[Part 2] Added command line option parser.

Author: Breakthrough

examples/part2-adaptive.py

@@ -7,23 +7,31 @@
 # This Python program implements a more advanced and optimized threshold-
 # based scene detection algorithm, and improves the output format so
 # the scene cuts can be more easily imported into other programs (e.g.
-# ffmpeg, mkvmerge). Usage:
+# ffmpeg, mkvmerge). Basic usage is:
 #
-#   > python part2-adaptive.py [video] [intensity] [min %] [blocksize]
+#   > python part2-adaptive.py [-h] -i VIDEO_FILE
 #
-# Where [video] is a path to the video to be parsed, [intensity] is the
-# pixel intensity from 0 to 255 to be used as a cut-off (default 16),
-# [min %] is the minimum percent of pixels in the frame from 0 to 100
-# that must fall under the threshold (default 90%), and [blocksize] is
-# the amount of rows in the image to check at once (default 32, can be
-# changed/tuned to optimize performance).  Example:
+# Where -i denotes the input video, and -h shows the help message.
+# Optional arguments that can be passed after VIDEO_FILE are:
 #
-#   > python part2-adaptive.py testvideo.mp4 16 90 32
+#  -h, --help            show this help message and exit
+#  -i VIDEO_FILE, --input VIDEO_FILE
+#                        [REQUIRED] Path to input video. (default: None)
+#  -t intensity, --threshold intensity
+#                        8-bit intensity value, from 0-255, to use as a fade
+#                        in/out detection threshold. (default: 8)
+#  -m percent, --minpercent percent
+#                        Amount of pixels in a frame, from 0-100%, that must
+#                        fall under [intensity]. (default: 95)
+#  -b rows, --blocksize rows
+#                        Number of rows in frame to check at once, can be tuned
+#                        for performance. (default: 32)
+#  -s offset, --startindex offset
+#                        Starting index for chapter/scene output. (default: 0)
 #
-# Note that you must specify all options, unless you want to use the
-# above default values, in which case simply specify [video]:
-#
-#   > python part2-adaptive.py testvideo.mp4
+# Example:
+#   > python part2-adaptive.py -i testvideo.mp4
+#   > python part2-adaptive.py -i testvideo.mp4  -t 8  -m 95  -b 32  -s 0
 #
 # For each fade/cut that is detected, the timecodes and frame numbers
 # are printed to stdout. Note that this program depends on the Python
@@ -40,3 +48,66 @@
 # ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 # OTHER DEALINGS IN THE SOFTWARE.
 #
+
+
+import sys
+import argparse
+
+import cv2
+import numpy as np
+
+
+def int_type_check(min_val, max_val = None, metavar = None):
+    if metavar == None: metavar = 'value'
+    def _type_check(value):
+        value = int(value)
+        valid = True
+        msg   = ''
+        if (max_val == None):
+            if (value < min_val): valid = False
+            msg = 'invalid choice: %d (%s must be at least %d)' % (
+                value, metavar, min_val )
+        else:
+            if (value < min_val or value > max_val): valid = False
+            msg = 'invalid choice: %d (%s must be between %d and %d)' % (
+                value, metavar, min_val, max_val )
+        if not valid:
+            raise argparse.ArgumentTypeError(msg)
+        return value
+    return _type_check
+
+
+def get_cli_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class = argparse.ArgumentDefaultsHelpFormatter)
+    parser._optionals.title = 'arguments'
+
+    parser.add_argument('-i', '--input', metavar = 'VIDEO_FILE',
+        type = file, required = True,
+        help = '[REQUIRED] Path to input video.')
+    parser.add_argument('-t', '--threshold',  metavar = 'intensity',
+        type = int_type_check(0, 255, 'intensity'), default = 8,
+        help = '8-bit intensity value, from 0-255, to use as a fade in/out detection threshold.')
+    parser.add_argument('-m', '--minpercent', metavar = 'percent',
+        type = int_type_check(0, 100, 'percentage'), default = 95,
+        help = 'Amount of pixels in a frame, from 0-100%%, that must fall under [intensity].')
+    parser.add_argument('-b', '--blocksize',  metavar = 'rows',
+        type = int_type_check(0, None, 'number of rows'), default = 32,
+        help = 'Number of rows in frame to check at once, can be tuned for performance.')
+    parser.add_argument('-s', '--startindex', metavar = 'offset',
+        type = int, default = 0,
+        help = 'Starting index for chapter/scene output.')
+
+    return parser
+
+
+def main():
+    args = get_cli_parser().parse_args()
+
+    print args
+
+    pass
+
+    
+if __name__ == "__main__":
+    main()