Tools forbreaking a video down into a series of still images.

panelize.py

from __future__ import print_function

import csv
import os
import sys

import cv2


def freak_out(msg):
    print('Failed:', msg, file=sys.stderr)
    sys.exit(1)

def divide_and_round_up(dividend, divisor):
    q, r = divmod(dividend, divisor)
    if r:
        q += 1
    return q


def main():
    PANEL_WIDTH  = 16
    PANEL_HEIGHT = 16
    COLOR_COMPONENT_COUNT = 3

    # Inspect input.
    source, = sys.argv[1:]
    if not os.path.exists(source):
        freak_out('File not found at %s' % source)

    # Make output directory. Name it after input.
    destination = os.path.splitext(source)[0]
    if os.path.exists(destination):
        freak_out('Destination already exists.')
    os.mkdir(destination)

    # Load file.
    content = cv2.imread(source)
    if content is None:
        freak_out('Failed to load %s' % source)

    row_count, column_count, _ = content.shape
    # TODO(danielwong): Freak out if these are not divisible by
    # PANEL_HEIGHT and PANEL_WIDTH respectively.

    # Iterate over panels.
    for i in xrange(0, row_count, PANEL_HEIGHT):
        for j in xrange(0, column_count, PANEL_WIDTH):
            slice_ = content[
                i:i+PANEL_HEIGHT, j:j+PANEL_WIDTH]
            w, h, _ = slice_.shape
            panel_content = slice_.reshape(
                w * h, COLOR_COMPONENT_COUNT)
            panel_file_name = '%d_%d.csv' % (
                i / PANEL_HEIGHT, j / PANEL_WIDTH)
            with open(os.path.join(destination, panel_file_name),
                      'wb') as panel_file:
                writer = csv.writer(panel_file)
                for color in panel_content:
                    writer.writerow(map(str, color))

    print('Success!', file=sys.stderr)


if __name__ == '__main__':
    main()

render_panel.py

from __future__ import print_function

import csv
import os
import sys

import cv2
import numpy

# TODO(danielwong): These constants are used elsewhere
# (e.g. panelize). DRY! On the other hand, only depending on the std
# lib is ncie...
PANEL_WIDTH  = 16
PANEL_HEIGHT = 16

COLOR_COMPONENT_COUNT = 3


def freak_out(msg):
    print('Failed:', msg, file=sys.stderr)
    sys.exit(1)


def main():
    source, = sys.argv[1:]

    # Make sure destination doesn't already exist.
    destination = os.path.splitext(source)[0] + '.jpg'
    if os.path.exists(destination):
        freak_out('Destination already exists.')

    out = numpy.zeros(
        (PANEL_HEIGHT, PANEL_WIDTH, COLOR_COMPONENT_COUNT), int)
    
    with open(source, 'rb') as panel_file:
        reader = csv.reader(panel_file)
        for k, color in enumerate(reader):
            i, j =  divmod(k, PANEL_WIDTH)
            out[i,j] = map(int, color)

    ok = cv2.imwrite(destination, out)


if __name__ == '__main__':
    main()

vid2frames.py

from __future__ import print_function

import os
import sys

import cv2


def freak_out(msg):
    print('Failed:', msg, file=sys.stderr)
    sys.exit(1)
    

def main():
    # Inspect input.
    source, = sys.argv[1:]
    if not os.path.exists(source):
        freak_out('Source does not exist.')

    # Make output directory. Name it after input.
    destination = os.path.splitext(source)[0]
    if os.path.exists(destination):
        freak_out('Destination already exists.')
    os.mkdir(destination)

    # Open input.
    capture = cv2.VideoCapture(source)
    frame_number = 0

    # Read each frame, and write it to its own file.
    while True:
        ok, content = capture.read()
        if not ok:
            freak_out('Unable to read frame %d (0 is first frame).'
                      % frame_number)

        ok = cv2.imwrite(os.path.join(destination,
                                      '%d.jpg' % frame_number),
                         content)
        if not ok:
            freak_out('Unable to write frame %d (0 is first frame).'
                      % frame_number)

        frame_number += 1

    # Clean up.
    cap.release()
    print('Success!', file=sys.stderr)


if __name__ == '__main__':
    main()