how to serve image files without disk use?

[Ray Schumacher]

I'm trying to make a small camera server using VideoCapture.py and
socket. I needed to construct a complete image file with headers etc
for a browser to recognize it, but I couldn't find a combination of
StringIO and wx image methods to avoid disk saves, without PIL.

If I save a temp.jpg file to disk I can serve the image easily:
....
self.cam = VideoCapture.Device(devnum=0, showVideoWindow=0)
buff, width, height = self.cam.dev.getbuffer()
im = wx.EmptyImage(width, height)
im.SetData(buff)
im.Mirror().SaveFile('temp.jpg', wx.BITMAP_TYPE_JPEG)
....
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
while 1:
data = conn.recv(1024)
if data[:3] == 'GET':
conn.send("HTTP/1.0 200 OK"+"\015\012")
conn.send("Server: RJS_video/0.0.1"+"\015\012")
conn.send("Content-type: image/bmp"+"\015\012")
conn.send("Content-Length: "+str(352*288*3+256)+"\015\012")
conn.send("\015\012")
fh = file('temp.jpg', 'rb')
conn.send(fh.read())
fh.close()
else: break

But, how can I avoid disk writes? wx's *.SaveFile() needs a string
file name (no objects).
I'm going to investigate PIL's im.save(), as it appears to allow
file-objects.


Ray

 

[Tom Plunket]

But, how can I avoid disk writes? wx's *.SaveFile() needs a string
file name (no objects).
I'm going to investigate PIL's im.save(), as it appears to allow
file-objects.

Take a look at the img2*.py files in wx.tools. They're sorta sketchy
imo, but they do the trick. encode_bitmaps.py, with the wx demo app, is
used to generate all of the bitmap data that's in Python files embedded
into the app, and following the chain of logic from there might yield
you something interesting.

Mind, I haven't tried it myself, but it's where I'd start looking.

Good luck,
-tom!

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