Document how to create a more interesting VideoFont

[vidi-player.git] / contrib / ges-split-samples.py

diff --git a/contrib/ges-split-samples.py b/contrib/ges-split-samples.py
new file mode 100755 (executable)
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())