[kaffeine] [Bug 371540] New: kaffeine 2.0.4 hangs on changing channels plus

[Alan via KDE Bugzilla]

https://bugs.kde.org/show_bug.cgi?id=371540

Bug ID: 371540
Summary: kaffeine 2.0.4 hangs on changing channels plus
Product: kaffeine
Version: unspecified
Platform: Kubuntu Packages
OS: Linux
Status: UNCONFIRMED
Severity: crash
Priority: NOR
Component: general
Assignee: mchehab+***@kernel.org
Reporter: ***@gmail.com

Kaffeine 2.0.4 on kubuntu 16.10.
On entry the last selected TV channel will be playing.
An attempt to select another channel causes it to hang.
Continued attempts produce error messages like this when run from a terminal.
[00007f6ec4000e38] core stream error: cannot pre fill buffer

Several stations on the programme guide show gibberish in the title column.
e.g.
23/10/2016 22:45 00:15 [wierd characters] BBC NEWS HD

Reproducible: Always

Steps to Reproduce:
1. Just execute.
2.
3.

Actual Results:
As described above.


When run from a terminal, the terminal will display this right from the start:

23-10-16 20:32:16.049 [Warning ] Error while preparing statement 'table
RecordingSchedule has no column named Subheading Unable to execute statement'
23-10-16 20:32:16.050 [Warning ] Error while preparing statement 'no such
column: Subheading Unable to execute statement'
23-10-16 20:32:16.050 [Warning ] Error while executing statement 'no such
column: Subheading Unable to execute statement'
23-10-16 20:32:19.466 [Info ] Using built-in dvb device manager
23-10-16 20:32:19.552 [Info ] Found dvb device P1131716062800011: TurboSight
TBS 62x0 DVBT/T2 frontend
23-10-16 20:32:19.556 [Info ] Found dvb device P1131716062800011: TurboSight
TBS 62x0 DVBT/T2 frontend

[Jan Michel]

https://bugs.kde.org/show_bug.cgi?id=371540

Jan Michel <***@mueschelsoft.de> changed:

What |Removed |Added
----------------------------------------------------------------------------

Post by Alan via KDE Bugzilla
Kaffeine 2.0.4 on kubuntu 16.10.
[00007f520409c318] core stream error: cannot pre fill buffer

I have the same problem. In some cases (about 20%) changing channels (by any
means, e.g. in the channel list or by typing the number or with Channel-Up/Down
shortcut) does not work. Screen stays black. Changing channels several times
more and it works again.

Receiver is a Hauppauge soloHD:
[107784.603983] si2168 8-0064: Silicon Labs Si2168-B40 successfully identified
[107784.603984] si2168 8-0064: firmware version: B 4.0.2
[107784.605638] si2157 9-0060: Silicon Labs Si2147/2148/2157/2158 successfully
attached

The other symptoms mentioned by Alan do not appear in my case.
The problem never appeared with Kubuntu 16.04 or earlier versions.

[Alan]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #2 from Alan <***@gmail.com> ---
Now version 2.0.5 under Mageia 6 sta1 is much the same.

To change channels I have to select one exit from kaffeine and bring it up
again.

The title column ion the Program Guide has some entries readable and some
complete garbage.

When configuring source, I can only use autoscan. The UK channels do not show
up in the listing.

[Mauro Carvalho Chehab]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #3 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #0)

Post by Alan via KDE Bugzilla
23-10-16 20:32:16.049 [Warning ] Error while preparing statement 'table
RecordingSchedule has no column named Subheading Unable to execute statement'
23-10-16 20:32:16.050 [Warning ] Error while preparing statement 'no such
column: Subheading Unable to execute statement'
23-10-16 20:32:16.050 [Warning ] Error while executing statement 'no such
column: Subheading Unable to execute statement'

The above messages indicate that the sql lite database is corrupted.
You could remove it by removing this file:
~/.local/share/kaffeine/sqlite.db
and then re-add your recording schedule and other configuration options that
are stored there.

Post by Alan via KDE Bugzilla
23-10-16 20:32:19.466 [Info ] Using built-in dvb device manager
TurboSight TBS 62x0 DVBT/T2 frontend
TurboSight TBS 62x0 DVBT/T2 frontend

Those messages are OK, but don't help to diagnose any problem. You should
enable debug messages by calling kaffeine with the "--debug" option in order to
have more logs.

Post by Alan via KDE Bugzilla
Several stations on the programme guide show gibberish in the title column.
e.g.
23/10/2016 22:45 00:15 [wierd characters] BBC NEWS HD

Program guides in UK uses non-standard charset tables. Currently, Kaffeine
doesn't have support for that. One of the issues is that it seems that there
are some patent issues related to the usage of such tables.

[Mauro Carvalho Chehab]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #4 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #0)

Post by Alan via KDE Bugzilla
Kaffeine 2.0.4 on kubuntu 16.10.
On entry the last selected TV channel will be playing.
An attempt to select another channel causes it to hang.

What do you mean by hang? It would be nice to have the debug logs showing what
happens when you change the channel.

Post by Alan via KDE Bugzilla
Continued attempts produce error messages like this when run from a terminal.
[00007f6ec4000e38] core stream error: cannot pre fill buffer

Such message comes from libVlc and simply indicate that it failed to parse or
display a MPEG Transport Stream. If you're getting this, Kaffeine didn't hang.
Probably, it switched the channel and sent the data to libVlc, but either the
TS stream is corrupted (week signal or too much interference) or it failed to
identify the start of the TS frames. LibVlc 2.x has some issues decoding
MPEG-4. Although still experimental, libVlc 3.0 seems better to parse streams
with MPEG-4.

[Alan]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #5 from Alan <***@gmail.com> ---
Dear Mauro

I did a little research on your behalf. See below:


On 02/12/16 08:21, Mauro Carvalho Chehab wrote:
https://bugs.kde.org/show_bug.cgi?id=371540

Post by Alan via KDE Bugzilla
Several stations on the programme guide show gibberish in the title column.
e.g.
23/10/2016 22:45 00:15 [wierd characters] BBC NEWS HD

You wrote:
---------

Program guides in UK uses non-standard charset tables. Currently, Kaffeine
doesn't have support for that. One of the issues is that it seems that there
are some patent issues related to the usage of such tables.

From the uk.tech.digital.tv Newsgroup
-------------------------------------

Monday 05 Dec 2016 13:34:36

Post by Alan via KDE Bugzilla
I had been struggling to deploy a computer program called Kaffeine
2.0.5 because that version supposedly could process DVB-T2 (HD)
signals.
However I couldn't test it because its channel search routine seemed
to find and list everything from Berlin to Hanoi but not UK channels.
Finding no help on the wwww I finally wrote to the developer,
receiving the following reply a couple of days ago.
"Program guides in UK uses non-standard charset tables. Currently,
Kaffeine doesn't have support for that. One of the issues is that it
seems that there are some patent issues related to the usage of such
tables."
So why are we Brits locked out?
Another reason for Bill to Brexit I'll bet. :)
Alan

On DVB-T2 the EIT tables are compressed using Huffman coding, using the
same coding table as Freesat. This reduces the size of the EIT and thus
the bandwidth that has to be used to broadcast it.

I believe that the coding table is subject to copyright and is not
generally made available. However it was speedily reverse engineered and
most open-source media players include the reverse-engineered version by
default.
Dave

Regards, Alan Secker

[Mauro Carvalho Chehab]

https://bugs.kde.org/show_bug.cgi?id=371540

Mauro Carvalho Chehab <mchehab+***@kernel.org> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |CONFIRMED
Ever confirmed|0 |1

--- Comment #6 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #5)

Post by Alan
On DVB-T2 the EIT tables are compressed using Huffman coding, using the
same coding table as Freesat. This reduces the size of the EIT and thus
the bandwidth that has to be used to broadcast it.
I believe that the coding table is subject to copyright and is not
generally made available. However it was speedily reverse engineered and
most open-source media players include the reverse-engineered version by
default.

Yes, UK uses FreeSat's huffman codes. There are some open source programs that
implement it. The huffman decoding itself is OK. The problem is that Freesat
use some char tables that seem to be under some copyright protection. Adding it
to Kaffeine (or to libdvbv5) could cause some legal issues, with would prevent
distros to be able to ship it.

The best would be to have some sort of plugin that would allow someone to
download such tables and/or a huffmann parsing library. Unfortunately,
currently, I don't have time to work on such code. If someone wants to develop
it in a way that would keep the Kaffeine code clean of legal issues, I'll
gladly apply it.

[Mauro Carvalho Chehab]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #7 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #0)

Post by Alan via KDE Bugzilla
Kaffeine 2.0.4 on kubuntu 16.10.
On entry the last selected TV channel will be playing.
An attempt to select another channel causes it to hang.
Continued attempts produce error messages like this when run from a terminal.
[00007f6ec4000e38] core stream error: cannot pre fill buffer

This BZ ended by being diverged to a different issue (EPG guide on UK).

Not sure if what's reported on this BZ still occurs, e. g. : "kaffeine hangs on
changing channels".

Today, I solved a relevant performance issue related to EPG handling that could
be badly affecting channel switch.

Could you please check if the problem on switching channels were solved on the
upstream version?

[Alan]

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #8 from Alan <***@gmail.com> ---
I'm sorry no. Kaffeine does not support UK HD channels, which led to the
OS being replaced by MAG 5.1.


On 16/02/17 12:18, Mauro Carvalho Chehab wrote:

https://bugs.kde.org/show_bug.cgi?id=371540

--- Comment #7 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #0)

Post by Alan via KDE Bugzilla
Kaffeine 2.0.4 on kubuntu 16.10.
On entry the last selected TV channel will be playing.
An attempt to select another channel causes it to hang.
Continued attempts produce error messages like this when run from a terminal.
[00007f6ec4000e38] core stream error: cannot pre fill buffer

This BZ ended by being diverged to a different issue (EPG guide on UK).

Not sure if what's reported on this BZ still occurs, e. g. : "kaffeine hangs on
changing channels".

Today, I solved a relevant performance issue related to EPG handling that could
be badly affecting channel switch.

Could you please check if the problem on switching channels were solved on the
upstream version?

[Mauro Carvalho Chehab]

https://bugs.kde.org/show_bug.cgi?id=371540

Mauro Carvalho Chehab <mchehab+***@kernel.org> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|CONFIRMED |RESOLVED
Resolution|--- |WORKSFORME

--- Comment #9 from Mauro Carvalho Chehab <mchehab+***@kernel.org> ---
(In reply to Alan from comment #8)

(In reply to Mauro from comment #7)

Post by Mauro Carvalho Chehab
Could you please check if the problem on switching channels were solved on
the
upstream version?

I'm sorry no. Kaffeine does not support UK HD channels, which led to the
OS being replaced by MAG 5.1.

Ok. Well, as this bug can't be reproduced anymore, I'll close it with
WORKSFORME status.

If you or anyone has a similar issue and can reproduce it, just re-open.

With regards to UK HG EPG handling, we'll need either some formal authorization
from copyright owners of their Huffman-based encoding or some way to allow
plugin an external parser for it that could be shipped outside Kaffeine, in
order to avoid possible legal issues for distributions.