[vdr] Small VDR-streamdev patch for Popcorn Hour NMT

jori.hamalainen at teliasonera.com jori.hamalainen at teliasonera.com
Tue Nov 11 13:02:48 CET 2008


>> > TS-Doctor seems to log what it had to fix. Did it give you a hint?
>> 
>> Actually I started fixing it what was analyzed on my previous mail,  
>> log starts with: - Transfering this back to PCH is out to todays 
>> tuning time so I need to test later if this fixed file works..
>> 
>> Starting at packet 1 00:00:00.000
>> ERROR: For video PID 0202 000000E2: Wrong PSCPrefix
>>(...)
>> ERROR: For audio PID 0289 00002002: Wrong PSCPrefix

> It seems that those messages refer to the very beginning of the stream
> only. I assume PSCPrefix is the PES PACKET_START_CODE_PREFIX. Maybe the
>  PSCPrefix message is logged for incomplete PES packets at the beginning 
> of the stream.

Here is what TS-Doctor developer answered on NMT forums

------
the PSCPrefix error is not a big problem because this error is only at the
beginning of the stream. This error shows that the header of some PES
packets 
are not starting with the right value, so that every of this not compliant 
packets are ignored (discarded).

The video_full_range_flags lines are only for debugging if there are
problems 
with the flag. You can ignore them because they are not marked as errors or 
warnings!
------

>> ----------- PMT 0 -----------
>> Packet                   : 1 

> The fixed file starts with a PMT packet. Could PCH be choking on the fact 
> that the TS stream starts right in the middle of nowhere?

I think this is a good quess. I don't know how much PCH reads the stream for
PMT table (first 10kB, first 100kB,...?), so if it does not have it in time
it quits the stream.

So could streamdev be easily modified to provide PMT at stream start? And 
could PMT be rewritten later if new streams are found. With this I mean on 
first PMT you have audio/video-stream. And subtitle appears 60 seconds from 
the start so give new PMT with private subtitles streams as well?

--

How about the other symptom I was giving output. My VDR machine and its
mplayer. Sometimes it recognizes stream as MPEG-2, and sometimes H.264. What
do you believe, problem with TS stream or problem with Mplayer stream
recognition.

What is the best linux tool to diagnoze problems on TS? TS-Doctor is windows
software and does not run under terminal emulator.

>> What I can tell this just deletes two subtitle PIDS (swe and fin)

> Maybe streamdevs cStreamdevPatFilter::GetPid() filtered too much. 

I don't believe this is problem, as not all shows have subtitles. But 
they could have empty packets submitted?

> Could you recompile streamdev with debug output enabled:

> cd STREAMDEV_SRC_DIR; make clean; DEBUG=1 make all

> Plese post the debug output (sent to stderr) as well as the messages from
the log.

I need to check this one when I have access..

- Jori
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