Support and General Use > Plugins/Viewers
Holy cripes, the video project has finally gotten started!
bk:
--- Quote from: senab on August 09, 2006, 01:06:23 PM ---1) The broadcom core (on iPod 5G) needs to figured out how to be used
2) The decoder will need optimizing big time (as will the audio)
3) The iPod's video out pin on the 3.5mm needs to be figured out how to be utilized
--- End quote ---
I believe the broadcom chip does the bulk of the decoding (not sure if it's both audio and video), so that leaves number one as the major obstacle.
senab:
The broadcom would mainly do the video decoding due to it support floating point. The PortalPlayer chip is mainly used for audio.
linuxstb:
--- Quote from: senab on August 10, 2006, 05:05:29 AM ---The broadcom would mainly do the video decoding due to it support floating point. The PortalPlayer chip is mainly used for audio.
--- End quote ---
The Broadcom chip appears to do both audio and video decoding. There is also nothing to suggest it has a hardware floating point unit, but it does have DSP hardware.
My understanding is that Apple firmware (running on the PP chip) reads the compressed data from disk and passes it to the Broadcom chip. The Broadcom chip does the decoding, displaying the video on the LCD, and passing the uncompressed audio back to the PP chip for it to send to the DAC.
So the Broadcom chip isn't there to help the main CPU - it does the whole job, with the CPU just managing the process.
senab:
Hmmm, I'm sure read somewhere that the Broadcom chip supports floating point. I'll have a dig around to see if I can find it again.
According to this article, the Broadcom chip doesn't display the video but still passes it to the Toshiba LCD controller:
http://www.commsdesign.com/showArticle.jhtml?articleID=177105035
--- Quote ---As with the PortalPlayer SoC, Broadcom's processor integrates an LCD controller. However, Apple is using a separate LCD driver/controller from Toshiba in the iPod Video.
--- End quote ---
linuxstb:
--- Quote from: senab on August 10, 2006, 05:40:41 AM ---According to this article, the Broadcom chip doesn't display the video but still passes it to the Toshiba LCD controller:
--- End quote ---
Passing the data to the LCD controller is what I meant by "display the video".
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