Results 1 to 6 of 6

Thread: mencoder slow when using threads with xvid

  1. #1
    Join Date
    May 2007
    Beans
    563
    Distro
    Kubuntu 8.04 Hardy Heron

    mencoder slow when using threads with xvid

    xvid 1.2.0 supports multi-threaded encoding, so theorically it should be faster in dual core processors.

    I downloaded xvidcore-1.2.1.tar.bz2 and compiled in my kubuntu hardy (amd64)

    I also compiled and installed nasm 2.03.01-1, otherwise xvid was extremely slow.

    But I realized that actually mencoder is slower when using threads with xvid.

    This is the command-line I use:
    Code:
    mencoder -noodml -o $OUTPUT \
      -oac copy \
      -ovc xvid \
      -xvidencopts bitrate=1000 \
      $FILE
    without the threads option it gives about 80 fps while encoding a 624x352 video.

    If I use threads=2

    Code:
    mencoder -noodml -o $OUTPUT \
      -oac copy \
      -ovc xvid \
      -xvidencopts bitrate=1000:threads=2 \
      $FILE
    I see that it's really using the two cores but encoding speed falls to 70 or 75 fps.

    Actually the more threads I use, the slower it is. Using threads=3 gives 28 fps. threads=4 gives 15 fps.

    Is this normal?

  2. #2
    Join Date
    May 2007
    Beans
    563
    Distro
    Kubuntu 8.04 Hardy Heron

    Re: mencoder slow when using threads with xvid

    I tried to compile the xvid daily snapshot (xvid_latest.tar.gz). I noticed that this time it used yasm to compile the assembler code (instead of nasm), but still encoding is slower when using threads

    I can't understand why threads=2 is slower than threads=1...

    BTW, I've uploaded the xvid 1.2.1 packages to https://launchpad.net/~rvm4000/+archive/ppa just in case someone else would like to test it and compare.
    Developer of SMPlayer.

  3. #3
    Join Date
    Sep 2007
    Beans
    5

    Re: mencoder slow when using threads with xvid

    Thanks for the package. I just tried it, and two threads were a bit faster than only one thread (25fps vs. 20fps).

    [CPU: Intel T5600@1.83GHz]

    *dankuoni

  4. #4
    Join Date
    May 2007
    Beans
    563
    Distro
    Kubuntu 8.04 Hardy Heron

    Re: mencoder slow when using threads with xvid

    Did you use the i386 or the amd64 package?
    Developer of SMPlayer.

  5. #5

    Re: mencoder slow when using threads with xvid

    Can't help out cause still using a P4, but last week I wanted to see what was happening with Ht while doing something. The sysstat package proved useful. (mpstat

  6. #6
    Join Date
    Sep 2007
    Beans
    5

    Re: mencoder slow when using threads with xvid

    The i386 package.

    I forogt to mention in my first post that using more than 2 threads slows everything down.

    *dankuoni

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •