126 lines
No EOL
3.3 KiB
Markdown
126 lines
No EOL
3.3 KiB
Markdown
+++
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title = 'Command Line Call'
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date = 2024-05-27T20:15:23-05:00
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draft = true
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+++
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# Calling from the command line
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I was thinking about setting up Jitsi recently and have been researching internet audio and video calling.
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# One to one example code
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```bash
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# Record audio and send it to whatever's listening on 127.0.0.1:6969
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arecord -f S16 -r 48000 - | nc -u 127.0.0.1 6969
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# Receive audio from port 6969 and play it
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nc -lvp 6969 | aplay -f S16 -r 48000 -
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```
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# Multiple people chat example
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## Client(s)
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```bash
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# Record audio and send it to whatever's listening on 127.0.0.1:6969
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#arecord -f S16 -r 48000 - | nc -u 127.0.0.1 6969
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# Receive audio from port 6969 and play it
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#nc -u <server> 6970 | aplay -f S16 -r 48000 -
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arecord -f S16 -r 48000 - | nc -u <server> 6969 | aplay -f S16 -r 48000 -
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```
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## Server
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```perl
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#!/usr/bin/env perl
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use v5.36;
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use IO::Socket::INET;
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use Time::HiRes 'gettimeofday';
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my $listen_addr = "0.0.0.0";
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my $port = 6969;
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my $udp_max_datagram_size = 65535;
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my $sample_rate = 48000;
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my $sample_template = "s";
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my $last_time;
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my $buffer;
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sub fit_together($audio_in) {
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my @temp1 = unpack "$sample_template*", $buffer;
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my @temp2 = unpack "$sample_template*", $audio_in;
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my $time_diff = gettimeofday() - $last_time;
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my $sample_skip = floor($time_diff * $sample_rate);
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@temp1 = @temp1[ $sample_skip .. $#temp1 ];
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while ($#temp1 < $#temp2) {
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push @temp1, 0;
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}
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while ($#temp2 < $#temp1) {
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push @temp2, 0;
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}
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$last_time = gettimeofday();
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return (@temp1, @temp2);
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}
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sub process_audio_in($peer, $audio_in) {
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if(not $last_time) {
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$last_time = gettimeofday();
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$buffer = $audio_in;
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} else {
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my (@temp1, @temp2) = fit_together($audio_in);
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$buffer = pack "$sample_template*",
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map {
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my $addition = $temp1[$_]+$temp2[$_];
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if($addition > $sample_max) {
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$sample_max
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} elsif($addition < $sample_min) {
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$sample_min
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} else {
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$addition
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}
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} 0..$#temp1;
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}
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}
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my $sock = IO::Socket::INET->new(
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LocalAddr => "$listen_addr:$port",
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Proto => "udp"
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) or die "INET Socket no work :( $@";
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say "Listening for clients on addr $listen_addr:$port";
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while("humanity" != "extinct") {
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my $audio_data_in = eval {
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$sock->recv($udp_max_datagram_size) or die "INET Socket recv() fail: $!";
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};
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if ($@) {
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say "Peer ".$sock->peername." sent invalid request, skipping: $@";
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next;
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}
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process_audio($sock->peername, $audio_data_in);
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eval {
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$sock->send($buffer, $#next_packet) or die "INET Socket recv() fail: $!";
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}
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if ($@) {
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say "Failed to send audio packet to ".$sock->peername.": $@";
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}
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}
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```
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The issue with this is that it's not private or anonymous. My attempts to tackle these issues is detailed below:
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# Making it secure
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Anonymity and privacy can be easily added by simply running nc with `torsocks` on the sending end and running `nc` behind `tor` on the receiving end. i2p could also probably be used for this.
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```bash
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arecord -f S16 -r 48000 - | torsocks nc example.onion 6969
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```
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The audio will be anonymous due to tor's design. The audio will also be encrypted by the hidden service tunnel.
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# Authentication
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TOR Access Keys |