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HDMI cord affecting 24 frames per second

post #1 of 7
Thread Starter 
I habe an Integra 70.1 reciever for my dedicated HT. I purchased top notch HDMI cords and NEVER had an issue. I just too my reciever to my brother's house (He's almost done his build ) to show his old reciever that doesn't process TRUE HD audio and the HUGE difference it makes. Everything going great and he was blown away by the audio, BUT we notice that even with my reciever's video output set to "through" it would only output to 1080p/60 frames per and NOT 1080p/24 per second. We check all connections, settings on the player and everyting indicates it should out put 24 frame per second from the reciever. The only other thing is his HDMI cord going from the reciever to the projector is a sub par cable....could that cable be the issue? the cable worked fine going from the player to the projector. I'm confused and frustraed.

-Alan:mad:
post #2 of 7
I would not worry about it.
post #3 of 7
It's not the cable. The HDMI cable does not know anything and it does not control the frame rate or resolution of the signal. If you are getting 1080p/60 then the HDMI chipset in the source is what is signaling the player to send at 1080p/60. It could be because the display is indicating that it doesn't understand 1080p/24.

I'd check the TV specs first and if it can handle 1080p/24 over HDMI, then I'd check the TV owner's manual and if that didn't work I'd check the "owner's only" forum in AVSForum for that model of TV. I would not check the HDMI cable since it just stands of copper and insulator with two connectors on each end. Bad cable results in no picture or a picture with defects, not a different resolution or frame rate.
post #4 of 7
forgive me Andy... but I was wondering about the "cable does know anything"..... that's true but it is part of the whole system. The reason I ask / question this is I think (no I haven't read any spec) that there is a "degree of negotiation" that goes on besides the "my sink can receive this, my source can send this"... because even though they both may indeed have compatible choices of res, I think I have seen where the system choose a lower res as a result of some "condition" during that "negotiation".... possibly inadequate "bandwidth" between the two points (ie. send / receive circuitry, AND cable). Is this a "true" understanding? This comes from a system that does things one way with a mechanical switch and then another way without.... so the changes are basically "physical" and not part of either sink or source capabilities.
post #5 of 7
I really said the cable does not know anything.

Your understanding is true. By the cable not knowing anything, what I meant was that if you put the worst HDMI cable in the loop, the sources will still trying to get the EDID handshake to find out what resolutions they can send. That and the HDCP handshake are the two handshaking items. So, even with this worst cable, the system will still try to send his information for the highest resolution the sink can handle. Assuming that EDID is received, then the source will send that highest resolution even if the cable is bad.

For instance, if you leave Deep Color enabled on a PS3, you can see the handshake fall apart with a cheaper cable and you get no signal. The funny thing there is that after a while you sometimes do get a signal. Does the PS3 timeout and try without Deep Color? Or does it just try again and it just happens to hit a window with no bit errors? Obviously that isn't resolution-related but it shows some of the HDMI "witchcraft" that is difficult to understand.

Fortunately or unfortunately, the HDMI system has no ability to "try" different resolutions to see if a lower resolution will work better. I suspect (but don't know) that this is the result of HDCP protection. If I keep trying different ways to send the signal, I might give away part of the key or I might make it easier to listen-in on the data.

So, that's what I meant by the cable doesn't really influence the source signal.

Your mechanical switch is an interesting situation. Is there any chance the mechanical switch can change the EDID? If it is a pure mechanical switch then the answer is no. In something like a receiver, the EDID is modified to change the sink's characteristics. So, I don't have a good answer for you with the mechanical switch. Maybe Colm or one of our other folks can pick-up where my knowledge has fallen-off?

One possbility I just thought of is that the sources are seeing a different sink with the switch included than without since the electrical characterists have changed. But, that would require the EDID to have been truncated or modified and I still don't have a good mechanism for that to happen.
Edited by alk3997 - 12/31/12 at 7:37am
post #6 of 7
thanks for the extra info. My mechanical switch is indeed purely mechanical.... had to even "oil" it to get the "mult-switch/gang" to slide (push button). Your conjecture about the hdcp may be in the ball park as the situation was a up converting dvd (philips) to a samsung dlp tv. Without the switch, the player and tv were quite happy to play at full upconversion but with the switch and associated extra cable, a lower resolution was "resolved" if I recall (I don't have that setup any more).... the player was set on "auto" for resolution so maybe its function has a bit more to it... and probably not really directly related to hdmi. Anyways, I thought perhaps there was some "negotiation" going on much like VGA type connections.
post #7 of 7
Is it safe to assume your brothers Projector is ‘old’ too – same vintage as the AVR?

If yes then chances are the Projector doesn’t support 1080p at 24fps and that is what is stopping you sending 1080p24 from the Source – direct to the PJ or via your AVR/Processor.

Probably best to let folk know which Projector you are working with.

Joe
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