This is a test in which PCM data is sent from the server and played back on the client at hand. It may be used when you want to listen to music on a PC with no capacity (?)
The audio file is 〆. Convert to wav with ffmpeg and strip it with sox. For the time being, for CD sound quality.
$ ffmpeg -i hoge.m4a hoge.wav
$ sox hoge.wav -r44100 -c2 -b16 hoge.raw
I still don't know how to use FIFO well. We will write .raw to this FIFO later.
$ mkfifo queue
Use nc to listen for a connection. Send the contents of the FIFO you created earlier (with a little work).
This person will not come back without Ctrl-C. Those who came from the top of this article will not be able to use this terminal here. Launch the next virtual terminal.
$ tail -n99999999 -f queue | cat | base64 | nc -l 50000
Use tail -f to monitor the addition to the FIFO (described later). -n99999999 is a spell to get all the contents of the first time spit out.
The following cat is a relaxing magic. I'm going to imitate the buffer.
Make the data look like 7-bit with base64. The recipient doesn't know if he can receive 8-bit data, so I'm just making it 7-bit.
Listen to port 50000 with nc -l 50000. I'm not sure because I use nc in the atmosphere.
Point the server with telnet. Use aplay for audio playback.
$telnet server address 50000 2>/dev/null | sed '1,3d' | base64 -d | aplay -f cd
telnet connects to the server. Discard the error.
sed truncates the log“ Connecting telnet. Please change if necessary.
Decode with base64 -d.
Play the audio with aplay. -f cd means CD sound quality. If you are interested in speaker aging, you can hear white noise by doing cat/dev/urandom | aplay -f cd.
First, start the server. Then start the client. To play the song, write (additionally) a .raw file to the created FIFO.
$ cat hoge.raw >> queue &
This operation may not come back soon, so I decided to add & to make it work in the background. If you want to continue adding songs, you can execute as follows.
$ wait; cat fuga.raw >> queue &
This command line will probably return when the previous song has finished playing.
The end.
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