Initial commit

generate-am-radio/bin/build

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+#!/bin/bash
+
+gcc filter-radio.c -static -lm -o filter-radio

generate-am-radio/bin/filter-radio.c

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+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+
+float level_with_fading (float level, long t, float fast_period, float medium_period, float long_period, float extralong_period) {
+  return level
+         + 0.4 * level * sin(t / extralong_period)
+         + 0.3 * level * sin(t / long_period)
+         + 0.2 * level * sin(t / medium_period)
+         + 0.1 * level * sin(t / fast_period);
+}
+
+int main (int argc, char *argv[]) {
+
+  // Randomize from frequency value
+  srand(atof(argv[3]));
+
+  // Signal component levels
+  // Payload signal
+  float signal_level_mkv = 10.0;
+  if (argc > 4) {
+    signal_level_mkv = (float) atoi(argv[4]);
+  }
+  float signal_fading_fast_period = rand() % 1000 + 300,
+        signal_fading_medium_period = rand() % 15000 + 17500,
+        signal_fading_long_period = rand() % 40000 + 60000,
+        signal_fading_extralong_period = rand() % 200000 + 150000;
+
+  // Payload signal echo
+  float echo_level_mkv = 0.3,
+        echo_fading_fast_period = rand() % 2000 + 1500,
+        echo_fading_medium_period = rand() % 7000 + 4000,
+        echo_fading_long_period = rand() % 50000 + 25000,
+        echo_fading_extralong_period = rand() % 200000 + 150000;
+  const int echo_size_samples = 1000;
+
+  // Background signal
+  float bg_signal_level_mkv = 0.2,
+        bg_signal_fading_fast_period = rand() % 2000 + 1500,
+        bg_signal_fading_medium_period = rand() % 7000 + 4000,
+        bg_signal_fading_long_period = rand() % 50000 + 25000,
+        bg_signal_fading_extralong_period = rand() % 200000 + 150000;
+
+  // Interference noise
+  float interference_level_mkv = 0.02,
+        interference_freq_factor = rand() % 1000 / 1000.0 * 3.0 + 1.0,
+        interference_fading_fast_period = rand() % 2000 + 1500,
+        interference_fading_medium_period = rand() % 7000 + 4000,
+        interference_fading_long_period = rand() % 50000 + 25000,
+        interference_fading_extralong_period = rand() % 200000 + 150000;
+
+  // White (or brown) noise
+  float noise_level_mkv = 0.1;
+
+  // Vars
+  // Signal component values
+  float signal,
+        echo,
+        bg_signal,
+        noise, noise_src,
+        interference;
+
+  // Current levels
+  float signal_cur_level,
+        echo_cur_level,
+        bg_signal_cur_level,
+        noise_cur_level,
+        interference_cur_level;
+  float common_cur_level, common_signal_src;
+
+  // Other vars
+  float output, prev_output;
+
+  // Time counter
+  long t = 0;
+
+  // Signal source
+  FILE *f, *bg_f;
+  f = fopen(argv[1], "r");
+  bg_f = fopen(argv[2], "r");
+
+  // Echo source
+  float echo_buffer[echo_size_samples];
+  memset(echo_buffer, 0, echo_size_samples);
+
+  while (!feof(f)) {
+
+    // Signals
+    signal = fgetc(f);
+    echo = echo_buffer[t % echo_size_samples];
+    bg_signal = fgetc(bg_f);
+    interference = 100 + 100 * sin(t / interference_freq_factor);
+    noise_src = rand() % 256;
+    noise = 0.5 * noise + 0.5 * noise_src;
+
+    // Current levels
+    signal_cur_level       = level_with_fading(signal_level_mkv, t, signal_fading_fast_period, signal_fading_medium_period, signal_fading_long_period, signal_fading_extralong_period);
+    echo_cur_level         = level_with_fading(echo_level_mkv, t, echo_fading_fast_period, echo_fading_medium_period, echo_fading_long_period, echo_fading_extralong_period);
+    bg_signal_cur_level    = level_with_fading(bg_signal_level_mkv, t, bg_signal_fading_fast_period, bg_signal_fading_medium_period, bg_signal_fading_long_period, bg_signal_fading_extralong_period);
+    noise_cur_level        = noise_level_mkv;
+    interference_cur_level = level_with_fading(interference_level_mkv, t, interference_fading_fast_period, interference_fading_medium_period, interference_fading_long_period, interference_fading_extralong_period);
+
+    // Common level
+    common_cur_level = signal_cur_level + echo_cur_level + bg_signal_cur_level + noise_cur_level + interference_cur_level;
+
+    // Common signal
+    common_signal_src = signal * signal_cur_level + echo * echo_cur_level + bg_signal * bg_signal_cur_level + noise * noise_cur_level + interference * interference_cur_level;
+
+    // Output with AGC
+    output = common_signal_src / common_cur_level;
+    printf("%c", (char)(0.5 * output + 0.5 * prev_output));
+
+    echo_buffer[t % echo_size_samples] = signal;
+    prev_output = output;
+
+    t++;
+  }
+
+  fclose(f);
+  fclose(bg_f);
+  return 0;
+}

generate-am-radio/bin/play-to-stream-vorbis.xml.tpl

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+<ezstream>
+    <url>http://127.0.0.1:8092/[FREQ]am</url>
+    <sourcepassword>hackme</sourcepassword>
+
+    <format>VORBIS</format>
+    <filename>stdin</filename>
+
+    <stream_once>1</stream_once>
+
+    <svrinfourl>/[FREQ]am</svrinfourl>
+
+    <svrinfobitrate>32</svrinfobitrate>
+    <svrinfoquality>3.0</svrinfoquality>
+    <svrinfochannels>1</svrinfochannels>
+    <svrinfosamplerate>8000</svrinfosamplerate>
+
+    <svrinfopublic>0</svrinfopublic>
+</ezstream>

generate-am-radio/bin/stream-radio

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+#!/bin/bash
+
+DIR=`cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd`
+
+sed 's/\[FREQ\]/'$3'/g' $DIR/play-to-stream-vorbis.xml.tpl > $DIR/config/play-to-stream-vorbis-${3}am.xml
+chmod 644 $DIR/config/play-to-stream-vorbis-${3}am.xml
+
+mkfifo $DIR/pipes/pipe-main-${3}am
+mkfifo $DIR/pipes/pipe-bg-${3}am
+
+ffmpeg -v 0 -i $1 -f wav -ar 8000 -ac 1 -acodec pcm_u8 - | pv -q > $DIR/pipes/pipe-main-${3}am &
+ffmpeg -v 0 -i $2 -f wav -ar 8000 -ac 1 -acodec pcm_u8 - | pv -q > $DIR/pipes/pipe-bg-${3}am &
+
+$DIR/filter-radio $DIR/pipes/pipe-main-${3}am $DIR/pipes/pipe-bg-${3}am $3 $4 \
+    | oggenc -Q -r -B 8 -R 8000 -C 1 - -o - \
+    | ezstream -c $DIR/config/play-to-stream-vorbis-${3}am.xml

generate-am-radio/stop-all-streams

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+#!/bin/bash
+
+killall stream-radio
+killall ffmpeg
+killall ezstream
+rm bin/pipes/*

generate-am-radio/stream-template-1206am

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+#!/bin/bash
+
+DIR=`cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd`
+
+$DIR/bin/stream-radio \
+  "PUT_YOUR_FAVORITE_AUDIO_STREAM_HERE"\
+  "PUT_HERE_ANY_BACKGROUND_STREAM"\
+  1206\
+  1\
+  &

icecast/icecast-config.xml

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+<icecast>
+    <limits>
+        <clients>100</clients>
+        <sources>10</sources>
+        <threadpool>5</threadpool>
+        <queue-size>131072</queue-size>
+        <client-timeout>30</client-timeout>
+        <header-timeout>30</header-timeout>
+        <source-timeout>30</source-timeout>
+        <burst-on-connect>1</burst-on-connect>
+        <burst-size>32768</burst-size>
+    </limits>
+
+    <authentication>
+        <source-password>hackme</source-password>
+        <relay-password>hackme</relay-password>
+        <admin-user>admin</admin-user>
+        <admin-password>hackme</admin-password>
+    </authentication>
+
+    <hostname>localhost</hostname>
+
+    <listen-socket>
+        <port>8092</port>
+    </listen-socket>
+
+    <fileserve>1</fileserve>
+    <paths>
+        <basedir>/usr/share/icecast2</basedir>
+        <logdir>.</logdir>
+        <webroot>/usr/share/icecast2/web</webroot>
+        <adminroot>/usr/share/icecast2/admin</adminroot>
+        <pidfile>/usr/share/icecast2/icecast.pid</pidfile>
+        <alias source="/" dest="/status.xsl"/>
+    </paths>
+
+    <logging>
+        <accesslog>access.log</accesslog>
+        <errorlog>error.log</errorlog>
+        <loglevel>1</loglevel>
+        <logsize>10000</logsize>
+    </logging>
+
+    <security>
+        <chroot>0</chroot>
+        <changeowner>
+            <user>icecast2</user>
+            <group>icecast</group>
+        </changeowner>
+    </security>
+</icecast>

icecast/start-icecast

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+#!/bin/bash
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+icecast2 -b -c $DIR/icecast-config.xml

icecast/stop-icecast

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+#!/bin/bash
+
+pkill icecast2