carrier wave kill, raw mode

[ghost]

This patch adds arguments to kill the carrier wave on exit, or kill a carrier wave that's still active and clean up the dma after an unclean exit.

It also moves the argument info printing to a separate function and when the program is run without arguments just shows the argument info and exits.

The "raw mode" commits basically do what T4d3o's pull request does but also add a switch to make it optional, support named pipes and won't quit when the pipe blocks: It plays silence until new data arrives instead.

[RamonSmit]

👍 I'm totally going to build this one!

[peppi001]

Unfortunately this version too kill the onboard (pwm, jack) sound output.
Only a reboot solve this problem :(

[ghost]

Yeah, that's because DMA0 which pifm uses is also used for analog sound.
Maybe re-loading the sound driver works, but sound wont work simultaneously
with pifm.
On 25 Feb 2015 21:09, "peppi001" [email protected] wrote:

Unfortunately this version too kill the onboard (pwm, jack) sound output.
Only a reboot solve this problem :(

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[peppi001]

Reloading the sound driver does't solve the problem.
I don't want use simultaneously, but always need to reboot the pi after i use pifm :(
And when i use the analog sound output after reboot and stop playing, and then want to use pifm it doesn't work :(

[ghost]

I'll look into it as soon as i have the time. I'm not familiar with the
inner workings of DMA, but i'd like to be :)
On 26 Feb 2015 08:08, "peppi001" [email protected] wrote:

Reloading the sound driver does't solve the problem.
I don't want use simultaneously, but always need to reboot the pi after i
use pifm :(
And when i use the analog sound output after reboot and stop playing, and
then want to use pifm it doesn't work :(

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#23 (comment)
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[peppi001]

Thanks, that sounds good.

[ghost]

@peppi001 I have learned how the DMA works, but i'm not going to update the code to allow jack audio and radio at the same time. I've bought a realtek dbv-t stick and checked what PiFM does to the the spectrum using sdr#.... holy sh**. It creates strong interference on a 200MHZ wide band and has harmonics even further away than that.

@ChristopheJacquet was not kidding about "don't connect any kind of wire". Sorry.

[peppi001]

@Hatagashira Thx.

[MattDietz]

I can verify this works. Tested with lightshowpi streaming the decoded frames into PiFmRds as a subprocess and it all worked beautifully.