

Even one HD transcode will suck up all your processor.

[jalyst]

Site seemed to be down last night, had to go to bed.

How can you say that one transcode will suck-up all my processor when at the same time you say the info provided is too vague?
Isn't it a little premature to come such a conclusion?

In what way do I need to be more specific? If lack of parameters is the issue, why not suggest some commonly used formats?
Once we know source and end formats, then we should be able to draw conclusions from there.

Cheers

[Guest]

Sorry, not interested in debates.

Try a single HD transcode MPEG2->AVC with decent settings on your processor and see what happens.

[jalyst]

I'll try to bite my lip and not take offence to that...

Okay lets try to rejig this... In your experience:
Is it possible to have more than a single HD transcode occurring whilst watching a stream or two?

I ask this because I'm building a much newer machine soon & need to know requirements

[Guest]

You can set a lower priority for the transcode process(es), in which case the player would take priority for CPU and the transcodes would run in any leftover cycles.

But here we come back to vagueness. You can run 100 transcodes at low priority while playing something at high priority (assuming you don't run into other resource limits than CPU). But they will take years to complete.

You haven't made clear what your actual goals are.

[jalyst]

goal is to have up to four MPEG2->AVC conversions ocurring whilst one stream is being watched (1020p) over a 2hr period and not have any jittery viewing or faulty recordings.

[Guest]

You can probably capture/watch one at a high priority while transcoding four at lower priority. Capturing/watching two will be doubtful.

The low priority processes will not be impacted quality-wise. They will just take longer to complete.

[jalyst]

Thank-you, that's "all" I wanted to know, coming from someone who's already tinkered a lot.
Sounds as though it should be sufficient for my needs, will continue moving ahead...

all the best

[Ghitulescu]

goal is to have up to four MPEG2->AVC conversions ocurring whilst one stream is being watched (1020p) over a 2hr period and not have any jittery viewing or faulty recordings.

You can do what you intended, don't worry...
...just buy 3 more top computers

[jalyst]

yep as i suspected, distributing the load, I have 3 core2duo-based machines & 1 AMD...

[Ghitulescu]

BTW, there is a standalone that can record 4 streams at once (even 4 HD streams at once) while playing a 5th one (even HD). It's called Humax iCord HD (SAT only, no DVB-C or -T yet). The transcoding you still need to do it on another machine :)

[jalyst]

BTW, there is a standalone that can record 4 streams at once (even 4 HD streams at once) while playing a 5th one (even HD). It's called Humax iCord HD (SAT only, no DVB-C or -T yet). The transcoding you still need to do it on another machine :)

nah it needs to be mostly dvb-t and maybe one or two dvb-s/c
but thanks for the suggestion, ill have at humax's other offerings.