from __future__ import division, unicode_literals import base64 import io import itertools import os import time import xml.etree.ElementTree as etree from .fragment import FragmentFD from ..compat import ( compat_urlparse, compat_urllib_error, ) from ..utils import ( struct_pack, struct_unpack, xpath_text, ) 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 struct_unpack('!Q', self.read(8))[0] def read_unsigned_int(self): return struct_unpack('!I', self.read(4))[0] def read_unsigned_char(self): return struct_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) self.read_unsigned_int() # BootstrapinfoVersion # Profile,Live,Update,Reserved flags = self.read_unsigned_char() live = flags & 0x20 != 0 # time scale self.read_unsigned_int() # CurrentMediaTime self.read_unsigned_long_long() # SmpteTimeCodeOffset self.read_unsigned_long_long() self.read_string() # MovieIdentifier 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(quality_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, 'live': live, } 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] fragment_run_entry_table = boot_info['fragments'][0]['fragments'] first_frag_number = fragment_run_entry_table[0]['first'] fragments_counter = itertools.count(first_frag_number) for segment, fragments_count in segment_run_table['segment_run']: for _ in range(fragments_count): res.append((segment, next(fragments_counter))) if boot_info['live']: res = res[-2:] return res def write_unsigned_int(stream, val): stream.write(struct_pack('!I', val)) def write_unsigned_int_24(stream, val): stream.write(struct_pack('!I', val)[1:]) def write_flv_header(stream): """Writes the FLV header to stream""" # FLV header stream.write(b'FLV\x01') stream.write(b'\x05') stream.write(b'\x00\x00\x00\x09') stream.write(b'\x00\x00\x00\x00') def write_metadata_tag(stream, metadata): """Writes optional metadata tag to stream""" SCRIPT_TAG = b'\x12' FLV_TAG_HEADER_LEN = 11 if metadata: stream.write(SCRIPT_TAG) write_unsigned_int_24(stream, len(metadata)) stream.write(b'\x00\x00\x00\x00\x00\x00\x00') stream.write(metadata) write_unsigned_int(stream, FLV_TAG_HEADER_LEN + len(metadata)) def _add_ns(prop): return '{http://ns.adobe.com/f4m/1.0}%s' % prop class F4mFD(FragmentFD): """ A downloader for f4m manifests or AdobeHDS. """ FD_NAME = 'f4m' def _get_unencrypted_media(self, doc): media = doc.findall(_add_ns('media')) if not media: self.report_error('No media found') for e in (doc.findall(_add_ns('drmAdditionalHeader')) + doc.findall(_add_ns('drmAdditionalHeaderSet'))): # If id attribute is missing it's valid for all media nodes # without drmAdditionalHeaderId or drmAdditionalHeaderSetId attribute if 'id' not in e.attrib: self.report_error('Missing ID in f4m DRM') media = list(filter(lambda e: 'drmAdditionalHeaderId' not in e.attrib and 'drmAdditionalHeaderSetId' not in e.attrib, media)) if not media: self.report_error('Unsupported DRM') return media def _get_bootstrap_from_url(self, bootstrap_url): bootstrap = self.ydl.urlopen(bootstrap_url).read() return read_bootstrap_info(bootstrap) def _update_live_fragments(self, bootstrap_url, latest_fragment): fragments_list = [] retries = 30 while (not fragments_list) and (retries > 0): boot_info = self._get_bootstrap_from_url(bootstrap_url) fragments_list = build_fragments_list(boot_info) fragments_list = [f for f in fragments_list if f[1] > latest_fragment] if not fragments_list: # Retry after a while time.sleep(5.0) retries -= 1 if not fragments_list: self.report_error('Failed to update fragments') return fragments_list def _parse_bootstrap_node(self, node, base_url): if node.text is None: bootstrap_url = compat_urlparse.urljoin( base_url, node.attrib['url']) boot_info = self._get_bootstrap_from_url(bootstrap_url) else: bootstrap_url = None bootstrap = base64.b64decode(node.text.encode('ascii')) boot_info = read_bootstrap_info(bootstrap) return (boot_info, bootstrap_url) def real_download(self, filename, info_dict): man_url = info_dict['url'] requested_bitrate = info_dict.get('tbr') self.to_screen('[%s] Downloading f4m manifest' % self.FD_NAME) manifest = self.ydl.urlopen(man_url).read() doc = etree.fromstring(manifest) formats = [(int(f.attrib.get('bitrate', -1)), f) for f in self._get_unencrypted_media(doc)] if requested_bitrate is None: # get the best format formats = sorted(formats, key=lambda f: f[0]) rate, media = formats[-1] else: rate, media = list(filter( lambda f: int(f[0]) == requested_bitrate, formats))[0] base_url = compat_urlparse.urljoin(man_url, media.attrib['url']) bootstrap_node = doc.find(_add_ns('bootstrapInfo')) boot_info, bootstrap_url = self._parse_bootstrap_node(bootstrap_node, base_url) live = boot_info['live'] metadata_node = media.find(_add_ns('metadata')) if metadata_node is not None: metadata = base64.b64decode(metadata_node.text.encode('ascii')) else: metadata = None fragments_list = build_fragments_list(boot_info) if self.params.get('test', False): # We only download the first fragment fragments_list = fragments_list[:1] total_frags = len(fragments_list) # For some akamai manifests we'll need to add a query to the fragment url akamai_pv = xpath_text(doc, _add_ns('pv-2.0')) ctx = { 'filename': filename, 'total_frags': total_frags, } self._prepare_frag_download(ctx) dest_stream = ctx['dest_stream'] write_flv_header(dest_stream) if not live: write_metadata_tag(dest_stream, metadata) self._start_frag_download(ctx) frags_filenames = [] while fragments_list: seg_i, frag_i = fragments_list.pop(0) name = 'Seg%d-Frag%d' % (seg_i, frag_i) url = base_url + name if akamai_pv: url += '?' + akamai_pv.strip(';') if info_dict.get('extra_param_to_segment_url'): url += info_dict.get('extra_param_to_segment_url') frag_filename = '%s-%s' % (ctx['tmpfilename'], name) try: success = ctx['dl'].download(frag_filename, {'url': url}) if not success: return False (down, frag_sanitized) = sanitize_open(frag_filename, 'rb') down_data = down.read() down.close() 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 if live: os.remove(encodeFilename(frag_sanitized)) else: frags_filenames.append(frag_sanitized) except (compat_urllib_error.HTTPError, ) as err: if live and (err.code == 404 or err.code == 410): # We didn't keep up with the live window. Continue # with the next available fragment. msg = 'Fragment %d unavailable' % frag_i self.report_warning(msg) fragments_list = [] else: raise if not fragments_list and live and bootstrap_url: fragments_list = self._update_live_fragments(bootstrap_url, frag_i) total_frags += len(fragments_list) if fragments_list and (fragments_list[0][1] > frag_i + 1): msg = 'Missed %d fragments' % (fragments_list[0][1] - (frag_i + 1)) self.report_warning(msg) self._finish_frag_download(ctx) for frag_file in frags_filenames: os.remove(encodeFilename(frag_file)) return True