streaming.js

// Import modules
import React, { useEffect, useRef, useState } from "react";

// Define a custom hook for using media source buffers
const useMediaSourceBuffer = (url, mimeType) => {
  // Create a ref for the media source object
  const mediaSourceRef = useRef();

  // Create a ref for the source buffer object
  const sourceBufferRef = useRef();

  // Create a state for the media source ready state
  const [readyState, setReadyState] = useState("");

  // Create a state for the source buffer updating flag
  const [updating, setUpdating] = useState(false);

  // Create a state for the queue of chunks to be appended to the source buffer
  const [queue, setQueue] = useState([]);

  // Initialize the media source object and attach it to the URL
  useEffect(() => {
    // Create a new media source object
    mediaSourceRef.current = new MediaSource();

    // Set the URL to be a blob URL created from the media source object
    url.current = URL.createObjectURL(mediaSourceRef.current);

    // Add an event listener for when the media source is open

    mediaSourceRef.current.addEventListener("sourceopen", () => {
      // Set the ready state to open
      setReadyState(mediaSourceRef.current.readyState);

      // Create a new source buffer object with the given mime type
      sourceBufferRef.current =
        mediaSourceRef.current.addSourceBuffer(mimeType);

      // Add an event listener for when the source buffer is updating
      sourceBufferRef.current.addEventListener("updatestart", () => {
        // Set the updating flag to true
        setUpdating(true);
      });

      // Add an event listener for when the source buffer is updated
      sourceBufferRef.current.addEventListener("updateend", () => {
        // Set the updating flag to false
        setUpdating(false);

        // If there are chunks in the queue, shift the first one and append it to the source buffer
        if (queue.length > 0) {
          sourceBufferRef.current.appendBuffer(queue.shift());
        }
      });
    });

    // Return a cleanup function to revoke the blob URL and close the media source
    return () => {
      URL.revokeObjectURL(url.current);
      mediaSourceRef.current.endOfStream();
    };
  }, [url, mimeType]);

  // Define a function to append a chunk to the source buffer or the queue
  const appendChunk = (chunk) => {
    // If the source buffer is not updating and the media source is open, append the chunk to the source buffer
    if (!updating && readyState === "open") {
      sourceBufferRef.current.appendBuffer(chunk);
    } else {
      // Otherwise, push the chunk to the queue
      setQueue((prevQueue) => [...prevQueue, chunk]);
    }
  };

  // Return the append chunk function
  return appendChunk;
};

// Define a custom hook for fetching audio chunks from a server
const useFetchAudioChunks = (url, appendChunk) => {
  // Create a state for the fetch controller
  const [controller, setController] = useState(null);

  // Create a state for the fetch signal
  const [signal, setSignal] = useState(null);

  // Create a state for the fetch reader
  const [reader, setReader] = useState(null);

  // Create a state for the fetch done flag
  const [done, setDone] = useState(false);

  // Fetch audio chunks from the server and append them to the media source buffer
  useEffect(() => {
    // If the URL is not defined, return
    if (!url) return;

    // Create a new abort controller and signal
    const newController = new AbortController();
    const newSignal = newController.signal;

    // Set the controller and signal states
    setController(newController);
    setSignal(newSignal);

    // Define an async function to fetch and process audio chunks
    const fetchAndProcessChunks = async () => {
      try {
        // Fetch the audio file from the server with the signal and range headers
        const response = await fetch(url, {
          signal,
          headers: {
            Range: "bytes=0-", // Change this according to your desired range
          },
        });

        // If the response is not ok, throw an error
        if (!response.ok) {
          throw new Error(`Fetch error: ${response.status}`);
        }

        // Get the reader from the response body
        const newReader = response.body.getReader();

        // Set the reader state
        setReader(newReader);

        // Define a recursive function to read and append chunks
        const readAndAppendChunks = async () => {
          // Read a chunk from the reader
          const { value, done } = await reader.read();

          // If done is true, set the done state to true and return
          if (done) {
            setDone(true);
            return;
          }

          // If value is defined, append it to the media source buffer using the append chunk function
          if (value) {
            appendChunk(value);
          }

          // Call the function again until done is true
          readAndAppendChunks();
        };

        // Call the function for the first time
        readAndAppendChunks();
      } catch (error) {
        // If the error is not an abort error, log it to the console
        if (error.name !== "AbortError") {
          console.error(error);
        }
      }
    };

    // Call the async function
    fetchAndProcessChunks();

    // Return a cleanup function to abort the fetch and cancel the reader
    return () => {
      controller.abort();
      reader && reader.cancel();
    };
  }, [url, signal, reader, appendChunk]);

  // Return the done flag
  return done;
};

// Define a custom hook for using an HTML5 audio element with a media source buffer URL
const useAudioElement = (url, done) => {
  // Create a ref for the audio element
  const audioRef = useRef();

  // Create a state for the audio duration
  const [duration, setDuration] = useState(0);

  // Create a state for the audio current time
  const [currentTime, setCurrentTime] = useState(0);

  // Create a state for the audio paused flag
  const [paused, setPaused] = useState(true);

  // Initialize and update the audio element with the URL and done flag
  useEffect(() => {}, []); // Incomplete from here need guidance to complete it
};