Warning on adding actions that potentially can cause output result being wasted

[Grobe]

Background
I recently made an attempt to compress a video record from a team meeting (unfortunately this means I cannot share video, even for bug fixing purposes). I have done similar encoding several times before without any issues.


The one thing I did different this time was to cut off a part of the video in the middle (recorded the coffee break as well), as well as some minutes both at start and end of the video.

After a long time after the process was done, I opened the newly opened .mkv file - just to find the audio was totally garbled, like a broken/stuck jack hammer noise, same flat sound all the way of the output video.

Same result in W10 with two versions of Avidemux:
v2.8.1

Code Select Expand

Build Target: Microsoft Windows (x86-64)
User Interface: Qt (5.12.5)
Operating System: Microsoft Windows (6.2.9200; 64-bit)
Time: Tue Jan  7 16:32:52 2025

0: C:\Users\keirg\Downloads\AvidemuxPortable\App\Avidemux64\avidemux_portable.exe
Avidemux v2.8.2 (241212_ce994de41a6)

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Compiler: GCC 13.3.0
Build Target: Microsoft Windows (x86-64)
User Interface: Qt (5.15.15)
Operating System: Microsoft Windows (6.2.9200; 64-bit)
Time: Wed Jan 08 14:25:30 2025

0: C:\Users\keirg\tools\portable\avidemux_64\avidemux.exe

Suggestion

Since the nature of many (maybe mostly all) encoding jobs done using Avidemux takes long times, users should get a warning ahead of time when actions (such as splitting parts from middle part of videos) that is prone to give corrupted output files.



Workarounds
- Encoding the whole video, and then cut middle section (not tested)
- Use another tool when removing something from the middle, e.g. Shotcut (tested but doesn't have same level of granular control when encoding the resulting video, compared to Avidemux)



Question - any means of recover the sound to add it afterwards
So - I fortunately have saved the project file (py) - and also have the source video file - so that I do know exactly what time of the cut off.

Is there any steps I can take in order to recover the broken sound, so that I can mux it into the resulting video file at the end ?

[eumagga0x2a]

For starters, please attach the textual report of MediaInfo for the source file to your reply (don't try to post it inline, CleanTalk doesn't like that).

Is Avidemux 2.8.2 r241212 (the ancient 2.8.1 release may be useful for regression testing purposes only) able to play the source file with correct audio in all parts of the recording?

If not, please provide admlog.txt from starting Avidemux, loading the source file and closing Avidemux.

If yes, please provide the project script reflecting the settings used to generate output with garbled audio.

In general, on-the-fly-changes to audio tracks are unsupported in Avidemux (with the only notable exception of AC3 switching from stereo to surround and only when using the a52dec (liba52) audio decoder plugin (not the libavcodec one) which will then automatically downmix to stereo after the switch).

[Grobe]

Answers:

• Can VLC info dialog boxes do instead of MediaInfo? The video source is MS Teams so I guess the output video encoding follows a predictable standard
• Avidemux 2.8.2 r241212 are fully capable to play the input video.

edit offtopic while typing: Why wouldn't the forum accept 7z compressed files, just zip ?

Contains
admlog.txt
videoEncodingSettingsAvidemux.py
vlc_codec-info/vlc_screenshot_Codec.png
vlc_codec-info/vlc_screenshot_Statistics.png
You cannot view this attachment.
 

[eumagga0x2a]

First of all, the FDK_AAC configuration in the project script is invalid, likely a result of mixing 2.8.1 and more or less current builds. However, it doesn't seem to be related to the problem which is

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<!>12:19:56-197 [ADM_AudioEncoder::reorder] Cannot map channel 0 : FRONT_CENTER
For some reason outgoing channel map becomes wrong, not sure why. Does using a different audio encoder for AAC (e.g. the libavcodec one) help?