Frequently asked questions

???? How do I know what version/revision I'm using? ????

If for some reason you don't know or don't remember, you can see this in the Help > About … menu. You should see the major.minor version, along with the exact revision number (rXXXX). At the time of writing (2009-07-28), the latest version available is Avidemux v'2'.'5' (r'5152').

???? Where do I find the log file? ????

The log file ('admlog.txt'), along with the crash project file created by avidemux when it b0rks ('crash.js'), can be found in the '%APPDATA%/avidemux' folder. Entering %APPDATA%/avidemux/admlog.txt directly in the windows explorer address bar loads the log file in your text editor (usually Notepad).

???? Where do I find the job files? ????

They're in the %APPDATA%/avidemux/jobs folder, as .js files. They're editable with any raw text editor.

???? I can't hear any sound in Avidemux ????

Make sure the correct audio output is selected in preferences (Preferences→Audio→Audio(nbsp)output). On Microsoft Windows, this would be win32, on Linux, it could be ALSA, OSS, ESD or aRts. If you cannot hear sound with some particular audio formats, it could mean Avidemux either does not support that format or that support for the particular decoder was not compiled into Avidemux. You can see which decoders Avidemux supports by opening Help→Built-in(nbsp)Support.

???? I compiled Avidemux for Linux but there is no support for feature * or decoder/encoder * ????

Make sure you have the development packages installed for the libraries. For example, if you want FAAC support, you must also install (lib)faac-dev or (lib)faac-devel. Then recompile Avidemux.

???? Avidemux won't open my DV or miniDV file ????

Avidemux can only open type-2 DV files at the moment. Two types of DV files exist: type 1 and type 2 (read the information at Microsoft.com about the differences between them). However, some cameras produce type-1 DV video. To convert them to type-2 DV, you can either use the Canopus DV File Converter or the Ulead DV Converter.

???? When I save a file with Avidemux, my player/file manager does not recognize the filename extension ????

Avidemux does not add filename extensions automatically. When you want to save an AVI file called “myvideo”, save it as “myvideo.avi”. If you already saved it as “myvideo”, just rename it to “myvideo.avi” in your file manager. A complete list of the extensions to be used with each output format is available in the Supported output formats section.

???? I encoded a video with Avidemux but I only get black screen when I try to play it back ????

Make sure your video player supports the video format. For example, if you're using Windows Media Player and encoded the video into MPEG-4 (ASP or AVC), a third-party MPEG-4 decoder must be installed on your system, because there is no MPEG-4 decoder included in Microsoft Windows. ffdshow tryouts contains audio and video decoders for the most common modern audio and video formats.

???? When I use some filters/subtitles in Avidemux, the saved file is like the original AKA The filters/subtitles aren't applied to the output video ????

This usually happens when you've set the Video to “Copy”, and is expected behavior. Copy, by definition, copies the video from the input file to the output file without modifying it, so no filters will be applied. When the video dropdown menu is set to “Copy”, the “Filters” button is disabled, and the “Video > Filters” menu pops a warning that says “Video filters cannot be used in copy mode”. You might have thought choosing an encoder other than “Copy”, adding filters, and setting it back to copy would apply filters without re-encoding … well, that's not how things work. ;)

To apply some video filters, choose the appropriate encoder in the Video dropdown menu (whatever suits your needs best) and choose the format and file extension accordingly.

NB: Older versions of Avidemux didn't show the warning via the “Video > Filters” menu, and even older versions didn't disable the “Filters” button at all. When Format is set to “AVI, unpack VOP” (which is done automatically when you answer yes to a question whether you want to unpack the video), the video is saved in copy mode, too, so filters cannot be applied either.

???? I encoded a DVD or Video with Avidemux and the picture is blurry. What settings can I change to keep as much details as possible? ????

First, check that post-processing is turned off for the current session in the “Video > Post processing …” menu. You can also turn it off definitely in the “Tools > Preferences” menu, in the Video tab. Next, if you added a resize filter, set it to resize using the Lanczos3 method instead of Bilinear or Bicubic. Lanczos3 is the most accurate resizer, or so to say. However, resizing kills details by nature, there's no way around it. Not resizing might be a better option sharpness-wise depending on what you're trying to do. Finally, tweak the encoder settings. Discussing the best quality settings for each encoder isn't the FAQ's goal. Encoder-specific guidelines are available in the avidemux forum or on the web.

???? I use 2-pass encoding and the output file size is bigger than I wanted (e.g. 1300 MB instead of 1200 MB) ????

The target size entered in the 2-pass codec settings is for video, without audio. The audio track adds the additional megabytes. To calculate only the video size, use the Calculator in Avidemux(nbsp)– enter the target file size, format and audio bitrate, click Apply (which will store the 2-pass video size in the selected encoder) and close it.

Note: You may also encounter a similar problem when using versions prior to v2.4.4 on Windows if you have non-ANSI letters in the output path (e.g. éàùôèí etc.) when using the Xvid codec. In that case, the stats file won't be created and Xvid will go into fixed quantizer mode (with a quantizer 2). If an update isn't possible for you, simply send the output file to a path without such characters to avoid triggering this old bug.

???? I use 2-pass encoding and the output file size is smaller than I wanted (e.g. 800 MB instead of 1400 MB) ????

A smaller file often means it's saturated, encoded at the highest quality the codec can achieve and therefore the file size cannot be increased without changing the settings (like increasing the resolution or choosing less compressible encoder options). This is harmless, there is no point in trying to make the file larger than needed. You can see if the video was really encoded at the highest quality by opening it in Avidemux, navigating in it and observing the frame type information: . If the number in the brackets is always 2 for all frames (or 4 for B-frames), then the file was indeed encoded at the lowest quantizer (2), which means the highest quality.

???? How do I disable automatic AVI file splitting (create AVI files larger than 4 GB)? ????

By default, Avidemux creates standard AVI files, which imposes a 4(nbsp)GB file size limit. OpenDML files do not have this limitation. You can enable OpenDML output in Avidemux by checking “Create OpenDML files” in preferences.