Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm trying to script some testing of Wowza Media Server. Basically, I'm attempting to just beat the living bejeepers out of the thing. I have 5 slightly older computers, originally XP boxes, which I have installed Mint 15 on. I have a script that basically calls the file (or a symbolic link to the file) and takes it into avconv, then dumps it into null.

The idea here is that with 5 of these computers all starting a new thread every second, up to the max they can handle without freezing, we'll get a decent idea of what our current implementation can handle. The script I have works great, but only on some machines. The systems are all the same hardware, and I installed the same software on them in the beginning, although some of them may have had additional packages installed for various tasks since then. The command I issue in script is:

avconv version 0.8.6-6:0.8.6-1ubuntu2, Copyright (c) 2000-2013 the Libav developers
built on Mar 30 2013 22:20:06 with gcc 4.7.2
[h264 @ 0xd87ae0] mmco: unref short failure
[applehttp @ 0xd80d40] max_analyze_duration reached
[applehttp @ 0xd80d40] Estimating duration from bitrate, this may be inaccurate
Input #0, applehttp, from     '':
  Duration: 02:05:54.00, start: 27.728000, bitrate: N/A
    Stream #0.0: Data: [21][0][0][0] / 0x0015
      variant_bitrate : 1610015
    Stream #0.1: Video: h264 (Main), yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 23.98 tbr, 90k tbn, 47.95 tbc
      variant_bitrate : 1610015
    Stream #0.2: Audio: aac, 48000 Hz, 5.1, s16
      variant_bitrate : 1610015
[buffer @ 0x13e02c0] w:1280 h:720 pixfmt:yuv420p
[libvo_aacenc @ 0x12c49c0] Unable to set encoding parameters
Output #0, mp4, to '/dev/null':
    Stream #0.0: Video: mpeg4, yuv420p, 1280x720 [PAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 23.98 tbc
      variant_bitrate : 1610015
    Stream #0.1: Audio: libvo_aacenc, 48000 Hz, 5.1, s16, 200 kb/s
      variant_bitrate : 1610015
Stream mapping:
  Stream #0:1 -> #0:0 (h264 -> mpeg4)
  Stream #0:2 -> #0:1 (aac -> libvo_aacenc)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height

Any clues would be greatly appreciated. Thanks!

share|improve this question

The problem seems to be that your input is 5.1 and libvo_aacenc only supports stereo.

So either use a different encoder or downmix (-ac 2) or don't transcode audio at all (-c:a copy).

share|improve this answer
@slhck and Anton, can you suggest a 5.1 encoder? or a command to list them in ffmpeg? – jiggunjer Dec 8 '15 at 4:38
@jiggunjer The -encoders option lists all encoders. I would try to use libfdk_aac, which is one of the highest quality encoders with 5.1 support. (You may need to compile avconv/ffmpeg with libfdk support.) – slhck Dec 9 '15 at 9:35
@slhck Thanks. I won't be compiling it for my windows anytime soon, the configure/make toolchain gives me a headache. If only they knew cmake... – jiggunjer Dec 10 '15 at 0:58

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .