[mythtv-users] Changing chanel + DVB = :-(

[Stephen Longhurst]

> Fresh install with latest DVB-kernel drivers ( CVS for kernel2.6 )
> Still the same problem when i change channels.
> 
> root at mythtv:~ # mythbackend &
> [1] 1458
> root at mythtv:~ # Starting up as the master server.
> 2004-06-17 22:55:51 DVB#0 Using DVB card 0, with frontend Philips TDA10045H.
> 2004-06-17 22:55:57 DVB#0 WARNING - Status: NO LOCK!
> 2004-06-17 22:55:57 DVB#0 Successfully tuned to channel 3.
>  is defined, but isn't attached to a cardinput.

I've not seen this specific error before, but channel 3 tends to be
the one that is set in the 'tune to this channel at startup' setting
for the capture card.

> <snip>
> 2004-06-17 22:57:58 Changing from None to WatchingLiveTV
> 2004-06-17 22:57:58 DVB#0 Recorder: Card opened successfully.
> Audiostream: Layer: 2  BRate: 192 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 4:3  Size = 720x576  FRate: 25 fps  BRate: 8.00 Mbit/s
> 2004-06-17 22:58:07 DVB#0 WARNING - Status: SIGNAL | NO LOCK!
> 2004-06-17 22:58:07 DVB#0 WARNING - Status: VITERBI | SYNC | NO LOCK!
> 2004-06-17 22:58:07 DVB#0 Successfully tuned to channel 4.
> 2004-06-17 22:58:07 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> 2004-06-17 22:58:07 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> Audiostream: Layer: 2  BRate: 256 kb/s  Freq: 48.0 kHz
> 2004-06-17 22:58:07 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> 2004-06-17 22:58:18 DVB#0 WARNING - No data from card in 1 second.
> 2004-06-17 22:58:19 DVB#0 WARNING - Transport Stream Continuity Error.
> PID = 1049
> 2004-06-17 22:58:19 DVB#0 WARNING - Transport Stream Continuity Error.
> PID = 1048
> 2004-06-17 22:58:19 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> 2004-06-17 22:58:19 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> 2004-06-17 22:58:19 DVB#0 WARNING - Uncorrectable error in packet, dropped.
> 2004-06-17 22:58:20 DVB#0 WARNING - No data from card in 1 second.
> 2004-06-17 22:58:21 DVB#0 WARNING - No data from card in 1 second.
> 2004-06-17 22:58:22 Couldn't read data from the capture card in 15 
> seconds.  Game over, man.
> 
> The " is defined, but isn't attached to a cardinput." could be a problem
> but i have no idea how to get rid of it.

I looks to me like you're not getting a very good signal on the
channel you tried to tune to.  How did you get the DVB settings for
the channel?  Using 'scan' that comes with the DVB drivers?  If you've
still got the channels.conf file (or whatever you generated), can you
get a picture using dvbstream and mplayer, after tzap'ing to card to
the channel?

I'm assuming you're using DVB-T here, correct me if I'm wrong.  I find
that DVB-T can vary signal strength all over the place.  Many channels
only broadcast at certain times during the day, and you'll get no data
from the card at other times.  Also, during the summer, I tend to lose
about half the channels I otherwise get, although I've no idea why!

I don't know if it'll be of any use, but I used this small script to
verify the channels in my channels.conf file:

#!/bin/bash

# Full path of tzap executable
tzap=/usr/src/linuxtv-dvb-apps-1.1.0/util/szap/tzap

# Full path of dvbstream
dvbstream=/usr/src/linuxtv-cvs/dvbstream/dvbstream

# Full path to channels.conf file
ch_file='/root/channels.conf'

if [ -z "$1" ]
then
  echo "Usage: $0 [-l | channel]"
  echo "       -l list channels"
  echo "       channel must match a known channel name"
  exit 1
fi

if [ "$1" == "-l" ]
then
  cut -f1 -d':' $ch_file
  exit 0
fi

channel=$1

qam=`grep "$channel" $ch_file | cut -f7 -d':' | cut -c5-`
fec=`grep "$channel" $ch_file | cut -f5 -d':' | cut -c5-`
video_pid=`grep "$channel" $ch_file | cut -f11 -d':'`
audio_pid=`grep "$channel" $ch_file | cut -f12 -d':'`

$tzap -c /root/channels.conf $channel > /dev/null &
$dvbstream  -o -ps -qam $qam -cr $fec $video_pid $audio_pid | mplayer -
kill `ps -ef | grep tzap | grep -v grep | awk '{print $2}'`

Cheers,

       Steve

-- 
Stephen Longhurst
steve at longsteve.com