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• How to install ffmpeg for PHP

  1er mai 2021, par Julie Bsd

  I've successfully installed ffmpeg using ssh, as root, on my dedicated server (CentOS 7).
  
ffmpeg works fine - but now I need to use it without root access.

  



  When i try to use ffmpeg without root access, I get the following error :

  



  ffmpeg: error while loading shared libraries: libx264.so.148: 
        cannot open shared object file: No such file or directory


  



  The final goal is to be able to use ffmpeg inside my PHP scripts which do not root access.

  


• Unable to use Multithread for librosa melspectrogram

  15 avril 2019, par Raven Cheuk

  I have over 1000 audio files (it’s just a initial development, in the future, there will be even more audio files), and would like to convert them to melspectrogram.

  Since my workstation has a Intel® Xeon® Processor E5-2698 v3, which has 32 threads, I would like to use multithread to do my job.

  My code

  import os
  
  import librosa
  
  from librosa.display import specshow
  
  from natsort import natsorted
  
  import numpy as np
  
  import sys 
  
  # Libraries for multi thread
  
  from multiprocessing.dummy import Pool as ThreadPool
  
  import subprocess
  
  pool = ThreadPool(20) 
  
  
  
  songlist = os.listdir('../opensmile/devset_2015/')
  
  songlist= natsorted(songlist)
  
  
  
  def get_spectrogram(song):
  
      print("start")
  
      y, sr = librosa.load('../opensmile/devset_2015/' + song)
  
  
  
      ## Add some function to cut y
  
      y_list = y
  
      ##
  
  
  
      for i, y_i in enumerate([y_list]): # can remove for loop if no audio is cut
  
          S = librosa.feature.melspectrogram(y=y, sr=sr, n_mels=128,fmax=8000)
  
          try:
  
              np.save('./Test/' + song + '/' + str(i), S)
  
          except:
  
              os.makedirs('./Test/' + song)
  
              np.save('./Test/' + song + '/' + str(i), S)
  
          print("done saving")
  
  
  
  pool.map(get_spectrogram, songlist)

  My Problem

  However, my script freezes after finished the first conversion.

  To debug what’s going on, I commented out S = librosa.feature.melspectrogram(y=y, sr=sr, n_mels=128,fmax=8000) and replace it by S=0.
  Then the multi-thread code works fine.

  What’s wrong with the librosa.feature.melspectrogram function ? Does it not support multi-thread ? Or is it a problem of ffmpeg ? (When using librosa, it asks me to install ffmpeg before.)

• Unable to Play Video Stream on Flask-FFmpeg Media Server on Subsequent Requests

  12 juin 2024, par yternal

  Problem Description :

  


  I am trying to create a media server using Flask and FFmpeg. The server converts an RTSP stream to FLV format for playback in a web browser, and I am testing it using ffplay. The server starts successfully, and the data returned from the first request can be played using ffplay. However, when I interrupt the ffplay request and make it again, ffplay is unable to play the video and displays an "Invalid data found when processing input" error.

  


  I am using the following command to test with ffplay :

  


  ffplay http://127.0.0.1:8000/flv/0


  


  My current Flask code：

  


  import queue
import subprocess
import threading

from flask import Flask, Response, stream_with_context
from gevent import monkey
from gevent.pool import Pool
from gevent.pywsgi import WSGIServer
from geventwebsocket.handler import WebSocketHandler
from loguru import logger

monkey.patch_all()
app = Flask(__name__)

stream_queue = queue.Queue(maxsize=10000)


def update_stream():
    process = subprocess.Popen(
        ['ffmpeg', '-i', 'rtsp://192.168.1.168/0', '-f', 'flv', '-'],
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE
    )
    while True:
        data = process.stdout.read(4096)
        if not data:
            break
        if stream_queue.full():
            stream_queue.get()
        stream_queue.put(data)
        logger.debug(f"stream_queue size: {stream_queue.qsize()}")


@app.route('/flv/')
def flv_stream(stream_id):
    @stream_with_context
    def generate():

        while True:
            data = stream_queue.get()
            yield data

    return Response(generate(), mimetype='video/x-flv')


if __name__ == '__main__':
    HOST = "0.0.0.0"
    PORT = 8000

    threading.Thread(target=update_stream, daemon=True).start()

    logger.info(f"listen in: {HOST}:{PORT}")
    pool = Pool(10000)
    http_serve = WSGIServer((HOST, PORT), app, handler_class=WebSocketHandler, spawn=pool)
    http_serve.max_accept = 30000
    http_serve.serve_forever()


  


  The error message when attempting to play the stream again with ffplay is :

  


  http://127.0.0.1:8000/flv/0: Invalid data found when processing input


  


  I tried adding some parameters to FFmpeg, such as analyzeduration and probesize, but it had no effect.