Tivo vs AV Receiver for up-conversion ?

[CrashMeister]

Most pieces of new video equipment have up-conversion for video signals. So my Tivo will up-convert, my (new Onkyo SR707) AV Receiver will up-convert and I suspect my Plasma TV will up-convert. Up-conversion is a tricky business so you want to use the piece of equipment that has the best up-conversion algorithms.

The issue I am having, is that if I let the AV processor do the up-conversion, then it keeps on switching in and out depending on what the Tivo is doing (pause, FF etc.). If I let the Tivo do the up-conversion then I get a lot of judder (image shaking) in action like soccer.

Is the switching issue being handled badly by the Onkyo, or will all AV receivers act in a similar fashion with Tivo ?

Thanks,
Craig.

[aaronwt]

I've never had any problem with the picture dropping out during FF, REW etc. Only when the resolution changes and that is for 1 or two seconds.
And I run my TiVos, through an HDMI switch, then through an Algolith HDMI flea, then through an HDMI splitter, then HDMI through my DVDO edge video processor, then over HDMI to my Denon receiver before going to the TV over HDMI.

There is certainly some issue if yours is cutting out during FF, pause and REW if I have no problems when going through all those devices.

[richsadams]

And I run my TiVos, through an HDMI switch, then through an Algolith HDMI flea, then through an HDMI splitter, then HDMI through my DVDO edge video processor, then over HDMI to my Denon receiver before going to the TV over HDMI.Wow! :eek: Curious, have you ever run HDMI directly from one of your TiVo's to your TV? Just wondering how much better things look with or without all of the bits in between. TIA.

[CrashMeister]

I am going to do some more testing to separate the Audio and Video issues. It may just be an audio issue, not a video one (other than the judder, which is visual only).

I'll report back later tonight.

[CrashMeister]

Allrighty then... I was typing from memory when I posted above.

The video issue is: Whenever switching from watching a program to a Tivo generated screen (like a menu, or the show's info page), then the TV screen blanks and says 'No Signal', then a couple of seconds later, it gets the signal back and carries on. I suspect this is because the source material is changing from one format to another.

The Audio issue is the AV receiver trying to catch up with Tivo switching between 'Stereo', 'All Mono' and 'Dolby-D' depending on the source material. The AV receiver makes some clicking sounds while switching, then continues in the new mode.

In a perfect world, the AV receiver would NOT stop sending a signal to the TV while it was switching source format. The AV is set up to always send 1080p to the TV.

Any ideas on how to set these things up so that they work seamlessly ?

Thanks,
Craig.

[Mars Rocket]

Set your TiVo to output 1080i fixed and it won't blank when switching around like it does now.

[rlcarr]

Yes, but if you do what Mars Rocket says then the TiVo will be doing the upconversion. And there's an excellent chance you'll get better picture quality if you have your AV processor or the TV do the upconversion.

[MeStinkBAD]

I don't understand why people care about so called "up-converion". First of all, unless your television is a CRT model, your TV is limited to a single resolution. All incoming video signals have to be resampled to match that resolution. Another thing, up converting doesn't improve the quality of the picture. It can decrease the quality if it's being scaled sloppily. But really, it doesn't matter anymore. The quality of scaling has reached the point where you can't distinguish anymore.

Listen just use the TiVo to display at a fixed (1080i) resolution. Don't bother w/ the AV receiver. If not the TiVo then use the T.V.

[aaronwt]

Wow! :eek: Curious, have you ever run HDMI directly from one of your TiVo's to your TV? Just wondering how much better things look with or without all of the bits in between. TIA.

Yes I have and it looks worse straight to the TV, especially with the deinterlacing problems and mosquito noise and other artifacts..

[aaronwt]

I don't understand why people care about so called "up-converion". First of all, unless your television is a CRT model, your TV is limited to a single resolution. All incoming video signals have to be resampled to match that resolution. Another thing, up converting doesn't improve the quality of the picture. It can decrease the quality if it's being scaled sloppily. But really, it doesn't matter anymore. The quality of scaling has reached the point where you can't distinguish anymore.

Listen just use the TiVo to display at a fixed (1080i) resolution. Don't bother w/ the AV receiver. If not the TiVo then use the T.V.

That would depend on what scaling/deinterlacing chips are in the receiver. They are not all the same.
I can certainly see the difference between going through my DVDO EDGE or DUO compared to going straight to the TV or using the scaling/deinterlacing chip in my Denon 3808.

Now the new Denons have a different chip that does a much better job than my 3808 does. But eitehr way they do a better job than most TVs will do.

[Saturn]

Yes, but if you do what Mars Rocket says then the TiVo will be doing the upconversion. And there's an excellent chance you'll get better picture quality if you have your AV processor or the TV do the upconversion.

The S3 actually has a very respectable upconversion chip in it. I don't know about the TiVoHD or TiVoXL...

[petew]

I'm not an expert but I'd expect upconversion of MPEG2 to have the pottential to be better than upconversion of an uncompressed signal since MPEG2 P and B frames identify how a macroblock is moving. Allowing the upconverter to plot that movement based on the resolution of the upconverted video output.

However since most Display devices are Progressive scan and the Tivo can only output 1080i I can see where Broadcast 720p -> 1080i -> 1080p would cause problems due to the interlacing and de-interlacing that would need to happen. Given the need for compromise setting the Tivo to fixed 720p output might be preferable when watching 1080i material than setting the Tivo to 1080i fixed and watching 720p material, since this would result in only interlaced material being de-interlaced.

[jrm01]

Given the need for compromise setting the Tivo to fixed 720p output might be preferable when watching 1080i material than setting the Tivo to 1080i fixed and watching 720p material, since this would result in only interlaced material being de-interlaced.

This would result in 1080i > 720p > 1080p which I think would be the worst option due to downscaling followed by upscaling.

[b3ar]

The S3 actually has a very respectable upconversion chip in it. I don't know about the TiVoHD or TiVoXL...

It's been too long since I've had a S3, but I can comment on the HD. The Broadcom chip in it isn't very good -- no motion adaptive deinterlacing for HD, and the SD algorithms show combing fairly readily. The scaling "isn't bad". I would pay extra for a Tivo that used a decent VP chip (ABT2010, etc.), but I can't imagine one is on the horizon.

[petew]

This would result in 1080i > 720p > 1080p which I think would be the worst option due to downscaling followed by upscaling.

The OP was complaining about Judder when watching sport which may be due to interlacing/de-interlacing if the sports were being broadcast in 720p

[b3ar]

The OP was complaining about Judder when watching sport which may be due to interlacing/de-interlacing if the sports were being broadcast in 720p

You don't get judder going from i -> p in even multiples unless his display is using an odd refresh rate, then he would get judder all the time on just about everything (e.g., 60 Hz on a 72 Hz display). If there is tearing or horizontal banding, then this is the result of bad interlacing/deinterlacing, and it is what I was mentioning, above. The BRCM chips in the TiVo are not terribly sophisticated for display on a modern HD set. You are usually far better off having the TiVo output "native", and letting something else do the actual conversion/scaling.

The downside with this approach is that some implementations can take a significant amount of time to reestablish a "lock" on the signal. What is worse is that this can cascade down your signal chain. For example:

TiVo outputs a native signal. You are watching a program in 1080i. It ends, and then you hit "List" to check what else you have recorded. TiVo switches to 480p since it doesn't yet have an HD user interface.

Your receiver is doing the deinterlacing and scaling, so it takes a few seconds for it to re-establish sync with the inbound signal, process it appropriately and send a signal to the TV.

The TV, having lost a signal because the processing chips in the receiver don't know how to maintain a constant output signal, now has to re-establish its own sync with the receiver, even though the resolution it sees isn't really changing and it won't be required to do any processing (unless its native resolution is different than what is being sent to it from the receiver).

The above scenario probably explains 95%+ of the people who see "extended" time lag between switching formats/resolution.

Bill

[richsadams]

You don't get judder going from i -> p in even multiples unless his display is using an odd refresh rate, <snip> That was a very clear and concise explaination for us "layman". Well done and thanks! :up:

[SNJpage1]

Yep that explains why mine is doing the same thing with my onkyo 705. Tivohd is fixed at 1080 and all the hand shaking causes the delays. It even happens with the audio on mine. I get the video back before the audio. I did have an up converting DVD player but it bit the dust. The extended warrenty outfit gave me my money back instead of fixing it. I went back to a 5 yr old DVD player recorder and use the 705 to up convert. The image looks really good.