Python video stacker

videostacker

import os, sys, numpy, PIL
from PIL import Image

# Build list of source video clips from arguments
clips = []
for i in range(1,len(sys.argv),2):
    path = sys.argv[i]
    offset = sys.argv[i+1]
    filename, ext = path.split('.')
    clip = { 'path': path,
             'offset': int(offset),
             'name': filename,
             'frames': [],
             }
    clips.append(clip)

min_frame_count = None
max_frame_count = None

for clip in clips:

    # Process clip to frames    
    print('[STACK] Splitting ' + clip['name'] + ' into frames...')
    try:
        os.mkdir(clip['name'])
        ffmpeg_cmd = 'ffmpeg -i ' + clip['path'] + ' -s hd720 -qscale:v 2 ' + clip['name'] + '/image%05d.jpg'
        os.system(ffmpeg_cmd)
    except OSError:
        print("[STACK] " + clip['name'] + " already processed to frames; skipping processing step.")

    # Load frame files to clip object
    frames = os.listdir(clip['name'])
    clip['frames'] = sorted([filename for filename in frames if filename[-4:] in [".jpg"]])

    # Track min and max frame counts
    frame_count = len(clip['frames']) + clip['offset']
    if (min_frame_count == None):
        min_frame_count = frame_count
    else:
        min_frame_count = min(min_frame_count, frame_count)
    if (max_frame_count == None):
        max_frame_count = frame_count
    else:
        max_frame_count = max(max_frame_count, frame_count)

print("[STACK] min_frame_count: " + str(min_frame_count))
print("[STACK] max_frame_count: " + str(max_frame_count))

# Prepare output directory for composite frames
os.mkdir('composite')

# Advance through frames across clips to build and export composite frames
print("[STACK] Generating composite video frames: ")
step = max_frame_count / 10
for f in range(0,max_frame_count):

    composite = numpy.zeros((720,1280,3),numpy.float)
    divisor = 0

    for clip in clips:
        frame_index = f - clip['offset']
        if 0 <= frame_index < len(clip['frames']):
            frame_path = clip['name'] + '/' + clip['frames'][frame_index]
            clip_frame = numpy.array(Image.open(frame_path), dtype=numpy.float)
            composite += clip_frame
            divisor += 1

    if divisor > 0:
        composite /= divisor

    # Round values in array and cast as 8-bit integer
    composite = numpy.array(numpy.round(composite), dtype=numpy.uint8)

    # Generate the composite frame
    frame = Image.fromarray(composite, mode="RGB")
    frame_path = 'composite/%05d.jpg' % f 
    frame.save(frame_path)

    # Update progress output
    if (f % step == 0):
        print '\b.',
        sys.stdout.flush()

# Combine composite frames into video
print("[STACK] Generating composite video file...")
os.chdir('composite')
os.system('ls -1tr > frames.txt')
mencoder_cmd = 'mencoder -nosound -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell:autoaspect:vqscale=3:threads=4 -vf scale=1280:720 -mf type=jpeg:fps=30 mf://@frames.txt -o ../composite.mov'
os.system(mencoder_cmd)
os.chdir('../')

# Clean everything up
print("[STACK] Cleaning up...")
for clip in clips:
    os.system('rm -r ' + clip['name'])
os.system('rm -r composite')

print("[STACK] Done.")