Pygame：通过网络发送图像PodSixNet

Question

I am trying to send an image over the network with PodSixNet. How I am doing this:

Client side:

    #...
    image = pygame.image.load("character.png")
    img = pygame.image.tostring(image, "RGBA")
    connection.Send({"action":"setPlayerCharacter", 'playerName': self.playerName, 'playerImage': img})

Server side:

  def Network_setPlayerCharacter(self, data):
    self.playerName = data['playerName']

    img = data['playerImage']
    self.playerImage = pygame.image.fromstring(img, (50, 50), "RGBA")
    self._server.SendPlayers() # Send data to other players

But PodSixNet does not like bytes. Getting this error:

error: uncaptured python exception, closing channel <__main__.ClientChannel 127.0.0.1:54822 at 0x3925ef0> (<class 'UnicodeDecodeError'>:'utf-8' codec can't decode byte 0xff in position 1611: invalid start byte [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\asyncore.py|read|83] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\asyncore.py|handle_read_event|422] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\asynchat.py|handle_read|171] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\site-packages\PodSixNet\Channel.py|found_terminator|21] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\site-packages\PodSixNet\rencode.py|loads|333] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\site-packages\PodSixNet\rencode.py|f|320] [C:\Users\Mikal\AppData\Local\Programs\Python\Python37-32\lib\site-packages\PodSixNet\rencode.py|decode_string|196])

Any way around this?

Answer 1

I'm not familiar with PodSixNet, but a simple way around this seems to be a Base64 encoding of the binary image data.

import base64
...

image       = pygame.image.load( "tiny_alien.png" )
image_bytes = pygame.image.tostring( image, "RGBA" )
image_str   = base64.b64encode( image_bytes ).decode('iso-8859-1') # ASCII(ish)

For whatever reason, the base64 module returns a bytes-like object, not a string, so it needs to be further decoded.

Note that if you use base64.a85encode(...) the resultant string will be significantly smaller.

On the other side, use base64.b64decode(...) to get the string back to a binary again:

image_bytes = base64.b64decode( image_str ) # back to pygame.tostring() format