We pipe the information outputted by the -i option directly to grep to search for the line containing the text "Duration" and pipe it to cut to extract the duration (i.e., 00:00:10 for ten seconds) from this line. Therefore, we must extract the duration from the input's information, which is outputted by the -i option.Ģ>&1 redirects standard error ( 2 for stderr) to standard output ( 1 for stdout). Unfortunately, there's no convenient variable like w or tw for accessing the input's duration. This thumbnail image will be a JPEG file. Let's test the drawtext filter by extracting the thumbnail image from the beginning of the video and writing "Test Text" to the center of this image. To write a piece of text onto the thumbnail image, use the drawtext video filter. Connecting multiple filters forms a directed graph called a filtergraph. When a filter finishes modifying the input media, it outputs the result, and this result is piped to the next available filter as its input.
A video filter modifies/transforms the media streaming through it, and it is specified with the -vf option. If the -ss option is not provided to the ffmpeg command, then by default, the frame will be extracted from the 00:00:00.000 ( hour:minute:seconds.milliseconds) timestamp.ĭraw the title and duration onto the thumbnail image via the drawtext video filter. The -ss option ("start timestamp") allows you to pick a timestamp within the video from which to extract the single frame from. The thumbnail only requires an image of a single frame. If you’d like to learn more I recommend diving into the documentation.To generate a thumbnail from a video with ffmpeg:ĭecide on a frame to extract the thumbnail image from via the -ss and -vframes options. Using FFmpeg to quickly trim a video is only touching the surface of what the tool is capable of. Note: both -ss and -to are optional if you’d like to include content from the start or end of the source video. copy is a special value in FFmpeg that tells FFmpeg not to reencode your video. In this case the copy codec is used to help improve the speed of encoding. This will cause the exported clip to only include content up to the provided time in the input source.
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