youtube-dl/youtube_dl/downloader/f4m.py

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Python
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2013-12-23 15:39:49 +00:00
from __future__ import unicode_literals
import base64
import io
import itertools
import os
from struct import unpack, pack
import time
import xml.etree.ElementTree as etree
from .common import FileDownloader
from .http import HttpFD
from ..utils import (
compat_urllib_request,
compat_urlparse,
format_bytes,
encodeFilename,
sanitize_open,
)
class FlvReader(io.BytesIO):
"""
Reader for Flv files
The file format is documented in https://www.adobe.com/devnet/f4v.html
"""
# Utility functions for reading numbers and strings
def read_unsigned_long_long(self):
return unpack('!Q', self.read(8))[0]
def read_unsigned_int(self):
return unpack('!I', self.read(4))[0]
def read_unsigned_char(self):
return unpack('!B', self.read(1))[0]
def read_string(self):
res = b''
while True:
char = self.read(1)
if char == b'\x00':
break
res += char
return res
def read_box_info(self):
"""
Read a box and return the info as a tuple: (box_size, box_type, box_data)
"""
real_size = size = self.read_unsigned_int()
box_type = self.read(4)
header_end = 8
if size == 1:
real_size = self.read_unsigned_long_long()
header_end = 16
return real_size, box_type, self.read(real_size-header_end)
def read_asrt(self):
# version
self.read_unsigned_char()
# flags
self.read(3)
quality_entry_count = self.read_unsigned_char()
# QualityEntryCount
for i in range(quality_entry_count):
self.read_string()
segment_run_count = self.read_unsigned_int()
segments = []
for i in range(segment_run_count):
first_segment = self.read_unsigned_int()
fragments_per_segment = self.read_unsigned_int()
segments.append((first_segment, fragments_per_segment))
return {
'segment_run': segments,
}
def read_afrt(self):
# version
self.read_unsigned_char()
# flags
self.read(3)
# time scale
self.read_unsigned_int()
quality_entry_count = self.read_unsigned_char()
# QualitySegmentUrlModifiers
for i in range(quality_entry_count):
self.read_string()
fragments_count = self.read_unsigned_int()
fragments = []
for i in range(fragments_count):
first = self.read_unsigned_int()
first_ts = self.read_unsigned_long_long()
duration = self.read_unsigned_int()
if duration == 0:
discontinuity_indicator = self.read_unsigned_char()
else:
discontinuity_indicator = None
fragments.append({
'first': first,
'ts': first_ts,
'duration': duration,
'discontinuity_indicator': discontinuity_indicator,
})
return {
'fragments': fragments,
}
def read_abst(self):
# version
self.read_unsigned_char()
# flags
self.read(3)
# BootstrapinfoVersion
bootstrap_info_version = self.read_unsigned_int()
# Profile,Live,Update,Reserved
self.read(1)
# time scale
self.read_unsigned_int()
# CurrentMediaTime
self.read_unsigned_long_long()
# SmpteTimeCodeOffset
self.read_unsigned_long_long()
# MovieIdentifier
movie_identifier = self.read_string()
server_count = self.read_unsigned_char()
# ServerEntryTable
for i in range(server_count):
self.read_string()
quality_count = self.read_unsigned_char()
# QualityEntryTable
for i in range(server_count):
self.read_string()
# DrmData
self.read_string()
# MetaData
self.read_string()
segments_count = self.read_unsigned_char()
segments = []
for i in range(segments_count):
box_size, box_type, box_data = self.read_box_info()
assert box_type == b'asrt'
segment = FlvReader(box_data).read_asrt()
segments.append(segment)
fragments_run_count = self.read_unsigned_char()
fragments = []
for i in range(fragments_run_count):
box_size, box_type, box_data = self.read_box_info()
assert box_type == b'afrt'
fragments.append(FlvReader(box_data).read_afrt())
return {
'segments': segments,
'fragments': fragments,
}
def read_bootstrap_info(self):
total_size, box_type, box_data = self.read_box_info()
assert box_type == b'abst'
return FlvReader(box_data).read_abst()
def read_bootstrap_info(bootstrap_bytes):
return FlvReader(bootstrap_bytes).read_bootstrap_info()
def build_fragments_list(boot_info):
""" Return a list of (segment, fragment) for each fragment in the video """
res = []
segment_run_table = boot_info['segments'][0]
# I've only found videos with one segment
segment_run_entry = segment_run_table['segment_run'][0]
n_frags = segment_run_entry[1]
fragment_run_entry_table = boot_info['fragments'][0]['fragments']
first_frag_number = fragment_run_entry_table[0]['first']
for (i, frag_number) in zip(range(1, n_frags+1), itertools.count(first_frag_number)):
res.append((1, frag_number))
return res
def write_flv_header(stream, metadata):
"""Writes the FLV header and the metadata to stream"""
# FLV header
stream.write(b'FLV\x01')
stream.write(b'\x05')
stream.write(b'\x00\x00\x00\x09')
# FLV File body
stream.write(b'\x00\x00\x00\x00')
# FLVTAG
# Script data
stream.write(b'\x12')
# Size of the metadata with 3 bytes
stream.write(pack('!L', len(metadata))[1:])
stream.write(b'\x00\x00\x00\x00\x00\x00\x00')
stream.write(metadata)
# Magic numbers extracted from the output files produced by AdobeHDS.php
#(https://github.com/K-S-V/Scripts)
stream.write(b'\x00\x00\x01\x73')
def _add_ns(prop):
return '{http://ns.adobe.com/f4m/1.0}%s' % prop
class HttpQuietDownloader(HttpFD):
def to_screen(self, *args, **kargs):
pass
class F4mFD(FileDownloader):
"""
A downloader for f4m manifests or AdobeHDS.
"""
def real_download(self, filename, info_dict):
man_url = info_dict['url']
self.to_screen('[download] Downloading f4m manifest')
manifest = self.ydl.urlopen(man_url).read()
self.report_destination(filename)
http_dl = HttpQuietDownloader(self.ydl, {'continuedl': True, 'quiet': True, 'noprogress': True})
doc = etree.fromstring(manifest)
formats = [(int(f.attrib.get('bitrate', -1)), f) for f in doc.findall(_add_ns('media'))]
formats = sorted(formats, key=lambda f: f[0])
rate, media = formats[-1]
base_url = compat_urlparse.urljoin(man_url, media.attrib['url'])
bootstrap = base64.b64decode(doc.find(_add_ns('bootstrapInfo')).text)
metadata = base64.b64decode(media.find(_add_ns('metadata')).text)
boot_info = read_bootstrap_info(bootstrap)
fragments_list = build_fragments_list(boot_info)
total_frags = len(fragments_list)
tmpfilename = self.temp_name(filename)
(dest_stream, tmpfilename) = sanitize_open(tmpfilename, 'wb')
write_flv_header(dest_stream, metadata)
# This dict stores the download progress, it's updated by the progress
# hook
state = {
'downloaded_bytes': 0,
'frag_counter': 0,
}
start = time.time()
def frag_progress_hook(status):
frag_total_bytes = status.get('total_bytes', 0)
estimated_size = (state['downloaded_bytes'] +
(total_frags - state['frag_counter']) * frag_total_bytes)
if status['status'] == 'finished':
state['downloaded_bytes'] += frag_total_bytes
state['frag_counter'] += 1
progress = self.calc_percent(state['frag_counter'], total_frags)
byte_counter = state['downloaded_bytes']
else:
frag_downloaded_bytes = status['downloaded_bytes']
byte_counter = state['downloaded_bytes'] + frag_downloaded_bytes
frag_progress = self.calc_percent(frag_downloaded_bytes,
frag_total_bytes)
progress = self.calc_percent(state['frag_counter'], total_frags)
progress += frag_progress / float(total_frags)
eta = self.calc_eta(start, time.time(), estimated_size, byte_counter)
self.report_progress(progress, format_bytes(estimated_size),
status.get('speed'), eta)
http_dl.add_progress_hook(frag_progress_hook)
frags_filenames = []
for (seg_i, frag_i) in fragments_list:
name = 'Seg%d-Frag%d' % (seg_i, frag_i)
url = base_url + name
frag_filename = '%s-%s' % (tmpfilename, name)
success = http_dl.download(frag_filename, {'url': url})
if not success:
return False
with open(frag_filename, 'rb') as down:
down_data = down.read()
reader = FlvReader(down_data)
while True:
_, box_type, box_data = reader.read_box_info()
if box_type == b'mdat':
dest_stream.write(box_data)
break
frags_filenames.append(frag_filename)
self.report_finish(format_bytes(state['downloaded_bytes']), time.time() - start)
self.try_rename(tmpfilename, filename)
for frag_file in frags_filenames:
os.remove(frag_file)
fsize = os.path.getsize(encodeFilename(filename))
self._hook_progress({
'downloaded_bytes': fsize,
'total_bytes': fsize,
'filename': filename,
'status': 'finished',
})
return True