How to end noisy MKV start?

[Paultx]

I have a video in MKV that starts with this annoying, loud buzzy noise. Is there a way I can remove or reduce the noise volume to a more bearable level? Or I can only get rid of it by cutting the initial seconds with that noise? TIA.

[aedipuss]

i'd extract the video and audio from the mkv. edit the audio and then merge them back to mkv.

[Paultx]

i'd extract the video and audio from the mkv. edit the audio and then merge them back to mkv.

How can I do that?

I have here on my Windows 10 Pro system:

DVDFab 11.0.2.4 (x64)
HandBrake 1.2.2 (portable)
Inviska MKV Extract 7.0 Portable
mkvtoolnix-64-bit-32.0.0 / MKVExtractGUI2
Format Factory 4.6.0.0

[aedipuss]

mkvextractgui2 save out the audio and video. download audacity(it's a free audio editor). open the audio in audacity, mark out the bad section, reduce the volume there or use a fade in a couple times to reduce the noise. use mkvtoolnix to load the video and audio files and create a new mkv.

[jagabo]

If you install the ffmpeg source plugin for Audacity you don't need to demux the audio from the source MVK file. It can import the audio directly from the MKV.

https://manual.audacityteam.org/man/faq_installing_the_ffmpeg_import_export_library.html

[netmask56]

jajabo beat me to it! what the man said is the simplest!

[jagabo]

If you're only go to use Audacity this one time, it's easier to demux the audio track to edit it. Installing the ffmpeg source filter is a little tricky. On the other hand, if you think you might be using Audacity more in the future it's worth the trouble to install the source filter.

[johns0]

You can also use Mkvmerge and cut to the first key frame which is usually 5 seconds,no need to use any other editors unless the first few seconds contains video you don't want to cut out.

[drjtech]

You can also use Mkvmerge and cut to the first key frame which is usually 5 seconds,no need to use any other editors unless the first few seconds contains video you don't want to cut out.

That's the best fix if it doesn't remove wanted video. I have seen this initial bzzz caused by trimming the start of an mkv file to a non-key frame.

[Paultx]

I used Inviska MKV Extract 7.0 Portable to extract the English audio, which was an MPEG-2 Advanced Audio Coding file, and the video, which was an H264 file.

When I played the audio alone, there was no such noise. So I took these two files and created a new MP4 using HandBrake 1.2.2 (portable). It was not necessary to edit the audio. Now I have the MP4 playing without that annoying noise.

The problem is solved and now I know why the noise is there if I play the original MKV. It has three audio tracks:

- Video_Audio01.ac3
- Video_Audio02.ac3
- Video_Audio03.aac

The first file on the list, which plays when I start the video, is the one with the noise. It's an original Brazilian Portuguese dub.