Weird Sync Issues

[koberulz]

I've got an MP4 file, in which the audio is 7.7 seconds ahead of the video when played in VLC. I searched through here for a way to fix it, and came across mention of AVIDemux. Upon opening the file with AVIDemux, the missing 7.7 seconds of video is there, and thus the sound is perfectly in sync.

What on earth is going on?

General
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 58.2 MiB
Duration : 5mn 37s
Overall bit rate : 1 448 Kbps
Encoded date : UTC 2008-02-14 02:34:54
Tagged date : UTC 2008-02-14 02:34:54

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 5mn 36s
Bit rate : 1 300 Kbps
Maximum bit rate : 2 434 Kbps
Width : 592 pixels
Height : 432 pixels
Display aspect ratio : 1.370
Frame rate mode : Constant
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.203
Stream size : 52.7 MiB (90%)
Writing library : x264 core 58 svn-736M
Encoding settings : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x1:0x131 / me=hex / subme=5 / me-prepass=0 / brdo=0 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / chroma_qp_offset=0 / threads=3 / nr=0 / decimate=1 / mbaff=0 / bframes=3 / b_pyramid=0 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / bime=0 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=abr / bitrate=1300 / ratetol=1.0 / rceq='blurCplx^(1-qComp)' / qcomp=1.00 / qpmin=10 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:0.5:13.0
Encoded date : UTC 2008-02-13 15:48:35
Tagged date : UTC 2008-02-14 02:35:01
Material_Duration : 337440
Material_StreamSize : 55331466
Material_FrameCount : 8436

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 5mn 37s
Bit rate mode : Variable
Bit rate : 132.3 Kbps
Maximum bit rate : 140 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 5.27 MiB (9%)
Encoded date : UTC 2008-02-14 02:35:01
Tagged date : UTC 2008-02-14 02:35:01

[transporterfan]

Before I get your hopes up, I have no idea why. I hate AviDemux as it kept crashing on me. Haven't used it for a couple of years.
Best I can offer is the hope you may be able to re-sync the audio with similar help I gave here:

https://forum.videohelp.com/threads/344683-AVIDEMUX-syncing-problems

Someone else may be able to show you a script to do it another way. Good Luck

[test2]

What happens if you save a new mp4 with avidemux?

[koberulz]

The video is fine (including the previously-missing 7.7 seconds), but the audio is running several times faster than it should be. It said something about it being a H.264 file when I first opened it, and recommended I switch to a different mode but warned I would lose frame sync. Which might have something to do with it, or might not, I've no idea.

[hech54]

It's only a 58MB file....and that 58MB file is not going to disappear once you save it as another file.....just try it.

[koberulz]

If you're talking about saving a new mp4 file with avidemux, I did. The video works, but the audio plays absurdly fast. I just said that. The video is 5:37 long, and the audio goes fast enough to be silent by 3:00.

[koberulz]

Anyone?

[Baldrick]

Try several different methods.

Have you tried reconvert it with some other converters? ffmpeg ( winff).

Extract the audio to wav with avidemux. Check if the audio sounds okey. Convert to aac/mp4. Remux to the mp4.

[Selur]

1st try another player than vlc, i.e. smplayer, kmplayer,...
2nd if 1st didn't show that it is a vlc bug, remux with mkvmergegui (mmg, part of mkvtoolnix) by simply starting the tool loading the source and saving it under a new name.
3rd if 2nd didn't help do a full analysis with mediaInfo to see if it detects an audio/video delay and reencode the audio using Hybrid, ffmpeg, avidemux,... or whatever tool you like,...

[koberulz]

It plays fine in MPC. As well as TMPGEnc, which will allow me to burn it to DVD fine anyway, so it doesn't appear as though there's anything that needs fixing. No idea what's wrong with VLC though.

[Hoser Rob]

You could try the newest beta build of avidemux 2.6 ... haven't tried .264 on it myself but I hear it supports it a lot better. It did work fine with a .mpg that crashed 2.5.

I usually avoid betas but there are a few exceptions. Avidemux is one ... with some programs, the betas can be more stable than the betas.