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• Can ffmpeg transcode an audio track and add it as a second audio track at the same time, or if not, how to do it as separate commands ?

  31 mai 2020, par wb6vpm

  A bit of history. I am using Plex as my media server, but for reasons unknown, it has issues transcoding the DTS-HD MA 7.1 audio to EAC3 stereo and keeps buffering (the server has plenty of horsepower on all fronts, CPU/RAM/drive space & speed, gigabit networks connections for all devices. The playback device (TCL Roku TV, with a 3rd party soundbar connected via HDMI ARC) doesn't support the built-in 7.1 audio, so I get silence if I play it back directly by putting the file on a USB stick.

  



  Also, I am by no means a ffmpeg guru, I figured out what I do know by Google University and asking questions, so please be kind and forgive me if I ask follow-up questions that may seem n00b-ish, and please provide example commands (preferably in the context of my command below so that I can have a known point of reference to start with).

  



  I have a movie with 4K (HEVC Main 10 HDR) video and DTS-HD MA 7.1 audio that I am looking to leave the video and audio untouched, but to add a 2nd audio track in either EAC3 or if necessary, just AC3 in stereo

  



  So what I am looking for is as follows :

  



  video.mkv

  



  

  • Existing->4k video file (no change)

  


  • Existing->7.1 audio (no change)

  


  • Convert and add->stereo audio as a 2nd audio track to the output.mkv file

  


  



  Below is the command I've historically used with ffmpeg to convert and replace the audio file with the stereo audio, but since I'd prefer to leave the 7.1 audio in place, this doesn't work :
ffmpeg -i "D:\video.mkv" -c:v copy -c:a aac -b:a 128k "D:\output.mkv"

  



  And if this cannot be done as a single command, please also let me know what steps I do need to take to be able to do it.

  



  Thanks in advace,
Mike

  


• Persistent AbortError During Reconnection Attempts in Discord Bot

  17 mai 2024, par Nerevaine

  I'm working on a Discord bot that connects to a voice channel, listens to the audio, and sends it to a WebSocket server. Initially, everything works fine, but after some time, when I try to reconnect after losing the connection, I encounter `AbortError` repeatedly. Despite several attempts to handle this error, the problem persists. The error occurs during the reconnection attempts. Here is the error message I keep receiving :

  


  Attempting to reconnect: Try 1 of 5Reconnect attempt 2 failed: AbortError: The operation was abortedat EventTarget.abortListener (node:events:1008:14)at [nodejs.internal.kHybridDispatch] (node:internal/event_target:822:20)at EventTarget.dispatchEvent (node:internal/event_target:757:26)at abortSignal (node:internal/abort_controller:374:10)at AbortController.abort (node:internal/abort_controller:396:5)at Timeout.<anonymous> (/path/to/project/node_modules/@discordjs/voice/dist/index.js:1931:39)at listOnTimeout (node:internal/timers:573:17)at process.processTimers (node:internal/timers:514:7) {code: &#x27;ABORT_ERR&#x27;,[cause]: DOMException [AbortError]: This operation was abortedat new DOMException (node:internal/per_context/domexception:53:5)at AbortController.abort (node:internal/abort_controller:395:18)at Timeout.<anonymous> (/path/to/project/node_modules/@discordjs/voice/dist/index.js:1931:39)at listOnTimeout (node:internal/timers:573:17)at process.processTimers (node:internal/timers:514:7)}&#xA;</anonymous></anonymous>

  


  Here are the key parts of the code I use to handle the connection and reconnection attempts :

  


  1. Handling Connection and WebSocket :

  


  let connection; let count = 0;  await entersState(connection, VoiceConnectionStatus.Ready, 30000); console.log('Voice connection ready:', voiceChannel.id); let player = createAudioPlayer(); connection.subscribe(player);  let ws = new WebSocket('ws://...');  ws.on('open', () => {   console.log('WebSocket connection opened');   voiceChannel.members.forEach(member => {     if (member.user.id !== client.user.id) {       member.voice.setMute(false);     }   }); });  ws.on('error', (error) => {   console.error('WebSocket error:', error); });  ws.on('close', () => {   console.log('WebSocket connection closed, attempting to reconnect...');   reconnectWebSocket(ws); });


  


  

  2. Reconnecting Logic :

  


  


  async function attemptReconnect(client, voiceChannel, player, retries = 5, delay = 10000) {
  for (let i = 0; i < retries; i++) {
    try {
      console.log(`Attempting to reconnect: Try ${i + 1} of ${retries}`);
      connection.destroy();
      connection = joinVoiceChannel({
        channelId: voiceChannel.id,
        guildId: voiceChannel.guild.id,
        adapterCreator: voiceChannel.guild.voiceAdapterCreator,
        selfDeaf: false,
        selfMute: false
      });

      await entersState(connection, VoiceConnectionStatus.Ready, 30000);
      console.log('Reconnected to voice channel:', voiceChannel.id);
      connection.subscribe(player);
      return;
    } catch (error) {
      console.error(`Reconnect attempt ${i + 1} failed:`, error);
      if (error.code === 'ABORT_ERR') {
        console.log('Reconnect attempt aborted, will retry');
      }
      if (i < retries - 1) {
        await new Promise(resolve => setTimeout(resolve, delay));
        delay *= 2; // Increase delay exponentially
      }
    }
  }
  console.error('Failed to reconnect to voice channel after several attempts, restarting connection');
  restartConnection(client, voiceChannel);
}


  


  

  3. Restarting Connection :

  


  


  function restartConnection(client, voiceChannel) {
  try {
    if (connection) {
      connection.destroy();
      console.log('Connection destroyed');
    }
    handleAudio(client, voiceChannel);
  } catch (error) {
    console.error('Error restarting connection:', error);
  }
}


  


  

  • Implement Exponential Retries : I have increased the delay between each reconnection attempt.

  


  • Destroy and Recreate Connections : Ensure the voice and WebSocket connections are destroyed before reconnecting.

  


  • Restart Complete Connection : After several failed attempts, I attempt to restart the entire connection.

  


  


• DirectShow RTSP SourceFilter with MPEG-4 Video Stream

  5 octobre 2011, par 6.45.Vapuru

  I create a simple direct show source filter using FFmpeg.I read rtp packets from RTSP source and give them to decoder. It works for h264 stream.

  MyRtspSourceFilter[H264 Stream] ---> h264 Decoder --> Video Renderer

  The bad news is that it does not work for MPEG-4. I can able to connect my rtsp source filter with MPEG-Decoder. I got no exception but video renderer does not show anything. Actually just show one frame then nothing [just stop]... Decoders and Renderers are 3rd party so i can not debug them.

  MyRtspSourceFilter[MP4 Stream] ---> MPEG-4 Decoder --> Video Renderer

  I can able to get rtp packets from MPEG-4 RTSP Source using FFmpeg sucessfully.There is no problem with it.

  It seems that i have not set something(?) in my Rtsps Source
  Filter which is not necessary for H264 stream but may be important for
  MPEG-4 stream

  What may cause this h264 stream and MPEG-4 stream difference in a direct show rtsp source filter ? Any ideas.

  More Info :

  — First i try some other rtsp source filters for MPEG-4 Stream...Although my rtsp source is same i see different subtypes in their pin connections.

  — Secondly i realy get suspicious if the source is really MPEG-4 SO i check with FFmpeg...FFmpeg gives the source codec id as "CODEC_ID_MPEG4".

  Update :
  [ Hack ]

  I just set m_bmpInfo.biCompression = DWORD('xvid') it just worked fine...But it is static. How to dynamically get/determine this value using ffmpeg or other ways...