A performance issue on single-core processors fixed in build 3770 (Stanley posted on June 14th, 2007 )

Today I found that recent builds have a critical performance slowdown on single-core processors. As I am using a Intel Core2 which is a dual-core processor, I failed to notice this issue until I was told that MediaCoder’s speed on single-core processors has recently become very slow under some combinations of settings.

After some investigations, I concluded that this issue occurs when following factors meet together:

  • Target video format is XviD
  • Target container is other than AVI (e.g. MP4)
  • Audio is not disabled
  • Audio encoder is an executable (instead of a DLL)

The root cause of the issue is the the priority of audio encoder process is not set properly, which causes the audio transcoding thread to fall behind the video thread seriously and brings performance penalty.

On dual-core processor, this won’t be an issue because a low-priority process (in this case, the audio encoder process, e.g. lame.exe) won’t be blocked by another busy process (in this case, the process of MediaCoder).

Luckily it is found out and fixed. Please update to build 3770.

COMMENTS: 8 Comments »


8 Responses

  1. BlinkN says:

    No wonder I saw, “Priority is set to low”, in the console window when using the default setting.

  2. stanley says:

    Have you ever noticed this issue?

  3. Well hope the audio and video synchronization works for Xvid cos in version 6.x it was off especially in 2-pass mode and with video greater than 30 mins (320×250 avi container Lame MP3).

    It is weird cos it only effects some PC’s like my single core 64bit but not on my old AMD 2800.

    I would have posted this in the forum but I do not think the confirmation emails are being sent out to register.

  4. BlinkN says:

    In the past I did. Not so much now as far as I can tell.

  5. Devanshu says:

    I downloaded the build 3770 but before the installer starts i get NSIS Error : The installer you are trying to use is corrupted or incomplete. This could be the result of a damaged disk, a failed download or a virus. etc ….
    Any reason to this error … i am using windows vista.

  6. dennyhalim says:

    oot. any support for 3gp?

  7. BlinkN says:

    Re-download MediaCoder Devanshu.

  8. Taeko says:

    dennyhalim, yes, MediaCoder supports 3GP and 3GP2 😉