Screen Format Override

Currently, the Tablo DVRs utilize the metadata sent from the broadcaster to set the screen format (4:3 or 16:9). Recently, one of the channels I watch a lot switched RF channels (it actually went to a new broadcast tower), and the metadata indicates that it is 4:3, however, the shows are in 16:9 format.

On all of my TVs, regardless of their age, there is a setting that allows to set it manually (4:3, 16:9, stretch, fill, auto). The Tablo does not have this, and because of the incorrect metadata (which the “broadcasters” claim to have not changed it), the channel isn’t watchable on the screen.

So, the “fix” was to change the way I view TV. I purchased a distribution amplifier, and ran coax to all of my TVs, and receive the channels in a viewable format. Now, unless there is a program I recorded that I want to watch, the Tablo sits idle. For 3 years, I have used Tablo as my primary source for streaming TV.

How difficult is it to have a format override selection for the Tablo to allow for manual selection for one channel, or all channels to a specific format?

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I think when I had that problem in the past, I manually set the TV to “wide” when on that channel on the Tablo, and it turned the compressed screen into normal. But after awhile the broadcast channel changed something and it didn’t happen anymore, so I didn’t have to do that anymore.

Even with the TV set to 16:9, this is what happens - it is only one channel…but on a 60" TV - the borders are 9" for the one channel, and 3" for the other - both are SD channels.

You sure it doesn’t just take what it gets? I get MeTV, my TV says it’s 16:9. Of course no classic show is. Some are broadcast in original unedited 4:3. Star Trek for example. Others are completely edited and broadcast to fill the display 16:6. While other are in, what I’ve learned to be 14:9 with black side bars.

It could be not all programming is properly modified before leaving the network, being sent to the broadcaster. Or it is just flubbed up before it gets to your tablo.

Your TV settings if for personal preference to compensate for something else, it’s not that your TV reformat it and you have to re-adjust it. (suggesting your tablo modifies it and it won’t let you re-adjust it)

[ it’s not referenced - https://en.wikipedia.org/wiki/MeTV, about MeTV format changes in the National expansion section]

There is metadata that is sent, and although the original program was formatted in 4:3 for broadcast, it is expanded. In the case of H&I, the original broadcast is in 16:9 (old SD programs are in the 4:3 format still, even though it said 16:9). Somewhere, the meta data is mixed up (between the Llano KVBO station (originator), KXAN and KEYE (the broadcasting companies in Austin that rebroadcast the signal), and a 4:3 picture is “double compressed” (normally, a SD program has about a 3"-4" side bar on my 60" TV, and now, on the tablo it has a 9" side bar, and everything is “super skinny”).

Even changing the format of the TV to 16:9 doesn’t fix the Tablo format. However, overriding the standard broadcast signal to 16:9 makes it a normal 4:3 viewing of the program.

Tablo sends the signal to my computer, tablet, phone, roku, firetv, etc., and it doesn’t allow for changing the format.

It would be nice to see Tablo allow for the override, just as every TV I have allows for it.

I realize you do know what you’re talking about over all… this is semantics - SD, Standard-definition television, is digital TV and part of ATSC standards which allows 480 to be 4:3 x 16:9

Isn’t meta data mostly informational? If tablo transcodes the raw video stream, regardless of what it’s told about it… it has raw data and takes the raw H.264/MPEG-4 data and, as determined by it’s settings, transcodes it at whatever rate not modifying it.

As for playback, that’s a “feature” of your player to set the dimension or aspect of the output, isn’t it?

But yea, if the stations are screwing things up - it’ll be a hard fix to convenience an engineer they have their equipment set wrong.

All the “meta data” my TV gets says all my 480i channels are 16:9. It never fluctuates with programming, the programs my change, the actual broadcast stays constant. Some have modern shows, some have old shows, some have bars while others have tops of heads cut off. Still the information the TV is getting says 16:9.
(and yes, if I take a 4:3, inside of a 16:9 and change the TV to 4:3 it is “double compressed”)

The METV screenshot looks ok to me. I believe they slightly enlarge the SD picture for broadcast so the bars on the sides are smaller. I agree the other screen still looks distorted.

The MeTV screen shot was for comparison - this is what it should look like.

The H&I screenshot is 3X the amount of sidebars as compared to MeTV…

Aren’t 720p and 1080I always considered high definition digital and transferred as 16:9. And isn’t 480i just digital and the broadcaster can transmit it as either 4:3 or 16:9.

If it’s 16:9 the broadcaster could have applied the picture stretch into the actual broadcast. Or they could have taken a true 4:3 show and applied letterbox, or pillarbox, or windowbox before it’s broadcast as 16:9.

And I doubt very few tablo users have the recording quality set to 480I. So tablo is transcoding the 480I into high definition.

So do you think that H&I, which switched broadcasters, is now transmitting as 16:9 with broadcaster applied pillarbox?

The previous channel was 480i with a 16:9 picture (it had the sidebars for original 4:3 content), but the screen took up the fill screen (you could see the H&I logo split between the picture & the sidebar), with commercials taking up 100% of the screen. When they had HD content, it was transmitted at 480i and 16:9 (full screen).

Now, someone, somewhere is compressing it 4:3, and the Tablo sees the metadata that is 4:3, so it displays it as 4:3 (shrinking the picture even further giving 9" sidebars. If I watch on normal TV screens, it shows 4:3 (with 4" sidebars), but if I tell the TV it is 16:9, it shows as it normally would.

So, if Tablo had the option like the TV did to override the metadata, it would show properly. The ultimate fix is for the TV station to fix the metadata.

So it’s not determined by the source?

If a network showing a classic original NTSC program, broadcasting at 720p, resizing it to 16:9 - would it become high definition digital show?

If a sub-network is showing a re-run of a modern, original HD 16:9 program, broadcasting at 480i they can optionally transmit it at 4:3? and then blame tablo for not having settings to compensate for it?

Of course most televisions have controls to control how the screen appears (aspect ratio) regardless of how it’s broadcast. On my TV these only work via the remote for channels broadcast in 480I. There are internal screen control options affecting the screen but I choose to keep my sanity and not play around with them.

ATSC includes two primary high definition video formats, 1080i and 720p. It also includes standard-definition formats, although initially only HDTV services were launched in the digital format.

The ATSC system supports a number of different display resolutions, aspect ratios, and frame rates. The formats are listed here by resolution, form of scanning (progressive or interlaced), and number of frames (or fields) per second (see also the TV resolution overview at the end of this article).

This sounds like something to open a support ticket directly with Tablo. They can look at your logs and might reach out to the broadcaster to get it fixed.

They’ve done it in the past for other issues like video being flipped upside down, etc.

This is not to say it won’t take months to get fixed.

Hi Ronintexas, Tablo team, and All,

I’m of a mind that the root cause of these “extra squeezed” situations is indeed the Aspect Ratio, AFD, or other metadata setting at the TV station, and likely can’t be overcome just on one’s Tablo.

But I’m in need of a succinct way to explain this when contacting my local stations. Perhaps someone with broadcast TV experience, or at Tablo, can draft the thoughts to convey.

With fear of boring you all, here’s my situation:

My wife enjoys occasionally watching According to Jim, which is running on LAFF.

We’re fortunate enough that our location in Western Michigan allows us to receive both WOOD TV 8 (broadcasting on RF7), with LAFF on 8-3; and WWTV 9 (RF9), with LAFF on 9-4.

WOOD TV 8 has 3 total streams, so the picture looks better than from within WWTV 9’s 6 total streams (as they bit-starve the diginets in favor of 1080i CBS on 9-1 and 720p FOX on 9-2).

But, through the Tablo, both live viewing and recordings of According to Jim are horizontally squeezed when coming from 8-3. (Wikipedia advises that According to Jim’s later seasons were shot as 720p, but all seasons appear horizontally squeezed from 8-3). The 9-4 sourced episodes always look properly proportioned–Jim isn’t skinny! But the bit-starving has some looking like they were captured on re-used VHS tape. Also, the commercials are horizontally pillarboxed from the 8-3 source.

WOOD TV 8-3 example frame:

WWTV 9-4 almost identical time:

Per the TSReader captures I’ve made (and submitted to the site Rabbitears.info), the difference seems to be that WOOD has 8-3 set to an Aspect Ratio value of 4:3, and WWTV has 9-4 set to 16:9.

I had read in this forum or another site that most TVs accomplish an “auto zoom” of some sort, such that when we’re watching the current linear presentation of According to Jim through our Samsung smart TVs, and flip back and forth from 8-3 to 9-4, it always fills the screen correctly, without either sizing the characters and scenes differently. Jim is always the same size when we switch between 8-3 and 9-4 on the TV real-time.

I’ve also read on AVSForum that possibly AFD (Active Format Description) might be in play, as the best my naïve mind can understand it’s a program-by-program setting that may function as an override to the “default” Aspect Ratio for the subchannel. But then another place mentioned that AFD was really only between broadcast sources and cable TV, so might not be sent in the TS data when received OTA.

There, confused yet?

Thus, my request is that if someone could provide some guidance on how to appropriately request of a station to revise their Aspect Ratio or AFD setting, I’ll happily try to get that passed along to the engineers at WOOD TV. My first attempt of submitting a “Help with Reception” entry on their website has gone unanswered from early this month–and I bet it’s because I was confusing with my meticulous explanation without knowing the proper terminology.

The kicker with this is that WOOD TV is owned by Nexstar, so should have some ways to collaborate with other stations. WWTV is owned by little Heritage Broadcasting, as their flagship–but they tend to always do things top notch, honestly. (Granted, I grew up on a farm within sight of their tower, so maybe I’m a bit partial.)

Thanks in advance for your assistance,
Cheers! ~~ Statmanmi

IMHO, maybe submit a ticket request to Tablo. If the station isn’t sending the appropriate aspect ratio. Which, as I understand it, can change.

A lot of TVs do allow you to “force it”, but of course, that can also cause the very problem.

The TV stations send “metadata” that tell a tuner how to format the picture. It should include resolution (480, 720, 1080, etc), aspect ratio (4:3 or 16:9), audio formats, etc. The tuner then assigns those properties (if you have it set to automatic). On my TV’s, it has the option to override, and display the picture 16:9 (normal 16:9 is displayed correctly, and a 4:3 format would then be “stretched” to fill the screen). Since they are incorrectly showing the aspect ratio of 4:3, it is “normalized” on my TV.

I spoke to KEYE-TV (Sinclair) CBS in Austin who is transmitting on their tower, and they said they are only rebroadcasting the signal, not modifying it. When I contacted KXAN (Nexstar) NBC in Austin (who has the rebroadcast rights for Austin), they never answered. The move from the KXAN to the KEYE tower was due to ATSC 3.0.

If Tablo had an aspect ratio override like the TV did, the problem would be solved. So, my fix was to run the antenna cabling to the TVs, and only use the Tablo to occasionally record a program.

Hi there, just chiming in on this. I’ve consulted with our development team and I can confirm the Tablo cannot override or change an aspect ratio being received from an OTA broadcaster. I’m sorry to say that we can’t work around this one - our recommendation is to file this with the local broadcaster.

Interesting. I am assuming this limitation is based on the video players on the playback devices (Roku, Fire TV, Apple TV)?

The actual format from the broadcaster is 16:9, however, the metadata indicates that it is 4:3, so my Tablo DVR is “overriding” the format, and pinching it in. The request isn’t for the Tablo to “reformat” the picture (it is actually doing that), it is to override what the metadata is being sent.

When I view it on TV, and tell the TV that it is 16:9, it displays correctly. If I leave it on “auto” (which selects the format based on the metadata), it shows in 4:3 format (the 16:9 shows are seen at 4:3, and the 4:3 shows are compressed even further).

I have contacted both TV stations involved (KXAN TV has the license to rebroadcast the channel, but it is being sent to KEYE-TV’s tower for broadcast). No response from KXAN, and KEYE claims they aren’t changing anything in the signal.

KXAN Contact: david.cantu@kxan.com (David Cantu)
KEYE-TV Contact: glweaver@sbgtv.com (Gerald Weaver)