native-messaging-quickjs VS captureSystemAudio

QuickJS https://github.com/guest271314/native-messaging-quickjs (after strip the executable is less than 1MB; the last time I checked node executable is well over 80MB) to run ImageMagick and pipe the result to local file system, remote end-point, or to the browser as a stream.

Dynamically set arbitrary Web pages as "externally_connectable" and forward messages from the Web page to Native Messaging host the forward messages from Native Messagin host back to arbitrary Web page https://github.com/guest271314/native-messaging-quickjs/tree/dynamic-externally-connectable

I can ship qjs in a browser extension with no undue constraint on storage, and run qjs from the browser from any Web site https://github.com/guest271314/native-messaging-quickjs/tree/dynamic-externally-connectable. That is a different story for node and deno, when we really analyze the built-ins we use, do not amount to all of the built-ins, however, there is no way that I am aware of to reduce the size of V8 engine; even d8 is what, 20MB, and not simple to extend to actually use stdin, stdout.

Working JavaScript (QuickJS) version: https://github.com/guest271314/native-messaging-quickjs/blob/main/nm_qjs.js

A QuickJS Native Messaging host that echoes input https://github.com/guest271314/native-messaaging-quickjs from client. Have fun.

Synchronous. Though non-blocking when we read the message from the browser, execute the command, then stream data output from the local application to the browser piped from QuickJS std.popen(), capture_system_audio.js

I've already achieved the requirement multiple ways, already; from using Native Messaging https://github.com/guest271314/native-messaging-espeak-ng, to using GNU Core Utilities tail, to Deno.watchFs() https://github.com/guest271314/fs, et al., see captureSystemAudio. The one approach I have not yet achieved is compiling to Emscripten - with SSML support.

Sure, see https://github.com/guest271314/captureSystemAudio/blob/master/native_messaging/capture_system_audio/background.js, in pertinent part

This is my second time writing C source code capture_system_audio.c. I got a lot of help doing that, too . I basically implemented the same Native Messaging host algorithm in C, C++, Python, WASI/WebAssembly, and JavaScript (Node.js, QuickJS) which is the programming language I write code most using.

I just fetch the nightly node executable, get rid of everything else in the archive, use .mjs extension for import to work without package.json, then I can connect to the host https://github.com/guest271314/native-messaging-nodejs, and start subprocesses, e.g., raw PCM streams, where stdout is streamed to the client (browser), e.g, https://github.com/guest271314/captureSystemAudio/blob/master/native_messaging/capture_system_audio/capture_system_audio_node.js.

Technically I can just serve the raw data as long as the server is capable of opening creating sub-processes, e.g., using EventSource https://plnkr.co/edit/qX5tepJ38BuDOSZj?preview, in which case I would just need to convert this https://github.com/guest271314/captureSystemAudio/blob/master/native_messaging/capture_system_audio/capture_system_audio.c to accept GET request, read the URL, and send the named event stream to the client.

Chromium and Chrome refuses to capture monitor devices on Linux. Read this https://github.com/edisionnano/Screenshare-with-audio-on-Discord-with-Linux README and the README at https://github.com/guest271314/captureSystemAudio very carefully. At best you can capture tab audio, not whatever is output to speakears and headphones, in spite of the systemAudio constraints, which is poorly named, and actually misleading.

How is capturing speechSynthesis.speak() a security vector https://github.com/guest271314/captureSystemAudio?

Capture audio output to speakers or headphones to MP3 or Opus in WebM https://github.com/guest271314/captureSystemAudio/tree/master/native_messaging/capture_system_audio

An example of using Native Messaging to capture "What-U-Hear", sound output to speakers and headphone, launching native GUI's https://github.com/guest271314/captureSystemAudio/tree/master/native_messaging/capture_system_audio; an adapter for espeak-ng so we can capture the output of speech synthesis engine and stream output to the browser https://github.com/guest271314/native-messaging-espeak-ng.