The lost ALSA to Jack hack - anybody know how?

It is arguable whether it deserves the status of a hack, or only following directions from other distributions, but somehow, I installed Remix_OS and figured out how to play e.g. YouTube videos from Firefox through my Jack-connected Firewire device, the Presonus FP-10. I'd gotten it to work, but didn't write down what I did. I tried to install KDEnlive however, and it complained about the libmlt2 library won't be installed.

I then tried to install Mepis, but in a reportedly unheard of event, it deleted my nicely set-up Remix_OS partition. I reinstalled Remix in the freshly unallocated space, and it is working with KDEnlive installed, and hasn't broken Jack. In order to use sound with KDEnlive, which I was able to install after removing OpenShot, and the existing MLT libraries, I will need to find out how to run ALSA application output into Jack again (or perhaps PulseAudio, although reports about whether it co-exists well with Jack vary). Can anybody give me instructions, or point me to an applicable guide as to how to get ALSA applications, including Flash in Firefox, working in Remix_OS? I know it is possible. I've done it before. I should have taken better notes, because when I try it now, one time I got the music player to play in ALSA, but only a ~ 20 sec. before it seized, and started making a sort of "machine-gun" sound. I was able to stop it. Then I followed some different instructions, and only got an error regarding a PCM device.

Now, I only lack getting ALSA to drive Jack, and all of the essentials I need in a distro will work in Remix_OS

TIA,
CodeLurker

Try "lib64asound2-plugins" or "libasound2-plugins"and read about http://jackaudio.org/routing_alsa

Although it is a 64-bit distribution, I don't find lib64asound2-plugins. Do I need to add a repository? I found libasound2-plugins, and added a script that did the trick before, but it doesn't work currently. I think it is the same script on that webpage. I wonder if I need to install libflashsupport-jack, as suggested on Jack Flash to get flash working. I'll work through your suggestions later today as best I can, and let u know how it went. Thx!

OK, I gave it a try, and the same thing happened that happened when I tried it after the reinstall. I've got Jack up and working through Qjackctl. I installed "libasound2-plugins", not finding a 64-bit version, and have created an ".asoundrc" as directed in the link you gave me. I have chosen the device "plughw:0" and the driver "firewire", and can get Audacious to play back when it is using the Jack driver. When I tell Audacious to use the default output device, it says, in the Preferences | Audio | Current output plugin, "ASLA Output Plugin". Well enough. When I tell it to use the default PCM device by clicking the Preferences button, which seems to be ASLA preferences, and try to play something, I get "snd_pcm open failed. Invalid argument". When I click this same preferences button, and tell it to use Jack as the PCM device, I get the exact same error. When I start Firefox and try to play some sound, such as a youtube page or mp3, I get no sound. I had gotten it to work before, but I can't remember what I did different.

When I try the given example:

"aplay -D pcm.jack ~/afile.wav"

it says

"ALSA lib pcm_plug.c:1273:(_snd_pcm_plug_open) Unknown field playback_ports
aplay: main:660: audio open error: Invalid argument"

I get a similar error when I just execute
"aplay ~/afile.wav"

Interestingly, VLC player will play audio on ALSA set to Jack, but so far, Audacious will not; nor will KDEnlive. It does turn out that KDEnlive will play over ALSA when set to consumer grade audio devices I have. Also, running the Jack control as root gets Reaper running, but seems to break Audacious and VLC player running even with Jack output. I seem to have no sound output at all from Firefox, even over consumer sound devices.

I put my solution to this problem into a complete setup guide for Remix_OS and the applications I use, in the post How I installed Remix_OS and got ALSA and Jack to play nicely together.