Recherche avancée

Sur d’autres sites (7742)

• Getting Error message Unknown encoder 'libx264' , any help appreciated

  16 janvier 2022, par Alex.Foster

  I am trying to compress videos files to a target size within python using ffmpeg-python for an A level project as part of my coursework, I keep getting this error saying it doesn't know the encoder. Not sure what I'm meant to do as this is literally an entirely new space to me. Am I meant to have installed the codec or something, or is there an alternative I can use ?

  


  import os, ffmpeg
##import section:this part is where I import all of the modules I will use
import  tkinter
import shutil
from tkinter import filedialog
import os


def fileSelect():                                                                           #start of fileSelect function
    global startingLocation                                                                 #declares startingLocation as global variable
    global originalName                                                                     #declares originalName as global variable
    global fileType                                                                         #declares fileType as global variable
    startingLocation = filedialog.askopenfilename(initialdir="/", title="Select file",      #tkinter function that opens file explorer, lets user select file saves the file path as a variable
                    filetypes=(("video files", "*.mp4"),("images", "*.jpg*")))
    originalName = os.path.basename(startingLocation)                                       #os function that gets the actaul file name from the path string
    print (originalName)                                                                    #print statement to check if originalName has been found
    fileType = startingLocation.split('.')                                                  #splits original name where any full stop in found and saves array as variable
    fileType = fileType[-1]                                                                 #changes variable to have the str value of the final item in the array; the file type
    fileType = '.' + fileType                                                               #adds fullstop to the start of the file type so i dont have to repeatedly do it
    print (fileType)                                                                        #print statement to check file type is found correctly

def outputSelect():                                                                         #start of outputSelect function
     global outputLocation                                                                  #declares outputLocation as global variable
     outputLocation = filedialog.askdirectory(initialdir="/", title="Select folder")        #tkinter function that opens file explorer, lets the user select of folder as saves the folder path as a variable

def fileNewName():                                                                          #start of fileNewName function
    global customName                                                                       #declares customName as global variable
    customName = input("Enter the end name of your file")                                   #simple code assigning user input to the custom name vairable
    customName = customName + fileType                                                      #add the fileType onto the end of the custom name

def compress():                                                                             #start of compress function
    fileSelect()                                                                            #calls the fileSelect function
    outputSelect()                                                                          #calls the outputSelect function
    fileNewName()
    global src
    global dst                                                                           #calls the fileNewName function
    src = startingLocation                                                                  #assigns startingLocation str as src, so the shutil module is able to use it in a cleaner way
    dst = outputLocation                                                                    #assigns outputLocation dst as src, so the shutil module is able to use it in a cleaner way
    shutil.copy(src, dst)                                                                   #shutil command that copies the file from src to dst
    src = outputLocation + '/' + originalName                                               #reassigns src as the location of the file copy
    dst = outputLocation + '/' + customName                                                 #reassigns dst as the location of the file copy but with a new name
    shutil.move(src,dst)


def compress_video(video_full_path, output_file_name, target_size):
    # Reference: https://en.wikipedia.org/wiki/Bit_rate#Encoding_bit_rate
    min_audio_bitrate = 32000
    max_audio_bitrate = 256000

    probe = ffmpeg.probe(video_full_path)
    # Video duration, in s.
    duration = float(probe['format']['duration'])
    # Audio bitrate, in bps.
    audio_bitrate = float(next((s for s in probe['streams'] if s['codec_type'] == 'audio'), None)['bit_rate'])
    # Target total bitrate, in bps.
    target_total_bitrate = (target_size * 1024 * 8) / (1.073741824 * duration)

    # Target audio bitrate, in bps
    if 10 * audio_bitrate > target_total_bitrate:
        audio_bitrate = target_total_bitrate / 10
        if audio_bitrate < min_audio_bitrate < target_total_bitrate:
            audio_bitrate = min_audio_bitrate
        elif audio_bitrate > max_audio_bitrate:
            audio_bitrate = max_audio_bitrate
    # Target video bitrate, in bps.
    video_bitrate = target_total_bitrate - audio_bitrate

    i = ffmpeg.input(video_full_path)
    ffmpeg.output(i, os.devnull,
                  **{'c:v': 'libx264', 'b:v': video_bitrate, 'pass': 1, 'f': 'mp4'}
                  ).overwrite_output().run()
    ffmpeg.output(i, output_file_name,
                  **{'c:v': 'libx264', 'b:v': video_bitrate, 'pass': 2, 'c:a': 'aac', 'b:a': audio_bitrate}
                  ).overwrite_output().run()

compress()
compress_video(dst, outputLocation, 3 * 1000)


  


• FFMPEG stream video to Youtube Live

  13 juin 2022, par BlessedHIT

  I have a mov file and I'm using ffmpeg to stream it to youtube live using the following command,

  


  ffmpeg -re -i "episode.mov" -pix_fmt yuvj420p -x264-params keyint=48:min-keyint=48:scenecut=-1 -b:v 4500k -b:a 128k -ar 44100 -acodec aac -vcodec libx264 -preset medium -crf 28 -threads 4 -f flv "rtmp://a.rtmp.youtube.com/live2/YOUTUBE.LIVESTREAM.KEY"


  


  But im getting the following message on youtube,

  


  YouTube is not receiving enough video to maintain smooth streaming. As such, viewers will experience buffering


  


  My ffmpeg output showed my bitrate being between 800 - 1000 mbps, way lower than what i have specified in my ffmpeg command.

  


  I am using a not so powerful virtual machine, and so i thought this might be why i am not getting the desired bitrate.

  


  To overcome my hardware limitations, I then decided to encode the file for streaming using this command :

  


  ffmpeg -i episode.mov -c:v libx264 -preset medium -b:v 4500k -maxrate 4500k -bufsize 6000k -vf "scale=1280:-1,format=yuv420p" -g 50 -c:a aac -b:a 128k -ac 2 -ar 44100 episode.flv


  


  Then I stream copy the file using :

  


  ffmpeg -re -i episode.flv -c copy -f flv "rtmp://a.rtmp.youtube.com/live2/YOUTUBE.LIVESTREAM.KEY"


  


  And that seems to give me a stream that youtube is happy with.

  


  My question is, is there a way I can rewrite my ffmpeg command to livestream with the desired bitrate without needing to first encode my mov to another file or is adding more memory the only way forward here ?

  


• Concatenate multiple video files alongside delayed audio files

  28 mars 2022, par Spartan 117

  I am currently working on a utility that is responsible for pulling audio and video files from the cloud and merging them together via FFMPEG. As I am new to FFMPEG, I am going to split the question into an FFMPEG part and a C# part just so people can answer either 1 part or the other (or both !).

  


  FFMPEG Part

  


  Currently, I have a working FFMPEG arg if there is only 1 video file present and it needs to be merged with multiple files.

  


  ffmpeg -i input1.mkv -i input1.mka -i input2.mka -i input3.mka -i input4.mka -filter_complex "[1:a]adelay=0s:all=1[a1pad];[2:a]adelay=20s:all=1[a2pad];[3:a]adelay=30s:all=1[a3pad];[4:a]adelay=40s:all=1[a4pad];[a1pad][a2pad][a3pad][a4pad]amix=inputs=4:weights=1|1|1|1[aout]" -map [aout] -map 0:0 output4.mkv


  


  The delays you see in there are determined by subtracting the start time of each file from the start time of the earliest created audio or video file. I know that if I wanted to create a horizontal stack of multiple videos, i could just do

  


  ffmpeg -i input1.mkv -i input1.mka -i input2.mkv -i input2.mka -i input3.mka -i input4.mka
-filter_complex 
"[2:v]tpad=start_duration=120:color=black[vpad]; 
 [3:a]adelay=120000:all=1[a2pad]; 
 [4:a]adelay=180000:all=1[a3pad];
 [5:a]adelay=200000:all=1[a4pad]; 
 [0:v][vpad]hstack=inputs=2[vout]; 
 [1:a][a2pad][a3pad][a4pad]amix=inputs=4:weights=1|1|1|1[aout]" 
 -map [vout] -map [aout] 
 output.mkv


  


  but what I want to do is both keep those delays for the audio and video files AND concatenate (not stack) those videos, how would i go about doing that ?

  


  C# Part

  


  You see that giant arg up there ? The utility is supposed to generate that based on a List of recordings. Here is the model.

  


  List<filemodel> _records;&#xA;public class FileModel {&#xA;  public string Id { get; set; }&#xA;  public string FileType { get; set; }&#xA;  public string StartTime { get; set; }&#xA;}&#xA;</filemodel>

  


  The utility has to then go through that list and create the arg (as seen in the FFMPEG part) to be executed by the Xabe.FFMPEG package. The way i was thinking to approach this is to basically create 2 string builders. 1 string builder will be responsible for dealing with the inputs, the other string builder. Here is what i have so far

  


  private async Task CombineAsync()
    {
        var minTime = _records.Min(y => Convert.ToDateTime(y.StartTime));
        var frontBuilder = new StringBuilder("-y ");
        var middleBuilder = new StringBuilder("-filter_complex \"");
        var endString = $" -map [vout] -map [aout] {_folderPath}\\CombinedOutput.mkv";

        for (var i = 0; i < _records.Count; i++)
        {
            var type = _records[i].FileType.ToLower();
            var delay = (Convert.ToDateTime(_records[i].StartTime).Subtract(minTime)).TotalSeconds;
            frontBuilder.Append($"-i {_folderPath + "\\" + _records[i].Id} ");
            var addColon = i != _records.Count - 1 ? ";" : "";
            middleBuilder.Append(type.Equals("video") ? $"[{i}:v]tpad=start_duration={delay}:color=black[v{i}pad]{addColon} " : $"[{i}:a]adelay={delay}s:all=1[a{i}pad]{addColon} ");
        }
        middleBuilder.Append("\"");
        Console.WriteLine(frontBuilder.ToString() + middleBuilder.ToString() + endString);
        // var args = frontBuilder + middleBuilder + endString;
        // try
        // {
        //     var conversionResult = await FFmpeg.Conversions.New().Start(args);
        //     Console.WriteLine(JsonConvert.SerializeObject(conversionResult));
        // }
        // catch (Exception e)
        // {
        //     Console.WriteLine(e);
        // }
    }


  


  


  1. Is this the correct way to go about building the argument out ?

     


  


  2. How in god's name do i get something like this in there, since it relies on naming and total count for the piping and inputs=

     


       [0:v][vpad]hstack=inputs=2[vout]; // This part will change for video concatenation depending on what gets answered above
  [1:a][a2pad][a3pad][a4pad]amix=inputs=4:weights=1|1|1|1[aout]