[mythtv-users] Everything works on my rebuilt DVR except the tuner cards. Help?

[Stephen Worthington]

On Wed, 16 Oct 2013 14:45:12 -0700, you wrote:

>On Wed, Oct 16, 2013 at 12:46 PM, Rajil Saraswat <rajil.s at gmail.com> wrote:
>
>> >> Yes, your deduction is correct. The main card works fine in 3.10.7, it
>> is
>> >> only the daughter card which is broken.
>> >
>> > Have you done a git bisect to determine which commit caused the breakage?
>> > That would be helpful to the developers, I'm sure, so they could find the
>> > cause more easily.
>> >
>> > Karl
>> >
>>
>> The results of the git bisect are here
>> http://www.spinics.net/lists/linux-media/msg68963.html
>>
>> wm8775 seems to be the culprit.
>>
>
>Glad you found it. Thanks for taking that time. Now I hope they can fix it.
>Maybe the fix will also solve the occasional problem I have with minor
>audio distortion on my PVR-500 using the on-bracket composite input (it
>sounds tinny and slightly scratchy).
>
>Thanks,
>
>Karl

Your PVR-500 audio problem is likely the same as mine - the drivers
seem to have a bug that causes audio to be mixed in from other inputs.
I have a script that works around the problem, both for recording FM
radio for my mother with her PVR-150 and for me recording S-Video from
my STB with my PVR-500.

This is the fix script for recording S-Video from my PVR-500
(ivtv_audio_fix.sh):

#!/bin/sh

# Workaround for bug which causes audio distortion on some recordings.
# From http://urlgrey.net/?p=231

sleep 3

if [ $# -eq 0 ]; then
    device=/dev/video0
else
    device=$1
fi

# First, set the audio input in turn to each of the unwanted audio
inputs.
# This only became necessary as of Mythbuntu 12.04.
v4l2-ctl -d$device --set-audio-input=2
v4l2-ctl -d$device --set-audio-input=0

# Next, also set the tuner frequency.  This also seems to be necessary
# since Mythbuntu 12.04 to suppress a slightly different audio
distortion.
# The frequency should be for an unused part of the spectrum, as the
unwanted
# audio is coming from whatever the TV tuner is tuned to.
v4l2-ctl -f 420

# Reset the audio input to source 1 (the wanted input).
v4l2-ctl -d$device --set-audio-input=1


And this fixed FM recording from my mother's PVR-150:

#!/bin/sh

# Workaround for bug which causes audio distortion on some recordings.
# From http://urlgrey.net/?p=231

sleep 3

if [ $# -eq 0 ]; then
    device=/dev/video0
else
    device=$1
fi

# First, set the audio input in turn to each of the unwanted audio
inputs.
# This only became necessary as of Mythbuntu 12.04.
v4l2-ctl -d$device --set-audio-input=2
v4l2-ctl -d$device --set-audio-input=0

# Next, also set the tuner frequency.  This also seems to be necessary
# since Mythbuntu 12.04 to suppress a slightly different audio
distortion.
# The frequency should be for an unused part of the spectrum, as the
unwanted
# audio is coming from whatever the TV tuner is tuned to.
# DO NOT DO THIS FOR RADIO RECORDINGS
#v4l2-ctl -f 420

# Reset the audio input to source 1 (the wanted input).
v4l2-ctl -d$device --set-audio-input=1

The fix script should be called from the channel change script.  Use &
to make it run in parallel with the channel change script, after the
channel has been changed.  Here is my channel change script for using
my PVR-500 with my STB:

#!/bin/sh

REMOTE_NAME=Pace_RC-30
cmd="$1"

# If things work OK with sleep 1, try this for faster channel changes:
# sleep 0.3
sleep_amt=1.0

# See if this helps with missing digits at the start of a channel
change.
sleep 1.0

#echo Change channel: $cmd >>/tmp/irsend.txt

case $cmd in
    [0-9]*)
    # make sure we unmute by hitting vol up
    #/usr/bin/irsend SEND_ONCE $REMOTE_NAME Vol+
    #sleep $sleep_amt
    for digit in $(echo $1 | sed -e 's/./& /g'); do
            #echo irsend SEND_ONCE $REMOTE_NAME $digit
>>/tmp/irsend.txt
        /usr/bin/irsend SEND_ONCE $REMOTE_NAME $digit
        sleep $sleep_amt
    done
    ;;

    *)
        /usr/bin/irsend SEND_ONCE $REMOTE_NAME $cmd
        ;;
esac


# Workaround for bug which causes audio distortion on some recordings.
/usr/local/bin/ivtv_audio_fix.sh $video &