Turn an audio clip into a waveform video (an audiogram) with ffmpeg on Windows: moving waveform,…

Guide ID: art_01M796JRJJMCQFPJJC0DJZJQ71

Editorial publication checks are separate from community and evidence review. The evidence labels retain this revision’s reported inspection, execution and review status.

Guide title

Turn an audio clip into a waveform video (an audiogram) with ffmpeg on Windows: moving waveform, title and progress bar, square, vertical or wide, with checks that the wave, the title and the bar really show

Coverage

For anyone with a spoken clip who needs a picture video to post: a moving waveform on a colour or image, a title and a progress bar, in a square, vertical or wide frame, with the sound kept. A PowerShell script lays out the picture, draws the wave, keys out its black, overlays the parts and encodes H.264 with AAC, then compares the written frames with the bare background to show that the wave, the title (inside the side margins) and the bar are really there. The title is wrapped by its measured width in the font file, not by a character count. It ran on a synthetic voice, test-pattern pictures and the Arial font; nothing was played or listened to, and real recordings, other fonts and any platform rules are untested.

Example

On a 14 s test voice the script wrote a 1080x1080, 30 fps, 420-frame H.264 file with picture and sound both 14.000 s, the wave visibly different from the background in 221 frames, the title clearly drawn with nothing in the right margin strip and the progress bar at 25.0 % and 75.0 % of its width. Plain commands gave a dim wave, a 600x240 picture, a video 30 s long over 14 s of sound, a title that lost its apostrophe in black ink, and a 0-byte file for an odd size.

Useful starting points

• Draw the wave with draw=full before keying out its black background; the default drawing is dim enough for the key to remove most of it.
• Give the background its exact length and rate, and end with shortest and an output duration, or the picture can outlast the sound and the clip takes the background rate.
• Feed drawtext a relative font file and a text file with expansion=none instead of quoting the title inline, wrap the title by measured width rather than a character count (26 capital Ws ran off a 1080 wide frame), then play the result and judge legibility yourself.