ok, I guess I wasn't clear enough so I will go into a bit of more detail on what's going on... I'm using Node-Red with a Raspberry Pi for this project. I have an online video stream that plays all of the time on this device. It's being used for several different functions all at the same time but once it's setup it will just be hooked up to a tv and no user interaction on it. What it does currently is, it plays the online stream without problem(it's a low quality stream so there's not a huge amount of bandwidth or cpu power needed). It also checks every few seconds to see if the video is changing. It does this by taking a picture of the screen every few seconds and compares it with the last picture taken (file size really, using the du command) to see if the video is continuing to play. It will then send me an email and start an alarm if the video stops (I also got it setup to call me on the phone using Twilio too! that was fun). What i want now is a similar check for audio. for it to stop recording if there's silence (or sound below a certain threshold) for 5 seconds. Also, from reading the documentation of SoX and rec, it looks like it can record into a null file (not from a null file) so as to use the other parts of it (the silence detection). The recording source needs to be the same as the system's audio output. Raspberry pi 3 with the normal Raspian distro of linux, doesn't have any built in way to record audio but by searching online I'd found a loopback device by running the command "sudo modprobe snd-aloop". My problem is that when i connect to the pi via ssh and run any kind of rec or sox command, I can't figure out how to get it to use the loopback for recording, and because I can't seem to be able to record from it, I can't even see if it's looping back the system audio... I had thought to use pulseaudio but I couldn't get that to work for me at all because all of the commands will be given from Node-Red in the end... Thanks for the help guys and girls! I really am a newbie at linux and raspberry pi's... --James -- View this message in context: http://sox.10957.n7.nabble.com/Sox-recording-to-null-of-an-audio-loopback-tp5749p5753.html Sent from the SoX mailing list archive at Nabble.com. ------------------------------------------------------------------------------ _______________________________________________ Sox-users mailing list Sox-users@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/sox-users
