Quiet or non-existent voices, loud explosions and background audio problem with AC3 audio:
As this seems to be the closest thread to my problem, I post here. Playing Xvid (.avi) video files encoded with AC3 (5.1 surround) audio, the voices are non existent or too quiet. I found by right clicking on the screen, MediaMonkey showed the audio file details. On the advice from another thread, downloaded the XP Codec Pack (X Codec Pack), reluctantly, because I don't wish to clog system with codecs. This gave me access via the Start Menu X Codec Pack tab to Alexsander Vigovsky's AC3Filter (Properties dialogue box). More reading online, and found that the problem of quiet voices, loud explosions and background was common on many systems even properly setup 5.1 systems. But much worse for those playing 5.1 AC3 on a stereo system, such as TV speakers. After much fiddling with the AC3Filter, on the Main Page, I set the Output Format to Stereo (not 5.1 surround, nor "Do not change"), (and the Rate to 48000, Format 16 bit). Everything solved once the AC3 set to Stereo output.

[quote="Peke"]Due to nature of MM licensing AC3 is not included in Codec pack[/quote]
Fair enough. Installing K-Lite fixes the issue.

Due to nature of MM licensing AC3 is not included in Codec pack, we will try to find way to make that possible.

There are already few solutions worked on but none still satisfying enough.

Also Just try single AC3Filter http://ac3filter.net/

Additionally try this: http://ptf.com/download/microsoft_windows_xp_video_decoder_checkup_utility/6842/

[quote="Peke"]Have you two tried K-Lite Codec Pack?[/quote]
I have not. I used to install that codec pack with every update they did... but that's been years, and a few systems ago. Though... [i]should[/i] I? How many people who may look to use MM as their video player is going to know about this codec pack and want to install it? Besides, algorithm_colon already notes that non-MM ffdshow plays AC3 fine while MM's version doesn't (something I would be inclined to believe, as VLC has no trouble but MM does).

k-lite codec pack contains ffdshow i believe? Normal ffdshow plays back ac3 audio no problem, it is just the version included in the mediamonkey codec pack that doesn't

Have you two tried K-Lite Codec Pack?

I can't get the version of ffdshow in the codec pack to play anything with ac3 audio (Dolby Digital). If you install ffdhow normally then mediamonkey will use it to play ac3. Maybe ac3 playback is disabled for licensing reasons.

Stream 0
	Type: Video
	Codec: H264 - MPEG-4 AVC (part 10)(avc1)
	Resolution: 1280x720
	Frame rate: 29.970628
Stream 1
	Type: Audio
	Codec: A52 Audio (aka AC3)(a52)
	Language: English
	Channels: Stereo
	Sample rate: 48000 Hz
	Bitrate: 384 kb/s

Stream 0
	Type: Video
	Codec: H264 - MPEG-4 AVC (part 10)(avc1)
	Resolution: 704x400
	Frame rate: 29.970628
Stream 1
	Type: Audio
	Codec: MPEG AAC Audio (mp4a)
	Channels: Stereo
	Sample rate: 48000 Hz

I don't think that GSpot handles MKVs (fully anyway)? Putting in the file that doesn't work, it gives "File Type: Unknown" & "Mime Type: Unknown" and putting in one that works with MM simply gives "File Type: Matroska media file (.MKV)" & "Mime Type: video/x-matroska". Doesn't really tell any information about the codecs? I don't know how to play files with GSpot?

However, it seems VLC gives some info regarding codecs.

File that will play [i]without[/i] audio:
[code]Stream 0
Type: Video
Codec: H264 - MPEG-4 AVC (part 10)(avc1)
Resolution: 1280x720
Frame rate: 29.970628
Stream 1
Type: Audio
Codec: A52 Audio (aka AC3)(a52)
Language: English
Channels: Stereo
Sample rate: 48000 Hz
Bitrate: 384 kb/s[/code]
File that will play [i]with[/i] audio:
[code]Stream 0
Type: Video
Codec: H264 - MPEG-4 AVC (part 10)(avc1)
Resolution: 704x400
Frame rate: 29.970628
Stream 1
Type: Audio
Codec: MPEG AAC Audio (mp4a)
Channels: Stereo
Sample rate: 48000 Hz[/code]

So maybe it [i]is[/i] AC3 that's the problem? Yeah, it definitely seems to be AC3, as I found an AVI with AC3 audio and it too plays without audio in MM4 but is fine in VLC. Perhaps AC3 just isn't supported (yet).

Try http://www.headbands.com/gspot/ to see what codecs is used to play that non-playing MKV and doues GSpot play it.

I've got some MKVs which will play fine video-wise, but have no audio. Yet I have other MKVs which play just fine. Though that's too surprising, as isn't MKV just a container? Anyway, I couldn't tell you what audio encodings are in the ones that play properly, but the couple I've tried that don't play properly have had the following in their comment:

[quote]Stream count: 2
1: video stream, V_MPEG4/ISO/AVC, 1280x720, display: 1280x720, 29.970 fps
2: audio stream, A_AC3, 2 ch., 48000.000 Hz[/quote]

I'm guessing that it's details on the encoding of said videos. I imagine the "audio stream" portion is the only thing relevant. I wouldn't think that it would be AC3 that is the problem, as isn't it a pretty common audio encoding for videos these days? Beyond that, the rest of it could be a foreign language and I would understand it about as well. Honestly not too up on video standards and the like. If need be, I can provide a link to a video that this occurs on.

Note that the videos in question play perfectly fine with VLC. Though MM does do better than WMP, as it doesn't seem to like MKVs at all.