commit 62831c5067126fefaa2d7c0289c07e00ec84b0eb
Author: j <j@mailb.org>
Date:   Wed Aug 9 12:30:58 2017 +0200

    minimal editing system

diff --git a/ffmpeg.py b/ffmpeg.py
new file mode 100644
index 0000000..e680d3e
--- /dev/null
+++ b/ffmpeg.py
@@ -0,0 +1,63 @@
+#!/usr/bin/python3
+import json
+import os
+import subprocess
+import sys
+
+def run(cmd):
+    print(' '.join('"%s"' % c for c in cmd))
+    #subprocess.call(cmd)
+
+
+edit_json = sys.argv[1]
+edit = json.load(open(edit_json))
+
+render = '/tmp/out'
+output = '/tmp/test.mp4'
+height = 270
+aspect = 16/9
+width = int(height * aspect)
+
+n = 0
+files = []
+for clip in edit:
+    out = render + '/%06d.ts' % n
+    clip_aspect = clip['resolution'][0] / clip['resolution'][1]
+    if clip_aspect < aspect:
+        x = width
+        y = int(x / clip_aspect)
+    else:
+        y = height
+        x = int(y * clip_aspect)
+    vf = 'scale=%s:%s' % (x, y)
+    if x != width:
+        vf += ',crop=%s:%s' % (width, height)  # crop center
+    elif y != height:
+        offset = int((y - height) / 2)
+        vf += ',crop=w=%s:h=%s:x=0:y=%s' % (width, height, offset)
+    options = [
+        '-vf', vf,
+        '-aspect', aspect,
+        '-c:v', 'libx264',
+        '-b:v', '8M',
+        '-r:v', '25',
+        '-c:a', 'aac',
+        '-ar', '48000',
+        '-ac', '2',
+        '-b:a', '192k',
+    ]
+    cmd = [
+        'ffmpeg',
+        '-ss', str(clip['in']),
+        '-i', clip['path']
+    ] + options + [
+        '-t', str(clip['out'] - clip['in']),
+        out
+    ]
+    files.append(out)
+    run(cmd)
+    n += 1
+
+files = '|'.join(files)
+cmd = ['ffmpeg', '-y', '-i', 'concat:' + files, '-c', 'copy', output]
+run(cmd)