Showing posts with label FFmpeg. Show all posts

FFmpeg Picture in Picture

by GarciaPL on Thursday, 29 May 2014

In this post you can find a small piece of code which should allows you to make picture in picture using ffmpeg. More information about this effect you can find in reference section of this post.

ffmpeg -i \tmp\stream1.mp4 -r 29.97 -vf "movie=\tmp\stream2.mp4, scale=212:120 [vid2]; [in][vid2] overlay=main_w-overlay_w-10:10 [out]" \tmp\output.mp4 &

I used ampersand at the end of this command because I would like to create a new process of merging those two input videos files in background. I also uploaded below some example how it should looks like in final. I pointed using red circle the video which was added using stream2.mp4 source. Do not hesitate to modify this command above. I'm sure that you will adapt it for your own purposes.

Picture in Picture using FFmpeg

Reference : [1] Picture-in-picture Wikipedia

Kill FFmpeg process smoothly

by GarciaPL on Thursday, 3 April 2014

Let's assume that you use FFmpeg distribution in your application. One of your function is for instance saving some HLS stream (HTTP Live Streaming) into file. I suppose you are using python subprocess module to create process in Linux OS to obtain this stream to your hard disk.

In normal way if you would like to stop saving this content using FFmpeg on your storage, you will just press 'q' button while you are in terminal. Due to this FFmpeg will be able to finish saving content and do not damage the file at the end.

There is some kind of problem if you would like to kill this FFmpeg process in smooth way without damaging the file while you do not have access to the terminal.

You can use below solution written in Python to kill this FFmpeg process from your application. Only input which you need to ensure is PID (Process IDentifier) which describes your  process. You can use below shell code in Linux :

ps -ef | grep ffmpeg | awk '{print $2}'

Once you know PID of your FFmpeg process just use this Python code : 
import psutil
import os
import signal

pids = psutil.get_pid_list()

for pid in pids:
      if (pid == <your_PID>):
            os.kill(pid,signal.SIGINT)
One thing is worthy of attention. You suppose to use mainly signal.SIGINT while you invoke os.kill function, because of it simulates in FFmpeg case the user interrupt of this process (typically initiated by pressing Control-C) which allow to FFmpeg to end his work properly.

Reference : [1] Python.org Subprocess Docs [2] Thelightfromtheblackhole.blogspot.com Sending sighup signal to some external [3] Unix signal - SIGINT

FFmpeg parse video/audio bitrate

by GarciaPL on Tuesday, 25 March 2014

Have you ever thought how receive the bitrate of your video/audio file using ffmpeg in command line ? Before I will show you a solution of this problem I would like to paste below some example output of video file which can be obtained using ffmpeg :

ffmpeg version git-2013-10-30-94a80e3 Copyright (c) 2000-2013 the FFmpeg developers
  built on Oct 30 2013 15:46:23 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu8)
  configuration: --prefix=/home/user/ffmpeg_build --extra-cflags=-I/home/user/ffmpeg_build/include --extra-ldflags=-L/home/luszcwoj/ffmpeg_build/lib --bindir=/home/luszcwoj/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab
  libavutil      52. 48.100 / 52. 48.100
  libavcodec     55. 39.100 / 55. 39.100
  libavformat    55. 19.104 / 55. 19.104
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'aquarium.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 0
    compatible_brands: isom3gp4
    creation_time   : 2013-09-08 23:38:41
  Duration: 00:00:03.44, start: 0.000000, bitrate: 3933 kb/s
    Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuvj420p(pc), 640x480 [SAR 1:1 DAR 4:3], 2250 kb/s, 29.70 fps, 29.67 tbr, 90k tbn, 30 tbc (default)
    Metadata:
      creation_time   : 2013-09-08 23:38:41
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 123 kb/s (default)
    Metadata:
      creation_time   : 2013-09-08 23:38:41
      handler_name    : SoundHandle


If you would like to get the bitrate just use this command : 
ffmpeg -i aquarium.mp4 2>&1 | grep bitrate: | awk '{print $6}'

Reference : [1] FFmpeg Home Page