doc for preferences added

Author: voun7

README.md

@@ -10,14 +10,14 @@ A free program that extracts hard coded subtitles from a video and generates an
 
 **Features**
 
-- Detect subtitle area by searching common area
-- Manual resize or change of subtitle area (click and drag mouse to perform)
-- Single and Batch subtitle detection and extraction
-- Start and Stop subtitle extraction positions can be selected (use arrow keys for precise selection)
-- Resize video display (Zoom In (Ctrl+Plus), Zoom Out (Ctrl+Minus))
-- Non subtitle area of the video can be hidden to limit spoilers
-- Toast Notification available on Windows upon completion of subtitle detection and extraction
-- Preferences available for modification of options when extraction subtitles
+- Detect subtitle area by searching common area.
+- Manual resize or change of subtitle area (click and drag mouse to perform).
+- Single and Batch subtitle detection and extraction.
+- Start and Stop subtitle extraction positions can be selected (use arrow keys for precise selection).
+- Resize video display (Zoom In (Ctrl+Plus), Zoom Out (Ctrl+Minus)).
+- Non subtitle area of the video can be hidden to limit spoilers.
+- Toast Notification available on Windows upon completion of subtitle detection and extraction.
+- [Preferences docs](docs/Preferences.md) available for modification of options when extraction subtitles.
 - Multiple languages supported through [PaddleOCR](https://github.com/PaddlePaddle/PaddleOCR). They will be
   automatically downloaded as needed.
 
@@ -59,7 +59,7 @@ installed. The program will not start without it.
 
 - [Windows CPU Version](https://github.com/voun7/Video_Sub_Extractor/releases/download/v1.0/VSE-windows-cpu.zip)
 
-## Demo
+## Demo Video
 
 [![Demo Video](docs/images/demo%20screenshot.png)](https://youtu.be/nnm_waobgnI "Demo Video")
 

docs/Preferences.md

@@ -0,0 +1,80 @@
+## Preferences
+
+### Subtitle Detection
+
+<img src="images/sub%20det.png" width="400">
+
+Split Start: Frame position where subtitle detection will start from. It is relative to the length of the video. 0.0
+will start subtitle detection at the beginning of the video.
+
+Split Stop: Frame position where subtitle detection will stop. It is relative to the length of the video. 0.5 will stop
+subtitle detection at the middle of the video and 0.95 will stop the detection towards the end of the video.
+
+No of Frames: The number of frames from the start and stop position that will be taken for subtitle detection. Too
+little frames and the program will fail to detect the subtitles. Too many and detection takes more time.
+
+X Axis Padding: The x-axis padding determines the length of the horizontal line of the boundary box. Subtitle detection
+is unable to quickly determine the max x-axis length by looking at all the frames. 1.0 would mean the longest subtitle
+spans the entire width of the video. The value is relative to the width of the video.
+
+Y Axis Padding: The y-axis padding prevents the vertical line of the boundary box from being too close to the detected
+subtitle text. This value is fixed for all video heights.
+
+Use Default Search Area: The default part of the video frame will be searched to detect subtitles. When unchecked the
+entire video frame is searched when detecting subtitles.
+
+### Frame Extraction
+
+<img src="images/frame%20extract.png" width="400">
+
+Frame Extraction Frequency: The frequency of frame extraction from the video. 1 means every video frame will be
+extracted. The timing for the subtitles will be the most accurate and the subtitles might be more accurate. 2 means that
+extraction will happen after every 2 frames. The timing will be slightly off, but the entire subtitle extraction process
+will be significantly faster because only half of the frames will be used (total frames / 2).
+
+Frame Extraction Chunk Size: The number of frames to be extracted by each CPU core.
+
+### Text Extraction
+
+<img src="images/text%20extract.png" width="400">
+
+Text Extraction Chunk Size: The number of frames to be extracted by each CPU or GPU core/process.
+
+OCR CPU Max Processes: The maximum number of CPU cores to be used for extraction of text from the video.
+
+OCR GPU Max Processes: The maximum number of GPU processes to be used for extraction of text from the video. Using too
+many will cause a crash if GPU memory is not enough.
+
+OCR Recognition Language: The language of the subtitle in the video to be extracted.
+
+Text Drop Score: The minimum acceptable confidence score for every extracted text. A low score will result in more
+inaccurate text in the generated subtitle. A very high score will result in a more accurate text in the generated
+subtitle but lots of skipped text.
+
+Use Line Break: A line break will be used when more than one line of text is found in the same frame. This might not
+work properly if the OCR detects a lot of space on the same line of text.
+
+### Subtitle Generator
+
+<img src="images/sub%20gen.png" width="400">
+
+Text Similarity Threshold: The threshold for merging similar texts that appears successively but might be slightly
+different because of OCR variability. A lower threshold will result in texts that are different being merged.
+
+Minimum Consecutive Sub Duration: The minimum duration for subtitles that appear consecutively. Consecutively low
+duration usually means some background text in the video that appears for a short duration was detected.
+
+Max Consecutive Short Durations: The maximum number of allowed consecutive short subtitle durations. If the detected
+consecutive short durations are greater than the value, they will be removed.
+
+Minimum Sub Duration: Any subtitle with a duration less than or equal to this value will be removed.
+
+Use GPU if available: The GPU will for the subtitle extraction if available.
+
+### Notification
+
+<img src="images/notification.png" width="400">
+
+Notification Sound: The notification sound that is to be played after subtitle detection or generation is completed.
+
+Loop Notification Sound: The notification sound will be repeated.