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Discussion Starter · #1 ·
Hi-
I've got a 4 year old LG STB and a 1 week old TivoHD. I recorded (OTA) the football game last night on both and the Tivo seemed to have worse picture quatlity on my 100" screen. Still pictures looked the same. However, when panning, when there was a lot of fast action, or when the station used its animated logo after a replay, the picture quality went down hill. What I was seeing I can only describe as a digital look. I was seeing pixilation and a lack of detail.

The LG STB would also look worse during the same scenes, but it did not look as bad as the Tivo. In the TivoHD's favor, the LG reacts much worse to what I call digital hiccups. The hiccups result from the momentary loss of signal, and the LG STB seems to get one or two of them an hour. When this happens, the LG STB freaks out - pausing, then showing a broken up picture, then recovering. The Tivo showed the same sequence without any indication of a loss of signal.

So, has anybody compared the picture quality of the TivoHD to the original Series 3? I'll get the original Series 3 in a heart beat if has better PQ. The PQ of the TivoHD is almost enough for me to consider returning it. The TivoHd does so many other things so well, that I'd hate to give it up.
 

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Discussion Starter · #2 ·
Note:
I also recorded the game on my computer and a lot of the problems that I mention above are in the transport stream. In fact it is rather shocking how bad the broadcast looks. Rather than blame the TivoHD poor PQ, perhaps I should be praising it for letting me see exactly what is being broadcast.

It is possible that the reason the LG looks better is that it does more video processing than the TivoHD.
 

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If you are talking about a digital OTA recording, then there is no difference between the S3 and THD. In this case, no conversion is taking place, but it is displaying the actual content as it was recorded. In this regard there is no difference between the two. The only time there could be a difference is for analog recordings. However, I haven't seen any reports that the THD has a worse encoder than the S3.
 

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Did you use the same output type? And do you have both boxes set to output the same resolution? Obviously if the LG is set to output 1080i and the Tivo is set to output 720p, the results will not be comparable. Similarly, if one box is using component and the other is using HDMI, the results will not be comparable.

NBC uses 1080i for its broadcasts, so if either box was set to native, hybrid, hybrid 1080i, or fixed 1080i, and you were using HDMI, then you should not see any difference. If you use component or have either box set to 720p, then that would involve extra processing.

Output of the TivoHD and Series3 is identical when using the same resolution and the same connection.
 

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rainwater said:
If you are talking about a digital OTA recording, then there is no difference between the S3 and THD. In this case, no conversion is taking place, but it is displaying the actual content as it was recorded. In this regard there is no difference between the two. The only time there could be a difference is for analog recordings. ....
I am not certain that's necessarily the case.

do both boxes have the same scaler? If the content was scaled at all that could make a difference (eg watching 1080i content from CBS or NBC on a fixed pixel display.)

Also- I think there's threads about some weirdness going on with SA cablecards messing up the THD picture but there's a software fix- not sure if it just effected cable content or everything.

And last bit- i could be wrong but sometimes the tuner can make a difference- no? In years past there have been weird situations where like a particular channel was messup up under certain hardware builds on certain S2 hardware. (granted that was all analog but if the tuner messed up the digital signal you could get breakups more i guess...)
 

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bkdtv said:
...

Output of the TivoHD and Series3 is identical when using the same resolution and the same connection.
they have the same scaler chips? (I honestly havne't been paying attention)

otherwise as above- that may not be true.
 

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MichaelK said:
they have the same scaler chips? (I honestly havne't been paying attention)

otherwise as above- that may not be true.
The TivoHD uses Broadcom's newest decoder chip which replaced the parts used in the Tivo Series3.

The TivoHD (as of v8.1.7b2) software currently uses the Linux driver for the decoder in the Series3. Apparently the Broadcom driver for the new chip is not mature enough for use, so Tivo is using the old one.

Since both the TivoHD and Series3 currently use the same driver for decoding and scaling, and presumably the same algorithms defined by that driver, output should be the same. That was also my impression in viewing, although I did not compare using test patterns.
 

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The S3 and the TiVoHD definitely have a different output for recordings from analog channels. All my boxes are set to best quality for recordings from analog channels. I run a Series 3 and a TiVoHD through an HDMI Flea. I had to drastically change the settings on the Flea to get a picture close to the picture from the Series 3. And still the TiVoHD has less detail. This is the third TiVoHD I've had connected to the Flea and they all have looked the same.
I did get a second TiVoHD yesterday to use on a 37" 1080P Westinghouse. I also have a Series 3 connected to it and you can also see a difference with that. At least on the little bit of programming I saw this morning it was different between both boxes.
 

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Discussion Starter · #9 ·
aaronwt said:
The S3 and the TiVoHD definitely have a different output for recordings from analog channels. All my boxes are set to best quality for recordings from analog channels. I run a Series 3 and a TiVoHD through an HDMI Flea. I had to drastically change the settings on the Flea to get a picture close to the picture from the Series 3. And still the TiVoHD has less detail. This is the third TiVoHD I've had connected to the Flea and they all have looked the same.
I did get a second TiVoHD yesterday to use on a 37" 1080P Westinghouse. I also have a Series 3 connected to it and you can also see a difference with that. At least on the little bit of programming I saw this morning it was different between both boxes.
So, you're saying that the Series 3 has more detail? Will the Flea help remove a lot of the blocks and other junk that gets put in the broadcast because of the low bit rate? I really think that is the cause of most of my problem.
 

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Discussion Starter · #10 ·
After carefully checking my three methods of recording (THD, LG LST-3401a, and my computer), I've decided that they are almost all exactly the same. The PQ advantage I thought I saw in the LG 3410a was because I'd not looked at the exact same sequence. This time I went to bad sections I found on the computer recording and checked them on the other two sources. These sections appear to be identical. Then I went to the crisp sections of the broadcast (like the guys talking in the booth at the start of the game), and all three appear to be identical.

So, I have to rethink my first post and say that the TivoHD is doing as good a job of recording as can be expected. It could do a little better (as could my other methods of recording), but the quality of the broadcast is pretty low. I'd be a lot happier if the networks would do a better job of broadcasting sports events.
 

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Hyrax said:
So, you're saying that the Series 3 has more detail? Will the Flea help remove a lot of the blocks and other junk that gets put in the broadcast because of the low bit rate? I really think that is the cause of most of my problem.
He's talking about analog channels.

The Tivo Series3 and TivoHD do use completely different MPEG-2 encoder hardware (and drivers) for analog channels, so differences there are not unexpected.

This doesn't have any effect on digital channels. Both boxes record the same digital stream from cable and OTA. Both use the same driver to decode those digital channels.
 

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Discussion Starter · #12 ·
Thanks, bk. I was just checking to make sure :)

I am really surprised at how bad the football game looked on a big screen. I don't remember them looking this bad when I first started recording off the air four years ago. I'm going to complain to my local station, but I'm pretty sure it will be a wasted effort.
 

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MichaelK said:
do both boxes have the same scaler? If the content was scaled at all that could make a difference (eg watching 1080i content from CBS or NBC on a fixed pixel display.)
If the content is 1080i and the TiVo is set to output it at 1080i, it doesn't do any scaling. The TV does the scaling.
 

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Hyrax,
The issue might just be NBC's presentation. I receive our NBC station in HD from Comcast cable, but during the season last year, I viewed Sunday Night NFL from NBC in HD from a couple of different cable sources as well as via OTA at a friend's house in Pittsburgh. In each case (including from my house Thursday night), the picture quality was very poor compared to what I am used to from CBS, ESPN, and even Fox. The picture tends to be much, much softer; it tends to "lose focus" for lack of a better term; and it tends to have artifacting more frequently than what I have seen while watching football from other providers.

This might be what's causing the issues you observed.
 

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Hyrax,

What is the average bitrate on your NBC HD broadcast? Anything much less than 16Mbps will not yield a satisfactory picture on live high-definition 1080i video (like sports).

If your broadcast is less than 16Mbps, I would complain to the engineering department of that affiliate.
 

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Discussion Starter · #16 ·
bkdtv said:
Hyrax,

What is the average bitrate on your NBC HD broadcast? Anything much less than 16Mbps will not yield a satisfactory picture on live high-definition 1080i video (like sports).
If your broadcast is less than 16Mbps, I would complain to the engineering department of that affiliate.
Thanks. The bitrate is 14.56Mbps. You're right, I should complain. I will give them a call now...
 

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bkdtv said:
Hyrax,

What is the average bitrate on your NBC HD broadcast? Anything much less than 16Mbps will not yield a satisfactory picture on live high-definition 1080i video (like sports).

If your broadcast is less than 16Mbps, I would complain to the engineering department of that affiliate.
Does the TiVoHD tell you the average bit rate of a recording? If so, that's a pretty cool feature. If not, how does one find out?
 

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Discussion Starter · #18 ·
mike_camden said:
Hyrax,
The issue might just be NBC's presentation. ... The picture tends to be much, much softer; it tends to "lose focus" for lack of a better term; and it tends to have artifacting more frequently than what I have seen while watching football from other providers.

This might be what's causing the issues you observed.
That is exactly what I observed. I swear that things looked a lot better 4 years ago when I started recording HD football games.
 

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Hyrax said:
That is exactly what I observed. I swear that things looked a lot better 4 years ago when I started recording HD football games.
4 years ago NBC didn't have the NFL package. I've noticed that their HD is less than perfect on their other programming, too. For some reason, Leno and Conan and SNL look good, but their series, like Studio 60, and their sports, not so much.

Anyone have Comcast SportsNet HD in Philly? I notice, when watching Phillies games, that every time they switch from a replay to the live picture, with the whooshing graphic, the live picture is out of focus for about 2-4 seconds. Really distracting.
 

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aindik said:
Does the TiVoHD tell you the average bit rate of a recording? If so, that's a pretty cool feature. If not, how does one find out?
It gives you the size in bytes (in the extended Info), and the running time. From those, you can derive the bitrate.

Hyrax said:
I swear that things looked a lot better 4 years ago when I started recording HD football games.
It could be that your station has added subchannels, taking away bandwidth from the main channel. But I think the most likely explanation is that you're just more used to HD than you were four years ago, and hence, less easily impressed. :)
 
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