full cuts: Support multiple ranges

This allows full cuts to support multiple ranges in the same way fast cuts do,
by using multiple inputs to ffmpeg and concat filters joining them.

This will be easy to add transitions to later as this is "just" replacing a concat filter
with an xfade + afade filter.

common/common/segments.py

@@ -651,40 +651,71 @@ def feed_input(segments, pipe):
 
 
 @timed('cut_range',
-	cut_type=lambda _, segments, start, end, encode_args, stream=False: ("full-streamed" if stream else "full-buffered"),
-	normalize=lambda _, segments, start, end, *a, **k: (end - start).total_seconds(),
+	cut_type=lambda _, segment_ranges, ranges, encode_args, stream=False: ("full-streamed" if stream else "full-buffered"),
+	normalize=lambda _, segment_ranges, ranges, *a, **k: range_total(ranges),
 )
-def full_cut_segments(segments, start, end, encode_args, stream=False):
+def full_cut_segments(segment_ranges, ranges, encode_args, stream=False):
 	"""If stream=true, assume encode_args gives a streamable format,
 	and begin returning output immediately instead of waiting for ffmpeg to finish
 	and buffering to disk."""
 
-	# Remove holes
-	segments = [segment for segment in segments if segment is not None]
+	# for now, hard-code no transitions
+	transitions = [None] * (len(ranges) - 1)
 
-	# how far into the first segment to begin
-	cut_start = max(0, (start - segments[0].start).total_seconds())
-	# duration
-	duration = (end - start).total_seconds()
+	inputs = []
+	for segments, (start, end) in zip(segment_ranges, ranges):
+		# Remove holes
+		segments = [segment for segment in segments if segment is not None]
+		# how far into the first segment to begin
+		cut_start = max(0, (start - segments[0].start).total_seconds())
+		# how long the whole section should be (sets the end cut)
+		duration = (end - start).total_seconds()
+		args = [
+			"-ss", cut_start,
+			"-t", duration,
+		]
+		inputs.append((segments, args))
+
+	filters = []
+	# with no transitions, the output stream is just the first input stream
+	output_video_stream = "0:v"
+	output_audio_stream = "0:a"
+	for i, transition in enumerate(transitions):
+		# combine the current output stream with the next input stream
+		input_streams = [
+			output_video_stream, output_audio_stream,
+			f"{i+1}:v", f"{i+1}:a"
+		]
+		input_streams = "".join(f"[{stream}]" for stream in input_streams)
+		# set new output streams
+		output_video_stream = f"v{i}"
+		output_audio_stream = f"a{i}"
+		outputs = f"[{output_video_stream}][{output_audio_stream}]"
+		if transition is None:
+			filters.append(f"{input_streams}concat=n=2:v=1:a=1{outputs}")
+		else:
+			raise NotImplementedError
 
 	if stream:
 		# When streaming, we can just use a pipe
-		tempfile = subprocess.PIPE
+		output_file = subprocess.PIPE
 	else:
 		# Some ffmpeg output formats require a seekable file.
 		# For the same reason, it's not safe to begin uploading until ffmpeg
 		# has finished. We create a temporary file for this.
-		tempfile = TemporaryFile()
+		output_file = TemporaryFile()
 
 	args = []
-	if cut_start is not None:
-		args += ['-ss', cut_start]
-	if duration is not None:
-		args += ['-t', duration]
-	args += list(encode_args)
-
-	with ffmpeg_cut_many([segments, ()], args, output_file=tempfile) as ffmpeg:
-		# When streaming, we can return data as it is available
+	if filters:
+		args += [
+			"-filter_complex", "; ".join(filters),
+			"-map", f"[{output_video_stream}]",
+			"-map", f"[{output_audio_stream}]",
+		]
+	args += encode_args
+
+	with ffmpeg_cut_many(inputs, args, output_file) as ffmpeg:
+		# When streaming, we can return data as it is available.
 		# Otherwise, just exit the context manager so tempfile is fully written.
 		if stream:
 			for chunk in read_chunks(ffmpeg.stdout):
@@ -692,7 +723,7 @@ def full_cut_segments(segments, start, end, encode_args, stream=False):
 
 	# When not streaming, we can only return the data once ffmpeg has exited
 	if not stream:
-		for chunk in read_chunks(tempfile):
+		for chunk in read_chunks(output_file):
 			yield chunk
 
 

cutter/cutter/main.py

@@ -418,11 +418,8 @@ class Cutter(object):
 						"streamable" if upload_backend.encoding_streamable else "non-streamable",
 						upload_backend.encoding_settings,
 					))
-					if len(job.video_ranges) > 1:
-						raise ValueError("Full cuts do not support multiple ranges")
-					range = job.video_ranges[0]
 					cut = full_cut_segments(
-						job.segment_ranges[0], range.start, range.end,
+						job.segment_ranges, job.video_ranges,
 						upload_backend.encoding_settings, stream=upload_backend.encoding_streamable,
 					)
 

restreamer/restreamer/main.py

@@ -400,10 +400,7 @@ def cut(channel, quality):
 		# encode as high-quality, without wasting too much cpu on encoding
 		stream, muxer, mimetype = (True, 'mpegts', 'video/MP2T') if type == 'mpegts' else (False, 'mp4', 'video/mp4')
 		encoding_args = ['-c:v', 'libx264', '-preset', 'ultrafast', '-crf', '0', '-f', muxer]
-		if len(ranges) > 1:
-			return "full cut does not support multiple ranges at this time", 400
-		start, end = ranges[0]
-		return Response(full_cut_segments(segment_ranges[0], start, end, encoding_args, stream=stream), mimetype=mimetype)
+		return Response(full_cut_segments(segment_ranges, ranges, encoding_args, stream=stream), mimetype=mimetype)
 	else:
 		return "Unknown type {!r}".format(type), 400