Changes between Version 12 and Version 13 of Creating multiple outputs

Timestamp:

Oct 10, 2013, 3:48:16 PM (4 years ago)

Author:

rogerdpack

Comment:

note this option (no picture yet :|)

Creating multiple outputs

@@ -77 +77 @@
 Another option is to output from FFmpeg to "-" then to pipe that to a "tee" command, which can send it to multiple other processes, for instance 2 different other ffmpeg processes for encoding (this may save time, as if you do different encodings, and do the encoding in 2 different simultaneous processes, it might do encoding more in parallel than elsewise).  Un benchmarked, however, see also [http://ffmpeg-users.933282.n4.nabble.com/Multiple-output-files-td2076623.html here].
 
+= Multiple encodings for same input =
+
+If you had one input, then run it through some filters, then encode it to (for instance) several different bitrates to multiple files, then you may be able to save processing power by performing the filtering only once. This can be accomplished via the "map" feature, for instance, in this example the rescaling is performed only once, then encoded to 2 outputs:
+
+{{{
+ffmpeg -i input -an -filter_complex "[0] scale=1000:1000,split=2 
+[a] [b]" -y -map "[a]" output1.avi -map "[b]" output2.avi 
+}}}
+
+Again, you could use the "tee" command, see Parallel Encoding, to possibly do this more quickly, but this example at least avoids scaling twice.
+
 = See also =