downloader.twitch: Deals with twitch specifics of playlist management

pull/2/head
Mike Lang 6 years ago
parent 961712b919
commit 8993773a22

@ -0,0 +1,104 @@
import logging
import random
import requests
import hls_playlist
def get_master_playlist(channel):
"""Get the master playlist for given channel from twitch"""
resp = requests.get(
"https://api.twitch.tv/api/channels/{}/access_token.json".format(channel),
params={'as3': 't'},
headers={
'Accept': 'application/vnd.twitchtv.v3+json',
'Client-ID': 'pwkzresl8kj2rdj6g7bvxl9ys1wly3j',
},
)
resp.raise_for_status() # getting access token
token = resp.json()
resp = requests.get(
"https://usher.ttvnw.net/api/channel/hls/{}.m3u8".format(channel),
params={
# Taken from streamlink. Unsure what's needed and what changing things can do.
"player": "twitchweb",
"p": random.randrange(1000000),
"type": "any",
"allow_source": "true",
"allow_audio_only": "true",
"allow_spectre": "false",
"fast_bread": "True",
"sig": token["sig"],
"token": token["token"],
# Also observed in the wild but not used in streamlink:
# "playlist_include_framerate": "true"
# "reassignments_supported": "true"
},
)
resp.raise_for_status() # getting master playlist
playlist = hls_playlist.load(resp.text, base_uri=resp.url)
return playlist
def get_media_playlist_uris(master_playlist, target_qualities):
"""From a master playlist, extract URIs of media playlists of interest.
Returns {stream name: uri}.
Note this is not a general method for all HLS streams, and makes twitch-specific assumptions,
though we try to check and emit warnings if these assumptions are broken.
"""
# Twitch master playlists are observed to have the following form:
# The first listed variant is the source playlist and has "(source)" in the name.
# Other variants are listed in order of quality from highest to lowest, followed by audio_only.
# These transcoded variants are named "Hp[R]" where H is the vertical resolution and
# optionally R is the frame rate. R is elided if == 30. Examples: 720p60, 720p, 480p, 360p, 160p
# These variants are observed to only ever have one rendition, type video, which contains the name
# but no URI. The URI in the main variant entry is the one to use. This is true even of the
# "audio_only" stream.
# Streams without transcoding options only show source and audio_only.
# We return the source stream in addition to any in target_qualities that is found.
def variant_name(variant):
names = set(media.name for media in variant.media if media.type == "VIDEO" and media.name)
if not names:
logging.warning("Variant {} has no named video renditions, can't determine name".format(variant))
return None
if len(names) > 1:
logging.warning("Variant {} has multiple possible names, picking one arbitrarily".format(variant))
return list(names)[0]
if not master_playlist.playlists:
raise ValueError("Master playlist has no variants")
for variant in master_playlist.playlists:
if any(media.uri for media in variant.medias):
logging.warning("Variant has a rendition with its own URI: {}".format(variant))
by_name = {variant_name(variant): variant for variant in master_playlist.playlists}
source_candidates = [name for name in by_name.keys() if "(source)" in name]
if len(source_candidates) != 1:
raise ValueError("Can't find source stream, not exactly one candidate. Candidates: {}, playlist: {}".format(
source_candidates, master_playlist,
))
source = by_name[source_candidates[0]]
variants = {name: variant for name, variant in by_name.items() if name in target_qualities}
variants["source"] = source
return {name: variant.uri for name, variant in variants.items()}
def get_media_playlist(uri):
resp = requests.get(uri)
resp.raise_for_status()
return hls_playlist.load(resp.text, base_uri=resp.url)
def get_segment(uri):
# Future work: Make this stream directly to a file + hash it as we go,
# to avoid keeping it all in memory at once.
resp = requests.get(uri)
resp.raise_for_status()
return resp.content
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