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• When using subprocess passthrough is not accepting both inputs

  30 janvier 2021, par Baraque Obahamas

  Im trying to have two subprocesses pipe into one and output via the passthrough. My goal is to make it possible to download 2 files (one video and one audio) and combine them with ffmpeg.

  


  header('Content-Description: File Transfer');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header("Content-Disposition: attachment; filename=\"ok.mp4\"");
header("Content-Type: application/octet-stream");

$cmd = "<(youtube-dl -f bestvideo[ext=mp4] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) <(youtube-dl -f bestaudio[ext=m4a] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) | ffmpeg -i - -i pipe:3 -movflags frag_keyframe+empty_moov+faststart -frag_duration 3600 -c:v copy -c:a copy -f mp4 -";

$cmd = passthru($cmd, $status);


  


  My error is : -bash : /dev/fd/63 : Permission denied

  


• Node.js asynchronous video conversion slow

  9 décembre 2016, par lukstei

  I wrote a little website/service, which can download a video from a website (currently Youtube) and converts it on the fly to an mp3 file and sends this file back as the response.

  For example, you when you request http://localhost:8000/v=http ://www.youtube.com/watch?v=HhoewflkQu0, then it will download this video and response the audio layer encoded in MP3.

  This all works very well, my problem is that this is very slow and I can’t figure out why.

  ---

  Simplified the script behaves like this :

  Download the video and write it to the stdin of ffmpeg, and the stdout goes to the response.
  Video (MP4, FLV) -> FFMPEG -> MP3

  I used curl to figure out how fast the script is :

  $ curl http://localhost:8000/v=http://www.youtube.com/watch?v=HhoewflkQu0

  I get only about 5-10k.

  So why is this so slow ?

  1. The server, from which I am downloading the video is slow.
  2. The conversion is slow (because of a slow CPU).
  3. The data transfer between node.js -> FFMPEG is slow.

  I tried to download the video in a normal download manager, and i got about 320k, which is my normal download speed, so the first point isn’t the bottleneck.

  To point 2 and 3, I tried to write a local file to the stdin, and I got about 600k so that isn’t it either.

  So why is my script so slow, and what can I do to make it faster ?

  https://gist.github.com/1304637

  Thanks in advance.

• RTSP Streaming Server C++

  24 août 2020, par Lakshya

  I would like to write a RTSP streaming server using C++. Multiple clients will be connected to this server for receiving the streamed data.

  


  What I understand is that I need to do socket programming in C++ for client server architecture.

  


  I know FFMPEG has command line support for streaming audio/video. But my requirement is writing a client server socket model in C++.

  


  I had a look at https://www.medialan.de/usecase0001.html

  


  I am also looking at this. https://www.youtube.com/watch?v=MEMzo59CPr8

  


  but I am not sure if this will help me.

  


  For streaming the audio/video data, Do i need to use FFMEPG APIs. If yes, which libraries of FFMPEG i need to use ?.