I have a problem with mp4 files in virtualdub, slow motion audio.

[barbur]

Hello everyone!

I have a problem with mp4 files, which i'm trying to convert to AVI files with VirtualDub software.
The thing is, when i open the mp4 file: the video is OK, but the audio sounds like a really slow motion movie (or slow playback).
again, the video is perfect but audio slow.

why does it happen and how can it be fixed (if possible)??

Thank you in advance!!

[aedipuss]

not a good thread title, the mods will point out you didn't read the forum rules.

be more specific. give more info about the source files and intended output and how you are going to use it. try mediainfo in text mode on the source and copy/paste the results here.

[barbur]

Thanks aedipuss... didn't know the rules... sorry.

basically, i'm trying to convert the MP4 file to AVI file and after that I want to add subtitles to the video (AVI file) with VD.
I know I can convert MP4 to AVI with other programs (not VD), but I have done this before and now I don't understand why the audio sounds like in slow motion video.

here are the video specs with mediainfo on the source video:

Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 768 MiB
Duration : 1h 49mn
Overall bit rate mode : Variable
Overall bit rate : 981 Kbps
Encoded date : UTC 2011-04-18 04:21:19
Tagged date : UTC 2011-04-18 04:21:19

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 8 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1h 49mn
Bit rate : 850 Kbps
Maximum bit rate : 3 983 Kbps
Width : 1 264 pixels
Height : 528 pixels
Display aspect ratio : 2.40:1
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.053
Stream size : 666 MiB (87%)
Writing library : x264 core 114 r1913 5fd3dce
Encoded date : UTC 2011-04-18 04:21:19
Tagged date : UTC 2011-04-18 04:22:05

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : HE-AAC / LC
Codec ID : 40
Duration : 1h 49mn
Bit rate mode : Variable
Bit rate : 128 Kbps
Maximum bit rate : 137 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz / 24.0 KHz
Compression mode : Lossy
Stream size : 100 MiB (13%)
Encoded date : UTC 2011-04-18 04:22:01
Tagged date : UTC 2011-04-18 04:22:05

thanks again!

[Baldrick]

Slow audio playback in virtualdub? Or/And after you exported to avi?


ANd I changed your thread title.

[barbur]

Hi Baldrick,

Yes, the slow audio playback is in virtualdub. The file type is mp4, so before I make the export to avi...

[Baldrick]

Try export a short sample and see how it sounds. The preview/playback in virtualdub is not that reliable.