I had it extract some general rules from this page and pasted them below: https://video.stackexchange.com/questions/26302/ffmpeg-cutting-3-seconds-at-the-begin

I had it extract some general rules from this page and pasted them below: https://video.stackexchange.com/questions/26302/ffmpeg-cutting-3-seconds-at-the-beginning-of-a-video-leaves-5-seconds-blank https://video.stackexchange.com/questions/26302/ffmpeg-cutti... USER given the following general rules: 1. The issue described in the text occurs when cutting a video between keyframes, resulting in blank video with original sound. 2. Potential solutions include overlaying the copied part with a few seconds of the re-encoded original, seeking to an earlier frame, finding the previous keyframe and clipping from that, or re-encoding the whole clip. 3. FFmpeg does not have a built-in feature to automatically resolve this issue. Are any of these rules applicable to the question below? "how do I use ffmpeg to slice out a video. and I only want 3 seconds of video." ASSISTANT Enter an assistant message here. ASSISTANT Yes, rule 1 and rule 3 are applicable to the question. The issue of cutting a video between keyframes may apply when slicing out a 3-second video using FFmpeg, and FFmpeg does not have a built-in feature to automatically resolve this issue. USER Given that what is the answer to the question ASSISTANT To use FFmpeg to slice out a 3-second video, you can use the following command: ```bash ffmpeg -i input.mp4 -ss START_TIME -t 3 -c:v libx264 -c:a copy output.mp4 ``` Replace `START_TIME` with the timestamp (in the format `hh:mm:ss`) from which you want to start the 3-second clip. For example, if you want to start at 1 minute and 30 seconds, the command would be: ```bash ffmpeg -i input.mp4 -ss 00:01:30 -t 3 -c:v libx264 -c:a copy output.mp4 ``` However, if you encounter an issue with blank video caused by keyframe cutting, you may need to seek to an earlier frame, find the previous keyframe, or re-encode the whole clip as mentioned in the provided rules. It seems to be able to find the applicable rules and apply them.