VideoPlayer-BackendProcessing-OpenGL

A simple video player backend built using FFmpeg for video decoding and OpenGL/GLFW for rendering, designed to process and display video frames with customizable transformations. This project currently supports playing a video with the option to double the width using a bilinear scaling shader, maintaining the original height for a stretched effect.

Features

• Decodes video files using FFmpeg's software decoding pipeline.
• Renders video frames in an OpenGL window using GLFW.
• Supports doubling the video width with smooth bilinear interpolation via an OpenGL shader.
• Maintains even dimensions for compatibility with FFmpeg's scaling requirements.
• Robust error handling to prevent crashes (e.g., access violations).
• MSVC-compatible file handling using fopen_s.

Requirements

• Operating System: Windows (tested on Windows 10/11)
• Compiler: Microsoft Visual Studio (tested with VS 2022)
• Dependencies:
  • FFmpeg: Libraries (libavformat, libavcodec, libavutil, libswscale) and DLLs (avformat-61.dll, avcodec-61.dll, avutil-59.dll, swscale-8.dll,avdevice-61,avfilter-10.dll,swresample-5.dll,postproc-58.dll )
  • GLEW: OpenGL Extension Wrangler Library (glew32.lib, glew32.dll)
  • GLFW: Window and input handling (glfw3.lib, glfw3.dll)
  • OpenGL: Provided by Windows (opengl32.lib)

Setup Instructions

Explanation of Dependencies

Here’s a detailed breakdown of the dependencies (GLEW, FFmpeg, GLFW, and OpenGL), including their libraries, DLLs, and how they integrate into the project.

1. GLEW (OpenGL Extension Wrangler Library)

• Purpose: Simplifies the use of OpenGL extensions by loading them at runtime. The code uses GLEW to access modern OpenGL functions (e.g., for shaders and textures).
• Files Needed:
  • Header: include/GL/glew.h
  • Static Library: lib/Release/x64/glew32.lib (links at compile time)
  • DLL: bin/Release/x64/glew32.dll (required at runtime)
• Why Both Lib and DLL?: The glew32.lib file tells the linker how to interface with glew32.dll, which contains the actual runtime code for OpenGL extension management.
• Source: Download from GLEW Releases or GitHub.

2. FFmpeg

• Purpose: Handles video file parsing, decoding, and color space conversion. The code uses FFmpeg’s libavformat (file I/O), libavcodec (decoding), libavutil (utilities), and libswscale (YUV-to-RGB conversion).
• Files Needed:
  • Headers: include/libavformat/avformat.h, include/libavcodec/avcodec.h, include/libavutil/imgutils.h, include/libswscale/swscale.h
  • Static Libraries: lib/avformat.lib, lib/avcodec.lib, lib/avutil.lib, lib/swscale.lib (links at compile time)
  • DLLs: bin/avformat-61.dll, bin/avcodec-61.dll, bin/avutil-59.dll, bin/swscale-8.dll (required at runtime)
• Why Both Lib and DLL?: The .lib files are import libraries that provide the interface for the linker to connect to the corresponding .dll files, which contain the actual FFmpeg functionality at runtime.
• Source: Download a shared and dev build from FFmpeg Builds or gyan.dev. Ensure the version matches your DLLs (e.g., 7.0 for avcodec-61.dll).

3. GLFW

• Purpose: Creates windows, handles input, and manages the OpenGL context. The code uses GLFW to open a window and render video frames.
• Files Needed:
  • Header: include/GLFW/glfw3.h
  • Static Library: lib-vc2022/glfw3.lib (links at compile time, adjust for your VS version)
  • DLL: glfw3.dll (required at runtime, location varies by build)
• Why Both Lib and DLL?: Similar to GLEW and FFmpeg, glfw3.lib provides the linker interface to glfw3.dll, which handles window and context management at runtime.
• Source: Download pre-compiled binaries or source from GLFW Downloads.

4. OpenGL

• Purpose: Provides the graphics API for rendering video frames. The code uses OpenGL to create textures, shaders, and render a quad.
• Files Needed:
  • Header: Provided by Windows SDK (include/GL/gl.h, included via GLEW)
  • Static Library: opengl32.lib (included with Windows SDK, links at compile time)
  • DLL: opengl32.dll (system-provided, no need to copy)
• Why Only Lib?: opengl32.lib interfaces with the system’s opengl32.dll, which is part of Windows and doesn’t need to be distributed.

Configuring Dependencies in Visual Studio

Here’s a step-by-step guide to set up the dependencies in Visual Studio 2022 for the VideoPlayer-BackendProcessing-OpenGL project. This assumes you’ve downloaded FFmpeg, GLEW, and GLFW and have their include, lib, and bin folders ready.

Step 1: Organize Dependency Files

1. FFmpeg:
   • Example path: C:\ffmpeg
   • Folders: C:\ffmpeg\include, C:\ffmpeg\lib, C:\ffmpeg\bin
   • Copy DLLs (avformat-61.dll, avcodec-61.dll, avutil-59.dll, swscale-8.dll,avdevice-61,avfilter-10.dll,swresample-5.dll,postproc-58.dll ) from C:\ffmpeg\bin to your project’s x64\Debug and x64\Release directories (e.g., VideoPlayer-BackendProcessing-OpenGL\x64\Debug).
2. GLEW:
   • Example path: C:\glew
   • Folders: C:\glew\include, C:\glew\lib\Release\x64, C:\glew\bin\Release\x64
   • Copy glew32.dll from C:\glew\bin\Release\x64 to where your .sln file is.

Step 2: Create or Open the Project

1. Open Visual Studio 2022 and create a new C++ project (e.g., Empty Project) or open your existing VideoPlayer-BackendProcessing-OpenGL.sln.
2. Add main.cpp (the code provided in the previous message) to the project.
3. Set the solution configuration to Debug and platform to x64 (Solution Explorer > Solution Platforms > x64).

Step 3: Configure Project Properties

1. Right-click the project in Solution Explorer > Properties.
2. Ensure the configuration is set to Debug and platform to x64 in the Property Pages dialog.
3. Update the following settings:
   • C/C++ > General > Additional Include Directories:

     C:\ffmpeg\include;C:\glew-2.1.0\include;C:\glfw-3.4.bin.WIN64\include
     

     Replace paths with your actual folder locations.
   • Linker > General > Additional Library Directories:

     C:\ffmpeg\lib;C:\glew-2.1.0\lib\Release\x64;C:\glfw-3.4.bin.WIN64\lib-vc2022
     

     Adjust paths as needed.
   • Linker > Input > Additional Dependencies:

     glew32.lib, glfw3.lib, opengl32.lib, user32.lib, gdi32.lib, shell32.lib, avcodec.lib, avdevice.lib, avfilter.lib, avformat.lib, avutil.lib, postproc.lib, swresample.lib, swscale.lib
     

4. Repeat for the Release configuration if you plan to build in Release mode (optional for now, as you’re using Debug).

Step 4: Verify DLL Placement

• Ensure the following DLLs are in x64\Debug (relative to your project’s executable):
  • avformat-61.dll
  • avcodec-61.dll
  • avdevice-61.dll
  • avfilter-10.dll
  • avutil-59.dll
  • swscale-8.dll
  • swresample-5.dll
  • postproc-58.dll
• If Visual Studio can’t find the DLLs at runtime, you’ll get an error like “The application was unable to start correctly (0xc000007b)”. Copying them to the executable directory resolves this.

Step 5: Prepare the Video File

• Place a valid H.264 MP4 video at C:\Users\ferni\Videos\Captures\video.mp4.
• Alternatively, edit main.cpp to update videoPath:

  const char* videoPath = "path\\to\\your\\video.mp4";