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[英]Using python with Sony Camera Remote API to create pc app
[英]Sony Camera Remote API, Liveview streaming slow
我正在嘗試在桌面上流式傳輸SONY FDR-X1000V相機的實時視圖。 我使用python調用API並下載包並使用opencv解碼jpeg。 當我運行它時,它幾乎不能每秒捕獲一幀。 后來我發現jpeg的有效載荷大小可以是8MB。 但是,FDR-X1000V不支持更改實時視圖大小。 但是,當我在iPhone上使用該應用程序進行實時視圖時,它會流暢地傳輸。 所以這是我的問題:1。jpeg有效載荷可以大到8MB是否正常? 2.如果是這樣,我怎樣才能流暢地播放實時視圖?
這是我的代碼:
try:
result = api.do('startLiveview')
url = result['result'][0]
except KeyError:
print result
f = urllib2.urlopen(url)
buff = ''
chunk_size = 32768
for i in xrange(3000):
if len(buff) < chunk_size:
time_s = time.time()
buff = buff + f.read(chunk_size)
print "Download Speed %f KB/s"%(chunk_size/1000/(time.time() - time_s))
time_s = time.time()
start_code = ''.join(buff).find('$5hy')
# print "LCS time cost", time.time() - time_s
if start_code < 0:
buff = buff[-12:]
print "skip", len(buff)-12
elif start_code < 8:
buff = buff[8:]
else:
if start_code > len(buff) - 129:
buff = buff + f.read(chunk_size)
payload_type = ord(buff[start_code-7])
payload_size, = struct.unpack('<I', buff[start_code+4:start_code+8].ljust(4,'\0'))
padding_size = ord(buff[start_code+8])
print "Type:%d\tPayload:%d\tPadding:%d\t"%(payload_type,payload_size,padding_size)
buff = buff[start_code+128:]
if payload_type == 1:
if payload_size + padding_size > len(buff):
time_s = time.time()
download_size = payload_size+padding_size-len(buff)
buff = buff + f.read(download_size)
print "Download Speed %f KB/s"%(download_size/1000/(time.time() - time_s))
img_data = buff[:payload_size]
buff = buff[payload_size:]
time_s = time.time()
d = np.asarray(bytearray(img_data), dtype='uint8')
img = cv2.imdecode(d,cv2.IMREAD_COLOR)
cv2.imshow('postview',img)
cv2.waitKey(30)
# print "Decode time cost", time.time() - time_s
一些輸出:
Type:1 Payload:8410624 Padding:0
Download Speed 679.626326 KB/s
一點無恥的促銷 - 但它可能會幫助你。 你嘗試過pysony代碼嗎?
您必須手動設置QX_ADDR,但這應該為您提供“更快”的實時視圖流... https://github.com/Bloodevil/sony_camera_api/issues/22
pygameLiveView示例有所需的構建塊,你只需要調整jpeg加載以拉入openCV而不是pygame
我相信問題可能是您正在解析“LiveView的有效負載標頭”中的“有效負載數據大小”,而不是3字節數據。 因此,在這種情況下,有效負載大小看起來比 這在“ 實時視圖數據JPEG容器的格式 ”下的文檔中進行了解釋。 嘗試更改此設置並告訴我它是否仍然不適合您。
@Simon Wood和@Robert的答案 - 索尼都非常有用! 我在代碼中犯了兩個錯誤。
一個是有效載荷大小是3個字節而不是4個字節。
另一個是我假設字節順序是little-endian而不是big-endian。
@Simon Wood提到的項目很好。 雖然它沒有在4字節的起始代碼上實現重新同步。
為了做到這一點,我用兩種方法編寫自己的代碼來檢查和重新同步它:
try:
result = api.do('startLiveview')
url = result['result'][0]
except KeyError:
print result
f = urllib2.urlopen(url)
#method 1
buff = ''
chunk_size = 8192
for i in xrange(300):
if len(buff) < chunk_size:
time_s = time.time()
buff = buff + f.read(chunk_size)
# print "Download Speed %f KB/s"%(chunk_size/1000/(time.time() - time_s))
time_s = time.time()
start_code = ''.join(buff).find('$5hy')
# print "LCS time cost", time.time() - time_s
if start_code < 0:
buff = buff[-12:]
print "skip", len(buff)-12
elif start_code < 8:
buff = buff[8:]
print "skip a header"
else:
if start_code > len(buff) - 129:
buff = buff + f.read(chunk_size)
start_byte = ord(buff[start_code - 8])
payload_type = ord(buff[start_code - 7])
sequence_num, = struct.unpack('>I', buff[start_code - 6:start_code - 4].rjust(4,'\0'))
time_stamp, = struct.unpack('>I', buff[start_code - 4:start_code].rjust(4,'\0'))
payload_size, = struct.unpack('>I', buff[start_code+4:start_code+7].rjust(4,'\0'))
padding_size = ord(buff[start_code+8])
print "StartByte:%d\t sequenceNum:%d\t timeStamp:%d\t Type:%d\t Payload:%d\t Padding:%d\t"%(
start_byte,sequence_num,time_stamp,payload_type,payload_size,padding_size)
buff = buff[start_code+128:]
if payload_type == 1:
if payload_size + padding_size > len(buff):
time_s = time.time()
download_size = payload_size+padding_size-len(buff)
buff = buff + f.read(download_size)
# print "Download Speed %f KB/s"%(download_size/1000/(time.time() - time_s))
img_data = buff[:payload_size]
buff = buff[payload_size:]
time_s = time.time()
d = np.asarray(bytearray(img_data), dtype='uint8')
img = cv2.imdecode(d,cv2.IMREAD_COLOR)
cv2.imshow('postview',img)
cv2.waitKey(10)
# print "Decode time cost", time.time() - time_s
#method 2
def checkbyte(f):
if f.read(4) == '$5hy':
return
state = 0
i = 1
while 1:
i+=1
if state == 0 :
if f.read(1) == '$':
state = 1
else:
state = 0
if state == 1 :
if f.read(1) == '5':
state = 2
else:
state = 0
if state == 2 :
if f.read(1) == 'h':
state = 3
else:
state = 0
if state == 3 :
if f.read(1) == 'y':
state = 4
else:
state = 0
if state == 4 :
print 'skip', i
return
for i in xrange(300):
buff = f.read(8)
start_byte ord(buff[0])
payload_type, = struct.unpack('>I',buff[1].rjust(4,'\0'))
sequence_num, = struct.unpack('>I',buff[2:4].rjust(4,'\0'))
time_stamp, = struct.unpack('>I',buff[4:8])
#payload header
checkbyte(f)
buff = f.read(124)
payload_size, = struct.unpack('>I',buff[0:3].rjust(4,'\0'))
padding_size= ord(buff[3])
print "StartByte:%d\t sequenceNum:%d\t timeStamp:%d\t Type:%d\t Payload:%d\t Padding:%d\t"%(
start_byte,sequence_num,time_stamp,payload_type,payload_size,padding_size)
d = f.read(payload_size)
if padding_size > 0:
f.read(padding_size)
if payload_type == 1:
# Type = 0x01
d = np.asarray(bytearray(d), dtype='uint8')
img = cv2.imdecode(d,cv2.IMREAD_COLOR)
cv2.imshow('postview',img)
cv2.waitKey(1)
print api.do('stopLiveview')
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