#Video Editing

Silent Video and WAV Match, but MP4 Rounds to Milliseconds
A silent video with 203 frames at 24 fps and a WAV with 406,000 samples at 48 kHz have exactly the same duration, but an MP4 written by ffmpeg with movie timescale 1000 stores its duration in integer milliseconds. I fixed this with timescale 48000 and compared durations using Fraction before handing over the files.

Speed Up Screen Recordings While Keeping the Original Clock
How to make a timelapse from a screen recording by speeding up idle sections more than active sections, using split, trim, and setpts, then joining them with concat. The main trap is that drawtext must come before setpts for the clock to follow the original timeline instead of the accelerated one.

Edit Videos with Claude Using Thai Prompts, No Video Editor Needed
How I actually use Claude in VS Code to trim, resize, join, and add background music to videos by typing in Thai, without memorizing ffmpeg commands or opening a video editor. Includes getting AI to compose music, NVIDIA GPU acceleration, and Mac and Linux instructions for people who have never used Claude.