Python program to download youtube video

2010-04-07 9 min read Linux

#!/usr/bin/env python

# Copyright (c) 2006-2008 Ricardo Garcia Gonzalez

# Permission is hereby granted, free of charge, to any person obtaining
a
# copy of this software and associated documentation files (the
”Software”),
# to deal in the Software without restriction, including without
limitation
# the rights to use, copy, modify, merge, publish, distribute,
sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be
included
# in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED ”AS IS”, WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

# Except as contained in this notice, the name(s) of the above copyright
# holders shall not be used in advertising or otherwise to promote the
# sale, use or other dealings in this Software without prior written
# authorization.

import getpass
import httplib
import math
import netrc
import optparse
import os
import re
import socket
import string
import sys
import time
import urllib2

# Global constants
const_1k = 1024
const_initial_block_size = 10 * const_1k
const_epsilon = 0.0001
const_timeout = 120

const_video_url_str = ’http://www.youtube.com/watch?v=%s’
const_video_url_re = re.compile(r’^((?:http://)?(?:\w+\.)?youtube
\.com/(?:v/|(?:watch(?:
\.php)?)?\?(?:.+&)?v=))?([0-9A-Za-z_-]+)(?(1)[&/].*)?$’)
const_video_url_format_suffix = ’&fmt=%s’
const_best_quality_format = 18
const_login_url_str = ’http://www.youtube.com/login?next=/watch%%3Fv%%3D
%s’
const_login_post_str = ’current_form=loginForm&next=%%2Fwatch%%3Fv%%3D%
s&username=%s&password=%s&action_login=Log+In’
const_age_url_str = ’http://www.youtube.com/verify_age?next_url=/watch%%
3Fv%%3D%s’
const_age_post_str = ’next_url=%%2Fwatch%%3Fv%%3D%
s&action_confirm=Confirm’
const_url_t_param_re = re.compile(r’, ”t”: ”([^”]+)”’)
const_video_url_real_str = ’http://www.youtube.com/get_video?video_id=%
s&t=%s’
const_video_title_re = re.compile(r’

YouTube – ([^< ]*) \’,

re.M | re.I)

# Print error message, followed by standard advice information, and then
exit
def error_advice_exit(error_text):
sys.stderr.write(&#8217;Error: %s.\n&#8217; % error_text)
sys.stderr.write(&#8217;Try again several times. It may be a temporary
problem.\n&#8217;)
sys.stderr.write(&#8217;Other typical problems:\n\n&#8217;)
sys.stderr.write(&#8217;* Video no longer exists.\n&#8217;)
sys.stderr.write(&#8217;* Video requires age confirmation but you did
not provide an account.\n&#8217;)
sys.stderr.write(&#8217;* You provided the account data, but it is not
valid.\n&#8217;)
sys.stderr.write(&#8217;* The connection was cut suddenly for some
reason.\n&#8217;)
sys.stderr.write(&#8217;* YouTube changed their system, and the
program no longer works.\n&#8217;)
sys.stderr.write(&#8217;\nTry to confirm you are able to view the
video using a web browser.\n&#8217;)
sys.stderr.write(&#8217;Use the same video URL and account
information, if needed, with this program.\n&#8217;)
sys.stderr.write(&#8217;When using a proxy, make sure http_proxy has
http://host:port format.\n&#8217;)
sys.stderr.write(&#8217;Try again several times and contact me if the
problem persists.\n&#8217;)
sys.exit(&#8217;\n&#8217;)

# Wrapper to create custom requests with typical headers
def request_create(url, extra_headers, post_data):
retval = urllib2.Request(url)
if post_data is not None:
retval.add_data(post_data)
# Try to mimic Firefox, at least a little bit
retval.add_header(&#8217;User-Agent&#8217;, &#8217;Mozilla/5.0 (Windows; U;
Windows NT 5.1; en-US; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11&#8217;)
retval.add_header(&#8217;Accept-Charset&#8217;,
&#8217;ISO-8859-1,utf-8;q=0.7,*;q=0.7&#8217;)
retval.add_header(&#8217;Accept&#8217;,
&#8217;text/xml,application/xml,application/xhtml
+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5&#8217;)
retval.add_header(&#8217;Accept-Language&#8217;, &#8217;en-us,en;q=0.5&#8217;)
if extra_headers is not None:
for header in extra_headers:
retval.add_header(header[0], header[1])
return retval

# Perform a request, process headers and return response
def perform_request(url, headers=None, data=None):
request = request_create(url, headers, data)
response = urllib2.urlopen(request)
return response

# Conditional print
def cond_print(str):
global cmdl_opts
if not (cmdl_opts.quiet or cmdl_opts.get_url):
sys.stdout.write(str)
sys.stdout.flush()

# Title string normalization
def title_string_norm(title):
title = &#8217;&#8217;.join((x in string.ascii_letters or x in
string.digits) and x or &#8217; &#8217; for x in title)
title = &#8217;_&#8217;.join(title.split())
title = title.lower()
return title
# Generic download step
def download_step(return_data_flag, step_title, step_error, url,
post_data=None):
try:
cond_print(&#8217;%s… &#8217; % step_title)
data = perform_request(url, data=post_data).read()
cond_print(&#8217;done.\n&#8217;)
if return_data_flag:
return data
return None

except (urllib2.URLError, ValueError, httplib.HTTPException,
TypeError, socket.error):
cond_print(&#8217;failed.\n&#8217;)
error_advice_exit(step_error)

except KeyboardInterrupt:
sys.exit(&#8217;\n&#8217;)

# Generic extract step
def extract_step(step_title, step_error, regexp, data):
try:
cond_print(&#8217;%s… &#8217; % step_title)
match = regexp.search(data)

if match is None:
cond_print(&#8217;failed.\n&#8217;)
error_advice_exit(step_error)

extracted_data = match.group(1)
cond_print(&#8217;done.\n&#8217;)
return extracted_data

except KeyboardInterrupt:
sys.exit(&#8217;\n&#8217;)

# Calculate new block size based on previous block size
def new_block_size(before, after, bytes):
new_min = max(bytes / 2.0, 1.0)
new_max = max(bytes * 2.0, 1.0)
dif = after – before
if dif < const_epsilon: return int(new_max) rate = bytes / dif if rate > new_max:
return int(new_max)
if rate < new_min: return int(new_min) return int(rate) # Get optimum 1k exponent to represent a number of bytes def optimum_k_exp(num_bytes): global const_1k if num_bytes == 0: return 0 return long(math.log(num_bytes, const_1k)) # Get optimum representation of number of bytes def format_bytes(num_bytes): global const_1k try: exp = optimum_k_exp(num_bytes) suffix = 'bkMGTPEZY'[exp] if exp == 0: return '%s%s' % (num_bytes, suffix) converted = float(num_bytes) / float(const_1k**exp) return '%.2f%s' % (converted, suffix) except IndexError: sys.exit('Error: internal error formatting number of bytes.') # Calculate ETA and return it in string format as MM:SS def calc_eta(start, now, total, current): dif = now - start if current == 0 or dif < const_epsilon: return '–:–' rate = float(current) / dif eta = long((total - current) / rate) (eta_mins, eta_secs) = divmod(eta, 60) if eta_mins > 99:
return &#8217;–:–&#8217;
return &#8217;%02d:%02d&#8217; % (eta_mins, eta_secs)

# Calculate speed and return it in string format
def calc_speed(start, now, bytes):
dif = now – start
if bytes == 0 or dif < const_epsilon: return 'N/A b' return format_bytes(float(bytes) / dif) # Title string minimal transformation def title_string_touch(title): return title.replace(os.sep, '%') # Create the command line options parser and parse command line cmdl_usage = 'usage: %prog [options] video_url' cmdl_version = '2008.03.22' cmdl_parser = optparse.OptionParser(usage=cmdl_usage, version=cmdl_version, conflict_handler='resolve') cmdl_parser.add_option('-h', '–help', action='help', help='print this help text and exit') cmdl_parser.add_option('-v', '–version', action='version', help='print program version and exit') cmdl_parser.add_option('-u', '–username', dest='username', metavar='USERNAME', help='account username') cmdl_parser.add_option('-p', '–password', dest='password', metavar='PASSWORD', help='account password') cmdl_parser.add_option('-o', '–output', dest='outfile', metavar='FILE', help='output video file name') cmdl_parser.add_option('-q', '–quiet', action='store_true', dest='quiet', help='activates quiet mode') cmdl_parser.add_option('-s', '–simulate', action='store_true', dest='simulate', help='do not download video') cmdl_parser.add_option('-t', '–title', action='store_true', dest='use_title', help='use title in file name') cmdl_parser.add_option('-l', '–literal', action='store_true', dest='use_literal', help='use literal title in file name') cmdl_parser.add_option('-n', '–netrc', action='store_true', dest='use_netrc', help='use .netrc authentication data') cmdl_parser.add_option('-g', '–get-url', action='store_true', dest='get_url', help='print final video URL only') cmdl_parser.add_option('-2', '–title-too', action='store_true', dest='get_title', help='used with -g, print title too') cmdl_parser.add_option('-f', '–format', dest='video_format', metavar='FORMAT', help='append &fmt=FORMAT to the URL') cmdl_parser.add_option('-b', '–best-quality', action='store_true', dest='best_quality', help='alias for -f 18') (cmdl_opts, cmdl_args) = cmdl_parser.parse_args() # Set socket timeout socket.setdefaulttimeout(const_timeout) # Get video URL if len(cmdl_args) != 1: cmdl_parser.print_help() sys.exit('\n') video_url_cmdl = cmdl_args[0] # Verify video URL format and convert to "standard" format video_url_mo = const_video_url_re.match(video_url_cmdl) if video_url_mo is None: sys.exit('Error: URL does not seem to be a youtube video URL. If it is, report a bug.') video_url_id = video_url_mo.group(2) video_url = const_video_url_str % video_url_id video_format = None if cmdl_opts.best_quality: video_format = const_best_quality_format video_extension = '.mp4' else: video_extension = '.flv' if cmdl_opts.video_format is not None: if video_format is not None and video_format != cmdl_opts.video_format: sys.exit('Error: conflicting video formats specified\n') video_format = cmdl_opts.video_format if video_format is not None: video_url = '%s%s' % (video_url, const_video_url_format_suffix % video_format) # Check conflicting options if cmdl_opts.outfile is not None and (cmdl_opts.simulate or cmdl_opts.get_url): sys.stderr.write('Warning: video file name given but will not be used.\n') if cmdl_opts.outfile is not None and (cmdl_opts.use_title or cmdl_opts.use_literal): sys.exit('Error: using the video title conflicts with using a given file name.') if cmdl_opts.use_title and cmdl_opts.use_literal: sys.exit('Error: cannot use title and literal title at the same time.') if cmdl_opts.quiet and cmdl_opts.get_url: sys.exit('Error: cannot be quiet and print final URL at the same time.') # Incorrect option formatting if cmdl_opts.username is None and cmdl_opts.password is not None: sys.exit('Error: password give but username is missing.') if cmdl_opts.use_netrc and (cmdl_opts.username is not None or cmdl_opts.password is not None): sys.exit('Error: cannot use netrc and username/password at the same time.') if cmdl_opts.get_url is None and cmdl_opts.get_title is not None: sys.exit('Error: getting title requires getting URL.') # Get account information if any account_username = None account_password = None if cmdl_opts.use_netrc: try: info = netrc.netrc().authenticators('youtube') if info is None: sys.exit('Error: no authenticators for machine youtube.') account_username = info[0] account_password = info[2] except IOError: sys.exit('Error: unable to read .netrc file.') except netrc.NetrcParseError: sys.exit('Error: unable to parse .netrc file.') else: account_username = cmdl_opts.username if account_username is not None: if cmdl_opts.password is None: account_password = getpass.getpass('Type YouTube password and press return: ') else: account_password = cmdl_opts.password # Get output file name if cmdl_opts.outfile is None: video_filename = '%s%s' % (video_url_id, video_extension) else: video_filename = cmdl_opts.outfile # Install cookie and proxy handlers urllib2.install_opener(urllib2.build_opener(urllib2.ProxyHandler())) urllib2.install_opener(urllib2.build_opener(urllib2.HTTPCookieProcessor())) # Log in and confirm age if needed if account_username is not None: url = const_login_url_str % video_url_id post = const_login_post_str % (video_url_id, account_username, account_password) download_step(False, 'Logging in', 'unable to log in', url, post) url = const_age_url_str % video_url_id post = const_age_post_str % video_url_id download_step(False, 'Confirming age', 'unable to confirm age', url, post) # Retrieve video webpage video_webpage = download_step(True, 'Retrieving video webpage', 'unable to retrieve video webpage', video_url) # Extract video title if needed if cmdl_opts.use_title or cmdl_opts.use_literal or cmdl_opts.get_title: video_title = extract_step('Extracting video title', 'unable to extract video title', const_video_title_re, video_webpage) # Extract needed video URL parameters video_url_t_param = extract_step('Extracting URL "t" parameter', 'unable to extract URL "t" parameter', const_url_t_param_re, video_webpage) video_url_real = const_video_url_real_str % (video_url_id, video_url_t_param) if video_format is not None: video_url_real = '%s%s' % (video_url_real, const_video_url_format_suffix % video_format) # Rebuild filename if needed if cmdl_opts.use_title or cmdl_opts.use_literal: if cmdl_opts.use_title: prefix = title_string_norm(video_title) else: prefix = title_string_touch(video_title) video_filename = '%s-%s%s' % (prefix, video_url_id, video_extension) # Check name if not video_filename.lower().endswith(video_extension): sys.stderr.write('Warning: video file name does not end in %s\n' % video_extension) # Retrieve video data try: cond_print('Requesting video file… ') video_data = perform_request(video_url_real) cond_print('done.\n') cond_print('Video data found at %s\n' % video_data.geturl()) if cmdl_opts.get_title: print video_title if cmdl_opts.get_url: print video_data.geturl() if cmdl_opts.simulate or cmdl_opts.get_url: sys.exit() try: video_file = open(video_filename, 'wb') except (IOError, OSError): sys.exit('Error: unable to open "%s" for writing.' % video_filename) try: video_len = long(video_data.info()['Content-length']) video_len_str = format_bytes(video_len) except KeyError: video_len = None video_len_str = 'N/A' byte_counter = 0 block_size = const_initial_block_size start_time = time.time() while True: if video_len is not None: percent = float(byte_counter) / float(video_len) * 100.0 percent_str = '%.1f' % percent eta_str = calc_eta(start_time, time.time(), video_len, byte_counter) else: percent_str = '-–.-' eta_str = '–:–' counter = format_bytes(byte_counter) speed_str = calc_speed(start_time, time.time(), byte_counter) cond_print('\rRetrieving video data: %5s%% (%8s of %s) at %8s/s ETA %s ' % (percent_str, counter, video_len_str, speed_str, eta_str)) before = time.time() video_block = video_data.read(block_size) after = time.time() dl_bytes = len(video_block) if dl_bytes == 0: break byte_counter += dl_bytes video_file.write(video_block) block_size = new_block_size(before, after, dl_bytes) if video_len is not None and byte_counter != video_len: error_advice_exit('server did not send the expected ammount of data') video_file.close() cond_print('done.\n') cond_print('Video data saved to %s\n' % video_filename) except (urllib2.URLError, ValueError, httplib.HTTPException, TypeError, socket.error): cond_print('failed.\n') error_advice_exit('unable to download video data') except KeyboardInterrupt: sys.exit('\n') # Finish sys.exit()

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