def dqt(flag, name, popper, print_details=False):
"""
DQT
:return:
"""
DQT = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
Pq = (content[0] & 0xf0) >> 4
Tq = content[0] & 0x0f
table = content[1:]
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
idx_seg = print_bytes(content[:1], idx_seg)
print(
'\t\t\t\t\t\t\t\t', '(Pq,Tq)',
'高四位Pq为量化表的数据精确度，Pq=0时，Q0~Qn的值为8位，Pq=1时，Qt的值为16位，Tq表示量化表的编号，为0~3。在基本系统中，Pq=0，Tq=0~1，也就是说最多有两个量化表。'
)
print('\t\t\t\t\t\t\t\t', '(Pq,Tq)=(%d,%d)' % (Pq, Tq))
print_bytes(table, idx_seg)
table = decode_dqt(table, Pq, print_details)
DQT['flag'] = flag
DQT['name'] = name
DQT['length'] = length
DQT['content'] = content
DQT['Pq'] = Pq
DQT['Tq'] = Tq
DQT['table'] = table
return DQT
def dht(flag, name, popper, print_details=False):
DHT = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
TcTh = content[0]
Tc = (TcTh & 0xf0) >> 4
Th = TcTh & 0x0f
cnts = dict(zip(range(1, 17), content[1:17]))
vals = content[17:]
vals_cur = 0
codes = {}
code_val = 0
for k in cnts:
# print(k, cnts[k])
for cnt in range(cnts[k]):
# print('\t', (bin(val), k))
# # codes[code]={len,value}
# codes[val] = {'len':k,'val':vals[vals_cur]}
# # codes[(code,len)]=value
codes[(code_val, k)] = vals[vals_cur]
vals_cur += 1
code_val += 1
code_val <<= 1
# print()
DHT['flag'] = flag
DHT['name'] = name
DHT['length'] = length
DHT['Tc'] = Tc
DHT['Th'] = Th
DHT['table'] = codes
if print_details:
for k in DHT:
if k == 'table':
print_huf_codes(DHT['table'], print_details)
else:
print('\t\t', '%8s' % k, '\t', DHT[k])
DHT['content'] = content
return DHT
def app_n(flag, name, popper, print_details=False):
"""
APP N
:return:
"""
APP_N = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
APP_N['flag'] = flag
APP_N['name'] = name
APP_N['length'] = length
APP_N['content'] = content
return APP_N
def sof_0(flag, name, popper, print_details=False):
"""
SOF0
:return:
"""
SOF0 = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
P = content[0]
Y = bytes_2_int(content[1:3])
X = bytes_2_int(content[3:5])
Nf = content[5]
Tqs = []
for c in range(Nf):
# 成分编号
Cn = content[6 + c * 3]
# 水平垂直采样因子
HnVn = content[7 + c * 3]
# 量化表编号
Tqn = content[8 + c * 3]
Tqs.append([Cn, HnVn, Tqn])
SOF0['flag'] = flag
SOF0['name'] = name
SOF0['length'] = length
SOF0['P'] = P
SOF0['Y'] = Y
SOF0['X'] = X
SOF0['Nf'] = Nf
SOF0['Tqs'] = Tqs
if print_details:
print('\tSOF0')
for k in SOF0:
print('\t\t', '%8s' % k, '\t', SOF0[k])
SOF0['content'] = content
return SOF0
def sos(flag, name, popper, print_details=False):
SOS = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
Ns = content[0]
CsTdas = []
for c in range(Ns):
Csn = content[1 + c * 2]
TdnTan = content[2 + c * 2]
CsTdas.append([Csn, TdnTan])
Ss = content[7]
Se = content[8]
AhAl = content[9]
Ah = (AhAl & 0xf0) >> 4
Al = AhAl & 0x0f
SOS['flag'] = flag
SOS['name'] = name
SOS['length'] = length
SOS['Ns'] = Ns
SOS['CsTdas'] = CsTdas
SOS['Ss'] = Ss
SOS['Se'] = Se
SOS['Ah'] = Ah
SOS['Al'] = Al
if print_details:
for k in SOS:
print('\t\t', '%8s' % k, '\t', SOS[k])
SOS['content'] = content
return SOS
def app_0(flag, name, popper, print_details=False):
"""
APP 0
:return:
"""
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
idx_seg = print_bytes(content, idx_seg)
identifier = bytes_2_int(content[:5])
version = bytes_2_int(content[5:7])
units = content[7]
x_density = bytes_2_int(content[8:10])
y_density = bytes_2_int(content[10:12])
x_thumbnail = content[12]
y_thumbnail = content[13]
if print_details:
print(''' {length:#06X}\tLength\t{length}
{identifier:#012X}\tIdentifier\t{identifier_b}
{version:#06X}\tVersion
{units:#04X}\tUnits\t零时表示未指定，为1表示英寸，为2表示厘米
{x_density:#06X}\tx_density\t{x_density}
{y_density:#06X}\ty_density\t{y_density}
{x_thumbnail:#04X}\tx_thumbnail\t{x_thumbnail}
{y_thumbnail:#04X}\ty_thumbnail\t{y_thumbnail}'''.format(
length=length,
identifier=identifier,
identifier_b=identifier.to_bytes(5, 'big'),
version=version,
units=units,
x_density=x_density,
y_density=y_density,
x_thumbnail=x_thumbnail,
y_thumbnail=y_thumbnail,
))
# remain = length - 16
# if remain > 0:
# remain = read_bytes(remain, False)
# print(remain)
# else:
# remain = b''
remain = content[12:]
return {
'flag': flag,
'name': name,
'length': length,
'identifier': identifier,
'version': version,
'units': units,
'x_density': x_density,
'y_density': y_density,
'x_thumbnail': x_thumbnail,
'y_thumbnail': y_thumbnail,
'data': remain,
'content': content
}