INTERACT FORUM

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: skipping when playing back iTunes m4a encoded files with heavy usage  (Read 3173 times)

e-head

  • World Citizen
  • ***
  • Posts: 121
skipping when playing back iTunes m4a encoded files with heavy usage
« on: May 19, 2008, 04:31:42 pm »
I have a P4 2.6 GHz machine.

If I do a lot of browsing in MC12 when I'm playing back an iTunes m4a encoded file it will start to skip. Setting the buffer up to 5 seconds doesn't really help much. iTunes plays these files back fine, but it's UI becomes extremely sluggish. Maybe iTunes has a higher priority thread for audio playback, I don't know. I know these files tax the CPU more than mp3's.

My question:
Is there some sort of fiddling I can do with the DirectShow Filters or something that might help? Maybe iTunes uses a faster filter/codec or something? I'm no expert on these matters.

I assume if I had a 2.4 GHz Core 2 Duo this wouldn't be an issue.
Logged

JimH

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 72438
  • Where did I put my teeth?
Re: skipping when playing back iTunes m4a encoded files with heavy usage
« Reply #1 on: May 19, 2008, 04:36:12 pm »
By default, MC would use the Quicktime engine to play those.  This is probably also what iTunes does. 
Logged

Alex B

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 10121
  • The Cosmic Bird
Re: skipping when playing back iTunes m4a encoded files with heavy usage
« Reply #2 on: May 19, 2008, 05:20:25 pm »
No problems here. I tried some heavy browsing and things like video thumbnail creation and searching for non-existent files during m4a playback. My playback bufffer was set to 0.5 s and I used a 2.8 GHz P4.

I use DirectShow for m4a decoding (instead of QuickTime). Here's my graph info:
Quote
Filter Graph Info (Graph for type: m4a):

    Filter 'JRiver Audio Renderer'
        CLSID: {EC1F74A8-7E55-4814-9F9F-D417489075CA}
        Host:
        Input Pin 'In'
            Connected to pin 'Out' of filter 'ffdshow Audio Decoder'
            Major type MEDIATYPE_Audio  Sub type MEDIASUBTYPE_PCM, Format type FORMAT_WaveFormatEx

    Filter 'ffdshow Audio Decoder'
        CLSID: {0F40E1E5-4F79-4988-B1A9-CC98794E6B55}
        Host: C:\Soft\CCCP\Filters\FFDShow\ffdshow.ax
        Output Pin 'Out'
            Connected to pin 'In' of filter 'JRiver Audio Renderer'
            Major type MEDIATYPE_Audio  Sub type MEDIASUBTYPE_PCM, Format type FORMAT_WaveFormatEx
        Input Pin 'In'
            Connected to pin 'Audio' of filter 'Haali Media Splitter'
            Major type MEDIATYPE_Audio  Sub type Unknown GUID Name: {000000FF-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx

    Filter 'Haali Media Splitter'
        CLSID: {55DA30FC-F16B-49FC-BAA5-AE59FC65F82D}
        Host: C:\Soft\CCCP\Filters\Haali\splitter.ax
        Output Pin 'Audio'
            Connected to pin 'In' of filter 'ffdshow Audio Decoder'
            Major type MEDIATYPE_Audio  Sub type Unknown GUID Name: {000000FF-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx

You should able to use the same filters by installing CCCP and enabling DirectShow playback for the m4a file type: http://wiki.jrmediacenter.com/index.php/MP4_and_M4A_File_Support
Logged
The Cosmic Bird - a triple merger of galaxies: http://eso.org/public/news/eso0755

e-head

  • World Citizen
  • ***
  • Posts: 121
Re: skipping when playing back iTunes m4a encoded files with heavy usage
« Reply #3 on: May 19, 2008, 08:08:54 pm »
Thanks for the tip Alex, I'm going to give that a shot. I hear that CCCP is a good mega-codec pack.

Edit:
That worked!
Thanks a million. No more skips.
The cross fade in and out works now too.
Logged

e-head

  • World Citizen
  • ***
  • Posts: 121
Re: skipping when playing back iTunes m4a encoded files with heavy usage
« Reply #4 on: May 19, 2008, 08:16:53 pm »
Hey, one more question for you, since your system is close to mine.

Can you do 1080p video files fine? I have some 1440x1080 wmv9 files encoded at around 8000 kbps and they just kill me (soaring to 100% CPU usage quite frequently). One player does the video fine but chops the audio. Another player does the audio fine but chops the video. I haven't even tried MC12. I have a socket 478 and I can upgrade to a 3 Ghz P4 I think. Someone said this was about the "magic" spot for playing back 1080 stutter free. Just curious if you've tried it on your 2.8. Maybe those ffdshow filters will help?
Logged
Pages: [1]   Go Up
« previous next »