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• Programming Language Levels

  20 mai 2011, par Multimedia Mike — Programming

  I’ve been doing this programming thing for some 20 years now. Things sure do change. One change I ponder from time to time is the matter of programming language levels. Allow me to explain.

  The 1990s
  When I first took computer classes in the early 1990s, my texts would classify computer languages into 3 categories, or levels. The lower the level, the closer to the hardware ; the higher the level, the more abstract (and presumably, easier to use). I recall that the levels went something like this :

  • High level : Pascal, BASIC, Logo, Fortran
  • Medium level : C, Forth
  • Low level : Assembly language

  Keep in mind that these were the same texts which took the time to explain the history of computers from mainframes -> minicomputers -> a relatively recent phenomenon called microcomputers or "PCs".

  Somewhere in the mid-late 1990s, when I was at university, I was introduced to a new tier :

  • Very high level : Perl, shell scripting

  I think there was some debate among my peers about whether C++ and Java were properly classified as high or very high level. The distinction between high and very high, in my observation, seemed to be that very high level languages had more complex data structures (at the very least, a hash / dictionary / associative array / key-value map) built into the language, as well as implicit memory management.

  Modern Day
  These days, the old hierarchy is apparently forgotten (much like minicomputers). I observe that there is generally a much simpler 2-tier classification :

  • Low level : C, assembly language
  • High level : absolutely every other programming language in wide use today

  I find myself wondering where C++ and Objective-C fit in this classification scheme. Then I remember that it doesn’t matter and this is all academic.

  Relevancy
  I think about this because I have pretty much stuck to low-level programming all of my life, mostly due to my interest in game and multimedia-type programming. But the trends in computing have favored many higher level languages and programming paradigms. I woke up one day and realized that the kind of work I often do — lower level stuff — is not very common.

  I’m not here to argue that low or high level is superior. You know I’m all about using the appropriate tool for the job. But I sometimes find myself caught between worlds, having the defend and explain one to the other.

  • On one hand, it’s not unusual for the multitudes of programmers working at the high level to gasp and wonder why I or anyone else would ever use C or assembly language for anything when there are so many beautiful high level languages. I patiently explain that those languages have to be written in some other language (at first) and that they need to run on some operating system and that most assuredly won’t be written in a high level language. For further reading, I refer them to Joel Spolsky’s great essay called Back to Basics which describes why it can be useful to know at least a little bit about how the computer does what it does at the lowest levels.
  • On the other hand, believe it or not, I sometimes have to defend the merits of high level languages to my low level brethren. I’ll often hear variations of, "Any program can be written in C. Using a high level language to achieve the same will create a slow and bloated solution." I try to explain that the trade-off in time to complete the programming task weighed against the often-negligible performance hit of what is often an I/O-bound operation in the first place makes it worthwhile to use the high level language for a wide variety of tasks.

    Or I just ignore them. That’s actually the best strategy.

• Issues with Discord JS Music Bot

  5 décembre 2020, par Thresio

  I am in the process of creating a Discord bot with JS, giving it management, auto role, etc. I just got to the music section of it and I can't quite figure out whats wrong.

  



  I believe I have installed FFmpeg correctly, as I have access to it from within the terminal. I have also used npm to bring ytdl-core and opusscript into my program.

  



  What this should do is make the bot join the chat, then play the Youtube link. Currently, I am not error checking the second argument as I just wanted to get it working initially. I have implemented several different instances of .toString() and String() however it always gives the same error listed below.

  



  . The program still throws this error :

  



  TypeError [ERR_INVALID_ARG_TYPE]: The "file" argument must be of type string. Received type object
TypeError [ERR_INVALID_ARG_TYPE]: The "file" argument must be of type string. Received type object

C:\Users\Thresio's PC\Desktop\Discord Bot\node_modules\opusscript\build\opusscript_native_wasm.js:8
var Module=typeof Module!=="undefined"?Module:{};var moduleOverrides={};var
key;for(key in Module){if(Module.hasOwnProperty(key))
{moduleOverrides[key]=Module[key]}}Module["arguments"]=
[];Module["thisProgram"]="./this.program";Module["quit"]=function(status,toThrow) {throw
toThrow};Module["preRun"]=[];Module["postRun"]=[];var ENVIRONMENT_IS_WEB=false;var 
ENVIRONMENT_IS_WORKER=false;var ENVIRONMENT_IS_NODE=false;var ENVIRONMENT_HAS_NODE=false;var 
ENVIRONMENT_IS_SHELL=false;ENVIRONMENT_IS_WEB=typeof window==="object";ENVIRONMENT_IS_WORKER=typeof 
importScripts==="function";ENVIRONMENT_HAS_NODE=typeof process==="object"&&typeof 
process.versions==="object"&&typeof 
process.versions.node==="string";ENVIRONMENT_IS_NODE=ENVIRONMENT_HAS_NODE&&!ENVIRONMENT_IS_WEB&&!ENVIRONM
ENT_IS_WORKER;ENVIRONMENT_IS_SHELL=!ENVIRONMENT_IS_WEB&&!ENVIRONMENT_IS_NODE&&!ENVIRONMENT_IS_WORKER;var
scriptDirectory="";function locateFile(path){i
abort(TypeError [ERR_INVALID_ARG_TYPE]: The "file" argument must be of type 
string. Received type object). Build with -s ASSERTIONS=1 for more info. 


  



  Here is my code for calling play :

  



  case 'play':

            function play(connection, message){
                var server = servers[message.guild.id];

                server.dispatcher = connection.playStream(ytdl(server.queue[0], {filter: 'audioonly'}));

                server.queue.shift();

                server.dispatcher.on('end', function(){
                    if(server.queue[0]){
                        play(connection, message);
                    }else {
                        connection.disconnect();
                    }
                })
            }

            if(!args[1]){
                message.channel.send('You need to provide a link!');
                return;
            }

            if(!message.member.voiceChannel){
                message.channel.send('You must be in a voice channel to play music!');
                return;
            }

            if(!servers[message.guild.id]) servers[message.guild.id] = {
                queue: []
            }

            var server = servers[message.guild.id];

            server.queue.push(args[1]);

            if(!message.guild.voiceConnection) message.member.voiceChannel.join().then(function(connection){
                play(connection, message);
            })
            break;


  



  If anyone could assist with this, I would be very grateful.

  



  EDIT : I unfortunately never figured out my main issue, but I have now found code that works (unlike mine :/).
For anyone else having this issue, I suggest using the code found here.
Works like a charm !

  


• PowerShell and ffmpeg : No such file or directory

  8 juillet 2022, par Matt Wilson

  I'm trying to use the below command in a Python script, however I'm seeing that it's a PowerShell issue in that it can't seem to find the video file I'm pointing to.

  


  I have a video file on a cloud drive Z: at the following location (for reproducibility, change this to whatever path you want with a video file in it) :

  


  Z:\Udemy_And_Misc_Downloads\TensorFlow Developer Certificate in 2021 Zero to Mastery\3. Neural network regression with TensorFlow\18. Setting up TensorFlow modelling experiments part 2 (increasing complexity).mp4

  


  Notice the spaces and special characters in the filename in case that matters.

  


  What I'm trying to do is down-sample that video file to a smaller size with the following command :

  


  ffmpeg -i "Z:\Udemy_And_Misc_Downloads\TensorFlow Developer Certificate in 2021 Zero to Mastery\[TutsNode.com] - TensorFlow Developer Certificate in 2021 Zero to Mastery\3. Neural network regression with TensorFlow\18. Setting up TensorFlow modelling experiments part 2 (increasing complexity).mp4" -y -vcodec libx264 -acodec ac3 -threads 1 "Z:\Udemy_And_Misc_Downloads\TensorFlow Developer Certificate in 2021 Zero to Mastery\[TutsNode.com] - TensorFlow Developer Certificate in 2021 Zero to Mastery\3. Neural network regression with TensorFlow\18. Setting up TensorFlow modelling experiments part 2 (increasing complexity)DOWNSAMPLED.mp4"

  


  I know it's long as it's mostly consumed by the filenames, but the error I'm getting is :

  


  Z:\Udemy_And_Misc_Downloads\TensorFlow Developer Certificate in 2021 Zero to Mastery\[TutsNode.com] - TensorFlow  Developer Certificate in 2021 Zero to Mastery\3. Neural network regression with TensorFlow\18. Setting up TensorFlow  modelling experiments part 2 (increasing complexity).mp4: No such file or directory

  


  The path IS correct, as it's a direct copy paste from the folder's URL bar.

  


  The things I've tried include :

  


  

  • using quotes around filename

  


  • not using quotes around filename

  


  • prepending quoted filename with "r" (where I got message saying `did you mean file:r ?)

  


  • prepending quoted filename with "file:r"

  


  • used double slashes \ in filepaths

  


  


  Is there a powershell pro out there that can tell me why it can't "find" the file ?

  


  UPDATE
The command runs if I find a filename with :

  


  $oldvids = Get-ChildItem *.mp4, *mov, *wmv, *avi -Recurse
foreach ($oldvid in $oldvids) 
{
    $newvid = [io.path]::ChangeExtension($oldvid.FullName, '_.mp4')
    ffmpeg -i $oldvid.FullName -y -vcodec libx264 -acodec ac3 -threads 1 $newvid
}


  


  When I print the $oldvid.name and $oldvid.FullName, the paths/filenames look like this :

  


  Z:\Udemy_And_Misc_Downloads\TensorFlow Developer Certificate in 2021 Zero to Mastery\5. Computer Vision and Convolutional Neu
ral Networks in TensorFlow\35. Multi-class CNN's part 9 Making predictions with our model on custom images.mp4

35. Multi-class CNN's part 9 Making predictions with our model on custom images.mp4


  


  ...that first one being an exact copy of what I'm trying to use in my posted code. So what's the difference ??

  


  SECOND UPDATE
I think the issue lies in that the file is located on a drive other than C:. Just tested it by moving the file onto my computer and running the command, and it worked. So I guess, is there a way to tell PowerShell to use the Z: drive to find the file ?