Identifying HDTV channels, not programs?

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wmorrison
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Identifying HDTV channels, not programs?

Post by wmorrison » Sat Nov 23, 2019 5:07 pm

Is there a way, with a sql query, to identify an HDTV channel? I don't find anything in mythconverg for this.

There is only program.hdtv, which is per-program, not channel.

I have noticed that channels that are HD sometimes have programs where program.hdtv=0. When I view such a program, the recording itself is 1080p. The picture sometimes looks as sharp and clear as I would expect for 1080p, and for other recordings a bit blurry, as if a 480p or 720p program has been upscaled to 1080p.

Here's a query to demonstrate this:

select distinct chanid,group_concat(distinct hdtv separator ',') as all_hdtv from program group by chanid;

For me, there are no channels that return only '1' for all_hdtv, only '0,1' and for non-hd channels just '0'.

Just trying to understand this for creating custom recording rules, because I've found, even if a program is not marked as hdtv, it looks better when broadcast on an hd channel than an sd channel. Sometimes it seems to be "true" 1080p even though it's not listed that way, and when it appears to have been upscaled, it still looks pretty good.

I suppose if nothing else, I could make a list of chanid's I know are HD and use that instead of, or in addition to, program.hdtv.

wmorrison
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Re: Identifying HDTV channels, not programs?

Post by wmorrison » Sat Nov 23, 2019 5:19 pm

I've also noticed there are channels (one, anyway) that broadcast HD, but none of the program listings reflect that.

My ION is 720p and the picture seems as clear as that, but schedule info never shows hdtv for anything on it.

I'm sure part of the mixup is because whoever creates the data for some channels, that SchedulesDirect licenses, has not done it correctly, or according to common standards.

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bill6502
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Re: Identifying HDTV channels, not programs?

Post by bill6502 » Sat Nov 23, 2019 8:18 pm

If you want to test your theory, use your favorite browser and this:

Code: Select all

yourBackend:6544/Guide/GetProgramDetails?ChanId=10201&StartTime=2019-11-23T00:00:00
Assumes you know your internal channel id (ChanId). Note that the StartTime is in UTC.

If the value of VideoProps is odd, then the HD bit is set for that program.

wmorrison
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Re: Identifying HDTV channels, not programs?

Post by wmorrison » Sun Nov 24, 2019 4:11 am

OK. Tried one. This is ION virtual channel 26.1 in the Hartford, CT area. "Law & Order: Special Victims Unit" EP003169780061 at 10pm EST, or 2019-11-24T03:00:00 UTC.

VideoProp is 0.

When I watch it live and press i twice, the popup shows it's HD720.

When I view the info screen for the program (press i when it's highlighted on in the program guide) it doesn't show HDTV. But When I go to the recording and press i, it does show Widescreen and 720p resolution.

I found another channel that is similar. MyNetworkTV is 720p. Some of the programs in the schedule show they are HDTV while others don't. But even the ones that don't show it are actually 720p. Just tested that.

So I know this isn't MythTV's fault, or even SchedulesDirect's fault, it's how the listings are provided. But at least I found there's actually more HDTV shows (720 and 1080) available to me than I thought, and found a way to account for that in custom recording rules.

wmorrison
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Re: Identifying HDTV channels, not programs?

Post by wmorrison » Sun Nov 24, 2019 5:12 pm

Some more info.

It's going to be hit or miss finding shows not flagged as HDTV that actually are.

I recorded one such movie last night from MyNetworkTV.

The recording is actually 720. But the image is a 4x3 letterboxed image that is obviously from an SD source. Blurry, but as watchable as any SD recording.

However, the commercial breaks are widescreen (16:9) and obviously full, clear 720 resolution.

Today, another show on the same channel, that was not flagged as HDTV, was also obviously full, clear 720 resolution.

So MyNetwork TV is a channel where some shows are listed as HDTV, some are not, and some that are not flagged actually are.

And ION is a channel where none of the shows are listed as HDTV, but at least most of them are. (Since you can only tell by watching, I'm not going to watch everything to find out.)

So to new users of MythTV, trying to figure this out, here are my (tentative) rules of thumb:

- If the listing for the program says it's HDTV, it is.
- If the listing for the program does not say it's HDTV, but it's on a channel that is HDTV, it might be "true" HDTV, or it might be just an upscaled SD image, no way to tell before it airs.
- You need to observe the usual conventions of your particular channels to get an idea of how often this happens.

One other puzzling thing.

When I start in the program guide, and choose a channel to watch, as soon as the image displays, there is a pop-up that shows the title and information about the current show.

It ALWAYS shows SD480 no matter the channel. But if I press i twice (once shows position, second time shows info) only THEN does it show HD720 or HD1080 for HD channels.

Is this a known bug? It's not causing me a problem because I've figured out how it works, but when I first started using MythTV, it was confusing because it appeared that all channels were SD when launched from the program guide.

halucigenia
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Re: Identifying HDTV channels, not programs?

Post by halucigenia » Wed Nov 27, 2019 6:17 pm

In the UK all channels that broadcast in HD have HD as a suffix in the channel name (maybe I am just assuming this?), even if they did not, if you can identify that a particular channel does broadcast HD content it should be a simple task to rename it and add the HD suffix.
I give any channels that broadcast in HD a higher recording priority.
When I re-scan for channels and re-order and re-name the channels, the last line of code in my script is:-

Code: Select all

UPDATE channel set recpriority=1 WHERE name LIKE '%HD'

wmorrison
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Re: Identifying HDTV channels, not programs?

Post by wmorrison » Wed Nov 27, 2019 11:50 pm

Yeah, I've already renamed channels that are HD so I can see that when manually searching.

For my "power search" rules where I only want to find HD shows, I've added a list of the chanids I know are HD. Sometimes I get a "true HD" recording, and sometimes "upscaled 480" but I just delete anything I don't want to watch.

I've confirmed that the XML downloaded from SchedulesDirect contains programs that are actually HD but not listed that way. mythfilldatabase deletes the file when it's finished, but if you check in /tmp/mythtv while it's still running, you can copy it somewhere.

But these shows are listed correctly on TitanTV as HD.

wmorrison
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Re: Identifying HDTV channels, not programs?

Post by wmorrison » Sat Dec 07, 2019 3:16 pm

Update:

The symptoms I described (actual HDTV programs not listed as such) were when I was using SchedulesDirect DataDirect.

I've just updated to the SchedulesDirect XMLTV/JSON grabber, and noticed that these programs are now listed as HDTV. Plus there seems to be a lot more info about programs (that shows up on the info page in parentheses where stuff like HDTV, rating, etc. appear.)

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