use ffmpeg to merge mp4 files, support clip extraction from multiple parts

pandora/item/models.py

@@ -498,14 +498,21 @@ class Item(models.Model):
                 p.wait()
                 return True
             elif format == "mp4":
-                fd, tmp_output = tempfile.mkstemp('.mp4')
-                shutil.copy(streams[0], tmp_output)
-                for s in streams[1:]:
-                    cmd = ['MP4Box', '-cat', s, tmp_output]
-                    p = subprocess.Popen(cmd, stdout=open('/dev/null', 'w'), stderr=open('/dev/null', 'w'), close_fds=True)
-                    p.wait()
-                shutil.copy(tmp_output, output)
-                os.unlink(tmp_output)
+                fd, tmp_output_txt = tempfile.mkstemp('.txt')
+                with open(tmp_output_txt, 'w') as f:
+                    f.write('\n'.join(["file '{}'".format(path) for path in streams]))
+                cmd = [
+                    settings.FFMPEG,
+                    '-nostats', '-loglevel', 'error',
+                    '-y',
+                    '-f', 'concat', '-safe', '0', '-i', tmp_output_txt,
+                    '-c', 'copy',
+                    output
+                ]
+                p = subprocess.Popen(
+                    cmd, stdout=open('/dev/null', 'w'), stderr=open('/dev/null', 'w'), close_fds=True)
+                p.wait()
+                os.unlink(tmp_output_txt)
                 return True
             else:
                 return None

pandora/item/views.py

@@ -1022,7 +1022,6 @@ def video(request, id, resolution, format, index=None, track=None):
     path = stream.media.path
 
     # server side cutting
-    # FIXME: this needs to join segments if needed
     t = request.GET.get('t')
     if t:
         def parse_timestamp(s):
@@ -1031,8 +1030,19 @@ def video(request, id, resolution, format, index=None, track=None):
             return float(s)
         t = list(map(parse_timestamp, t.split(',')))
         ext = '.%s' % format
+        duration = stream.info['duration']
+
+        # multipart request beyond first part, merge parts and chop that
+        if not index and streams.count() > 1 and stream.info['duration'] < t[1]:
+            video = NamedTemporaryFile(suffix=ext)
+            r = item.merge_streams(video.name, resolution, format)
+            if not r:
+                return HttpResponseForbidden()
+            path = video.name
+            duration = sum(item.json['durations'])
+
         content_type = mimetypes.guess_type(path)[0]
-        if len(t) == 2 and t[1] > t[0] and stream.info['duration'] >= t[1]:
+        if len(t) == 2 and t[1] > t[0] and duration >= t[1]:
             response = HttpResponse(extract.chop(path, t[0], t[1]), content_type=content_type)
             filename = u"Clip of %s - %s-%s - %s %s%s" % (
                 item.get('title'),