max bitrate for Sigma EM 8551 - showcenter

[musicnyman]

does anyone know the max bitrate of this chip? i need to set this max bitrate in divx so my movies won't stutter on my pinnacle shocenter.

thanks,

[SeeMoreDigital]

Unfortunately this is not the sort of information Sigma specifies on their web site...

That said, I'm sure the EM85xx series chip-sets will be able to cope with CBR bit-rates of well over 6000Kbps... and maybe even up-to 10,000Kbps (the chip-set on my old Xcard can do this).

Ever thought generating your encodes over two passes?


Cheers

[musicnyman]

well, here's the thing. i use autogk to encode 2 pass divx files at about 1.5 gigs, cause it makes my life easier and automatic. so there's no way , that i know of, to set the max bitrate in auto gk. i know i can do this in GK or Dr Divx, but won't let go of my Auto gk :)

so there's a way to change the max bitrate divx uses which bypasses all other max bitrate settings including the home theater profile. the main problem is us showcenter users are having is stuttering and freezing of divx/xvid files during high motion/pan scenes. if i were to guess, it stutters at about 4K. but not 100% sure. so i guess i can play with it, but would rather know the exact maximum so i know.

yeah, i checked their site, emailed them, and checked everywhere and it's not posted anywhere :(

thanks,

[SeeMoreDigital]

There could be quite a few reasons as to why the video stutters that are not necessarily associated with Sigma's chip-set. For instance: - Showcenters software/middle-ware could be b0rked
The network connection might not be set-up correctlyThere might also be problems with how the audio stream is decoded during high bit-rate video scenes. From what I remember DrDivX uses Lame's audio codec for MP3... But does the stuttering problem occur more with MP3 VBR or CBR audio. Or with AC3 audio?

Several months ago I generated some high bit-rate tests for my Xcard an noticed DrDivX encodes did not fair quite as well as ones generated using MPEG Mediator (with Radium's MP3 audio codec). That said, when the DrDivX audio and video streams were de-muxed and re-muxed using Alex Noé's "AVI-mux" they seemed to play much better.... But others will have to establish what this really means?

I can't imagine that the EM855x chip-set has been designed to top-out at anything less than 6000Kbps for Mpeg4... And the reason I mention this particular bit-rate is because anything higher and you might as well stick with the Mpeg2 source!

Now... I guess what I can try and do (when I have some time) is, encode and play some high-bitrate Mpeg4 encodes using my ADS Media-Link (MXL-581) device.

It uses the same Sigma EM8551 chip-set... So if they play okay with the ADS, one would assume they should with the Pinnacle ShowCenter!


Cheers

[musicnyman]

thanks! yes, that would prove that it's not the sigma chip but the software pinnacle uses...

in auto gk, i think it uses LAME mp3 to encode the audio as mp3.

i can try and use the original AC3 source instead of converting to mp3 to see if that helps... thanks,

also, in auto gk, i use ESS/home theater profile support so it shouldn't go above 4K.

[SeeMoreDigital]

Hi musicnyman,

Okay, I generated some encodes, at different bit-rates, from the PAL version of Star Wars II (Chapter 41 @ 6min 17sec).

All were encoded at 1:1 (ie: 720x576 = 414,720 total pixels) using the XviD codec in SP mode, with MP3 audio at 96Kbps CBR using the Radium codec. At 4000Kbps 2pass VBR, the video was rock solid with no stuttering.
At 5000Kbps 2pass VBR, the video was rock solid with no stuttering.
At 6000Kbps 2pass VBR, the video paused briefly twice during very high motion scenes
At 6000Kbps 1pass CBR, the video was rock solid with no stuttering.
At 9000Kbps 2pass VBR, the video paused multiple times
At 9000Kbps 1pass CBR, The video paused briefly twice during very high motion scenes
Preliminary Conclusion
It would seem 6000Kbps is the chip-sets safe "top-out" limit for 720x576 resolutions.

People generating Mpeg4 encodes at 720x480 (NTSC DVD) resolutions, might be able to raise the bit-rate a little more... And the same goes for people using even lower resolutions (but why they would want to raise the bit-rate any higher than 6000Kbps is beyond me).

When I have some more time I will generate some more high bit-rate encodes using ASP implementations.


I have to say, the ADS Media-Link device is impressive... try as I might I have not been able to lock it up... yet ;)


Cheers

[musicnyman]

very nice, thanks,

http://www.adstech.com/products/MXL-581/specifications/MXL-581_specs.asp?pid=MXL-581

is this the one you have? not bad, $199...

also, this is interesting.. sony is releasing a new player using the sigma HD EM8620L chip.

http://www.sigmadesigns.com/news/press_releases/050207.htm

and showcenter is releasing a new version of showcenter as well with that same new chip:

http://www.pinnaclesys.com/aboutus/PR/News.asp?NewsID=3908&Langue_ID=2
http://www.tomshardware.com/business/20050315/cebit_2005-09.html

so hopefully the new 200 showcenter will be able to help me watch high quality divx movies smoothly. i'm assuming since the new sigma chip supports HD, it would do a better job at handling high bandwidth non-HD divx files... but your ADS recommendation caught my eye... so i'll think about trying that out as well.

[SeeMoreDigital]

Originally posted by musicnyman
very nice, thanks,

http://www.adstech.com/products/MXL-581/specifications/MXL-581_specs.asp?pid=MXL-581

is this the one you have? not bad, $199... Yes... Although the European version I have comes fitted with a DVI output.

For anybody else who may be interested, I started a thread about Std-Def and High-Def Media Streaming Devices (http://forum.doom9.org/showthread.php?s=&threadid=87751) in January this year!


Cheers