Problem with k-lite codec pack

Before I installed K-lite Mega and using only the Windows 7 standard codecs, I was attempting to convert a .wtv file from mpeg-2 with an english ac3-384kbps 48000 6 channel to a mp4 video mpeg4 avc/h.264 with an AAC 128kbps 48000 6 channel. I have successfully converted to mp4 with ac3 and it played back fine as dolby D (5.1) using wmp 11 but would not play using vlc in anything other than dolby pro logic 2. None of the players played back dolby D (5.1) with the AAC file.

I tried encoding with vidcoder and xmedia recode.

So here is the problem...

1. Without K-lite installed the AC3 and WTV files will only play back in dolby D (5.1) in wmp 11 and windows media center. They will not play back in dolby D (5.1) in vlc or wpc. None of the aac files will play in Dolby D (5.1)
2. With K-lite mega installed none of the files (including the ac3) will play in Dolby D (5.1) except the original wtv file and then only in wmp 11 or windows media center.
3. What am I doing wrong and why can I not get the AC3 and ACC files to play back in Dolby D (5.1) with K-lite installed in wmp 11, vlc or wmc?

My setup is as follows Windows 7 Ultimate 64bit HDMI out to an Onkyo receiver to a HDMI TV. I am using the Onkyo to tell me what format it is playing for the audio. The Sound Playback output on my pc is NVIDIA High Definition Audio. All drivers are the latest I can find.

Thanks for any help you can provide.

Dolby Digital is just another name for the AC-3 audio format. It is not the name for 5.1 audio channels.

If you enable audio pass-through (a.k.a bitstreaming), then 5.1 AC-3 will not be decoded on the computer, but instead it is send directly to your receiver. The receiver will then do the actual decoding.

AAC audio is a completely different audio format than AC-3. It is not possible to send this format directly to your receiver. It will be decoded on the computer and converted into 5.1 PCM (= uncompressed audio). The decoded audio is then send to your receiver. HDMI should be capable of sending 5.1 channels, unless you have very old hardware. It is also important to you correctly configure the audio setting in the Windows Control panel. Otherwise just stereo (2.0) might get send to the receiver.

You can enable pass-through in ffdshow audio decoder. There is a checkbox on the "Output" page in its settings. Then Dolby Digital should also work with Media Player Classic.

So check your audio settings and enable bitstreaming. If you still have problem after that, come back, and I can give additional tips.

First thank you for your prompt reply to my first post. Your suggestions did what they needed to make it play with wpc and vlc on both ac3 and acc in multi channel dolby. The 2 things I did was enable pass through in ffdshow and made sure that 5.1 was set in windows control panel. Wmp did not work with AC3 on pass-through. The video opened but would not play (the file did play with just the stock W7 codecs before I installed k-lite). The video did play with wmp on acc in multi channel 5.1 but with about a 2 second delay in audio. I use media browser to play my movies in windows media center and it would not play the ac3 file and played the acc file with the same delay and the output was multi channel 5.1.

So 2 questions:

1. Any suggestions on how to get the AC3 file to play in wmp and wmc? The file did play before I installed k-lite in 5.1.
2. Any suggestions on how to get the acc file to play in wmp and wmc without the delay?

Actually I do not really care about wmp (just figure the 2 are related) but I do care about wmc because that is how we play all of our movies on the big screen and most of my family would not know how to move between wmc and other video players.

Again thank you for all your help. I have spent many many hours on this over the past several months encoding and recoding and different codecs etc and you solved 90% of my problem by sharing your knowledge.

WMP and WMC use codecs from Microsoft by default for playback of .wtv and .mp4 files. So the codec pack should not have any effect on it.

Also useful to know is that Windows uses a 32-bit version of WMP by default, but only includes a 64-bit version of WMC.

Things you can try:
1) Control Panel > Sounds > Your hdmi device > Properties > Advanced > Enable both options under "Exclusive Mode"
2) Control Panel > Sounds > Your hdmi device > Properties > Enhancements > Disable all sound effects
3) Codec Tweak Tool > MS Codec Tweaks > Disable Microsoft Audio decoder (this should be used as a last resort, and allows using decoders from the pack)

A delay of 2 seconds is very long. Strange, and certainly not normal. My first suggestion would be to update your sound driver.
As a workaround you could configure a delay in the audio decoder. ffdshow does not support a negative delay, so you need to use LAV Audio decoder instead. Disable AC-3 and AAC in ffdshow (on Codecs page in its settings). In LAV Audio decoder enable bitstreaming and set a delay of -2000 ms.

Does the delay also occur with for example MP3 audio, or only with AAC?