H.264级别（Level）计算器（JavaScript网页版）|『影音数码技术学习交流』 - 『漫游』酷论坛

#!/bin/env python
# coding: utf-8
#****************************************************************************
# avc_refcalc.py 0.20
# written by Chikezun
# Reference literature:
# インプレス標準教科書シリーズ改訂版 H.264/AVC教科書
# 著者：（監修）大久保榮／（編者）角野眞也、菊池義浩、鈴木輝彦
# http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC
# 猫科研究所(http://www.up-cat.net/FrontPage.html)
# 　x264(vbv-maxrate,vbv-bufsize,profile,level),H.264(Profile/Level)
#
#****************************************************************************
import sys
import math
def usage():
print "Usage: avc_refcalc.py [options]\n"
print " -r, --resolution <string> :set 'width x height' ('1280x720')"
print " -l, --level <string> :set 'level' ('4.1')"
print " -p, --profile <string> :set 'profile' ('high')"
print " -i, --interlaced :specify interlaced mode (not specified)"
print " -h, --help :display this help and exit\n"
def check_prof(pr, ip):
for i in ['baseline', 'main', 'high']:
if i == pr:
if i != 'baseline' or ip != 'interlaced':
return i
else:
print "ERROR : baseline cannot accept interlaced."
print "ERROR : invalid profile setting.\n"
usage()
sys.exit()
def check_level(lv, ip, dic):
lvl = lv.replace('0','').replace('.','')
if dic.has_key(lvl):
if ip[0] != 'i' or dic.get(lvl)[0] == 'i':
return lvl
else:
print "ERROR : specified level cannot accept interlaced."
print "ERROR : invalid level value.\n"
usage()
sys.exit()
def calc_mbs(w, h, ip):
mbh = int(math.ceil(float(w) / 16))
mbv = int(math.ceil(float(h) / 16))
if mbv % 2 == 1 and ip == 'interlaced':
mbv += 1
mbs = mbh * mbv
if mbs > 0:
return mbs
else:
print "ERROR : invalid resolution setting.\n"
usage()
sys.exit()
def calc_vbv(lv, pr, dic):
vbvmax = dic.get(lv)[1]
vbvbuf = dic.get(lv)[2]
if pr == 'high':
return [int(vbvmax * 1.25), int(vbvbuf * 1.25)]
else:
return [vbvmax, vbvbuf]
def calc_maxref(lv, mbs, dic):
ref = int(dic.get(lv)[3] / mbs)
if ref > 16:
ref = 16
if ref > 0:
return ref
else:
print "ERROR : resolution is too large to level.\n"
usage()
sys.exit()
options = sys.argv
len_opt = len(options)
#set default values
width = 1280
height = 720
level = '4.1'
prof = 'high'
mode = 'progressive'
help = 0
#H.264/AVC level dictionary {level: [interlaced flag, MaxBR, MaxCPB, MaxDbpMbs]}
avcdic = {'1' :['p', 64, 175, 396], '1b':['p', 128, 350, 396],
'11':['p', 192, 500, 900], '12':['p', 384, 1000, 2376],
'13':['p', 768, 2000, 2376], '2' :['p', 2000, 2000, 2376],
'21':['i', 4000, 4000, 4752], '22':['i', 4000, 4000, 8100],
'3' :['i', 10000, 10000, 8100], '31':['i', 14000, 14000, 18000],
'32':['i', 20000, 20000, 20480], '4' :['i', 20000, 25000, 32768],
'41':['i', 50000, 62500, 32768], '42':['p', 50000, 62500, 34816],
'5' :['p', 135000, 135000, 110400], '51':['p', 240000, 240000, 184320]}
if len_opt > 1:
for i in range(len_opt):
try:
if options[i] == '-r' or options[i] == '--resolution':
res = options[i + 1].split('x')
width = int(res[0])
height = int(res[1])
if options[i] == '-l' or options[i] == '--level':
level = options[i + 1]
if options[i] == '-p' or options[i] == '--profile':
prof = options[i + 1]
if options[i] == '-i' or options[i] == '--interlaced':
mode = 'interlaced'
if options[i] == '-h' or options[i] == '--help':
help = 1
except:
print "ERROR : invalid arguments\n"
help = 1
else:
pass
if help == 1:
usage()
sys.exit()
else:
usage()
profile = check_prof(prof, mode)
lv_tmp = check_level(level, mode, avcdic)
mbs = calc_mbs(width, height, mode)
vbv = calc_vbv(lv_tmp, profile, avcdic)
maxref = calc_maxref(lv_tmp, mbs, avcdic)
print " resolution : %i x %i" % (width, height)
print " level : %s" % level
print " profile : %s" % profile
print " mode : %s" % mode
print " vbv-maxrate(vlc) : %i" % vbv[0]
print " vbv-bufsize(vlc) : %i" % vbv[1]
print " max ref number : %i" % maxref