Howdy-

I have battled this issue before. Look here.

This problem resurfaced for me on fresh R5F27 install. Basically, alter your channel change script and add the delayed_settings.sh script as referenced on the thread. Sometimes your audio will randomly get louder and you will have to adjust the volume from your remote, but at least it is clear.

I have been running knoppmyth for around 3 years now and I am extremely tempted to just upgrade all of my video capture cards. I already had to replace my old economical MX4000 cards with FX55XX cards.

-Loco

Just an update on my system. I checked the volume in all my profiles and they're all at 90%. I've run R5C7, R5D1, R5E50 and R5F1 and this is the first time I've run into this tinny audio problem. I'm currently running R5F27. I do think I'm getting more good recordings than bad though.

It doesn't appear to me that actually creating the "delayed_settings.sh" script is necessary - wouldn't just putting:
v4l2-ctl --set-audio-input 1 -d /dev/video0
into the change_channel script work fine? It just needs to be run, and those of us with just one tuner and no video issues don't need all that complexity...

I'll try it later. I'm going to be moving from a 27" old tube set to a 37" HD LCD soon, so I'll be wanting better than RF tuner input, and I'll be dropping in more storage so I can move up from 480x480 2100 kbps; so I definitely need to get this issue actually fixed instead of kludged around.

Thanks for the link, I'll try these. I'd prefer to apply the ivtv patch but if the v4l2-ctl thing fixes it that works for me too.

I agree with you. I tried just putting it in the channel change script in the past and it was not 100% effective. It did not fix audio unless it changed channels. For instance, if it recorded something on Fox at 7:00 and then again at 9:00, it did not reset the audio. I took the "easy" route and reverted to the script instead of further troubleshootng.

This delayed settings script loops ths reset. I guess you could just copy the whole for-do loop (minus all of the picture settings)....

Also, should you decide to use the script, the commands in this referenced script changed. Look here.

-Loco

If you read the original posts about the delayed setting script you'll see that the point was to adjust the settings after MythTV makes them. Something which it doesn't do until after the channel change is completed.

The hack it uses is to have the channel changer leave a background job running that jumps out of the shadows a little while later and beats the card over the head with the desired settings when MythTV isn't looking.

I just discovered that I am having this problem also since upgrading last weekend. I see some suggestions that switching from S-Video to RF Coax makes it all go away. Can anyone confirm that?
It's not a great fix but better then not having sound you can understand.

_________________
LINHES 8.6.1 BE/FE - MSI K9N6SGM-V with AMD A64 X2 4600+, 4GB Ram. 1.5TB WD. HDHR Prime. Nvidia GT210. MCE remote.
FrontEnd - Dell Vostro 400 3.0GHz Core2Duo NVidia GeForce210. MCE Remote

Don't assume that switching away from S-video to Composite will help, my fresh install of R5f27 brought along this problem and I am using my comp connection into my pvr-150 from a directv receiver. On the last release I never had this problem; however, two variables changed, the release, and the fact that it was S-Video.

_________________
Athlon 64 X2 4200+ 2GB Ram
MSI K8N Neo4-F NF4 939
ASUS N EN6200TC256/TD/64M
500gb SATA
1x Plextor PX-M402U
1x HD5000
R5.5 Upgrade from F27

I'm now having this problem too.

I first noticed it when I moved over to a new motherboard--never ran into it before. I have a HD3000 and a PVR-150 in my backend. The PVR-150 is recording my set-top box via S-video and the line-in audio.

Post-upgrade, about every third PVR-150 scheduled recording would have the tinny audio.

Luckily everyone's agreed that this audio problem sounds "tinny" as searching for that turned up this and the other threads.

I copied the delayed_setting script, copied the change1.sh script, added my channel-change script to change1.sh, chmodded the scripts, ran mythtv-setup and made my channel-change script change1.sh, and tested that channels were changing. Yes they were.

Now my system is much more consistent: EVERY scheduled recording since the change has the tinny audio.

But if I pick "Watch TV" and tuner-switch over to the PVR-150, no tinny audio.

To quote Big Trouble in Little China "it's stuff like this that REEEALLLLY p*ss*s me off!" Any ideas of what to try now?

Despite arriflex's comments, switching from S-video back to channel 3 composite worked for me. No tinny sound for over 6 months. The advantage is that the audio is delivered with the video instead of through the external audio connections on the PVR-150.

I am sure that if I was able to do a "side by side" comparison of the video quality the S-Vid would look better but since I can't, the picture looks fine.

The problem started for me when I upgraded to R5F27. Never had the problem before that. I will probably try the S-video input on the next upgrade and see if it goes away.

_________________
LINHES 8.6.1 BE/FE - MSI K9N6SGM-V with AMD A64 X2 4600+, 4GB Ram. 1.5TB WD. HDHR Prime. Nvidia GT210. MCE remote.
FrontEnd - Dell Vostro 400 3.0GHz Core2Duo NVidia GeForce210. MCE Remote

Thanks for the reply. I'd hate to lose out on the image quality of S-video versus RF, but the audio is getting really annoying.

Arriflex was probably talking about composite video + line audio, as opposed to RF (which, although it's a "composite" of video and audio, isn't usually referred to as composite video).

Since I never even considered recording like that, what are the steps? Is it all mythtv-setup? You still have a channel-change script, and then there's some setting on that page (which I've ignored) that says to just keep the 150 tuned to Channel 3, or something like that.

Thanks again.

Yeah, I was referring to composite video, which is actually just a composite of the luminance and chrominance video signals into a single cable. Commonly the cable is the single yellow RCA one.
I will say that I've never been able to discern a difference between the quality of S-video and Composite, despite a technical inclination to do so. S-video should be better, as it carries the luminance and chroma video streams on separate conductors, I just can't see it even if my mind thinks it is better.

The scripts took care of my setup until I went and killed my box when I tried to add frontend access on my lan. Amongst other things, my card definitions got screwed up, and now my pvr-150 doesn't even get seen by the setup program.
Anyway, thats a story for another thread.

arri

_________________
Athlon 64 X2 4200+ 2GB Ram
MSI K8N Neo4-F NF4 939
ASUS N EN6200TC256/TD/64M
500gb SATA
1x Plextor PX-M402U
1x HD5000
R5.5 Upgrade from F27

cenvee
I was not able to get the Delayed settings script to work in my Channel Change script.

There might be a way to test that it is even working. Thought I saw something about logging the output.

I did test it and found that when a channel was tinny I could run that script from a terminal and it would clean it up.

So knowing that and knowing that 99% of my recordings are either at the top of the hour or at the bottom of the hour. I inserted a Cron that ran the script.

Since I also add a couple of extra minutes by default to account for the programmers slop, it usually gets everything in my captures clean.

Just a thought.

Do you mean the "delayed_settings.sh" script? Or just the single line of that script that deals with the 150's audio?

I know that getting cron to do it is overkill and inelegant, but I'd rather have good audio on my recordings, so that's a good option to consider. Thanks.

I just logged into the box that was actually doing my capture while it was having issues and ran



That always cleared up the audio when I had the correct card and video #

In the case of my PVR-500 it has two to set.

Once I had them figured out as root I ran crontab -e
and inserted the following.


Then of course did Control -X to close it accepting the write out option.

This was for my Box with a PVR-500.

When I start a recording about 40% start out with Tinny audio and at the Hour or half hour it clears up.

I have to admit it is not elegant and it is more like a messy but neatly placed sledge hammer but it -

Makes momma happy

Once of these days, I'll make it work when I change channels.

I just noticed one typo and one other difference in the script posted in the other thread. I've fixed the delayed_settings.sh script on my system and will hope it helps the script run.