pandora_t_for_time/management/commands/render.py

import json
import os
import subprocess

from django.core.management.base import BaseCommand
from django.conf import settings

from ...render import compose, render


class Command(BaseCommand):
    help = 'genrate kdenlive porject and render'

    def add_arguments(self, parser):
        parser.add_argument('--prefix', action='store', dest='prefix', default="/srv/t_for_time", help='prefix to build clips in')
        parser.add_argument('--duration', action='store', dest='duration', default="150", help='target duration in seconds')
        parser.add_argument('--offset', action='store', dest='offset', default="1024", help='inital offset in pi')
        parser.add_argument('--no-video', action='store_true', dest='no_video', default=False, help='don\'t render video')

    def handle(self, **options):
        prefix = options['prefix']
        target = int(options['duration'])
        base = int(options['offset'])

        with open(os.path.join(prefix, "clips.json")) as fd:
            clips = json.load(fd)
        scene = compose(clips, target=target, base=base)
        timelines = render(prefix, scene, 'scene-%s-' % base)
        with open(os.path.join(prefix, 'scene-%s.json' % base), 'w') as fd:
            json.dump(scene, fd, indent=2, ensure_ascii=False)
        if not options['no_video']:
            for timeline in timelines:
                ext = '.mp4'
                if '-audio.kdenlive' in timeline:
                    ext = '.wav'
                cmd = [
                    'xvfb-run', '-a',
                    'melt', timeline,
                    '-consumer', 'avformat:%s' % timeline.replace('.kdenlive', ext)
                ]
                subprocess.call(cmd)
                if ext == '.wav':
                    cmd = [
                        'ffmpeg', '-i',
                        timeline.replace('.kdenlive', ext),
                        timeline.replace('.kdenlive', '.mp4')
                    ]
                    subprocess.call(cmd)
                    os.unlink(timeline.replace('.kdenlive', ext))