Just got my Tablo 4-tuner a few days ago and so far I (mostly) love it. But one thing that is bothering me and I haven’t seen anyone else mention is that the picture quality is quite poor on 1080i channels when there is motion. I believe what I am seeing is interlacing artifacts or “combing” as a result of poor conversion from 1080i to 1080p. I have my Tablo set to record in 1080, my roku is set to 1080, and my TV is showing it is taking a 1080p signal from the Roku.
This. It’s actually one of the first things I noticed about the picture quality.
Same thing here. I got mine set up over the weekend, and actually watched some NASCAR (Gasp!) to see how it handled motion. I was a bit disappointed. It got me thinking about running some coax straight to the tv for watching similar events.
(No offense to NASCAR fans. I really did like that road course.)
Interesting… i wonder if it has anything to do with that Rokku 2XS.
@PiX64 the downstairs Roku is a 3, so I need to get it connected and have a look.
2. Tablo is connected to a gigabit router via ethernet, and to two Roku 3 devices via wifi at 5ghz. The router is about 20 feet from the primary Roku.
Most video looks very good through the Tablo, just not fast motion, especially horizontally, and especially light/white colors. For me, this is kind of a “streaking” in the image, I think it’s the same thing in @Pundit’s pic, but it’s hard to tell without motion. I also experienced some “stuttering” in the video feed. It was very minor, I would say it jumped ahead a fraction of a second, but did so regularly.
On another note, just today I found that my guide data was missing for all but two local channels. I re-scanned for channels, but that had no effect on the guide. Is there a way to force a reset/update of guide data?
Ah, “combing”, I was not familiar with that term. I just looked up some examples online, and I’m pretty sure that’s what I was experiencing. I need to get some viewing in today to see if it’s still happening though.
I noticed this issue as well…but only when I set the tablo to 1080p recording. I toyed with 1080p the first night I had it, and had it record a show. It was a 1080i channel, and it indeed looked pretty poor with some pretty bad combing and what appeared to be some dropped frames. I had already changed the Tablo to 720p before I noticed this (due to bandwidth issues to one of my Rokus), and haven’t noticed any combing since then. Perhaps the deinterlacing needs a fix.
Any chance you can try that same test with the roku 3 wired? Id bet the choppy and blocking goes away.
This effect is DEFINITELY due to poor/nonexistent deinterlacing of 1080i signals. If you do a google search for “combing artifacts” you’ll come up with tons of examples that look just like what I see. I have a Roku 3, so this has nothing to do with the version of Roku. If going to 720p solves this problem, I’d just assume do that, but its unfortunate that we can’t get the best quality possible.
I have the same thing. I will need to check the upstairs tv, but I was recording 1080, ran wireless to Roku 3 (forgot it has 1080 or 720 so not sure its setting). Tablo is ethernet to my network…
@napercort can you try the same thing? connect roku 3 to network via wire and see if the issue still exists?
@Auream - google searching will also reveal that just because 1080i is a higher number and pixel depth doesn’t mean necessarily that its a BETTER quality than 720P. you also have to factor in the progressive scanning technology vs interlacing… only reason i bring that up is that one could argue 720P IS a better pic quality than 1080i…
@PiX64 Sorry, The one isn’t via wire while the second is.
@PiX64, that is not correct in this context. If the original signal is 1080i, then you will preserve better quality by leaving the recording at 1080i than if you downsample to 720. Anything that says otherwise is referring to the original signal being either 1080i or 720p, in which case there are arguments for each. But once you already have one type of signal or the other, you’re better off quality-wise leaving it in the original resolution.
Also this has nothing to do with wired vs wireless. Its impossible for the signal being wireless to cause this issue.
For what it’s worth, the TV set post-processing can come into play as well. Don’t overlook these settings when troubleshooting.