djsundog/ffplayout
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
dc46591109
ffplayout/ffplayout.py
jb-alvarado dc46591109 higher tolerance in copy mode
2019-03-08 09:53:31 +01:00

867 lines
28 KiB
Python
Executable File
Raw Blame History

#!/usr/bin/env python3
# This file is part of ffplayout.
#
# ffplayout is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# ffplayout is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with ffplayout. If not, see <http://www.gnu.org/licenses/>.
# ------------------------------------------------------------------------------
import configparser
import logging
import json
import os
import re
import smtplib
import socket
import sys
from argparse import ArgumentParser
from ast import literal_eval
from datetime import date, datetime, timedelta
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import formatdate
from logging.handlers import TimedRotatingFileHandler
from shutil import copyfileobj
from subprocess import check_output, PIPE, Popen
from threading import Thread
from time import sleep
from types import SimpleNamespace
# ------------------------------------------------------------------------------
# read variables from config file
# ------------------------------------------------------------------------------
# read config
cfg = configparser.ConfigParser()
if os.path.exists("/etc/ffplayout/ffplayout.conf"):
cfg.read("/etc/ffplayout/ffplayout.conf")
else:
cfg.read("ffplayout.conf")
_mail = SimpleNamespace(
server=cfg.get('MAIL', 'smpt_server'),
port=cfg.getint('MAIL', 'smpt_port'),
s_addr=cfg.get('MAIL', 'sender_addr'),
s_pass=cfg.get('MAIL', 'sender_pass'),
recip=cfg.get('MAIL', 'recipient')
)
_log = SimpleNamespace(
path=cfg.get('LOGGING', 'log_file'),
level=cfg.get('LOGGING', 'log_level')
)
_pre_comp = SimpleNamespace(
w=cfg.getint('PRE_COMPRESS', 'width'),
h=cfg.getint('PRE_COMPRESS', 'height'),
aspect=cfg.getfloat(
'PRE_COMPRESS', 'width') / cfg.getfloat('PRE_COMPRESS', 'height'),
fps=cfg.getint('PRE_COMPRESS', 'fps'),
v_bitrate=cfg.getint('PRE_COMPRESS', 'v_bitrate'),
v_bufsize=cfg.getint('PRE_COMPRESS', 'v_bitrate'),
protocols=cfg.get('PRE_COMPRESS', 'live_protocols'),
copy=cfg.getboolean('PRE_COMPRESS', 'copy_mode'),
copy_settings=literal_eval(cfg.get('PRE_COMPRESS', 'ffmpeg_copy_settings'))
)
_playlist = SimpleNamespace(
path=cfg.get('PLAYLIST', 'playlist_path'),
start=cfg.getint('PLAYLIST', 'day_start'),
filler=cfg.get('PLAYLIST', 'filler_clip'),
blackclip=cfg.get('PLAYLIST', 'blackclip'),
shift=cfg.getint('PLAYLIST', 'time_shift'),
map_ext=cfg.get('PLAYLIST', 'map_extension')
)
_buffer = SimpleNamespace(
length=cfg.getint('BUFFER', 'buffer_length'),
tol=cfg.getfloat('BUFFER', 'buffer_tolerance'),
cli=cfg.get('BUFFER', 'buffer_cli'),
cmd=literal_eval(cfg.get('BUFFER', 'buffer_cmd'))
)
_playout = SimpleNamespace(
preview=cfg.getboolean('OUT', 'preview'),
name=cfg.get('OUT', 'service_name'),
provider=cfg.get('OUT', 'service_provider'),
out_addr=cfg.get('OUT', 'out_addr'),
post_comp_video=literal_eval(cfg.get('OUT', 'post_comp_video')),
post_comp_audio=literal_eval(cfg.get('OUT', 'post_comp_audio')),
post_comp_extra=literal_eval(cfg.get('OUT', 'post_comp_extra')),
post_comp_copy=literal_eval(cfg.get('OUT', 'post_comp_copy'))
)
# set logo filtergraph
if os.path.exists(cfg.get('OUT', 'logo')):
_playout.logo = ['-thread_queue_size', '16', '-i', cfg.get('OUT', 'logo')]
_playout.filter = [
'-filter_complex', '[0:v][1:v]' + cfg.get('OUT', 'logo_o') + '[o]',
'-map', '[o]', '-map', '0:a'
]
else:
_playout.logo = []
_playout.filter = []
# ------------------------------------------------------------------------------
# logging
# ------------------------------------------------------------------------------
stdin_parser = ArgumentParser(description="python and ffmpeg based playout")
stdin_parser.add_argument(
"-l", "--log", help="file to write log to (default '" + _log.path + "')"
)
# If the log file is specified on the command line then override the default
stdin_args = stdin_parser.parse_args()
if stdin_args.log:
_log.path = stdin_args.log
logger = logging.getLogger(__name__)
logger.setLevel(_log.level)
handler = TimedRotatingFileHandler(_log.path, when="midnight", backupCount=5)
formatter = logging.Formatter('[%(asctime)s] [%(levelname)s] %(message)s')
handler.setFormatter(formatter)
logger.addHandler(handler)
# capture stdout and sterr in the log
class ffplayout_logger(object):
def __init__(self, logger, level):
self.logger = logger
self.level = level
def write(self, message):
# Only log if there is a message (not just a new line)
if message.rstrip() != "":
self.logger.log(self.level, message.rstrip())
def flush(self):
pass
# Replace stdout with logging to file at INFO level
sys.stdout = ffplayout_logger(logger, logging.INFO)
# Replace stderr with logging to file at ERROR level
sys.stderr = ffplayout_logger(logger, logging.ERROR)
# ------------------------------------------------------------------------------
# global helper functions
# ------------------------------------------------------------------------------
# get time
def get_time(time_format):
t = datetime.today() + timedelta(seconds=_playlist.shift)
if time_format == 'hour':
return t.hour
elif time_format == 'full_sec':
sec = float(t.hour * 3600 + t.minute * 60 + t.second)
micro = float(t.microsecond) / 1000000
return sec + micro
else:
return t.strftime("%H:%M:%S")
# get date
def get_date(seek_day):
d = date.today() + timedelta(seconds=_playlist.shift)
if get_time('hour') < _playlist.start and seek_day:
yesterday = d - timedelta(1)
return yesterday.strftime('%Y-%m-%d')
else:
return d.strftime('%Y-%m-%d')
# send error messages to email addresses
def mail_or_log(message, time, path):
if _mail.recip:
msg = MIMEMultipart()
msg['From'] = _mail.s_addr
msg['To'] = _mail.recip
msg['Subject'] = "Playout Error"
msg["Date"] = formatdate(localtime=True)
msg.attach(MIMEText('{} {}\n{}'.format(time, message, path), 'plain'))
text = msg.as_string()
try:
server = smtplib.SMTP(_mail.server, _mail.port)
except socket.error as err:
logger.error(err)
server = None
if server is not None:
server.starttls()
try:
login = server.login(_mail.s_addr, _mail.s_pass)
except smtplib.SMTPAuthenticationError as serr:
logger.error(serr)
login = None
if login is not None:
server.sendmail(_mail.s_addr, _mail.recip, text)
server.quit()
else:
logger.error('{} {}'.format(message, path))
# calculating the size for the buffer in KB
def calc_buffer_size():
# in copy mode files has normally smaller bit rate,
# so we calculate the size different
if _pre_comp.copy:
list_date = get_date(True)
year, month, day = re.split('-', list_date)
json_file = os.path.join(
_playlist.path, year, month, list_date + '.json')
if check_file_exist(json_file):
with open(json_file) as f:
clip_nodes = json.load(f)
if _playlist.map_ext:
_ext = literal_eval(_playlist.map_ext)
source = clip_nodes["program"][0]["source"].replace(
_ext[0], _ext[1])
else:
source = clip_nodes["program"][0]["source"]
cmd = [
'ffprobe', '-v', 'error', '-show_entries', 'format=bit_rate',
'-of', 'default=noprint_wrappers=1:nokey=1', source]
bite_rate = check_output(cmd).decode('utf-8')
if is_int(bite_rate):
bite_rate = int(bite_rate) / 1024
else:
bite_rate = 4000
return int(bite_rate * 0.125 * _buffer.length)
else:
return 5000
else:
return int((_pre_comp.v_bitrate * 0.125 + 281.25) * _buffer.length)
# check if processes a well
def check_process(watch_proc, terminate_proc, play_thread):
while True:
sleep(4)
if watch_proc.poll() is not None:
logger.error(
'postprocess is not alive anymore, terminate ffplayout!')
terminate_proc.terminate()
break
if not play_thread.is_alive():
logger.error(
'preprocess is not alive anymore, terminate ffplayout!')
terminate_proc.terminate()
break
# check if input file exist,
# when not send email and generate blackclip
def check_file_exist(in_file):
if os.path.exists(in_file):
return True
else:
return False
# seek in clip and cut the end
def seek_in_cut_end(in_file, duration, seek, out):
if seek > 0.0:
inpoint = ['-ss', str(seek)]
else:
inpoint = []
if out < duration:
length = out - seek - 1.0
cut_end = ['-t', str(out - seek)]
fade_out_vid = '[0:v]fade=out:st=' + str(length) + ':d=1.0[v];'
fade_out_aud = '[0:a]afade=out:st=' + str(length) + ':d=1.0[a]'
end = ['-map', '[v]', '-map', '[a]']
else:
cut_end = []
fade_out_vid = ''
fade_out_aud = '[0:a]apad[a]'
end = ['-shortest', '-map', '0:v', '-map', '[a]']
if _pre_comp.copy:
return inpoint + ['-i', in_file] + cut_end
else:
return inpoint + ['-i', in_file] + cut_end + [
'-filter_complex', fade_out_vid + fade_out_aud
] + end
# generate a dummy clip, with black color and empty audiotrack
def gen_dummy(duration):
if _pre_comp.copy:
return ['-i', _playlist.blackclip]
else:
return [
'-f', 'lavfi', '-i',
'color=s={}x{}:d={}'.format(
_pre_comp.w, _pre_comp.h, duration
),
'-f', 'lavfi', '-i', 'anullsrc=r=48000',
'-shortest'
]
# when source path exist, generate input with seek and out time
# when path not exist, generate dummy clip
def src_or_dummy(src, duration, seek, out, dummy_len=None):
prefix = src.split('://')[0]
if _pre_comp.copy:
add_filter = []
else:
add_filter = [
'-filter_complex', '[0:a]apad[a]',
'-shortest', '-map', '0:v', '-map', '[a]']
# check if input is a live source
if prefix and prefix in _pre_comp.protocols:
cmd = [
'ffprobe', '-v', 'error', '-show_entries', 'format=duration',
'-of', 'default=noprint_wrappers=1:nokey=1', src]
live_duration = check_output(cmd)
if '404' in live_duration.decode('utf-8'):
mail_or_log(
'Clip not exist:', get_time(None),
src
)
if dummy_len and not _pre_comp.copy:
return gen_dummy(dummy_len)
else:
return gen_dummy(out - seek)
elif is_float(live_duration):
if seek > 0.0 or out < live_duration:
return seek_in_cut_end(src, live_duration, seek, out)
else:
return ['-i', src] + add_filter
else:
# no duration found, so we set duration to 24 hours,
# to be sure that out point will cut the lenght
return seek_in_cut_end(src, 86400, 0, out - seek)
elif check_file_exist(src):
if seek > 0.0 or out < duration:
return seek_in_cut_end(src, duration, seek, out)
else:
return ['-i', src] + add_filter
else:
mail_or_log(
'Clip not exist:', get_time(None),
src
)
if dummy_len and not _pre_comp.copy:
return gen_dummy(dummy_len)
else:
return gen_dummy(out - seek)
# compare clip play time with real time,
# to see if we are sync
def check_sync(begin):
time_now = get_time('full_sec')
start = float(_playlist.start * 3600)
# in copy mode buffer length can not be calculatet correctly...
if _pre_comp.copy:
tolerance = 60
else:
tolerance = _buffer.tol * 4
t_dist = begin - time_now
if 0 <= time_now < start and not begin == start:
t_dist -= 86400.0
# check that we are in tolerance time
if not _buffer.length - tolerance < t_dist < _buffer.length + tolerance:
mail_or_log(
'Playlist is not sync!', get_time(None),
str(t_dist) + ' seconds async'
)
# prepare input clip
# check begin and length from clip
# return clip only if we are in 24 hours time range
def gen_input(src, begin, dur, seek, out, last):
start = float(_playlist.start * 3600)
day_in_sec = 86400.0
ref_time = day_in_sec + start
time = get_time('full_sec')
if 0 <= time < start:
time += day_in_sec
# calculate time difference to see if we are sync
time_diff = _buffer.length + _buffer.tol + out - seek + time
if (time_diff <= ref_time or begin < day_in_sec) and not last:
# when we are in the 24 houre range, get the clip
return src_or_dummy(src, dur, seek, out, 20), None
elif time_diff < ref_time and last:
# when last clip is passed and we still have too much time left
# check if duration is larger then out - seek
time_diff = _buffer.length + _buffer.tol + dur + time
new_len = dur - (time_diff - ref_time)
logger.info('we are under time, new_len is: {}'.format(new_len))
if time_diff >= ref_time:
if src == _playlist.filler:
# when filler is something like a clock,
# is better to start the clip later and to play until end
src_cmd = src_or_dummy(src, dur, dur - new_len, dur)
else:
src_cmd = src_or_dummy(src, dur, 0, new_len)
else:
src_cmd = src_or_dummy(src, dur, 0, dur)
mail_or_log(
'playlist is not long enough:', get_time(None),
str(new_len) + ' seconds needed.'
)
return src_cmd, new_len - dur
elif time_diff > ref_time:
new_len = out - seek - (time_diff - ref_time)
# when we over the 24 hours range, trim clip
logger.info('we are over time, new_len is: {}'.format(new_len))
if new_len > 5.0:
if src == _playlist.filler:
src_cmd = src_or_dummy(src, dur, out - new_len, out)
else:
src_cmd = src_or_dummy(src, dur, seek, new_len)
elif new_len > 1.0:
src_cmd = gen_dummy(new_len)
else:
src_cmd = None
return src_cmd, 0.0
# test if value is float
def is_float(value):
try:
float(value)
return True
except ValueError:
return False
# test if value is int
def is_int(value):
try:
int(value)
return True
except ValueError:
return False
# check last item, when it is None or a dummy clip,
# set true and seek in playlist
def check_last_item(src_cmd, last_time, last):
if src_cmd is None and not last:
first = True
last_time = get_time('full_sec')
if 0 <= last_time < _playlist.start * 3600:
last_time += 86400
elif 'lavfi' in src_cmd and not last:
first = True
last_time = get_time('full_sec') + _buffer.length + _buffer.tol
if 0 <= last_time < _playlist.start * 3600:
last_time += 86400
else:
first = False
return first, last_time
# check begin and length
def check_start_and_length(json_nodes, counter):
# check start time and set begin
if "begin" in json_nodes:
h, m, s = json_nodes["begin"].split(':')
if is_float(h) and is_float(m) and is_float(s):
begin = float(h) * 3600 + float(m) * 60 + float(s)
else:
begin = -100.0
else:
begin = -100.0
# check if playlist is long enough
if "length" in json_nodes:
l_h, l_m, l_s = json_nodes["length"].split(':')
if is_float(l_h) and is_float(l_m) and is_float(l_s):
length = float(l_h) * 3600 + float(l_m) * 60 + float(l_s)
start = float(_playlist.start * 3600)
total_play_time = begin + counter - start
if total_play_time < length - 5:
mail_or_log(
'json playlist is not long enough!',
get_time(None), "total play time is: "
+ str(timedelta(seconds=total_play_time))
)
# validate json values in new Thread
# and test if file path exist
def validate_thread(clip_nodes):
def check_json(json_nodes):
error = ''
counter = 0
# check if all values are valid
for node in json_nodes["program"]:
if _playlist.map_ext:
_ext = literal_eval(_playlist.map_ext)
source = node["source"].replace(
_ext[0], _ext[1])
else:
source = node["source"]
prefix = source.split('://')[0]
if prefix and prefix in _pre_comp.protocols:
cmd = [
'ffprobe', '-v', 'error',
'-show_entries', 'format=duration',
'-of', 'default=noprint_wrappers=1:nokey=1', source]
output = check_output(cmd)
if '404' in output.decode('utf-8'):
a = 'Stream not exist! '
else:
a = ''
elif check_file_exist(source):
a = ''
else:
a = 'File not exist! '
if is_float(node["in"]) and is_float(node["out"]):
b = ''
counter += node["out"] - node["in"]
else:
b = 'Missing Value! '
c = '' if is_float(node["duration"]) else 'No DURATION Value! '
line = a + b + c
if line:
error += line + 'In line: ' + str(node) + '\n'
if error:
mail_or_log(
'Validation error, check json playlist, values are missing:\n',
get_time(None), error
)
check_start_and_length(json_nodes, counter)
validate = Thread(name='check_json', target=check_json, args=(clip_nodes,))
validate.daemon = True
validate.start()
# exaption gets called, when there is no playlist,
# or the playlist is not long enough
def exeption(message, dummy_len, path, last):
src_cmd = gen_dummy(dummy_len)
if last:
last_time = float(_playlist.start * 3600 - 5)
first = False
else:
last_time = (
get_time('full_sec') + dummy_len + _buffer.length + _buffer.tol
)
if 0 <= last_time < _playlist.start * 3600:
last_time += 86400
first = True
mail_or_log(message, get_time(None), path)
return src_cmd, last_time, first
# ------------------------------------------------------------------------------
# main functions
# ------------------------------------------------------------------------------
# TODO: this function is to messy, and should be rewrited as a class
# read values from json playlist
def iter_src_commands():
last_time = None
last_mod_time = 0.0
src_cmd = None
last = False
list_date = get_date(True)
dummy_len = 60
while True:
year, month, day = re.split('-', list_date)
json_file = os.path.join(
_playlist.path, year, month, list_date + '.json')
if check_file_exist(json_file):
# check last modification from playlist
mod_time = os.path.getmtime(json_file)
if mod_time > last_mod_time:
with open(json_file) as f:
clip_nodes = json.load(f)
last_mod_time = mod_time
logger.info('open: ' + json_file)
validate_thread(clip_nodes)
# when last clip is None or a dummy,
# we have to jump to the right place in the playlist
first, last_time = check_last_item(src_cmd, last_time, last)
if "begin" in clip_nodes:
h, m, s = clip_nodes["begin"].split(':')
if is_float(h) and is_float(m) and is_float(s):
begin = float(h) * 3600 + float(m) * 60 + float(s)
else:
begin = last_time
else:
# when clip_nodes["begin"] is not set in playlist,
# start from current time
begin = get_time('full_sec')
# loop through all clips in playlist
# TODO: index we need for blend out logo on ad
for index, clip_node in enumerate(clip_nodes["program"]):
if _playlist.map_ext:
_ext = literal_eval(_playlist.map_ext)
src = clip_node["source"].replace(
_ext[0], _ext[1])
else:
src = clip_node["source"]
seek = clip_node["in"] if is_float(clip_node["in"]) else 0
out = clip_node["out"] if \
is_float(clip_node["out"]) else dummy_len
duration = clip_node["duration"] if \
is_float(clip_node["duration"]) else dummy_len
# first time we end up here
if first and last_time < begin + duration:
# calculate seek time
seek = last_time - begin + seek
src_cmd, time_left = gen_input(
src, begin, duration, seek, out, False
)
first = False
last_time = begin
break
elif last_time and last_time < begin:
if clip_node == clip_nodes["program"][-1]:
last = True
else:
last = False
check_sync(begin)
src_cmd, time_left = gen_input(
src, begin, duration, seek, out, last
)
if time_left is None:
# normal behavior
last_time = begin
elif time_left > 0.0:
# when playlist is finish and we have time left
last_time = begin
list_date = get_date(False)
dummy_len = time_left
else:
# when there is no time left and we are in time,
# set right values for new playlist
list_date = get_date(False)
last_time = float(_playlist.start * 3600 - 5)
last_mod_time = 0.0
break
begin += out - seek
else:
# when we reach currect end, stop script
if "begin" not in clip_nodes or \
"length" not in clip_nodes and \
begin < get_time('full_sec'):
logger.info('Playlist reach End!')
return
# when playlist exist but is empty, or not long enough,
# generate dummy and send log
src_cmd, last_time, first = exeption(
'Playlist is not valid!', dummy_len, json_file, last
)
begin = get_time('full_sec') + _buffer.length + _buffer.tol
last = False
dummy_len = 60
last_mod_time = 0.0
else:
# when we have no playlist for the current day,
# then we generate a black clip
# and calculate the seek in time, for when the playlist comes back
src_cmd, last_time, first = exeption(
'Playlist not exist:', dummy_len, json_file, last
)
begin = get_time('full_sec') + _buffer.length + _buffer.tol
last = False
dummy_len = 60
last_mod_time = 0.0
if src_cmd is not None:
yield src_cmd, begin
# independent thread for clip preparation
def play_clips(out_file, iter_src_commands):
# send current file from json playlist to buffer stdin
for src_cmd, begin in iter_src_commands:
if begin > 86400:
tm_str = str(timedelta(seconds=int(begin - 86400)))
else:
tm_str = str(timedelta(seconds=int(begin)))
logger.info('play at "{}": {}'.format(tm_str, src_cmd))
if _pre_comp.copy:
ff_pre_settings = _pre_comp.copy_settings
else:
ff_pre_settings = [
'-s', '{}x{}'.format(_pre_comp.w, _pre_comp.h),
'-aspect', str(_pre_comp.aspect),
'-pix_fmt', 'yuv420p', '-r', str(_pre_comp.fps),
'-c:v', 'mpeg2video', '-intra',
'-b:v', '{}k'.format(_pre_comp.v_bitrate),
'-minrate', '{}k'.format(_pre_comp.v_bitrate),
'-maxrate', '{}k'.format(_pre_comp.v_bitrate),
'-bufsize', '{}k'.format(_pre_comp.v_bufsize / 2),
'-c:a', 's302m', '-strict', '-2', '-ar', '48000', '-ac', '2',
'-threads', '2', '-f', 'mpegts', '-'
]
try:
file_piper = Popen(
[
'ffmpeg', '-v', 'error', '-hide_banner', '-nostats'
] + src_cmd + list(ff_pre_settings),
stdout=PIPE,
bufsize=0
)
copyfileobj(file_piper.stdout, out_file)
finally:
file_piper.wait()
def main():
year, month, _day = re.split('-', get_date(False))
try:
# open a buffer for the streaming pipeline
# stdin get the files loop
# stdout pipes to ffmpeg rtmp streaming
mbuffer = Popen(
[_buffer.cli] + list(_buffer.cmd)
+ [str(calc_buffer_size()) + 'k'],
stdin=PIPE,
stdout=PIPE,
bufsize=0
)
try:
if _playout.preview:
# preview playout to player
playout = Popen([
'ffplay', '-v', 'error',
'-hide_banner', '-nostats', '-i', 'pipe:0'],
stdin=mbuffer.stdout,
bufsize=0
)
else:
# playout to rtmp
if _pre_comp.copy:
playout_pre = [
'ffmpeg', '-v', 'info', '-hide_banner', '-nostats',
'-re', '-i', 'pipe:0', '-c', 'copy'
] + _playout.post_comp_copy
else:
playout_pre = [
'ffmpeg', '-v', 'info', '-hide_banner', '-nostats',
'-re', '-thread_queue_size', '256',
'-fflags', '+igndts', '-i', 'pipe:0',
'-fflags', '+genpts'
] + _playout.logo + _playout.filter + \
_playout.post_comp_video + \
_playout.post_comp_audio
playout = Popen(
list(playout_pre)
+ [
'-metadata', 'service_name=' + _playout.name,
'-metadata', 'service_provider=' + _playout.provider,
'-metadata', 'year=' + year
] + list(_playout.post_comp_extra)
+ [
_playout.out_addr
],
stdin=mbuffer.stdout,
bufsize=0
)
play_thread = Thread(
name='play_clips', target=play_clips, args=(
mbuffer.stdin,
iter_src_commands(),
)
)
play_thread.daemon = True
play_thread.start()
check_process(playout, mbuffer, play_thread)
finally:
playout.wait()
finally:
mbuffer.wait()
if __name__ == '__main__':
main()
Reference in New Issue View Git Blame Copy Permalink