From 82139e2be34e13ac92432d9454fb6949d2ea5900 Mon Sep 17 00:00:00 2001
From: Antonio Ospite <ao2@ao2.it>
Date: Tue, 6 Dec 2016 16:19:34 +0100
Subject: [PATCH 1/1] Document how to create a more interesting VideoFont
Also add "contrib/ges-split-samples.py", an helper script to split
a video file according to labels defined in Audacity.
And add an example list of such a list of labels exported from Audacity,
it's in "contrib/keyboard videofont master C4 B5-samples.txt" and it can
be used to split in samples the example VideoFont at
https://youtu.be/7Btp80LPqRs
---
README.md | 47 ++++++++++-
contrib/ges-split-samples.py | 91 ++++++++++++++++++++++
.../keyboard videofont master C4 B5-samples.txt | 26 +++++++
3 files changed, 160 insertions(+), 4 deletions(-)
create mode 100755 contrib/ges-split-samples.py
create mode 100644 contrib/keyboard videofont master C4 B5-samples.txt
diff --git a/README.md b/README.md
index 4c4180c..9d2d858 100644
--- a/README.md
+++ b/README.md
@@ -10,17 +10,56 @@ vidi-timeline allows to create more easily videos like these:
* Vittorio Saggiomo - Mario Bros Column Chromatography - https://youtu.be/mxi3z2vDV_0
-Examples of use
-===============
+How to create a VideoFont
+=========================
-vidi-timeline.py
-----------------
+Synthetic VideoFont
+-------------------
Create a synthetinc VideoFont:
$ ./create_test_videofont.py videofont/
+From a video recording
+----------------------
+
+A VideoFont can also be created by recording a video, and then splitting the
+recording in samples, one sample per note.
+
+For an example of a master VideoFont see
+[keyboard videofont master C4 B5](https://youtu.be/7Btp80LPqRs)
+
+A file like the one above can be analyzed with [Audacity][1] to find the start
+and the end time of the individual samples:
+
+* use the `Analyze -> Sound Finder...` to find the samples;
+* use the [`Pitch Detect" plugin`][2] to find the pitch of the samples and name
+ them accordingly;
+* maybe add an interval named "rest" to represent the absence of sound;
+* export the labels track with `File -> Export Labels...`;
+
+[1]: http://www.audacityteam.org/
+[2]: http://wiki.audacityteam.org/wiki/Nyquist_Analyze_Plug-ins#Pitch_Detect
+
+An example of such a file prodiced by audacity can be found in the `contrib/`
+directory and it can be used as follows:
+
+ $ youtube-dl -t https://youtu.be/7Btp80LPqRs
+ $ ./contrib/ges-split-samples.py \
+ "keyboard videofont master C4 B5-7Btp80LPqRs.mp4" \
+ "contrib/keyboard videofont master C4 B5-samples.txt" \
+ videofont/ > split.sh
+ $ mkdir videofont/
+ $ sh split.sh && rm split.sh
+
+
+Examples of use
+===============
+
+vidi-timeline.py
+----------------
+
Play the timeline from a MIDI file using the samples from the VideoFont:
$ ./vidi-timeline.py examples/Beyer\ Op.\ 101\ -\ Exercise\ 008.midi videofont/
diff --git a/contrib/ges-split-samples.py b/contrib/ges-split-samples.py
new file mode 100755
index 0000000..167c4f1
--- /dev/null
+++ b/contrib/ges-split-samples.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+#
+# ges-split-samples - generate commands to split a video file into samples
+#
+# Copyright (C) 2016 Antonio Ospite <ao2@ao2.it>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import sys
+
+CLIP_FORMAT = "video/webm:video/x-vp8:audio/x-vorbis"
+CLIP_FILE_EXTENSION = "webm"
+CLIP_FILENAME_TEMPLATE = "sample_%s.%s"
+
+
+def parse_audacity_labels(samples_list_filename):
+ """Parse labels exported from Audacity.
+
+ NOTE: Audacity uses the current user locale when exporting the labels, but
+ this way there is no portable way to parse the output, so we just assume
+ here that the C locale was used.
+
+ Basically run "LANG=C audacity" before exporting the data.
+ """
+ samples = []
+
+ with open(samples_list_filename, "r") as samples_list_file:
+ for row in samples_list_file:
+ if row.startswith('#'):
+ continue
+
+ start_time, end_time, sample_name = row.split()
+
+ start_time = float(start_time)
+ end_time = float(end_time)
+
+ samples.append((sample_name, start_time, end_time))
+
+ return samples
+
+
+def usage():
+ print("usage: %s <video_file> <samples_list_file> <destination_dir>"
+ % os.path.basename(sys.argv[0]))
+ print("sample_list_file is in the format used by Audacity when exporting Label Tracks")
+
+
+def main():
+ if len(sys.argv) > 1 and sys.argv[1] in ["-h", "--help"]:
+ usage()
+ return 0
+
+ if len(sys.argv) < 4:
+ usage()
+ return 1
+
+ master_file = sys.argv[1]
+ samples_list_filename = sys.argv[2]
+ destination_dir = sys.argv[3]
+
+ samples = parse_audacity_labels(samples_list_filename)
+ for sample_name, start_time, end_time in samples:
+ duration = round(end_time - start_time, 2)
+ clip_filename = CLIP_FILENAME_TEMPLATE % (sample_name,
+ CLIP_FILE_EXTENSION)
+ clip_path = os.path.join(destination_dir, clip_filename)
+ print("ges-launch-1.0 +clip \"%s\" inpoint=%s duration=%s -o \"%s\" --format=\"%s\"" %
+ (master_file, start_time, duration, clip_path, CLIP_FORMAT))
+
+ if sample_name == "rest":
+ rest_sample_filename = CLIP_FILENAME_TEMPLATE % (sample_name, "png")
+ rest_sample_path = os.path.join(destination_dir,
+ rest_sample_filename)
+ print("gst-launch-1.0 filesrc location=\"%s\" ! decodebin ! videoconvert ! pngenc snapshot=1 ! filesink location=\"%s\"" %
+ (clip_path, rest_sample_path))
+
+
+if __name__ == "__main__":
+ sys.exit(main())
diff --git a/contrib/keyboard videofont master C4 B5-samples.txt b/contrib/keyboard videofont master C4 B5-samples.txt
new file mode 100644
index 0000000..bdc157e
--- /dev/null
+++ b/contrib/keyboard videofont master C4 B5-samples.txt
@@ -0,0 +1,26 @@
+# Samples list in https://youtu.be/7Btp80LPqRs
+4.050000 11.140000 C4
+13.290000 21.060000 C#4
+23.850000 30.210000 D4
+33.710000 38.360000 Eb4
+43.120000 47.430000 E4
+51.870000 56.010000 F4
+60.830000 65.490000 F#4
+69.750000 73.940000 G4
+78.850000 82.950000 Ab4
+86.920000 90.720000 A4
+96.110000 100.270000 Bb4
+104.690000 108.460000 B4
+111.820000 115.890000 C5
+118.920000 122.760000 C#5
+125.790000 130.070000 D5
+133.670000 138.080000 Eb5
+141.280000 146.030000 E5
+149.740000 154.330000 F5
+158.140000 163.260000 F#5
+166.370000 169.400000 G5
+171.810000 175.920000 Ab5
+178.050000 181.720000 A5
+184.510000 188.540000 Bb5
+192.340000 196.340000 B5
+199.000000 200.850000 rest
--
2.1.4