working. fixed width naming convention. multiple videos works too. v1.0

Readme.md

@@ -1,6 +1,8 @@
 # Video-to-Frames
 
-Simple python script to extract and store individual frames of a given video. 
+Simple python script to extract and store individual frames of a given video. If you have multiple videos for frame extraction, store them under a common `source directory` and then run the script as is. 
+
+The extracted frames will be stored under a separate `output directory`. In case of multiple videos, the script creates a separate folder for each video in the `output directory`.
 
 ## Setup
 1. Clone the repository using `git`.
@@ -10,4 +12,16 @@ Simple python script to extract and store individual frames of a given video.
     sudo apt-get update && install ffmpeg
     ```
 
-## TO DO: update usage  
+## Usage
+Change the following under `main` in `split_video.py`:
+1. `output_path`: path to store extracted frames of each video,
+2. `input_path`: path containing the videos to extract frames from,
+2. `pattern`: extension of the video files - `.mp4`, `.mkv` etc. 
+
+---
+
+<br>
+
+## TO DO
+- In case of multiple video extraction, add a boilerplate which enables creation of a dataframe containing details of extracted frames.
+

split_video.py

@@ -6,7 +6,19 @@
 
 def videos_to_imgs(output_path=None,
                    input_path=None,
-                   pattern="*.mp4"):
+                   pattern='*.mp4'):
+    """Function to split an input video into frames. It saves the frames with
+    a naming convention `videoname_f000000_t0000.00.png` where - second term represents 
+    the frame number and the third term represents its corresponding time-stamp. This function scales down
+    the video to a `250x250` resolution and also saves a `.txt` file containing time-stamps of the extracted
+    frames for additional use by the user. User can put multiple videos in a directory under `input_path` and
+    the extracted frames for each video will be stored in its own separate directory under `output_path`.
+
+    Args:
+        output_path (Path): Absolute path to the directory to store the extracted frames. Defaults to None.
+        input_path (Path): Absolute path to the directory which contains the videos to extract frames from. Defaults to None.
+        pattern (str, optional): Extension of the video files to extract frames from. Defaults to `*.mp4`.
+    """
 
     output_path = Path(output_path)
     input_path = Path(input_path)
@@ -25,6 +37,7 @@ def videos_to_imgs(output_path=None,
         out_folder = output_path / file_name
         out_folder.mkdir(exist_ok=True)
 
+        print(f'Start Writing time-stamps for Video {i+1}')
         # Writing time-stamps of each frame to `.txt` file
         os.system(
             f'ffprobe {video_path} -select_streams v -show_entries frame=coded_picture_number,pkt_pts_time -of csv=p=0:nk=1 -v 0 > {out_folder/file_name}.txt'
@@ -38,28 +51,33 @@ def videos_to_imgs(output_path=None,
         times_dict = {}
         with open(f'{out_folder/file_name}.txt') as file:
             for line in file:
-                (key, val) = line.strip().split(",")
+                (key, val) = line.strip().split(',')
                 times_dict[val] = f'{float(key):.2f}'
+        print(f'End Writing time-stamps for Video {i+1}')
 
         # Adding time-stamp corresponding to each frame in its name
-        frames = list(out_folder.glob("*.png"))
+        frames = list(out_folder.glob('*.png'))
         frames.sort()
         os.chdir(out_folder)
-        # Renaming loop
+        # Rename loop. 
         for frame in frames:
             try:
-                new_name = file_name + '_f' + frame.name.split('_')[1].split('.')[0] + '_t' + f'{times_dict[frame.stem.split("_")[1]]}' + '.png'
+                # vidname_f000000_t0000.00.png
+                new_name = (file_name + '_f' + format(int(frame.name.split('_')[1].split('.')[0]), '06d') + 
+                            '_t' + format(float(times_dict[frame.stem.split("_")[1]]), '07.2f') + '.png') 
 
                 frame.rename(new_name)
 
             except:
                 frame.unlink()
 
         # Print to terminal after completion of extracting each video
-        print("Done extracting: {}".format(i + 1))
+        print(f'Done extracting: {i+1}')
+        print(f'Number of frames extracted from Video {i+1}: {len(frames)}')
 
 
 if __name__ == "__main__":
-    videos_to_imgs(output_path="/home/prabhat/Videos/output",
-                    input_path="/home/prabhat/Videos/input", 
-                    pattern="*.mp4")
+    # Change `output_path` and `input_path` accordingly
+    videos_to_imgs(output_path='/home/prabhat/Videos/output',
+                    input_path='/home/prabhat/Videos/input', 
+                    pattern='*.mp4')