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• FFMPEG PERFORMING VERY SLOW

  6 septembre 2016, par Gary Mathis

  I’m trying to setup a media processing server. I’ve done a lot of research for FFMPEG and wrote a command. The command is as follows.

  ffmpeg -y -i "bbb_sunflower_2160p_60fps_normal.mp4" -c:v libx264 \
  
  -threads 7 -profile:v main -preset ultrafast -vf scale=1920:-1 \
  
  "process/video/1080p.mp4" -c:v libx264 -threads 7 -profile:v main \
  
  -preset ultrafast -vf scale=1280:-1 "process/video/720p.mp4" -c:v \
  
  libx264 -threads 7 -profile:v main -preset ultrafast -vf \
  
  scale=854:-1 "process/video/480p.mp4" -vf fps=5/60 \
  
  process/image/thumb_%d.jpg

  This command works and runs perfectly, but it is dirt slow. My server, which is dedicated to just running ffmpeg has the following specs :

  12 core intel Xeon X5650 (Hyperthreading enabled)
  64 GB ECC DDR3 RAM
  250 GB SSD Drive
  
  But when I use this command, the server CPU load hangs around 250-300%, which I would like it to hang around 2,000% while processing the video. Currently when processing the video, the server is rendering around 17 frames per second. This would take a very long time to process a 10 minute video that’s 60fps.

• Some mp4 files converted with ffmpeg are off by .01 frames/second, how can I fix this (without resampling) [closed]

  20 juin 2024, par twilightecologist

  I have several mp4 files with a frame rate of 119.88 frames/second, I need to convert these to 29.97 frames/second without resampling.

  


  To do this, I ran

  


  ffmpeg -itsscale 4 -i input.mp4 -c copy output_con.mp4


  


  However, some of these files return with a frame rate of 29.98 frames/second, this is messing me up in later analyses by throwing off some cross correlations between the mp4 files and related wav files. Any insight into how to remedy this would be much appreciated !

  


• Compiling FFmpeg staticly using NDK error - Not position independent executable

  27 février 2017, par David Barishev

  I have been trying to compile ffmpeg into a static library in order to use it in my android application, but i couldn’t get it to work.

  Im working with FFmpeg 3.2.4, and ndk r13b, using bash on windows 10(Ubuntu 14.04).

  Here is what i did :

  • I made a stand alone toolchain for x86_64 and api 21 using :
    python make_standalone_toolchain.py --api 21 --arch x86_64 --install-dir {}

  • Made a configuration script :

    ./configure \
    
    --target-os=android                                     \
    
    --arch=x86_64                                              \
    
    --prefix=/home/david/ffmpeg_x86_64_build                          \
    
    --cross-prefix=/home/david/x86_64_toolchain/bin/x86_64-linux-android-\
    
    --sysroot=/home/david/x86_64_toolchain/sysroot                    \
    
    --enable-cross-compile                                  \
    
    --pkg-config-flags="--static"                           \
    
    --enable-ffmpeg                                         \
    
    --disable-ffplay                                        \
    
    --disable-ffprobe                                       \
    
    --disable-ffserver                                      \
    
    --disable-doc                                           \
    
    --disable-htmlpages                                     \
    
    --disable-manpages                                      \
    
    --disable-podpages                                      \
    
    --disable-txtpages                                      \
    
    --extra-cflags="-fPIC"                                  \
    
    --extra-cxxflags="-fPIC"
    
    --disable-shared --enable-static \
    
    --enable-yasm
    
    
    
    make
    
    make install

  It produced an FFmpeg executable, however when i ran it on my API 23 emulator, i got an error message :error: only position independent executables (PIE) are supported.
  Even that i used -fPic

  How can i fix it ? Also i’m not sure about my configuration, there wasn’t up to date sources on how to compile it correctly for every ABI (arm,arm64,x86,x86_64,mips,mips64) that i need for my application.
  I have seen many script, and im not too familiar with compiling native code, so i wasn’t sure what settings i need, for example like C flags and etc.

  To be precise on how i tried to configure FFmpeg :

  • I need a static library
  • I Only need the ffmpeg command line utility
  • I want to compile the library for every ABI i listed above.This configuration tried to compile for x86_64.
  • Running on android of course

  I would greatly appreciate some help on how to configure and compile this correctly.