Gibberfish

Generate test video content with Node.js. Useful for subtitle synchronisation testing. Gibberfish utilises the say command, GraphicsMagick and ffmpeg.

Content is generated by creating multiple concurrent segments before concatenating them so the generation time is significantly shorter than the output running time.

The output is a ~10 minute video with H.264 video, AAC audio and separate SRT and VTT subtitle files. The subtitles match the synchronized displayed text and spoken (TTS) audio tracks.

Sample Output (YouTube)

Requirements

Gibberfish requires:

• macOS with say
• Node 6+
• GraphicsMagick
• ffmpeg (providing the ffmpeg and ffprobe commands)

Usage

npm install -g gibberfish

gibberfish output.mp4

• Generates output.mp4, output.srt and output.vtt with randomly-generated text input

gibberfish -f inputfile.txt output.mp4

• Generates outputs using the text provided

gibberfish -f - output.mp4

• Generates outputs using the text provided on STDIN