pandora_cdosea/render_mlt.py

#!/usr/bin/python
import os
import time
import sys
import json
import subprocess

import mlt
from PyQt5 import QtWidgets

# Avoid segfault in webvfx
app = QtWidgets.QApplication(sys.argv)

#mlt.mlt_log_set_level(40) # verbose
mlt.Factory.init()


tractor = mlt.Tractor()
tractor.mark_in = -1
tractor.mark_out = -1

multitrack = tractor.multitrack()

source = sys.argv[1]
target = source.replace('.json', '.xml')
target_audio = source.replace('.json', '.audio.xml')
target_vocals = source.replace('.json', '.vocals.xml')

with open(source) as fd:
    data = json.load(fd)

video = mlt.Playlist()
overlay = mlt.Playlist()
music = mlt.Playlist()
vocals = mlt.Playlist()
drones0 = mlt.Playlist()
drones1 = mlt.Playlist()

fps = 60
profile = mlt.Profile("atsc_1080p_%d" % fps)
#profile.set_explicit(1)

# get profile from clip
#clip = mlt.Producer(profile, 'test.mp4')
#profile.from_producer(clip)

def add_color(playlist, color, duration):
    red = mlt.Producer(profile, 'color:' + color)
    red.set_in_and_out(0, duration)
    playlist.append(red)

def add_clip(playlist, file_, in_, duration):
    if not isinstance(file_, str):
        file_ = file_.encode('utf-8')
    clip = mlt.Producer(profile, file_)
    clip.set_in_and_out(in_, in_+duration-1)
    playlist.append(clip)

def add_audio_clip(playlist, file_, duration):
    in_ = 0
    if not isinstance(file_, str):
        file_ = file_.encode('utf-8')
    clip = mlt.Producer(profile, file_)
    clip.set_in_and_out(in_, in_+duration-1)
    playlist.append(clip)

def add_silence(playlist, length):
    file_ = 'silence.wav'
    add_audio_clip(playlist, file_, length)

def add_blank(playlist, length):
    playlist.blank(length)

def add_text(playlist, value, length):
    if not isinstance(value, str):
        value = value.encode('utf-8')
    text = mlt.Producer(profile, 'webvfx:text.html')
    text.set('transparent', 1)
    text.set('title', value)
    text.set('length', length)
    playlist.append(text)


for clip in data['clips']:
    if clip.get('black'):
        # fixme seconds to fps! duration fame etc!!
        frames = int(clip['duration'] * fps)
        add_color(video, 'black', frames)
    else:
        #print(clip['duration'], clip['path'])
        if not os.path.exists(clip['path']):
            print(clip['path'], 'is missing')
            sys.exit(1)
        # fixme seconds to fps!
        in_ = int(clip['in'] * fps)
        frames = int(clip['duration'] * fps)
        add_clip(video, clip['path'], in_, frames)
add_color(video, 'black', 60)

for clip in data['text']:
    if clip.get('blank'):
        frames = int(clip['duration'] * fps)
        add_blank(overlay, frames)
    else:
        frames = int(clip['duration'] * fps)
        add_text(overlay, clip['text'], frames)

for clip in data['music']:
    frames = int(clip['duration'] * fps)
    if clip.get('blank'):
        add_silence(music, frames)
    else:
        add_audio_clip(music, clip['path'], frames)

for clip in data['vocals']:
    frames = int(clip['duration'] * fps)
    if clip.get('blank'):
        add_silence(vocals, frames)
    else:
        add_audio_clip(vocals, clip['path'], frames)

for name, plist in (
    ('drones0', drones0),
    ('drones1', drones1),
):
    for clip in data[name]:
        frames = int(clip['duration'] * fps)
        if clip.get('blank'):
            add_blank(plist, frames)
        else:
            add_audio_clip(plist, clip['path'], frames)

multitrack.connect(video, 0)
multitrack.connect(overlay, 1)
composite = mlt.Transition(profile, "composite")
#composite.set('fill', 1)

tractor.plant_transition(composite)

volume = mlt.Filter(profile, "volume")
volume.set("gain", '0.1')
tractor.plant_filter(volume)

def mix_audio_tracks(a, b, ratio):
    tractor = mlt.Tractor()
    tractor.mark_in = -1
    tractor.mark_out = -1

    audio = tractor.multitrack()
    audio.connect(a, 0)
    audio.connect(b, 1)
    mix = mlt.Transition(profile, "mix")
    mix.set("start", ratio)
    mix.set("end", ratio)
    tractor.plant_transition(mix)
    return tractor


consumer = 'xml'
consumer = mlt.Consumer(profile, consumer, target_vocals)
consumer.connect(vocals)
consumer.start()

# mix drones
drones = mix_audio_tracks(drones0, drones1, 0.5)

# mix drones + music
mtractor = mix_audio_tracks(drones, music, 0.20)
atractor = mix_audio_tracks(vocals, mtractor, 0.20)

consumer = mlt.Consumer(profile, 'xml', target_audio)
consumer.connect(atractor)
consumer.start()

target_audio_wav = target_audio + '.wav'
subprocess.call([
    'qmelt', target_audio, '-consumer', 'avformat:' + target_audio_wav,
])
audiomix = mlt.Producer(profile, target_audio_wav)

# mix vocals and music
#atractor = mix_audio_tracks(vocals, mtractor, 0.20)

# mix video + audio
#dtractor = mix_audio_tracks(atractor, tractor, 0.5)
dtractor = mix_audio_tracks(audiomix, tractor, 0.5)


output = mlt.Tractor()
tractor.mark_in = -1
tractor.mark_out = -1
output_tracks = output.multitrack()
output_tracks.connect(dtractor, 0)

norm = mlt.Filter(profile, "volume")
norm.set("gain", "-6dB")
output.plant_filter(norm)

consumer = 'xml'
consumer = mlt.Consumer(profile, consumer, target)
consumer.connect(output)
#consumer.set("real_time", -2)
consumer.start()