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v3l0c1r4pt0r / lkv-wiki

LKV373A and similar reverse engineering wiki
https://github.com/v3l0c1r4pt0r/lkv-wiki/wiki
MIT License
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U2 chip identification #4

Open v3l0c1r4pt0r opened 5 years ago

v3l0c1r4pt0r commented 5 years ago

It is marked with:

VCT6289H
1534-AXA

Any indicators in favor of particular chip should be posted here

v3l0c1r4pt0r commented 5 years ago

Most likely it is IT9919-H

danielkucera commented 5 years ago

LKV373A supports HDCP encrypted HDMI input

dougg3 commented 5 years ago

If it supports HDCP, then it has to either be the IT9919-H or the IT9917-H.

There are strings like "D:/code/720p/JEDI_9910/freertos/src/pal/msgq.c" in some of the update files. The 720p in the name is suspicious.

I'm assuming someone has confirmed that we've actually seen H.264 streams with a resolution of 1920x1080 out of the device?

The datasheet diagram for IT9917-H shows pins 4 and 5 as NC, but if you scroll down in the table below, they are still listed as XTALOUT and XTALIN. So I'm not sure if we can use the crystal pins as the way to eliminate IT9917-H as a possibility.

danielkucera commented 5 years ago

Mine does "1080p" https://blog.danman.eu/wp-content/uploads/2016/06/lkv373a_codecs.png

v3l0c1r4pt0r commented 5 years ago

@dougg3 Indeed pin 4 connects to crystal Y3 (bottom of it to be precise, looking at silkscreen from the right side, unlike danman's photo). Pin 6 connects to crystal's top left corner. So when comparing the two 9917H and 9919H, it must be the latter.

Regarding HDCP, I didn't hear of anybody able to unpack it, so according to my knowledge we can't tell for sure if it is present or not.

v3l0c1r4pt0r commented 5 years ago

The only chips in IT99xx series that can have crystal on pins 4-6 are IT9919-H and IT9919-N. We also have to keep in mind that presence of crystal is not enough to eliminate any variant. If pin is not connected to die, why can't it be connected to crystal anyway :) It just is pointless, but not impossible.

dougg3 commented 5 years ago

@v3l0c1r4pt0r Point taken that it can't eliminate any variant. :-) However, I do feel that I should point out that I think the crystal is also used on the IT9917-H, and there's a copy/paste mistake in the datasheet.

It makes no sense that the crystal would apply only to the IT9919-H and -N variants. If the crystal was needed for 1080p encoding, then the IT9919 would also need it. I believe the crystal is needed for HDMI RX. This would be consistent with the IT9917-H also requiring the crystal.

Edit: Further digging in the datasheet points out that the 27 MHz crystal on pins 4-6 is for the HDMI audio PLL. So I'm 99% sure the 9917-H also needs it.

idooley commented 4 years ago

The "720p" in the path is perhaps just the parent directory from which the fimrware was compiled.

After uncompressing a SMAZ section from an ezcap284 firmware downloaded from the ezcap website, I inspected the uncompressed binary data. I discovered what may be debug symbols such as this: "E:/Grabber/SDK/TW/Fengyun/JEDI_9910_Fengyun/freertos/src/pal/msgq.c" .

A google search led to finding this possible source code used to build the contents of this SMAZ: https://github.com/KennyOP2/JEDI_9910_Fengyun .