# 1080I vs 1080p?



## schatham (Mar 17, 2007)

My tv is 1080P. In settings (roamio) under 1080P it states pass through only. What does that mean? The Tivo is using 1080I at the moment and does not have this pass through only statement.


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## damondlt (Jan 5, 2014)

No network TV content is 1080p.
Your tv is 1080p, and will switch when content that is 1080p is available like PPV possibly.
1080i, and 720p are the only resolutions used by network currently.


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## schatham (Mar 17, 2007)

damondlt said:


> No network TV content is 1080p.
> Your tv is 1080p, and will switch when content that is 1080p is available like PPV possibly.
> 1080i, and 720p are the only resolutions used by network currently.


Ok, thanks. I'll just leave it on automatic settings then.


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## JoeKustra (Dec 7, 2012)

schatham said:


> Ok, thanks. I'll just leave it on automatic settings then.


You can set a Roamio to output only 1080p, something that can't be done with a Premiere or Mini. I would not do that however. I have mine set to 1080i and 1080/p24 (pass through). If you run the video test, it should find 1080/p60 even though there is no content for that format on TV. You could the deselect all formats other than 1080/p60 and that would force the 1080/p60 to be used. Don't do that. If you ask the TiVo to detect the best it should leave it at 1080i. The content from Amazon can be 1080/p24, which looks better to my eyes.

There is a difference between auto detect and test formats.


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## HarperVision (May 14, 2007)

JoeKustra said:


> You can set a Roamio to output only 1080p, something that can't be done with a Premiere or Mini. I would not do that however. *I have mine set to 1080i and 1080/p24 (pass through)*. If you run the video test, it should find 1080/p60 even though there is no content for that format on TV. You could the deselect all formats other than 1080/p60 and that would force the 1080/p60 to be used. Don't do that. If you ask the TiVo to detect the best it should leave it at 1080i. The content from Amazon can be 1080/p24, which looks better to my eyes. There is a difference between auto detect and test formats.


That isn't optimal when a progressive signal comes into the TiVo (480p, 720p) because then it will be scaled to 1080 and then interlaced (1080i), causing defects, then sent to the display and de-interlaced to 1080p, possibly causing other anomalies.

Your best bet if you have a 1080p display is to either set the Roamio to 1080p output, or set it to native and then send that signal to a video processor/scalar with its output set to 1080p.


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## JoeKustra (Dec 7, 2012)

HarperVision said:


> That isn't optimal when a progressive signal comes into the TiVo (480p, 720p) because then it will be scaled to 1080 and then interlaced (1080i), causing defects, then sent to the display and de-interlaced to 1080p, possibly causing other anomalies.
> 
> Your best bet if you have a 1080p display is to either set the Roamio to 1080p output, or set it to native and then send that signal to a video processor/scalar with its output set to 1080p.


I tried that. It must be my TV since I had a lot more audio issues when using 1080p. Video was ok though. But, you're right, I was projecting not analyzing.


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## Diana Collins (Aug 21, 2002)

Keep in mind that all flat panel TVs are progressive displays, even ones that are in TVs that only support up to 1080i inputs.

Broadcast/Cable TV is (as noted above) broadcast in 720p/60 or 1080i/60. 720p/60 gets upscaled to 1080p/60 and 1080i/60 is deinterlaced into 1080p/30.

The question is where to do the upscaling and deinterlacing. If your TV supports 1080p/60 inputs then you have the choice of letting the TV do it or letting the TiVo do it (or an external processor, but if you have such a unit, I assume you know how to use it). Let's assume you have a TV with 1080p/60 native support...

If you set the TiVo to output only 1080p then both the upscaling and deinterlacing is done by the TiVo and your TV just displays what it gets.

If you set your TiVo to output only 1080i, then the 720p/60 signal is upscaled to 1080 and interlaced (every other horizontal row of pixels from the upconverted video is discarded) by the TiVo to 1080i/60, sent to the TV, which deinterlaces it to 1080p/30. The end result is that for 720p sources, you throw away half the data.

If you set the TV to output "native" then the 720p/60 signal goes your TV in that format which then upscales it to 1080p/60 and sends it to the panel. The 1080i/60 goes to the TV too which then deinterlaces it to 1080p/30. No loss of data.

So, you should never leave the TiVo set to output only an interlaced format (1080i). At a minimum, you should enable 720p and 1080i. If you watch a lot of movies and your TV supports it, you should also enable 1080p/24 pass through. The question of turning on 1080p output or not depends on who does a better job of deinterlacing, the TV or the TiVo. Deinterlacing is not very technically challenging and most video processing chipsets do it quite well, so I personally don't think it matters. Some streaming content comes in 1080p/60 format (assuming your broadband is fast enough) so it if that is in your viewing sources, it makes sense to enable 1080p output from the TiVo.

Just remember that the trade-off on setting the TiVo to output multiple formats is that the TV then has to change resolutions. That slows down channel acquisition (and has been reported to cause HDCP errors in some set-ups).


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## Dan203 (Apr 17, 2000)

We've had this discussion before and determined that setting the Roamio to force 1080p/60 with the 1080p/24 passthrough option checked is the best solution for most people. The main reason is 720p content. Most HD is 1080i, but there are a few channels that use 720p. With 1080i it doesn't really matter if you allow the TiVo or the TV do the deinterlacing, it's still only going through one conversion step. However if you set the TiVo to 1080i then the TiVo will convert 720p content to 1080i and then your TV will convert that to 1080p. So it's going from progressive to interlaced and then back to progressive. If you set your TiVo to output 1080p then it stays progressive and is simply upsampled from 720 to 1080. The results should be a lot better. The only other way to accomplish the same thing using your TVs resizer is to enable both 1080i and 720p output, which will cause the TiVo to pass the video as-is. However that typically causes a violent flash on your TV as it switches resolutions. Whereas with the TiVo resizer it is seamless.


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## CCourtney (Mar 28, 2006)

Diana Collins said:


> Keep in mind that all flat panel TVs are progressive displays, even ones that are in TVs that only support up to 1080i inputs.
> 
> Broadcast/Cable TV is (as noted above) broadcast in 720p/60 or 1080i/60. 720p/60 gets upscaled to 1080p/60 and 1080i/60 is deinterlaced into 1080p/30.
> 
> ...


Ha, yeah my thoughts exactly. I saw this thread and was hoping I'd find links to reference material comparing the scaling and de-interlacing quality of the Roamio compared to some common sets (making me nostalgic for discussions on Faroudja chipset in DVD players - yeah I know it was 480p upscaling to 720p and 1080i...)

Anyway, looks like I'm going to have to go look over at AVSForum and see if I can't get some info as to whether my 3yr old 64" Samsung Plasma TV beats out the TiVo Roamio in the scaling and de-interlacing world. For the time being I just set it to 1080p and 1080p/24 passthrough. It seems to do a decent job for the little I've been able to enjoy it so far.


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## b-ball-fanatic (Aug 5, 2003)

Dan203 said:


> We've had this discussion before and determined that setting the Roamio to force 1080p/60 with the 1080p/24 passthrough option checked is the best solution for most people. The main reason is 720p content. Most HD is 1080i, but there are a few channels that use 720p. With 1080i it doesn't really matter if you allow the TiVo or the TV do the deinterlacing, it's still only going through one conversion step. However if you set the TiVo to 1080i then the TiVo will convert 720p content to 1080i and then your TV will convert that to 1080p. So it's going from progressive to interlaced and then back to progressive. If you set your TiVo to output 1080p then it stays progressive and is simply upsampled from 720 to 1080. The results should be a lot better. The only other way to accomplish the same thing using your TVs resizer is to enable both 1080i and 720p output, which will cause the TiVo to pass the video as-is. However that *typically causes a violent flash on your TV as it switches resolutions. Whereas with the TiVo resizer it is seamless.*


Your recommendation is what I use, and it's always worked well, for the reasons you describe. I've always wondered, though, why it is that the TiVo's resizer _always _seems to be better at this? Even really nice, high-end TVs seem to exhibit that violent flash when they have to do the processing....you'd think if TiVo can do it seamlessly, they could too.


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## Dan203 (Apr 17, 2000)

I think it's an HDMI handshake issue. I don't think there is a way for it to be seamless when the resolution coming across the HDMI suddenly changes. Whereas on TiVo it's all happening in the decoder chip, so the display receives a constant resolution stream across the HDMI.


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## b-ball-fanatic (Aug 5, 2003)

CCourtney said:


> Ha, yeah my thoughts exactly. I saw this thread and was hoping I'd find links to reference material comparing the scaling and de-interlacing quality of the Roamio compared to some common sets (making me nostalgic for discussions on Faroudja chipset in DVD players - yeah I know it was 480p upscaling to 720p and 1080i...)


I remember those days! 


> Anyway, looks like I'm going to have to go look over at AVSForum and see if I can't get some info as to whether my 3yr old 64" Samsung Plasma TV beats out the TiVo Roamio in the scaling and de-interlacing world. For the time being I just set it to 1080p and 1080p/24 passthrough. It seems to do a decent job for the little I've been able to enjoy it so far.


I understand the intent, but I think you might be making this more complicated than it needs to be. Rather than hunt down others' opinions on your Samsung vs your TiVo, just use your eyes.  In _your _house, with _your _content, with _your _equipment, you're the only one who can see what settings yield the optimal viewing experience for you.


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## b-ball-fanatic (Aug 5, 2003)

Dan203 said:


> I think it's an HDMI handshake issue. I don't think there is a way for it to be seamless when the resolution coming across the HDMI suddenly changes. Whereas on TiVo it's all happening in the decoder chip, so the display receives a constant resolution stream across the HDMI.


Okay, thanks....that makes sense. (Amazing how many issues seem to boil down to HDMI's "original sins!")


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## CCourtney (Mar 28, 2006)

b-ball-fanatic said:


> I remember those days!
> 
> I understand the intent, but I think you might be making this more complicated than it needs to be. Rather than hunt down others' opinions on your Samsung vs your TiVo, just use your eyes.  In _your _house, with _your _content, with _your _equipment, you're the only one who can see what settings yield the optimal viewing experience for you.


The thing is they both look pretty darn good from my vantage and if I wasn't a bit OCD  I probably would just sit back, relax and enjoy the show.

Since it takes time to switch and the image goes offscreen when doing it, it's hard for me to decipher the difference. I suppose I could setup my DSLR on a tripod and take some RAW images but that seems much more work than getting others existing analysis.


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## b-ball-fanatic (Aug 5, 2003)

If they're that close, I'd go with the one that's least disruptive. That is, if leaving it to the Samsung yields any of that channal-surf flashing, let the TiVo do it. Just my 1.5 cents...


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## CCourtney (Mar 28, 2006)

b-ball-fanatic said:


> If they're that close, I'd go with the one that's least disruptive. That is, if leaving it to the Samsung yields any of that channal-surf flashing, let the TiVo do it. Just my 1.5 cents...


Never noticed any Channel Surfing flashing on the Samsung w/ the TiVoHD which I've had the Samsung as the upscalar on it. I wouldn't expect it (but haven't looked for it either) when having the Roamio pass through native.


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## Dan203 (Apr 17, 2000)

Try changing the channel to ABC or ESPN they both use 720p and would cause the flash on your TV if coming from a 1080i channel. (I have yet to see a TV that doesn't flash in some way)


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## HarperVision (May 14, 2007)

CCourtney said:


> Ha, yeah my thoughts exactly. I saw this thread and was hoping I'd find links to reference material comparing the scaling and de-interlacing quality of the Roamio compared to some common sets (making me nostalgic for discussions on Faroudja chipset in DVD players - yeah I know it was 480p upscaling to 720p and 1080i...) Anyway, looks like I'm going to have to go look over at AVSForum and see if I can't get some info as to whether my 3yr old 64" Samsung Plasma TV beats out the TiVo Roamio in the scaling and de-interlacing world. For the time being I just set it to 1080p and 1080p/24 passthrough. It seems to do a decent job for the little I've been able to enjoy it so far.


Faroudja sucks! TAW Rock+ all the way baby!!!


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## schatham (Mar 17, 2007)

Dan203 said:


> We've had this discussion before and determined that setting the Roamio to force 1080p/60 with the 1080p/24 passthrough option checked is the best solution for most people. The main reason is 720p content. Most HD is 1080i, but there are a few channels that use 720p. With 1080i it doesn't really matter if you allow the TiVo or the TV do the deinterlacing, it's still only going through one conversion step. However if you set the TiVo to 1080i then the TiVo will convert 720p content to 1080i and then your TV will convert that to 1080p. So it's going from progressive to interlaced and then back to progressive. If you set your TiVo to output 1080p then it stays progressive and is simply upsampled from 720 to 1080. The results should be a lot better. The only other way to accomplish the same thing using your TVs resizer is to enable both 1080i and 720p output, which will cause the TiVo to pass the video as-is. However that typically causes a violent flash on your TV as it switches resolutions. Whereas with the TiVo resizer it is seamless.


To simplify this for me, I should check 1080p and 1080p pass through in the settings only, correct. I am using a mini with a 1080p tv also. Does the mini piggyback these settings or have their own? If their own what would be best, the same setting? Thanks.


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## JoeKustra (Dec 7, 2012)

schatham said:


> To simplify this for me, I should check 1080p and 1080p pass through in the settings only, correct. I am using a mini with a 1080p tv also. Does the mini piggyback these settings or have their own? If their own what would be best, the same setting? Thanks.


Series 1 Mini doesn't have 1080/p60. I leave mine at 1080i and have no problems. It also has the same 1080/p24 pass through. If 1080p/60 on the Roamio works for you, by all means leave it there.


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## Dan203 (Apr 17, 2000)

schatham said:


> To simplify this for me, I should check 1080p and 1080p pass through in the settings only, correct. I am using a mini with a 1080p tv also. Does the mini piggyback these settings or have their own? If their own what would be best, the same setting? Thanks.


Yes

The Mini has it's own settings and does not have a 1080p/60 option. So for the Mini you have to decide if you want to deal with resolution switch flash or the quality loss from either setting it to 1080i or 720p only.


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## schatham (Mar 17, 2007)

JoeKustra said:


> Series 1 Mini doesn't have 1080/p60. I leave mine at 1080i and have no problems. It also has the same 1080/p24 pass through. If 1080p/60 on the Roamio works for you, by all means leave it there.


I decided to go with 1080p on Roamio and 720p on the mini. Both also set with 1080p pass through. Seems some experts feel 720p is better than 1080i because of the splitting of the signal, so for fast motion it should be better.


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## aaronwt (Jan 31, 2002)

CCourtney said:


> The thing is they both look pretty darn good from my vantage and if I wasn't a bit OCD  I probably would just sit back, relax and enjoy the show.
> 
> Since it takes time to switch and the image goes offscreen when doing it, it's hard for me to decipher the difference. I suppose I could setup my DSLR on a tripod and take some RAW images but that seems much more work than getting others existing analysis.


If they both look the same then just set it for 1080P output. That is how my Roamios are set. I only use 1080P60 output with them. (1080i on the Minis since the vast majority of channels use 1080i) EVen though I use an external video scaler/processor, I let the TiVo only output 1080P60 to avoid the HDMI resync issues. It is only broadcast sources/streaming and they can only look so good with the bitrates that broadcast/streaming apps uses. They will never look anywhere close to Blu-ray Disc quality.


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## lessd (Jan 23, 2005)

aaronwt said:


> If they both look the same then just set it for 1080P output. That is how my Roamios are set. I only use 1080P60 output with them. (1080i on the Minis since the vast majority of channels use 1080i) EVen though I use an external video scaler/processor, I let the TiVo only output 1080P60 to avoid the HDMI resync issues. It is only broadcast sources/streaming and they can only look so good with the bitrates that broadcast/streaming apps uses. They will never look anywhere close to Blu-ray Disc quality.


I guess I am missing something as my Roamio has only 1080P pass through, how/where did you find a setting for 1080P60 ?. My Mini also has the same video outputs as the Roamio.


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## JoeKustra (Dec 7, 2012)

lessd said:


> I guess I am missing something as my Roamio has only 1080P pass through, how/where did you find a setting for 1080P60 ?. My Mini also has the same video outputs as the Roamio.


Try running the Test Formats operation.


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## schatham (Mar 17, 2007)

lessd said:


> I guess I am missing something as my Roamio has only 1080P pass through, how/where did you find a setting for 1080P60 ?. My Mini also has the same video outputs as the Roamio.


Is your tv 1080p?


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## aaronwt (Jan 31, 2002)

lessd said:


> I guess I am missing something as my Roamio has only 1080P pass through, how/where did you find a setting for 1080P60 ?. My Mini also has the same video outputs as the Roamio.


The bottom two options for video output from my Roamio Pro and Roamio Basic are:

1080P(60 fps)
1080p(pass-thru only)

I just have 1080P(60 fps) selected for both of them. I've used this setting with the eight or nine TVs I've had them connected to.


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## lessd (Jan 23, 2005)

schatham said:


> Is your tv 1080p?


My HDTV is a top end 80" Sharp from 2013, it sure has 1080P, I will have to test out my Roamio Plus as I don't remember anything but 1080P pass through.

Thanks for the information.

I guess I have not looked or I did not remember but 1080p60 is an Roamio video option and was checked for my HDTV, sorry.


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## CCourtney (Mar 28, 2006)

Not sure if this is known or not, this is my first new TiVo since the TiVoHD boxes. But you can force switch between then checked resolutions using the up arrow on the box (at least the 1080i / 1080p settings.) 

This is actually a reasonably quick change. I'm still having a problem telling the difference at seated distances, but I think I'll cut the distance in half and do another test this week and go from there.


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