[Solved] Sound problems

[JTe]

I have some sound problems (there is a small squick sound about once a minute) on the DVB-T channels received by my old DVB-T PCI card. I was making some logging and I get constantly the following messages.

Code Select Expand

[mp3 @ 0x575ac0] incorrect frame size
21:41:37.856343 [debug]  2017 Audio - saved audio: 672
[mp3 @ 0x575ac0] incomplete frame
21:41:37.863017 [debug]  2017 Audio - We can not decompress 506 save for later 1 42d7e0be 1088
    Last message repeated 2 times
[mp3 @ 0x575ac0] incorrect frame size
21:41:37.871029 [debug]  2017 Audio - saved audio: 672
[mp3 @ 0x575ac0] incomplete frame
21:41:37.876860 [debug]  2017 Audio - We can not decompress 556 save for later 1 42d7e36c 12b0
    Last message repeated 2 times
[mp3 @ 0x575ac0] incorrect frame size
21:41:37.882492 [debug]  2017 Audio - saved audio: 672
[mp3 @ 0x575ac0] incomplete frame
21:41:37.888229 [debug]  2017 Audio - We can not decompress 606 save for later 1 42d7e61a 1590


Solved: The aspect ratio change works after latest git updates! Sound problems caused by running vompclient with logging enabled. Without logging problems disappear. Also tuning the TCP Receive Window size to 16384 helped to get rid of the last sound problems.

[MartenR]

I need a sample, if you can reproduce it with a recording. If not, I see no way how to debug it.

Marten

[JTe]

Ok, you can find a sample form here:

http://wikisend.com/download/752080/00001.ts

It has some sound problems (sorry not in English...) and the errors I mentioned.

[MartenR]

I got it, but it is the old file.
Which is very short.
I do not recognize any distortions. (But it is a comic robot talking in a foreign languange, so it might be wrong, but I have to have some idea how it has to sound correctly).
It plays fine, in this case the messages do not seem to make any harm.

Marten

[JTe]

Sorry, I managed to upload the old file. Anyway here is the new one. The sound is breaking a little bit in the beginning of the recording and at the end again. I have also noticed that when watching channels with this kind of feed after about an hour the picture will change to black screen (only the MPEG2 feed, the menus on blue back ground work fine). To get the picture back I need to exit vomp client and restart it:

http://wikisend.com/download/365328/00001.ts

I found also an aspect ratio bug. If I watch a 4:3 live SD TV program and the next program is in 16:9 format the aspect ratio does not change to 16:9 but the display keeps in 4:3 aspect ratio with black bars on sides.

-Jussi

[MartenR]

Sorry, I managed to upload the old file. Anyway here is the new one. The sound is breaking a little bit in the beginning of the recording and at the end again.

I am not hearing any distortion, everything plays back fine, are you using analog audio or hdmi?

I have also noticed that when watching channels with this kind of feed after about an hour the picture will change to black screen (only the MPEG2 feed, the menus on blue back ground work fine). To get the picture back I need to exit vomp client and restart it:

Interesting, does it only happen on these particular channels? Do other channel work? Sounds like a crash of the firmware, the firmware does not like damaged streams.
So other channels you can watch for hours? (I suspect bad reception)
Do you mean restart or reboot? (Power button on remote?) Does seeking or channel change bring picture back?

I found also an aspect ratio bug. If I watch a 4:3 live SD TV program and the next program is in 16:9 format the aspect ratio does not change to 16:9 but the display keeps in 4:3 aspect ratio with black bars on sides.

Does it also happen if the deinterlacer is turned off? What connection are you using? Seeking should help. The firmware should handle this.

Marten

[JTe]

I am using HDMI and now when I checked the file with VLC player it was playing fine. So I guess it must be a combination of problems with that particular DVB-T card and the network connection with the VOMP client.

I am anyway in process of upgrading my VDR box and I will replace that old PCI-card at the same time, so the problem is not so big.

The "black screen" problem seems to happen only with the stream coming form that one card. I just updated the newest git firmware version and it seems that I have not had the black screen problem with that, so it might have been something to do with the firmware level. In the beginning it required total reboot of the raspi, but sometimes it had been enough just to stop the client and restart it. Anyway I have not had the problem for few days now. If the problem reoccurs I will try to get some log information.

The aspect ratio problem however is still there. It happens with all my DVB feeds (could it be because of the git level firmware?).  If I switch to a channel having a 4:3 SD broadcast and I keep watching it the aspect ratio does not change to 16:9 even it should when the next program is starting. If I however change then to another channel and return to the problem channel the aspect ratio changes to 16:9. So the problem occurs only with a "live" aspect ratio change. When switching channels everything works fine. I will try if the deinterlacer has any effect on it (it has been currently on). I am using HDMI only for both picture and sound.

-----

Recent Observations:

I did more testing with the aspect ratio problem and found out that it seems also that the subtitle channels do not change from program to another.

If the first program (on same tv channel) has for example subtitle channels "fre" and "eng" and the second has only "fre", the audio selection menu still shows subtitle channels "fre" & "eng" when the second program has been running already for 20 minutes. If I switch to another channel and back the situation is corrected and I now only have "fre", like it should be.

So it looks like when starting to watch a channel all the pids are correctly red, but if the pids change in the middle of the feed the change is never registered. I guess that might happen with the aspect ratio information too.

[MartenR]

Recent Observations:

I did more testing with the aspect ratio problem and found out that it seems also that the subtitle channels do not change from program to another.

If the first program (on same tv channel) has for example subtitle channels "fre" and "eng" and the second has only "fre", the audio selection menu still shows subtitle channels "fre" & "eng" when the second program has been running already for 20 minutes. If I switch to another channel and back the situation is corrected and I now only have "fre", like it should be.

So it looks like when starting to watch a channel all the pids are correctly red, but if the pids change in the middle of the feed the change is never registered. I guess that might happen with the aspect ratio information too.

Well, yes pids are only read from server, when you change to a channel, this was always like this also on mvp. (A change of pid need to open new receivers, so some kind of reinitialiation is necessary).
But it has nothing to do with the 16:9 stuff, since this is not part of service information but of the mpeg2 or h264 stream.

Marten

[JTe]

Ok, if the pids are only red at channel change that rules out an easy way to make automatic language choice for subtitles as the subtitle pids change very often between programs.

I finally found the reason of my sound problems. I have been running vomplient with logging on to make some debugging and the stream of the old DVB-T card produces so much error logging (on every packet), so that was jamming the sound. When I noticed that and ran the client without logging everything is fine!