HDMI DAC - HDCP, licences...?

[NeoY2k]

What would be good would be to find a small HDMI manufacturer to do it for you: the pinout etc is free, so you can make the board, but you ask them to program the chip -and you pay for it. If you propose an interesting price, they may be tempted - it would only take them 5 minutes to do it, and say, getting 150$ for 5 minutes of extra work is always welcome! It should probably be legal. (what wouldn't be, would be to batch copy the EEPROM... Thinking of an idea?).

[derwhalfisch]

Originally Posted by satgeek

It was hacked a while a ago.

That is incredible. I almost wet myself :3 I have no money to buy one tho!

[withnail]

Originally Posted by derwhalfisch

That is incredible. I almost wet myself :3 I have no money to buy one tho!

Thing is, it's SPDIF out, not I2S, which means the hack needs hacking really, plus it's waaay overpriced! Still, shows how easy it is

[rfbrw]

Originally Posted by NeoY2k

What would be good would be to find a small HDMI manufacturer to do it for you: the pinout etc is free, so you can make the board, but you ask them to program the chip -and you pay for it. If you propose an interesting price, they may be tempted - it would only take them 5 minutes to do it, and say, getting 150$ for 5 minutes of extra work is always welcome! It should probably be legal. (what wouldn't be, would be to batch copy the EEPROM... Thinking of an idea?).

Why waste time and effort trying to defeat HDCP ? Whatever widget you come up with will have to go into an enclosure of some sort so it might as well be a playback device with added digital outputs in parallel with onboard dacs.

[rfbrw]

Originally Posted by withnail

Thing is, it's SPDIF out, not I2S

For some, the prospect of 13 wires dangling out of the back holds little appeal.

[withnail]

Originally Posted by rfbrw

For some, the prospect of 13 wires dangling out of the back holds little appeal.

Yes, but I think also very few people have an amp with 4 simultaneous SPDIF inputs! It isn't much use as it is, plus SPDIF is awful!

[withnail]

Originally Posted by NeoY2k

What would be good would be to find a small HDMI manufacturer to do it for you: the pinout etc is free, so you can make the board, but you ask them to program the chip -and you pay for it. If you propose an interesting price, they may be tempted - it would only take them 5 minutes to do it, and say, getting 150$ for 5 minutes of extra work is always welcome! It should probably be legal. (what wouldn't be, would be to batch copy the EEPROM... Thinking of an idea?).

I daresay the ICs are designed so as to make it impossible to read the EEPROM. I mean, since HDCP can apparently be cracked with just 39 keys, anyone with 39 friends would have unlocked it ages ago. I imagine it's a case of write/erase only.
Hovever, it is academic to remember that unless you're mixing inputs, only one receiver is ever needed. This can apparently be bought for not too much.

It seems ridiculous that HDMI is so expensive - there is no function to the cost, other than to force out people like us, it costs nothing to maintain the database, and if it's for security reasons they really are stupid.
I mean, HDMI is superior to the only alternative, SPDIF, incomparably. It is long overdue in the audio sector. Why big business feels they must keep it to themselves is perhaps just something for the socialists to ponder.

[rfbrw]

Originally Posted by withnail

Yes, but I think also very few people have an amp with 4 simultaneous SPDIF inputs! It isn't much use as it is,

And fewer still have inputs for 13 dangling wires though most would probably send the outputs to a surround sound processor and the better ones have more than enough digital I/O.

[withnail]

Originally Posted by rfbrw

And fewer still have inputs for 13 dangling wires though most would probably send the outputs to a surround sound processor and the better ones have more than enough digital I/O.

I think you're overlooking the fact that this hack must be aimed at the DIY community. I am not aware of any commercial amps that can take 4xSPDIF inputs, and for the average consumer, s/he wants either analogue out or s/he'll buy an HDMI receiver. Even if I'm wrong, SPDIF introduces significant error to the signal, and will anyway still have to be decoded separately. Even for the weirdo with the 4xSPDIF amp, s/he still has to worry about quality at that stage. I2S of course is useless unless you shove it right back into another circuit board, but like I said, show me the unhappy consumer with the 4xSPDIF amp and I'll show you a lot more interested in modding DACs (here on this forum!).
Anyway, it doesn't matter - no need for us to argue! I personally think the hack is much too pricey to be much use to anyone anyway.
I'll let folk know how i get on when i get round to modding my own

[rfbrw]

This 4ch amp thing is a red herring. It is about access to uncompressed multichannel audio and something better than a two channel mix-down. Once it is unfettered and in a practical format you can do what you want with it. As for SPDIF introducing significant error, that is just plain cobblers.