videodinges/videodinges/models.py

import os
from datetime import datetime
from typing import NamedTuple, Optional, Union

from django.db import models
from django.db.models import constraints
from django.db.models.query_utils import Q

class Quality(NamedTuple):
	name: str
	width: int
	height: int
	priority: int

class TranscodingType(NamedTuple):
	name: str
	short_name: str
	description: str
	priority: int

	def __str__(self):
		return self.name

qualities = (
	Quality(name='360p', width=640, height=360, priority=1),
	Quality(name='480p', width=853, height=480, priority=2),
	Quality(name='720p', width=1280, height=720, priority=2),
	Quality(name='1080p', width=1920, height=1080, priority=1),
)

transcoding_types = (
	TranscodingType(name='video/webm', short_name='webm', description='Generic WebM', priority=1),
	TranscodingType(name='video/webm; codecs="vp8, vorbis"', short_name='vp8', description='WebM with VP8 and Vorbis',
		priority=80),
	TranscodingType(name='video/webm; codecs="vp9, opus"', short_name='vp9', description='WebM with VP9 and Opus',
		priority=100),
	TranscodingType(name='video/mp4', short_name='h.264', description='Generic MP4 with H.264', priority=1),
	TranscodingType(name='video/mp4; codecs="avc1.64001e,mp4a.40.2"', short_name='h.264',
		description='MP4 with H.264 (AVC1 profile High, Level 3.0) and AAC-LC', priority=50),
	TranscodingType(name='video/mp4; codecs="avc1.64001f,mp4a.40.2"', short_name='h.264',
		description='MP4 with H.264 (AVC1 profile High, Level 3.1) and AAC-LC', priority=50),
	TranscodingType(name='video/mp4; codecs="avc1.640028,mp4a.40.2"', short_name='h.264',
		description='MP4 with H.264 (AVC1 profile High, Level 4.0) and AAC-LC', priority=50),
	TranscodingType(name='video/mp4; codecs="avc1.640032,mp4a.40.2"', short_name='h.264',
		description='MP4 with H.264 (AVC1 profile High, Level 5.0) and AAC-LC', priority=50),
)

class Upload(models.Model):
	id = models.AutoField(primary_key=True)
	file = models.FileField()

	def __str__(self):
		return os.path.basename(self.file.path)

	class Meta:
		db_table = 'uploads'

class Video(models.Model):
	id = models.AutoField(primary_key=True)
	title = models.CharField(max_length=256)
	slug = models.CharField(max_length=256, unique=True)
	description = models.TextField()
	poster = models.OneToOneField(Upload, on_delete=models.PROTECT, blank=True, null=True, related_name='video_poster')
	og_image = models.OneToOneField(Upload, on_delete=models.PROTECT, blank=True, null=True, related_name='video_og_image')
	default_quality = models.CharField(
		choices=((quality.name, quality.name) for quality in qualities),
		max_length=128,
		blank=True,
		null=True
	)
	created_at = models.DateTimeField(default=datetime.now)
	updated_at = models.DateTimeField(default=datetime.now)

	def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
		self.updated_at = datetime.now()
		super().save(force_insert, force_update, using, update_fields)

	def __str__(self):
		return self.title

	class Meta:
		indexes = [models.Index(fields=['slug']), models.Index(fields=['created_at'])]
		db_table = 'videos'

class Transcoding(models.Model):
	id = models.AutoField(primary_key=True)
	video = models.ForeignKey(Video, on_delete=models.CASCADE, related_name='transcodings')
	quality = models.CharField(choices=((quality.name, quality.name) for quality in qualities), max_length=128)
	type = models.CharField(choices=((str(type_), str(type_)) for type_ in transcoding_types), max_length=128)
	upload = models.OneToOneField(Upload, on_delete=models.PROTECT, blank=True, null=True)
	url = models.CharField(max_length=256, null=True, blank=True, unique=True)

	def __str__(self):
		return self.quality

	@property
	def quality_obj(self):
		return get_quality_by_name(self.quality)

	class Meta:
		unique_together = ('video', 'quality', 'type')
		constraints = [
			constraints.CheckConstraint(
				check=Q(upload__isnull=False) | Q(url__isnull=False),
				name='upload_or_url_is_filled'
			),
			constraints.CheckConstraint(
				check=~(Q(upload__isnull=False) & Q(url__isnull=False)),
				name='upload_and_url_cannot_both_be_filled'
			),
		]
		db_table = 'transcodings'

class Track(models.Model):
	KINDS = (
		'subtitles',
		'captions',
		'descriptions',
		'chapters',
		'metadata',
	)
	id = models.AutoField(primary_key=True)
	video = models.ForeignKey(Video, on_delete=models.CASCADE, related_name='tracks')
	default = models.BooleanField(default=False)
	kind = models.CharField(choices=((kind, kind) for kind in KINDS), max_length=128, default=KINDS[0])
	lang = models.CharField(max_length=128)
	label = models.CharField(max_length=128, blank=True, null=True)
	upload = models.OneToOneField(Upload, on_delete=models.PROTECT)

	def __str__(self):
		return '%s_%s' % (self.kind, self.lang)

	class Meta:
		unique_together = ('video', 'kind', 'lang')
		constraints = (
			constraints.UniqueConstraint(
				fields=('video',), condition=Q(default=True), name='only_one_default_per_video'),
		)
		db_table = 'tracks'

def get_quality_by_name(name: str) -> Optional[Quality]:
	for quality in qualities:
		if quality.name == name:
			return quality

def get_transcoding_type_by_name(name: str) -> Optional[TranscodingType]:
	for t in transcoding_types:
		if t.name == name:
			return t

def get_short_name_of_transcoding_type(transcoding_type: Union[str, TranscodingType]) -> str:
	if isinstance(transcoding_type, str):
		for type_ in transcoding_types:
			if type_.name == transcoding_type:
				transcoding_type = type_

	if isinstance(transcoding_type, TranscodingType):
		return transcoding_type.short_name