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Development Guide

The bitstream mode 3 video parser can user under Windows and Linux, however the Windows setup is a bit more complicated, e.g. requires Visual Studio for compilation.

Repository structure

  • ExternalLibs: external dependencies for ffmpeg (only for Windows)
  • ffmpeg: libav* libraries from FFmpeg project
    • modified with // P.L. or //A.S. annotations
  • TestMain: test project for interfacing with the video parser
  • VideoParser: code for a DLL, parsing any video with the help of ffmpeg and providing statistical information on a frame basis

Building under Windows

Install the following requirements:

  • Windows 10 (most probably not required)
  • Visual Studio 2015 (Community Edition)
  • Visual C++ Redistributable 2015
  • C++ Tools for Visual Studio
  • YASM
    • Download the version for "64-Bit for VS2010 and above"
    • Copy the vsyasm.exe file to C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin
    • Copy the other files to C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\BuildCustomizations
    • In the .props file, replace the occurrence of $(Platform) with win$(PlatformArchitecture)

Building:

  • Open the Visual Studio solution file TestMain/TestMain.sln
  • Build the solution in 32-Bit or 64-Bit Debug mode
  • Note that some error messages related to linking are normal

This will output a DLL that can be included in another program. The DLL file is here:

\videoparser\TestMain\Debug\VideoParser.dll

The DLL will provide a per frame bitstream statistic of the parsed video. It contains 3 external functions:

OpenVideo( char* FileName, BYTE** Parser )
ReadNextFrame( BYTE* Parser )
GetFrameStatistics( BYTE* Parser, VIDEO_STAT* FrameStat)

In principle this is the way to use the DLL:

BYTE*   Parser ;
VIDEO_STAT   FrameStatistics

if( OpenVideo( FileName, &Parser ) )
  {
  do
    {
    MoreData  = ReadNextFrame( Parser ) ;
    GetFrameStatistics( Parser, &FrameStatistics ) ;
    }
  while( MoreData ) ;
  } ;

Building under Linux

Requirements:

  • Python 3
  • SCons build system
  • GCC

Under Ubuntu 18.04 (mostly FFmpeg dependencies):

sudo apt-get update -qq
sudo apt-get -y -qq install python3 python3-numpy python3-pip git scons autoconf automake build-essential libass-dev libfreetype6-dev libsdl2-dev libtheora-dev libtool libva-dev libvdpau-dev libvorbis-dev libxcb1-dev libxcb-shm0-dev libxcb-xfixes0-dev pkg-config texinfo wget zlib1g-dev yasm
pip3 install --user --upgrade pip
pip3 install --user pandas

Building:

# Configure, Build and Install ffmpeg
cd ffmpeg && ./configure_ffmpeg.sh && make -j $(nproc) && make install

# Build videoparser Application and libvideoparser
cd ../VideoParser && scons

Or, for a small test just run build_and_test.sh.

Debugging

C Code

There is a GDB-based debugging script under testmain.sh. Execute it with a file:

./testmain.sh /path/to/file.mp4

You are now in a GDB console and can inspect the code.

To debug with Visual Studio Code, a launch.json file is already provided, since setup is more complex. Simply uncomment the line with args and specify the path to the video file that should be launche.

The TestMain.cpp code partly reproduces what the Python module does.

Python

Simply add breakpoint() wherever you need it.