webcam/mth_webcam.py


import usocket as soc
import _thread as th
import camera
import time
import esp
from machine import Pin
import gc
from Wifi.Sta import Sta

#esp.osdebug(False)
esp.osdebug(True)

hdr = {
  # start page for streaming 
  # URL: /apikey/webcam
  'live': """HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8

<html>
<head>
<title>Web Camera</title>
</head>
<body>
  <center>
    <h1>Web Camera</h1>
    <img src="/apikey/live" width=720 height=540 />
  </center>
</body>
</html>

""",
  # live stream -
  # URL: /apikey/live
  'stream': """HTTP/1.1 200 OK
Content-Type: multipart/x-mixed-replace; boundary=frame
Connection: keep-alive
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Expires: Thu, Jan 01 1970 00:00:00 GMT
Pragma: no-cache

""",
  # live stream -
  # URL: 
  'frame': """--frame
Content-Type: image/jpeg

""",
  # still picture - 
  # URL: /apikey/snap
  'snap': """HTTP/1.1 200 OK
Content-Type: image/jpeg
Content-Length: """,
  # no content error
  # URL: all the rest
  'none': """HTTP/1.1 204 No Content
Content-Type: text/plain; charset=utf-8

Nothing here!

""",
  # bad request error
  # URL: /favicon.ico
  'favicon': """HTTP/1.1 404 


""",
  # bad request error
  # URL: all the rest
  'err': """HTTP/1.1 400 Bad Request
Content-Type: text/plain; charset=utf-8

Hello? Can not compile

""",
  # OK
  # URL: all the rest
  'OK': """HTTP/1.1 200 OK
Content-Type: text/plain; charset=utf-8

OK!

"""
}

def clean_up(cs):
   cs.close() # flash buffer and close socket
   del cs
   gc.collect()

def frame_gen():
   while True:
     buf = camera.capture()
     yield buf
     del buf
     gc.collect()

def send_frame(pp):
   cs, h = pp
   while True:
      ee = ''
      try:
         cs.send(b'%s' % h)
         cs.send(next(pic))
         cs.send(b'\r\n')  # send and flush the send buffer
      except Exception as e:
        ee = str(e)
      if ee == '': 
        time.sleep(0.005)  # try as fast as we can
      else:
        break

   clean_up(cs)
   return   

def servers():
   socks = []
   # port 80 server - streaming server
   s = soc.socket(soc.AF_INET, soc.SOCK_STREAM)
   s.setsockopt(soc.SOL_SOCKET, soc.SO_REUSEADDR, 1)
   a = ('0.0.0.0', 80)
   s.bind(a)
   s.listen(2)  # queue at most 2 clients
   socks.append(s)

   # port 81 server - still picture server
   s = soc.socket(soc.AF_INET, soc.SOCK_STREAM)
   s.setsockopt(soc.SOL_SOCKET, soc.SO_REUSEADDR, 1)
   a = ('0.0.0.0', 81)
   s.bind(a)
   s.listen(2)
   socks.append(s)

   # port 82 server - cmd server
   s = soc.socket(soc.AF_INET, soc.SOCK_STREAM)
   s.setsockopt(soc.SOL_SOCKET, soc.SO_REUSEADDR, 1)
   a = ('0.0.0.0', 82)
   s.bind(a)
   s.listen(2)
   socks.append(s)

   return socks

def port1(cs, rq):
   rqp = rq[1].split('/')
   if rqp[1] == 'apikey': # Must have /apikey/<REQ>
      if rqp[2] == 'webcam':
         cs.send(b'%s' % hdr['live'])
         clean_up(cs)
      elif rqp[2] == 'live': # start streaming
         cs.send(b'%s' % hdr['stream'])
         # start frame sending
         send_frame([cs, hdr['frame']])
      else: # 
         cs.send(b'%s' % hdr['none'])
         clean_up(cs)
   else:
      cs.send(b'%s' % hdr['err'])
      clean_up(cs)

def port2(cs, rq):
   rqp = rq[1].split('/')
   if rqp[1] == 'apikey': # Must have /apikey/<REQ>
      if rqp[2] == 'snap':
         try:
            img=next(pic)
            cs.send(b'%s %d\r\n\r\n' % (hdr['snap'], len(img)))
            cs.send(img)
            cs.send(b'\r\n')
         except:
            pass
      elif rqp[2] == 'blitz':
         try:
            flash_light.on()
            img=next(pic)
            flash_light.off()
            cs.send(b'%s %d\r\n\r\n' % (hdr['snap'], len(img)))
            cs.send(img)
            cs.send(b'\r\n')
         except:
            pass
      else:
         cs.send(b'%s' % hdr['none'])
   else:
      cs.send(b'%s' % hdr['err'])
   clean_up(cs)

def port3(cs, rq):
   rqp = rq[1].split('/')
   if rqp[1] == 'apikey': # Must have /apikey/<REQ>
      if rqp[2] == 'flash': # /apikey/flash/<what>
         if rqp[3] == 'on':
            flash_light.on()
         else:
            flash_light.off()
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'fmt':
         w = int(rqp[3])
         if w>=0 and w<=2:
            camera.pixformat(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'pix':
         w = int(rqp[3])
         if w>0 and w<13:
            camera.framesize(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'qua':
         w = int(rqp[3])
         if w>9 and w<64:
            camera.quality(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'con':
         w = int(rqp[3])
         if w>-3 and w<3:
            camera.contrast(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'sat':
         w = int(rqp[3])
         if w>-3 and w<3:
            camera.saturation(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'bri':
         w = int(rqp[3])
         if w>-3 and w<3:
            camera.brightness(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'ael':
         w = int(rqp[3])
         if w>-3 and w<3:
            camera.aelevels(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'aev':
         w = int(rqp[3])
         if w>=0 and w<=1200:
            camera.aecvalue(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'agc':
         w = int(rqp[3])
         if w>=0 and w<=30:
            camera.agcgain(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'spe':
         w = int(rqp[3])
         if w>=0 and w<7:
            camera.speffect(w)
         cs.send(b'%s' % hdr['OK'])
      elif rqp[2] == 'wbl':
         w = int(rqp[3])
         if w>=0 and w<5:
            camera.whitebalance(w)
         cs.send(b'%s' % hdr['OK'])
      else:
         cs.send(b'%s' % hdr['none'])
   else:
      cs.send(b'%s' % hdr['err'])
   clean_up(cs)

def srv(p):
  sa = socks[p] # start server; catch error - loop forever
  while True:
     try:
        ok = True
        ee = ''
        try:
           sa.settimeout(0.05) # in sec NB! default browser timeout (5-15 min)
           cs, ca = sa.accept()
           cs.settimeout(0.5) # in sec
        except Exception as e:
           ee = str(e)
        if ee != '':
           # print('Socket %d accept - %s' % (p, ee.split()[-1]))
           #ee = ''
           pass
           ok = False
        if ok: # No soc.accept timeout
           ee = ''
           try:
              # client accepted 
              r = cs.recv(1024)
              # REQ: b''  # may be due to very short timeout
           except Exception as e:
              ee = str(e)
           if ee != '':
              print(ee)
              ok = False
           else:
              ms = r.decode('utf-8')
              if ms.find('favicon.ico') < 0:
                 rq = ms.split(' ')
                 try:
                    print(rq[0], rq[1], ca)
                 except:
                    ok = False
              else:
                 cs.send(b'%s' % hdr['favicon']) # handle favicon request early
                 clean_up(cs)
                 ok = False
        if ok: # No soc.recv timeout or favicon request
           try:
              ports[p](cs, rq)
           except Exception as e:
              ee = str(e)
              if ee != '':
                 print(ee)
     except Exception as e:
        ee = str(e)
        if ee != '':
           print(ee)


#------------------
wc = 0
while True:
  cr = camera.init()
  print("Camera ready?: ", cr)
  if cr:
    break
  time.sleep(2)
  wc += 1
  if wc >= 5:
    break

if not cr:
  print("Camera not ready. Can't continue!")
else:
  # setup networking
  w = Sta()
  w.connect()
  w.wait()
  wc = 0
  while not w.wlan.isconnected():
     print("WIFI not ready. Wait...")
     time.sleep(2)
     wc += 1
     if wc >= 5:
       break
  if wc >= 5:
     print("WIFI not ready. Can't continue!")
  else:
     pic = frame_gen()
     flash_light = Pin(04,Pin.OUT)
     socks = servers()
     ports = [port1, port2, port3] # 80, 81, 82

     # schedule 2 servers for port 80
     # streaming hold socket until client terminate,
     # so, we service at most 2 clients on port 80
     th.start_new_thread(srv, (0,))
     th.start_new_thread(srv, (0,))

     # schedule 1 server for port 81
     th.start_new_thread(srv, (1,))

     #
     # schedule other processes here
     #

     # go for it!
     print("Up Up and Away!")

     # let the main thread take care of port 82 - block REPL
     srv(2)