Avidemux is a free, open-source video editor for cutting, filtering and converting video on Windows, macOS, Linux and BSD. It works on a video sequence with marked selections and separate controls for video, audio and the output container. Its editing tools suit extracting a clip, removing unwanted footage or preparing a file with different encoding settings; it does not provide a multitrack workspace for arranging a production.
Cutting a marked section
Markers A and B define the section being edited. Avidemux can save that range as a separate video or delete it from the sequence, leaving the remaining footage to be saved. Copy and paste operations let you reuse marked sections, while Append joins additional files to the sequence.
Video often stores complete keyframes with other frames depending on surrounding pictures. A cut that removes a needed reference can therefore affect playback at the join. Avidemux provides keyframe navigation and checks for problematic cut points, including some H.264 and HEVC cases where a keyframe boundary alone is insufficient.
Stream copy
The video and audio output controls each offer a Copy mode. This carries the selected compressed stream into the output without encoding it again, preserving its encoded quality. You can retain the original audio while converting the picture, or copy both streams when the edit and output format allow it. Joining files this way requires matching properties, including video dimensions and format, and audio format, bitrate and sampling rate.
The output container is a separate choice from the encoding. A container such as MP4 or Matroska holds the video and audio tracks together. Avidemux can change this wrapper while copying compatible streams, so changing a file’s container need not involve compressing its picture again. The selected container must support the tracks being saved.
Video encoding and the filter chain
Selecting a video encoder makes Avidemux create a new video stream. This permits format conversion, compression changes and cuts that cannot be made at suitable keyframe boundaries in Copy mode. Encoder configuration determines how the resulting picture is compressed; lossy encoding trades some picture information for reduced data.
Picture filters also require encoding. In the Video Filter Manager, filters form an ordered chain: decoded frames pass through the chosen operations before the encoder compresses them. Cropping removes image edges, resizing changes frame dimensions, and deinterlacing processes footage made from alternating fields. Color adjustments, noise reduction and subtitle rendering address different changes within that same chain.
Avidemux provides filter previews with a Peek Original control to compare the processed image with its source. Active filters can be temporarily disabled when assessing their contribution. Partial filters restrict an effect to a portion of the sequence, allowing a correction to apply only where it is needed. HDR-to-SDR tone mapping is also available for converting the picture’s dynamic range.
Audio tracks
Audio selection can retain tracks from the source or introduce an external audio file, with configuration for up to 32 tracks. External sources include WAV, MP3, AC3 and AAC audio.
An audio shift, entered in milliseconds, moves sound relative to the picture and can correct a constant synchronization offset even in Copy mode. Processing controls go further: gain changes level, the equalizer adjusts frequency bands, and dynamic range compression reduces differences between louder and quieter passages. Resampling changes the sample rate, while channel mixing can turn a surround soundtrack into stereo. These signal changes require audio encoding.
Avidemux projects and the job queue
An Avidemux project saves the editing instructions and processing settings rather than producing the finished movie. Its TinyPy script records items such as cuts and filters, allowing the processing setup to be reopened or adapted. Custom scripts can retain combinations of video encoding, audio processing, filters and container selections for reuse.
The job queue holds prepared projects for later processing or a batch run. Scripts can also apply the same operations across a directory.
