parameters.txt

Parameters
1. lang

The language of the subtitles. See attached "supported_languages.png" file

2. conf_threshold

Confidence threshold for word predictions. 

3. sim_threshold

Similarity threshold for subtitle lines. Subtitle lines with larger Levenshtein ratios than this threshold will be merged together. The default value 80 is fine for most cases.

Make it closer to 0 if you get too many duplicated subtitle lines, or make it closer to 100 if you get too few subtitle lines.

4. time_start and time_end

Extract subtitles from only a clip of the video. The subtitle timestamps are still calculated according to the full video length.

5. use_fullframe

By default, the specified cropped area is used for OCR or if a crop is not specified, then the bottom third of the frame will be used. By setting this value to True the entire frame will be used.

6. crop_x, crop_y, crop_width, crop_height

Specifies the bounding area in pixels for the portion of the frame that will be used for OCR.

7. use_gpu

Set to True if performing ocr with gpu

8. brightness_threshold

If set, pixels whose brightness are less than the threshold will be blackened out. Valid brightness values range from 0 (black) to 255 (white). This can help improve accuracy when performing OCR on videos with white subtitles.

9. similar_image_threshold

The number of non-similar pixels there can be before the program considers 2 consecutive frames to be different. If a frame is not different from the previous frame, then the OCR result from the previous frame will be used (which can save a lot of time depending on how fast each OCR inference takes).

10. similar_pixel_threshold

Brightness threshold from 0-255 used with the similar_image_threshold to determine if 2 consecutive frames are different. If the difference between 2 pixels exceeds the threshold, then they will be considered non-similar.

11. frames_to_skip

The number of frames to skip before sampling a frame for OCR. Keep in mind the fps of the input video before increasing.