Seekable recordings for audio recorder (e.g. using ts-ebml)

pjeby · 2021-12-20T07:01:43.253Z

Use case or problem

Skip ahead to later parts of a recording made using the audio recorder core plugin, without first playing through the whole thing. (You can’t, because the file doesn’t contain cue metadata.)

Proposed solution

The ts-ebml package on npm has a command-line tool to make a Chrome webm recording seekable; its Typescript API could be used directly in the audio recorder to rewrite the webm file when recording is complete. The actual CLI implementation is only a few lines, and should work reasonably well even if the recording has to be read back into memory and written out again:

github.com

legokichi/ts-ebml/blob/09fceb199ee53dfdab2b578ee395378443940a5a/src/cli.ts#L24-L35

    
      
          const decoder = new Decoder();
          const reader = new Reader();
          reader.logging = false;
          reader.drop_default_duration = false;
          const buf = fs.readFileSync(args[0]);
          const elms = decoder.decode(buf);
          elms.forEach((elm)=>{ reader.read(elm); });
          reader.stop();
          const refinedMetadataBuf = tools.makeMetadataSeekable(reader.metadatas, reader.duration, reader.cues);
          const body = buf.slice(reader.metadataSize);
          const refined = new Buffer(tools.concat([new Buffer(refinedMetadataBuf), body]).buffer);
          process.stdout.write(refined);

Current workarounds

Alternative 1: Use the ts-ebml CLI to copy to another file, then copy back to overwrite the original (since it can’t be done in place in the shell).

Alternative 2: Convert the webm to mp3 with an audio converter or ffpmeg, then manually replace the link and delete the original file.

Related feature requests (optional)

Have audio record in .mp3 instead of .webm? Help

I just discovered the audio recorder function, and was trying to play something back, but it seems that in the webm file you can’t scroll through. I converted it to an mp3 with VLC and it was automatically listed in Obsidian, and then I can use the search bar to scroll through. Is there a way to automatically have it record the audio in mp3? Thanks!

neonplants · 2022-01-08T20:57:44.828Z

Thanks for posting. I don’t understand how is the lack of this is acceptable in a software that seems made to capture and sort ideas.