Jump to content

Scrambled/corrupted picture with some channels and recordings.


e-charge

Recommended Posts

emg456
18 hours ago, ebr said:

Hi.  The known issue was solved.  Therefore, you must have some other combination of things happening or another outlier case of the issue so we will need specific details to find that.

You just saying "its happening again" does not help us find the issue.

Thanks.

In fairness @ebr, it looks like a secondary issue which was brought into the thread may have been solved but not the original issue  which was unrelated to 4K playback and transcoding.
I’m away just now but will check my setup again after the weekend. 

Link to comment
Share on other sites

4 minutes ago, crusher11 said:

Nah, 4K playback is fine for me, it's just DVDs that are borked.

PM'd logs.

Exactly what issue are you seeing here?  Can you include a screenshot?

If it is the same diagonal green lines I have no idea why because we are direct streaming and displaying a standard 720x480 resolution - so cannot be the same issue.

Link to comment
Share on other sites

1 hour ago, crusher11 said:

Bump. 

This is not helpful.

You may "Bump" an issue when you feel that it might have been forgotten after a longer period of time, but normally - and especially when there were according responses - you may rather assume that none of us has a useful idea about what might be wrong or what could be tried to narrow down the issue.

Just from a little bit of reading through our forums, you can see that most of the user issues that have been resolved are preceded by the exchange of an extensive amount of information and testing results. You won't find any issue where "X does not work" - "Bump" - "Bump" - "Bump" has lead to a resolution.

When I would say "I have no idea" and you say "Bump", then my response would be "Aha, but I still have no idea!".

If you want to really enforce and improve chances to identify the cause and a possible solution, then you need to provide information, information and even more information - asked and unasked. Also useful is helping to discriminate issues. When somebody says "My issue is 'doesn't work'" and we have actually re-solved at least a part of those, it is extremely unhelpful to report just something like "Still doesn't work". This just puts us into a "no idea" state and then you "Bump" us from "no idea" to "still no idea".

I understand that it can be disappointing when things don't work as expected. But our response can only be as good as the information we get (in cases like this, where it's not about a well- or widely-known issue).

Link to comment
Share on other sites

crusher11

Letting the thread drown amongst the others won't fix anything either.

I don't know what more detail I can provide. I've provided server logs, ffmpeg logs, app logs, and a description of which types of video are and are not affected.

Link to comment
Share on other sites

Please take my apologies! In fact I hadn't seen the logs you sent.

One thing I could see from the logs is that the problematic video ("All about..") is anamorphic:

image.png.a9660820022bf244c730876b9a7f6b70.png

 

And that's what I would focus on for further investigation, to see whether it might be the actual pattern which is causing trouble.
(the stream time base is also changed between ffmpeg input and output, but those green lines are typically related to line size and stride).

@ebr - what do you think?

Link to comment
Share on other sites

7 minutes ago, crusher11 said:

Is there a way to edit the header to test if it still screws up when playing as square pixels?

This sounds like a good idea!

MKVToolnix GUI has a header editor, but I've never used it that way and can't say whether it allows to produce the desired result. Probably worth to try at least.

Link to comment
Share on other sites

crusher11

I've recently bought the Blu-ray for All About Eve and will be replacing the DVD file on my server, so I don't much care how screwed up it gets.

Link to comment
Share on other sites

4 minutes ago, crusher11 said:

I've recently bought the Blu-ray for All About Eve and will be replacing the DVD file on my server, so I don't much care how screwed up it gets.

When you make a backup copy before trying, nothing will be screwed up.

Link to comment
Share on other sites

crusher11

No dice, same error. Tried Playback Correction and dropping the bitrate to force a transcode, both of which simply crashed back to the Item Details page with the message "too many errors, giving up". Logs sent from the app at 14:32 GMT+8, same user as previously. I'll PM @softworkz the server and ffmpeg logs.

Link to comment
Share on other sites

If transcoding doesn't fix it, I'm not even sure what else we could try to do.

Only thing I'm relatively sure of is that the folks who designed the Fire device never expected an anamorphic mpeg2 video to be played on it :).

Link to comment
Share on other sites

emg456

The issue for me is only with certain channels of live TV or the recorded files from those channels. How would I check whether they are encoded with square pixels?

Link to comment
Share on other sites

crusher11
2 hours ago, ebr said:

If transcoding doesn't fix it, I'm not even sure what else we could try to do.

Transcoding doesn't even work. It just crashes the player.

FWIW I have some DVD-sourced material that I retranscoded myself to remove PAL speedup. Still anamorphic, but now H.264. Plays just fine on the Fire stick.

So it's something to do with MPEG2. May not even be anamorphic-related at all.

Edited by crusher11
Link to comment
Share on other sites

3 hours ago, emg456 said:

How would I check whether they are encoded with square pixels?

When the quotient of width/height is identical to the aspect ratio.

E.g.:

image.png.b082f966a4b67f8085e929437890554d.png

 

720 / 480 = 1.5
279 / 157 = 1.777
=> Anamorphic (non-square pixels)

Opposite example:

1920 / 1080 = 1.777
16 / 9  = 1.777
=> Non-Anamorphic (square pixels)

Link to comment
Share on other sites

3 hours ago, crusher11 said:

So it's something to do with MPEG2. May not even be anamorphic-related at all.

Yea  maybe not. We don't know at this time. One thing that we have observed in general is that in case of MP2Video, behavior of all kinds of decoders is a lot more "picky", whereas for H.264 it's always clear that it could be virtually _any_ kind of resolution.

Another thing I'm wondering about: the DVD seems to provide NTSC standard video. Wouldn't it normally need to be interlaced?

Link to comment
Share on other sites

crusher11

I tried an MPEG2-encoded Blu-ray, it worked fine. So that narrows it down somewhat.

The video is flagged as progressive.

Link to comment
Share on other sites

crusher11

To clarify, "the video is flagged as progressive" applies to the DVD. It's also true of the Blu-ray, obviously.

Are there some resolutions or other things that I could throw at it to try and narrow things down?

Link to comment
Share on other sites

22 hours ago, crusher11 said:

I tried an MPEG2-encoded Blu-ray, it worked fine. So that narrows it down somewhat.

10 hours ago, crusher11 said:

Are there some resolutions or other things that I could throw at it to try and narrow things down?

I'm not familiar with the device itself, so I can't help with hands-on experience, but I can help with pinpointing strategies, and this is actually a good starting point:

  • We got our failing case
    and
  • We got something similar that works

Let's compare these two cases. Just create a single ffmpeg log file for each case, then we can look at the differences.
(I know you have sent many logs for the failing case already, but creating two logs directly one after another provides maximum differentiation from unexpected factors)

Link to comment
Share on other sites

crusher11

I just played All About Eve, and pulled up Stats for Nerds immediately, and it was direct playing for about five seconds then switched to Direct Stream. Weird.

Link to comment
Share on other sites

crusher11

I forgot to note the time I sent the log. Same user as previously, GMT+8, somewhere between 23:43 and 23:45.

Played Babel (MPEG2 BD), All About Eve (MPEG2 DVD), then S1E1 of The Alfred Hitchcock Hour (DVD-sourced but converted to H264 to remove PAL speedup).

Dropped quality to 1Mbps to force transcode.

Played Babel, All About Eve 2x, S1E1 AHH.

Transcoding worked for All About Eve this time, the issue last time must have been a one-off glitch. It also rectified the diagonal green line issue. So we have something of a workaround, at least, it would seem.

There is, however, a SfN issue as it insisted things were direct playing even when the OSD said they were transcoding during the latter test.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...