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• what FFMPEG performance settings to use for processing videos for the web

  21 mai 2020, par eAbi

  I have a few questions regarding usage of ffmpeg for processing videos for the web. I'm a beginner so please bear with me (although I read some docs on the internet)

  



  Performance

  



  

  • First of all, given the fact that FFMPEG utilizes all cores at 100%, what is the actual parallelism efficiency ?

  


  



  Let's assume the following scenario. I have a video (fullHD, doesn't matter what encoders / compression format was used to obtain the video) and I want to resize (downscale) to various sizes (e.g. 240px, 480px and 720px height) using mp4 format (thus using libx264 with aac codecs).

  



  Using ffmpeg, I see that all of my laptop's cores (8) are used at 100% and I was wondering what scenarios can improve the overall performance of the whole processing task. So this leads us to basically 2 scenarios : Assuming the video mentioned above as input, for obtaining the 3 output videos (@ 240px, 480px and 720px height sizes), we :

  



  

  1. Process input video and obtain 1 output video at a time, and let all the cores work at the same time at 100% ;

  


  2. Process the video to obtain all output videos in parallel, by bounding each output video to a single processor core which'll work at 100% ;

  


  



  So the question is actually reduced to the parallelism efficiency of the ffmpeg program.

  



  This means that letting ffmpeg process the task procVideo - which takes 1 input video to produce 1 single output video (transcoding/downscaling and so on) - on N processor cores doesn't mean it finish the task N times faster than letting it run the same task bound to a single core. So if the efficiency is smaller than 100%, it's better to have N procVideo tasks in parallel, each bound to a single core, rather than doing the task sequentially for each output video.

  



  ---

  



  Codecs

  



  Other than the above performance problem, the usage of codecs bugs me. I am trying to obtain mp4 videos because of the wide implementation of the format in html5 browsers.

  



  So having a video as input in any format, I want to convert it to mp4. So I'm using libx264 codec with aac.

  



  

  • Use libx264, x264 or h264 for video encoding/decoding ?

  


  • Use libfdk_aac, libaacplus or aac for audio encoding/decoding to aac ?

  


  



  Also, I would like to know what are the licesing fees for each of the above codec, as the online resources on these are quite limited / hard to understand.

  



  If anyone could shed some light on those questions, I would really be grateful ! Thanks for your time !

  


• what FFMPEG performance settings to use for processing videos for the web

  19 juin 2015, par eAbi

  I have a few questions regarding usage of ffmpeg for processing videos for the web. I’m a beginner so please bear with me (although I read some docs on the internet)

  Performance

  • First of all, given the fact that FFMPEG utilizes all cores at 100%, what is the actual parallelism efficiency ?

  Let’s assume the following scenario. I have a video (fullHD, doesn’t matter what encoders / compression format was used to obtain the video) and I want to resize (downscale) to various sizes (e.g. 240px, 480px and 720px height) using mp4 format (thus using libx264 with aac codecs).

  Using ffmpeg, I see that all of my laptop’s cores (8) are used at 100% and I was wondering what scenarios can improve the overall performance of the whole processing task. So this leads us to basically 2 scenarios : Assuming the video mentioned above as input, for obtaining the 3 output videos (@ 240px, 480px and 720px height sizes), we :

  1. Process input video and obtain 1 output video at a time, and let all the cores work at the same time at 100% ;
  2. Process the video to obtain all output videos in parallel, by bounding each output video to a single processor core which’ll work at 100% ;

  So the question is actually reduced to the parallelism efficiency of the ffmpeg program.

  This means that letting ffmpeg process the task procVideo - which takes 1 input video to produce 1 single output video (transcoding/downscaling and so on) - on N processor cores doesn’t mean it finish the task N times faster than letting it run the same task bound to a single core. So if the efficiency is smaller than 100%, it’s better to have N procVideo tasks in parallel, each bound to a single core, rather than doing the task sequentially for each output video.

  ---

  Codecs

  Other than the above performance problem, the usage of codecs bugs me. I am trying to obtain mp4 videos because of the wide implementation of the format in html5 browsers.

  So having a video as input in any format, I want to convert it to mp4. So I’m using libx264 codec with aac.

  • Use libx264, x264 or h264 for video encoding/decoding ?
  • Use libfdk_aac, libaacplus or aac for audio encoding/decoding to aac ?

  Also, I would like to know what are the licesing fees for each of the above codec, as the online resources on these are quite limited / hard to understand.

  If anyone could shed some light on those questions, I would really be grateful ! Thanks for your time !

• Discord bot not playing any audio

  7 mars 2023, par Markix

  I'm making a discord music bot with Discord.js v14, @discordjs/voice, and Typescript and I have this play command but it doesn't seem to be working. It successfully joins, throws no exceptions but... no audio.

  


  This is my code :

  


  import { CommandInteraction, SlashCommandBuilder } from "discord.js";
import { joinVoiceChannel, createAudioPlayer, getVoiceConnections, StreamType, AudioPlayerStatus } from "@discordjs/voice";
import { createAudioResource } from "@discordjs/voice";
import ytdl from 'ytdl-core';

module.exports = {
    data: new SlashCommandBuilder()
        .setName('play')
        .setDescription('Play příkaz')
        .addStringOption(option => 
            option
                .setName("link")
                .setDescription("Youtube link!")
                .setRequired(false)
        ),

async execute(interaction: CommandInteraction) {
        const link = interaction.options.get('link')?.value?.toString();
        const player = createAudioPlayer();
        const resource = createAudioResource(ytdl(`${link}`, { filter: "audioonly" }), { inlineVolume: 1.0, inputType: StreamType.WebmOpus });

    player.play(resource);

    const connection = joinVoiceChannel({
        channelId: "775815628619251743",
        guildId: "775761665786511370",
        adapterCreator: interaction.guild?.voiceAdapterCreator,
        selfMute?: false,
        selfDeaf: false
    });

    const subscription = connection.subscribe(player);
    interaction.reply("Now playing: .-.");
}


  


  This is "dependencies" in my package.json

  


    "dependencies": {
    "@discordjs/builders": "^1.2.0",
    "@discordjs/rest": "^1.5.0",
    "@discordjs/voice": "^0.14.0",
    "@types/express": "^4.17.14",
    "discord.js": "^14.4.0",
    "dotenv": "^16.0.2",
    "express": "^4.18.1",
    "ffmpeg": "^0.0.4",
    "ffmpeg-static": "^5.1.0",
    "libsodium-wrappers": "^0.7.11",
    "opusscript": "^0.0.8",
    "sequelize": "^6.23.2",
    "sqlite3": "^5.1.2",
    "ts-node": "^10.9.1",
    "ytdl-core": "^4.11.2"
  }


  


  (And yes I also have ffmpeg installed globally)

  


  markix@pop-os-lenovo-laptop:~$ apt list --installed | grep -i ffmpeg 

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

chromium-codecs-ffmpeg-extra/jammy,now 1:85.0.4183.83-0ubuntu2 amd64 [installed,upgradable to: 1:85.0.4183.83-0ubuntu2.22.04.1]
ffmpeg/jammy-security,jammy-updates,now 7:4.4.2-0ubuntu0.22.04.1 amd64 [installed,automatic]


  


  What am I doing wrong ?