diff --git a/.github/scripts/install-bionic.sh b/.github/scripts/install-bionic.sh
index 0078e9769..a39de7135 100755
--- a/.github/scripts/install-bionic.sh
+++ b/.github/scripts/install-bionic.sh
@@ -15,6 +15,7 @@ apt-get install -y gstreamer1.0-plugins-base \
   liquidsoap-plugin-vorbis \
   python3-gst-1.0 \
   silan \
+  ffmpeg \
   gcc \
   gir1.2-gtk-3.0 \
   python3-setuptools \
diff --git a/python_apps/airtime_analyzer/Makefile b/python_apps/airtime_analyzer/Makefile
index 3e7580b48..9d4260e07 100644
--- a/python_apps/airtime_analyzer/Makefile
+++ b/python_apps/airtime_analyzer/Makefile
@@ -10,7 +10,10 @@ lint:
 	pylint ${MODULE_APP}
 	pylint ${MODULE_TESTS}
 
-test:
+fixtures:
+	bash tests/fixtures/generate.sh
+
+test: fixtures
 	pytest -n ${CPU_CORES} --color=yes -v --cov=${MODULE_APP} ${MODULE_TESTS}
 
 all: lint test
diff --git a/python_apps/airtime_analyzer/tests/fixtures/.gitignore b/python_apps/airtime_analyzer/tests/fixtures/.gitignore
new file mode 100644
index 000000000..7d5670696
--- /dev/null
+++ b/python_apps/airtime_analyzer/tests/fixtures/.gitignore
@@ -0,0 +1 @@
+s*-*
diff --git a/python_apps/airtime_analyzer/tests/fixtures/__init__.py b/python_apps/airtime_analyzer/tests/fixtures/__init__.py
new file mode 100644
index 000000000..d6a02ee35
--- /dev/null
+++ b/python_apps/airtime_analyzer/tests/fixtures/__init__.py
@@ -0,0 +1,270 @@
+from collections import namedtuple
+from datetime import timedelta
+from pathlib import Path
+
+from pytest import approx
+
+here = Path(__file__).parent
+fixtures_path = here
+
+FILE_INVALID_DRM = here / "invalid.wma"
+FILE_INVALID_TXT = here / "invalid.txt"
+
+Fixture = namedtuple(
+    "Fixture",
+    ["path", "length", "cuein", "cueout", "replaygain"],
+)
+
+# length,cuein,cueout
+s1 = [10.0, 2.3, 10.0]
+s2 = [3.9, 0.0, 3.9]
+
+FILES = [
+    # Sample 1 MP3
+    Fixture(here / "s1-jointstereo.mp3", *s1, -1.6),
+    Fixture(here / "s1-mono.mp3", *s1, -0.7),
+    Fixture(here / "s1-stereo.mp3", *s1, -1.6),
+    # Sample 1 FLAC
+    Fixture(here / "s1-mono.flac", *s1, -1.6),
+    Fixture(here / "s1-stereo.flac", *s1, -2.3),
+    # Sample 1 AAC
+    Fixture(here / "s1-mono.m4a", *s1, -4.5),
+    Fixture(here / "s1-stereo.m4a", *s1, -2.3),
+    # Sample 1 Vorbis
+    Fixture(here / "s1-mono.ogg", *s1, -4.3),
+    Fixture(here / "s1-stereo.ogg", *s1, -2.3),
+    # Sample 2 MP3
+    Fixture(here / "s2-jointstereo.mp3", *s2, 6.1),
+    Fixture(here / "s2-mono.mp3", *s2, 6.1),
+    Fixture(here / "s2-stereo.mp3", *s2, 6.1),
+    # Sample 2 FLAC
+    Fixture(here / "s2-mono.flac", *s2, 5.2),
+    Fixture(here / "s2-stereo.flac", *s2, 5.2),
+    # Sample 2 AAC
+    Fixture(here / "s2-mono.m4a", *s2, 2.6),
+    Fixture(here / "s2-stereo.m4a", *s2, 6.1),
+    # Sample 2 Vorbis
+    Fixture(here / "s2-mono.ogg", *s2, 2.3),
+    Fixture(here / "s2-stereo.ogg", *s2, 5.2),
+]
+
+FixtureMeta = namedtuple(
+    "FixtureMeta",
+    ["path", "metadata"],
+)
+
+meta = {
+    "cuein": 0.0,
+    "sample_rate": 48000,
+    "length": str(timedelta(seconds=10)),
+    "length_seconds": approx(10.0, abs=0.1),
+    "ftype": "audioclip",
+    "hidden": False,
+    # Tags
+    "album_title": "Test Album",
+    "artist_name": "Test Artist",
+    "track_title": "Test Title",
+    "track_number": "1",
+    "track_total": "10",
+    "year": "1999",
+    "genre": "Test Genre",
+    "comment": "Test Comment",
+}
+
+FILES_TAGGED = [
+    FixtureMeta(
+        here / "s1-jointstereo-tagged.mp3",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(161094, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged.mp3",
+        {
+            **meta,
+            "bit_rate": approx(64000, abs=1e2),
+            "channels": 1,
+            "filesize": approx(80646, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged.mp3",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(161094, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged.flac",
+        {
+            **meta,
+            "bit_rate": approx(454468, abs=1e2),
+            "channels": 1,
+            "filesize": approx(576516, abs=1e2),
+            "mime": "audio/flac",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged.flac",
+        {
+            **meta,
+            "bit_rate": approx(687113, abs=1e2),
+            "channels": 2,
+            "filesize": approx(867323, abs=1e2),
+            "mime": "audio/flac",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged.m4a",
+        {
+            **meta,
+            "bit_rate": approx(65000, abs=5e4),
+            "channels": 2,  # Weird
+            "filesize": approx(80000, abs=1e5),
+            "mime": "audio/mp4",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged.m4a",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e5),
+            "channels": 2,
+            "filesize": approx(150000, abs=1e5),
+            "mime": "audio/mp4",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged.ogg",
+        {
+            **meta,
+            "bit_rate": approx(80000, abs=1e2),
+            "channels": 1,
+            "filesize": approx(81340, abs=1e2),
+            "mime": "audio/vorbis",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged.ogg",
+        {
+            **meta,
+            "bit_rate": approx(112000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(104036, abs=1e2),
+            "mime": "audio/vorbis",
+        },
+    ),
+]
+
+meta = {
+    **meta,
+    "album_title": "Ä ä Ü ü ß",
+    "artist_name": "てすと",
+    "track_title": "ｱｲｳｴｵｶｷｸｹｺｻｼｽｾｿﾀﾁﾂﾃ",
+    "track_number": "1",
+    "track_total": "10",
+    "year": "1999",
+    "genre": "Я Б Г Д Ж Й",
+    "comment": "Ł Ą Ż Ę Ć Ń Ś Ź",
+}
+
+FILES_TAGGED += [
+    FixtureMeta(
+        here / "s1-jointstereo-tagged-utf8.mp3",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(161161, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged-utf8.mp3",
+        {
+            **meta,
+            "bit_rate": approx(64000, abs=1e2),
+            "channels": 1,
+            "filesize": approx(80713, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged-utf8.mp3",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(161161, abs=1e2),
+            "mime": "audio/mp3",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged-utf8.flac",
+        {
+            **meta,
+            "bit_rate": approx(454468, abs=1e2),
+            "channels": 1,
+            "filesize": approx(576583, abs=1e2),
+            "mime": "audio/flac",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged-utf8.flac",
+        {
+            **meta,
+            "bit_rate": approx(687113, abs=1e2),
+            "channels": 2,
+            "filesize": approx(867390, abs=1e2),
+            "mime": "audio/flac",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged-utf8.m4a",
+        {
+            **meta,
+            "bit_rate": approx(65000, abs=5e4),
+            "channels": 2,  # Weird
+            "filesize": approx(80000, abs=1e5),
+            "mime": "audio/mp4",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged-utf8.m4a",
+        {
+            **meta,
+            "bit_rate": approx(128000, abs=1e5),
+            "channels": 2,
+            "filesize": approx(150000, abs=1e5),
+            "mime": "audio/mp4",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-mono-tagged-utf8.ogg",
+        {
+            **meta,
+            "bit_rate": approx(80000, abs=1e2),
+            "channels": 1,
+            "filesize": approx(81408, abs=1e2),
+            "mime": "audio/vorbis",
+        },
+    ),
+    FixtureMeta(
+        here / "s1-stereo-tagged-utf8.ogg",
+        {
+            **meta,
+            "bit_rate": approx(112000, abs=1e2),
+            "channels": 2,
+            "filesize": approx(104104, abs=1e2),
+            "mime": "audio/vorbis",
+        },
+    ),
+]
diff --git a/python_apps/airtime_analyzer/tests/fixtures/generate.sh b/python_apps/airtime_analyzer/tests/fixtures/generate.sh
new file mode 100755
index 000000000..fdc283a4f
--- /dev/null
+++ b/python_apps/airtime_analyzer/tests/fixtures/generate.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+
+set -u
+
+error() {
+  echo >&2 "error: $*"
+  exit 1
+}
+
+command -v ffmpeg > /dev/null || error "ffmpeg command not found!"
+
+cd "$(dirname "${BASH_SOURCE[0]}")" || error "could not change directory!"
+
+# <metadata> <input> <output>
+tag() {
+  metadata="$1" && shift
+  input="$1" && shift
+  output="$1" && shift
+  if [[ ! -f "$output" ]]; then
+    echo "tagging $output from $input with $metadata"
+    ffmpeg -y -i "$input" -f ffmetadata -i "$metadata" -c copy -map_metadata 1 "$output" \
+      2> /dev/null ||
+      error "could not tag $output"
+  fi
+}
+
+# <input> <output> <flags...>
+generate() {
+  input="$1" && shift
+  output="$1" && shift
+  if [[ ! -f "$output" ]]; then
+    echo "generating $output from $input"
+    ffmpeg -y -i "$input" -vn "$@" "$output" \
+      2> /dev/null ||
+      error "could not generate $output"
+  fi
+}
+
+# Generated sample 1
+generate  s1.flac s1-mono.flac         -ac 1   -acodec flac
+generate  s1.flac s1-mono.m4a          -ac 1   -acodec aac
+generate  s1.flac s1-mono.mp3          -ac 1   -acodec libmp3lame
+generate  s1.flac s1-mono.ogg          -ac 1   -acodec libvorbis
+generate  s1.flac s1-stereo.flac       -ac 2   -acodec flac
+generate  s1.flac s1-stereo.m4a        -ac 2   -acodec aac
+generate  s1.flac s1-stereo.mp3        -ac 2   -acodec libmp3lame
+generate  s1.flac s1-stereo.ogg        -ac 2   -acodec libvorbis
+generate  s1.flac s1-jointstereo.mp3   -ac 2   -acodec libmp3lame    -joint_stereo 1
+
+# Generated sample 2
+generate  s2.flac s2-mono.flac         -ac 1   -acodec flac
+generate  s2.flac s2-mono.m4a          -ac 1   -acodec aac
+generate  s2.flac s2-mono.mp3          -ac 1   -acodec libmp3lame
+generate  s2.flac s2-mono.ogg          -ac 1   -acodec libvorbis
+generate  s2.flac s2-stereo.flac       -ac 2   -acodec flac
+generate  s2.flac s2-stereo.m4a        -ac 2   -acodec aac
+generate  s2.flac s2-stereo.mp3        -ac 2   -acodec libmp3lame
+generate  s2.flac s2-stereo.ogg        -ac 2   -acodec libvorbis
+generate  s2.flac s2-jointstereo.mp3   -ac 2   -acodec libmp3lame    -joint_stereo 1
+
+# Tag sample 1
+tag metadata.txt  s1-mono.flac         s1-mono-tagged.flac
+tag metadata.txt  s1-mono.m4a          s1-mono-tagged.m4a
+tag metadata.txt  s1-mono.mp3          s1-mono-tagged.mp3
+tag metadata.txt  s1-mono.ogg          s1-mono-tagged.ogg
+tag metadata.txt  s1-stereo.flac       s1-stereo-tagged.flac
+tag metadata.txt  s1-stereo.m4a        s1-stereo-tagged.m4a
+tag metadata.txt  s1-stereo.mp3        s1-stereo-tagged.mp3
+tag metadata.txt  s1-stereo.ogg        s1-stereo-tagged.ogg
+tag metadata.txt  s1-jointstereo.mp3   s1-jointstereo-tagged.mp3
+
+# Tag utf8 sample 1
+tag metadata-utf8.txt   s1-mono.flac       s1-mono-tagged-utf8.flac
+tag metadata-utf8.txt   s1-mono.m4a        s1-mono-tagged-utf8.m4a
+tag metadata-utf8.txt   s1-mono.mp3        s1-mono-tagged-utf8.mp3
+tag metadata-utf8.txt   s1-mono.ogg        s1-mono-tagged-utf8.ogg
+tag metadata-utf8.txt   s1-stereo.flac     s1-stereo-tagged-utf8.flac
+tag metadata-utf8.txt   s1-stereo.m4a      s1-stereo-tagged-utf8.m4a
+tag metadata-utf8.txt   s1-stereo.mp3      s1-stereo-tagged-utf8.mp3
+tag metadata-utf8.txt   s1-stereo.ogg      s1-stereo-tagged-utf8.ogg
+tag metadata-utf8.txt   s1-jointstereo.mp3 s1-jointstereo-tagged-utf8.mp3
diff --git a/python_apps/airtime_analyzer/tests/test_data/unparsable.txt b/python_apps/airtime_analyzer/tests/fixtures/invalid.txt
similarity index 100%
rename from python_apps/airtime_analyzer/tests/test_data/unparsable.txt
rename to python_apps/airtime_analyzer/tests/fixtures/invalid.txt
diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo-invalid.wma b/python_apps/airtime_analyzer/tests/fixtures/invalid.wma
similarity index 100%
rename from python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo-invalid.wma
rename to python_apps/airtime_analyzer/tests/fixtures/invalid.wma
diff --git a/python_apps/airtime_analyzer/tests/fixtures/metadata-utf8.txt b/python_apps/airtime_analyzer/tests/fixtures/metadata-utf8.txt
new file mode 100644
index 000000000..b950d9662
--- /dev/null
+++ b/python_apps/airtime_analyzer/tests/fixtures/metadata-utf8.txt
@@ -0,0 +1,8 @@
+;FFMETADATA1
+album=Ä ä Ü ü ß
+artist=てすと
+title=ｱｲｳｴｵｶｷｸｹｺｻｼｽｾｿﾀﾁﾂﾃ
+track=1/10
+date=1999
+genre=Я Б Г Д Ж Й
+comment=Ł Ą Ż Ę Ć Ń Ś Ź
diff --git a/python_apps/airtime_analyzer/tests/fixtures/metadata.txt b/python_apps/airtime_analyzer/tests/fixtures/metadata.txt
new file mode 100644
index 000000000..5173fa5f0
--- /dev/null
+++ b/python_apps/airtime_analyzer/tests/fixtures/metadata.txt
@@ -0,0 +1,8 @@
+;FFMETADATA1
+album=Test Album
+artist=Test Artist
+title=Test Title
+track=1/10
+date=1999
+genre=Test Genre
+comment=Test Comment
diff --git a/python_apps/airtime_analyzer/tests/fixtures/s1.flac b/python_apps/airtime_analyzer/tests/fixtures/s1.flac
new file mode 100644
index 000000000..b347c5411
Binary files /dev/null and b/python_apps/airtime_analyzer/tests/fixtures/s1.flac differ
diff --git a/python_apps/airtime_analyzer/tests/fixtures/s2.flac b/python_apps/airtime_analyzer/tests/fixtures/s2.flac
new file mode 100644
index 000000000..7ed131704
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-dualmono.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-dualmono.mp3
deleted file mode 100644
index 1e98b616e..000000000
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-jointstereo.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-jointstereo.mp3
deleted file mode 100644
index 649dc371d..000000000
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-mono.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-mono.mp3
deleted file mode 100644
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-mp3-missingid3header.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-mp3-missingid3header.mp3
deleted file mode 100644
index 0e7181f64..000000000
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-simplestereo.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-simplestereo.mp3
deleted file mode 100644
index 1ae7f078c..000000000
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo-utf8.mp3 b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo-utf8.mp3
deleted file mode 100644
index 2e29e3f2a..000000000
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo.m4a b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo.m4a
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diff --git a/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo.wav b/python_apps/airtime_analyzer/tests/test_data/44100Hz-16bit-stereo.wav
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