Comments on LiveTV with DVB

irrelev4nt

2007-10-18, 14:06 #1

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Subject: Comments on LiveTV with DVB

I'm running LiveTV mode for watching DVB channels.
I should probably note that I'm running mythbackend at a different protocol version than is supported (I think I'm at 36 and you oly support upto 33. It seem sto work fine though, so I don't think it is related to my issues.

A few comments:
Can you make it possible to sort by channum rather than chanid? channum groups things the same way mythtv does. chanid puts channels that are numerically similar very far away.

I can't change channels successfully. I need to stop and start playback on another channel.

It takes a long time to start playing. I just timed it at 23 seconds between starting playback and getting video

I can't use the scrollbar to go back or skip ahead. Pause works fine though.

Otherwise it works quite well for me, and has made it more convenient to watch TV on other systems in the house.

Thanks!

Mikkel (Administrator) 2007-10-18, 21:21 #2

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# Protocol version
It should work with protocol version 36. Actually, I have increased the supported version to 36. (Will be in next release)

#Sort by chanmum
Already implemented

. (Will be in in next release )

#Channel changing
This should work. There still seems to be some problems with some cards, though. Could you try this version to see if it work now? www.sudu.dk/mythtvplayer/files/0.6/MythTvPlayer0.5.1pre4.zip
If it does not work, could you mail be the log file (log.txt) after trying to change the channel.

#Long time to start playing
This does not sound to good. Is this only the case for livetv or also for normal recordings? Could you mail be a log-file after experiencing the problem. Also, does the player produce stderr.txt with a lot of text? (if yes, it is a problem with the videocodec;( (In that case I have to update the codec)

#Scrollbar.
It is not possible to seek in livetv yet. I am currently working on it, but it is giving me some headache;), and I does not have much spare time at the moment. It will be fixed at some point.

Keep the feedback coming;)

\Mikkel

This post was edited 2 times, last on 2007-10-19, 16:18 by Mikkel.

prezident 2007-10-21, 10:55 #3

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Sorting works fine, but it always gets resetted when the list is refreshing.

Switching channels works a lot better for me now.
No more error messages about not being able to open some live tv recordings.
However the changing time is high, around 10sec for non scrambled and 15sec for scrambled channels.
To be fair, the frontend seems to take the same time, so I assume it is a tuning thing at the backend.
Recordings are opened with no delay.

One thing I'm really missing is a deinterlacing feature, as it's badly needed and should already be included in lavc.

Anyway you're making great progress and I'm looking forward for future versions, keep em coming

.

Edit: One problem I noticed, not every channel gets opened by 0.5.1 anymore, with 0.5.0 every channel is working fine, but switching ends up in an error message.

This post was edited on 2007-10-21, 11:10 by prezident.

Mikkel (Administrator) 2007-10-22, 07:23 #4

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Quote by prezident:
Sorting works fine, but it always gets resetted when the list is refreshing.

ahh..I totally forgot about this. Added to todo list.

Quote by prezident:
However the changing time is high, around 10sec for non scrambled and 15sec for scrambled channels.
To be fair, the frontend seems to take the same time, so I assume it is a tuning thing at the backend.
Recordings are opened with no delay.

My analog pvr150 tunes immediately. Is you card a DVB using TransportStream? It might be influenced by the fact that the player can't seek in recordings that are still being recorded. Let's see if the changing time gets better when I get time to fix this.

Quote by prezident:
One thing I'm really missing is a deinterlacing feature, as it's badly needed and should already be included in lavc.

What is 'lavc'?
I just got a patch that uses some kind of de-interlazing from ffmpeg. I have no idea what kind of deinterlazing, but I will include it in the next version.

Quote by prezident:
Anyway you're making great progress and I'm looking forward for future versions, keep em coming .

Quote by prezident:
Edit: One problem I noticed, not every channel gets opened by 0.5.1 anymore, with 0.5.0 every channel is working fine, but switching ends up in an error message.

Could you provide some more details? Maybe mail me a log file of the channelchange on 0.5.0 and 0.5.1 so I can see the difference... And what is the error message?
Do you have more than one tuner? And is the "malfunctioning" channels on all tuners?

prezident 2007-10-23, 13:35 #5

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In 0.5.0 tuning a channel works one time after every start/stop.
When trying to switch to another channel it says "Could not open stream ...".
Setting AlwaysOpenRecordingsFromBackend to 1 doesn't seem to fix it.
Never saw that error in 0.5.1pre4 but it might have a similiar problem as
tuning always seems to work when stopping playback before, except some crashes I
exceeded with AlwaysOpenRecordingsFromBackend on.

lavc is that decoding library you use (LibAVCodec).
e.g. it is used in ffdshow, too.

I use a budget DVB card over here (Terratec Cinergy 1200-C).

This post was edited on 2007-10-23, 13:38 by prezident.

Mikkel (Administrator) 2007-10-24, 07:19 #6

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Ahhh.. the libavcodec

. I actually got a patch which enabled the deinterlazing from lavc. (It is just one line of code;), but I have to add GUI options, etc) I have no idea what kind of deinterlazing it does, but I will include it in 0.5.1! I need to clean up some other issues before it is ready for deployment. (At a later stage I will use the deinterlazers from DScaler, but this is a good start and many people have asked for deinterlazing)

I am still not really sure what your problem with 0.5.1 is. Sorry if I am a bit slow minded;)
Can you change channel, or do you have to stop the player and the restart livetv on the new channel? And does it crash when you try to switch channel? Please send me the logfile 'log.txt', after you experienced the problem. I would like to see what is going on. It seems like there is still some minor issues with certain tuner-cards.

By the way the "AlwaysOpenRecordingsFromBackend" should only affect you if you have multiple backends or stream through an ssh-tunnel. In every recording there is a "host" field which determines which backend the recording is stored on. By setting the "AlwaysOpenRecordingsFromBackend", this field is ignored and the recording is ALWAYS opened from the host you have specified.

prezident 2007-10-24, 09:28 #7

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For deinterlacing features of lavc try to take a look at the ffdshow or mplayer source, both are based of lavc and make use of most of the builtin functions.

Sometimes I can change a channel, sometimes I have to stop and restart and some channels are not working at all in 0.5.1 (but in 0.5.0).
I included some logs which show that behaviour.
0.5.1 worked until tuning to AXN which made the player stop responding.
In 0.5.0 tuning works just fine, except the stop/restart workaround.

The author has attached one file to this post:

mtvp-log.rar 11.3 kBytes
You have no permission to open this file.

prezident 2007-10-27, 13:25 #8

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Any news on this problem?
For me it seems like 0.5.1pre hangs while PreBuffering.

Mikkel (Administrator) 2007-10-27, 14:38 #9

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I am working on it;). Will get back to you as soon as I have any news.

prezident 2007-10-28, 14:11 #10

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thx a lot

.

tried looking how the backend reacts on channel changes.
new recordings get created immediately and the filesize increases,
so tuning seems to work fine and fast.

other than that i tried building with visual studio but ended up in a lot of errors.

edit: did some research on the deinterlacing stuff. seems like lavc only includes
one simple function, with better alternatives out there. at least it does work.
for me kerneldeint does the best job.

This post was edited on 2007-10-28, 14:44 by prezident.

Mikkel (Administrator) 2007-10-28, 16:24 #11

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I looked into the lavc interlacing and got to the same result as you. I got it as a patch and have added a GUI option for it, so it is working now.. It is much better than nothing.. Later, I still want to added the deinterlazers for DScaler.
It is already in the trunk.

I think the problem with channelchange is that it does not handle recordings that are STILL recording. I have it partly fixed now.. It only work without network buffering though so I have to fix that first.. then I will upload a new pre version. (It turned out to requite quite a large change)

prezident 2007-11-01, 11:06 #12

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started building from the source to be up to date.
rev180 works quite well. can tune every channel and prebuffering issues are rare.
but got some rebuffering issues and a crash now or then (according to the log) due to audiobuffer underruns.
Settings Video and AudioPacketBuffer to 75 doesnt fix it all but makes it better.

one other thing, i deleted some channel via the webinterface but the player still shows them like this:
[Image: http://img502.imageshack.us/img502/671/mtvpbh9.png]

[Image: http://img502.imageshack.us/img502/671/mtvpbh9.png]

This post was edited on 2007-11-01, 11:09 by prezident.

Mikkel (Administrator) 2007-11-01, 19:52 #13

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Thanks for the feedback. I have not completed the handling of recordings that are still recording, so it might still be buggy.

Rebuffering: Did this happend in the old version as well or is this new? (The auidiobuffer underun is just how buffer underuns are detected. The audio part of the player reports that it is out of data and the player pauses and rebuffers)

Crashed: Do you mean lockups (Which is due to the buggy code for handling of files that are stil lrecording) or real crashes.

Channels I think it is because they are still in the database. The player does not remember the channels at all. Every time you start it, it build a list of channels on all recorders. So somehow, the recorders still list the channels you have deleted. If you send me the log file I can see how these "dummy" channels are reported and filter them out.

btw. Is the deinterlacing usable?

prezident 2007-11-01, 20:39 #14

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dont remember rebuffering issues in previous versions, but will test it later.

the crashes are real crashes, the player closes and windows shows that error at blabla popups.
it only happens after a buffer underrun, but not always.

channels are added like this and i really cant find them in the database...
08:28:50 MythRecorder: - Added channel ' ' (1124)
08:28:50 MythRecorder: - Added channel ' ' (1123)
08:28:50 MythRecorder: - Added channel ' ' (1122)

as already mentioned, not the best deinterlacing but a lot better than without (i would say it works

This post was edited on 2007-11-01, 20:40 by prezident.