Build and Use Video Generator

ViPPET includes a video generator that creates composite videos from images stored in subdirectories.

This guide is ideal for developers who want to work directly with the source code.

Build and Start the Tool:

• Follow the steps in How to Build from Source

• Run:

   docker compose exec videogenerator python3 imagetovideo.py
  

Make Changes

1. Change Input Images:

   To use your own images instead of the default sample images, follow these steps:

   • Navigate to the images folder and create subfolders for your new image categories, placing the relevant images inside.

   • Open the config.json file located at video_generator/config.json.

   • Update the object_counts to reference your new image folders. Replace the existing categories (e.g., cars or faces) with the names of the new categories you added in the images folder:

     {
        "background_file": "/usr/src/app/background.gif",
        "base_image_dir": "/usr/src/app/images",
        "output_file": "output_file",
        "target_resolution": [1920, 1080],
        "frame_count": 300,
        "frame_rate": 30,
        "swap_percentage" : 20,
        "object_counts": {
           "cars": 3,
           "persons": 3
        },
        "object_rotation_rate": 0.25, 
        "object_scale_rate": 0.25, 
        "object_scale_range": [0.25, 1],
        "encoding": "H264",
        "bitrate": 20000,
        "swap_rate": 1
     }
     

2. Configure Parameters:

   The program uses a config.json file to customize the video generation process. Below is an example configuration:

   {
      "background_file": "/usr/src/app/background.gif",
      "base_image_dir": "/usr/src/app/images",
      "output_file": "output_file",
      "target_resolution": [1920, 1080],
      "frame_count": 300,
      "frame_rate": 30,
      "swap_percentage" : 20,
      "object_counts": {
         "cars": 3,
         "persons": 3
      },
      "object_rotation_rate": 0.25, 
      "object_scale_rate": 0.25, 
      "object_scale_range": [0.25, 1],
      "encoding": "H264",
      "bitrate": 20000,
      "swap_rate": 1
   }
   

   The parameters in the config.json file can be updated as follows:

   • background_file: Path to a background image (GIF, PNG, etc.) to be used in composite frames.

   • base_image_dir: Path to the root directory containing categorized image subdirectories.

   • output_file: Path to the final generated video file. Preference is not to give the file extension and no . in filename (e.g., output_file).

   • target_resolution: Resolution of the output video in [width, height] format.

   • duration: Total duration of the generated video (in seconds).

   • frame_count: Total number of frames in the generated video.

   • swap_percentage: Percentage of images that should be swapped between frames.

   • object_counts: Dictionary specifying the number of images per category in each frame.

   • object_rotation_rate: Rate at which objects rotate per frame (e.g., 0.25 means a quarter rotation per frame).

   • object_scale_rate: Rate at which the size of objects changes per frame (e.g., 0.25 means the object size changes by 25% per frame).

   • object_scale_range: List specifying the minimum and maximum scale factors for the objects (e.g., [0.25, 1] means the object can scale between 25% and 100% of its original size).

   • encoding: Video encoding format (e.g., H264).

   • bitrate: Bitrate for video encoding (measured in kbps).

   • swap_interval: Frequency of image swapping within frames (in seconds).

   • Supported Encodings and Video Formats

     Encoding	Video Format
     H264	.mp4
     HEVC	.mp4
     VP8	.webm
     VP9	.webm
     AV1	.mkv
     MPEG4	.avi
     ProRes	.mov
     Theora	.ogg

3. Save Changes and Restart:

   • Save the file and restart the application:

     docker compose restart
     

Validation

1. Verify Build Success:

   • Check the logs. Look for confirmation messages indicating the microservice started successfully.

• Expected result: An MP4 file is created under the videos folder.