tasmota-webcam xdrv_81_webcam.ino stream should start with boundary marker

[mnsuk]

PROBLEM DESCRIPTION

A clear and concise description of what the problem is.
I am attempting to process the mjpeg stream produced by tasmota-webcam. I have use two different client libraries and both report that boundary string is missing. e.g from py-mjpeg:
mjpeg.ProtoError: Boundary string expected, but not found.
Looking at the code in xdrv_81_webcam.ino and confirming by examining the HTTP headers and content in python debug shows that the boundary string is sent after each jpeg frame. E.g. the following is sent:

HTTP/1.1 200 OK
Content-Type: multipart/x-mixed-replace;boundary=e8b8c539-047d-4777-a985-fbba6edff11e
Content-Type: image/jpeg
Content-Length: 17281
…….(image content)
—e8b8c539-047d-4777-a985-fbba6edff11e
Content-Type: image/jpeg
Content-Length: 17291
……..(image content)
—e8b8c539-047d-4777-a985-fbba6edff11e

So after the headers the content goes straight to the first jpeg image headers, then a boundary, then repeats for each image. I believe that the boundary should have been sent prior to the first jpeg image too (certainly that is what expected by the source for the python libraries I looked at). In summary the sequence should be:

headers
boundary
image
boundary
image
boundary
image
etc

whereas it is:

headers
image
boundary
image
boundary
etc

REQUESTED INFORMATION

Make sure your have performed every step and checked the applicable boxes before submitting your issue. Thank you!

• [ x] Read the Contributing Guide and Policy and the Code of Conduct
• [ x] Searched the problem in issues
• [ x] Searched the problem in discussions
• [ x] Searched the problem in the docs
• [ x] Searched the problem in the chat
• Device used (e.g., Sonoff Basic): _AIThinker ESP32Cam
• Tasmota binary firmware version number used: _9.4.0
  • [ x] Pre-compiled
  • Self-compiled
• Flashing tools used: _esptool.py
• Provide the output of command: Backlog Template; Module; GPIO 255:

  Configuration output here:
20:35:22.174 RSL: RESULT = {"NAME":"AITHINKER CAM","GPIO":[4992,1,1,1,1,5088,1,1,1,1,1,1,1,1,5089,5090,0,5091,5184,5152,0,5120,5024,5056,0,0,0,0,4928,1,5094,5095,5092,0,0,5093],"FLAG":0,"BASE":1}
20:35:22.380 RSL: RESULT = {"Module":{"0":"AITHINKER CAM"}}
20:35:22.586 RSL: RESULT = {"GPIO0":{"4992":"CAM_XCLK"},"GPIO1":{"0":"None"},"GPIO2":{"0":"None"},"GPIO3":{"0":"None"},"GPIO4":{"0":"None"},"GPIO5":{"5088":"CAM_DATA1"},"GPIO9":{"0":"None"},"GPIO10":{"0":"None"},"GPIO12":{"0":"None"},"GPIO13":{"0":"None"},"GPIO14":{"0":"None"},"GPIO15":{"0":"None"},"GPIO16":{"0":"None"},"GPIO17":{"0":"None"},"GPIO18":{"5089":"CAM_DATA2"},"GPIO19":{"5090":"CAM_DATA3"},"GPIO20":{"0":"None"},"GPIO21":{"5091":"CAM_DATA4"},"GPIO22":{"5184":"CAM_PCLK"},"GPIO23":{"5152":"CAM_HREF"},"GPIO24":{"0":"None"},"GPIO25":{"5120":"CAM_VSYNC"},"GPIO26":{"5024":"CAM_SIOD"}}
20:35:22.591 RSL: RESULT = {"GPIO27":{"5056":"CAM_SIOC"},"GPIO28":{"0":"None"},"GPIO29":{"0":"None"},"GPIO30":{"0":"None"},"GPIO31":{"0":"None"},"GPIO32":{"4928":"CAM_PWDN"},"GPIO33":{"0":"None"},"GPIO34":{"5094":"CAM_DATA7"},"GPIO35":{"5095":"CAM_DATA8"},"GPIO36":{"5092":"CAM_DATA5"},"GPIO37":{"0":"None"},"GPIO38":{"0":"None"},"GPIO39":{"5093":"CAM_DATA6"}}

• If using rules, provide the output of this command: Backlog Rule1; Rule2; Rule3:

  Rules output here:

• Provide the output of this command: Status 0:

  STATUS 0 output here:
20:35:53.118 RSL: STATUS = {"Status":{"Module":0,"DeviceName":"Tasmota","FriendlyName":["Tasmota"],"Topic":"tasmota_F063A0","ButtonTopic":"0","Power":0,"PowerOnState":3,"LedState":1,"LedMask":"FFFF","SaveData":1,"SaveState":1,"SwitchTopic":"0","SwitchMode":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"ButtonRetain":0,"SwitchRetain":0,"SensorRetain":0,"PowerRetain":0,"InfoRetain":0,"StateRetain":0}}
20:35:53.121 RSL: STATUS1 = {"StatusPRM":{"Baudrate":115200,"SerialConfig":"8N1","GroupTopic":"tasmotas","OtaUrl":"http://ota.tasmota.com/tasmota32/release/tasmota32-webcam.bin","RestartReason":"Software reset CPU","Uptime":"0T01:27:56","StartupUTC":"2021-06-15T18:07:57","Sleep":50,"CfgHolder":4617,"BootCount":13,"BCResetTime":"2021-06-07T17:54:22","SaveCount":30}}
20:35:53.124 RSL: STATUS2 = {"StatusFWR":{"Version":"9.4.0(webcam)","BuildDateTime":"2021-04-23T10:10:09","Core":"1_0_6","SDK":"v3.3.5-1-g85c43024c","CpuFrequency":240,"Hardware":"ESP32-D0WDQ6","CR":"366/699"}}
20:35:53.126 RSL: STATUS3 = {"StatusLOG":{"SerialLog":2,"WebLog":2,"MqttLog":0,"SysLog":0,"LogHost":"","LogPort":514,"SSId":["Penguins",""],"TelePeriod":300,"Resolution":"558180C0","SetOption":["00008009","2805C8000100060000005A0A000000000000","00000080","00006000","00000000"]}}
20:35:53.132 RSL: STATUS4 = {"StatusMEM":{"ProgramSize":1350,"Free":1856,"Heap":125,"PsrMax":4095,"PsrFree":3345,"ProgramFlashSize":4096,"FlashSize":4096,"FlashFrequency":40,"FlashMode":3,"Features":["00000809","8FDAC78F","00140001","000000CF","010013C0","40000981","80004000","00200000","00000024"],"Drivers":"1,2,3,4,5,7,8,9,10,12,20,21,24,26,27,29,50,81","Sensors":"1,2,3,5,6,87"}}
20:35:53.135 RSL: STATUS5 = {"StatusNET":{"Hostname":"tasmota_F063A0-0928","IPAddress":"192.168.0.151","Gateway":"192.168.0.1","Subnetmask":"255.255.255.0","DNSServer":"192.168.0.7","Mac":"24:0A:C4:F0:63:A0","Webserver":2,"WifiConfig":0,"WifiPower":17.0}}
20:35:53.138 RSL: STATUS6 = {"StatusMQT":{"MqttHost":"","MqttPort":1883,"MqttClientMask":"DVES_%06X","MqttClient":"DVES_F063A0","MqttUser":"DVES_USER","MqttCount":0,"MAX_PACKET_SIZE":1200,"KEEPALIVE":30,"SOCKET_TIMEOUT":4}}
20:35:53.141 RSL: STATUS7 = {"StatusTIM":{"UTC":"2021-06-15T19:35:53","Local":"2021-06-15T20:35:53","StartDST":"2021-03-28T02:00:00","EndDST":"2021-10-31T03:00:00","Timezone":"+01:00","Sunrise":"04:46","Sunset":"20:55"}}
20:35:53.146 RSL: STATUS10 = {"StatusSNS":{"Time":"2021-06-15T20:35:53","ESP32":{"Temperature":73.3},"TempUnit":"C"}}
20:35:53.150 RSL: STATUS11 = {"StatusSTS":{"Time":"2021-06-15T20:35:53","Uptime":"0T01:27:56","UptimeSec":5276,"Heap":127,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":0,"Wifi":{"AP":1,"SSId":"Penguins","BSSId":"C0:C9:E3:53:82:F6","Channel":8,"RSSI":100,"Signal":-46,"LinkCount":1,"Downtime":"0T00:00:06"}}}

• Set weblog to 4 and then, when you experience your issue, provide the output of the Console log:

  Console output here:
n/a

TO REPRODUCE

Steps to reproduce the behavior:
Flash an ESP32 cam with tasmota-webcam. Attempt to process resultant mjpeg stream with py-mjpeg client code. (Using this library is just an easy example to reproduce, I've tried others that exhibit the same problem with the stream)
Using library https://pypi.org/project/py-mjpeg/

from mjpeg.client import MJPEGClient

url='http://david:81/cam.mjpeg'

# Create a new client thread
client = MJPEGClient(url)

# Allocate memory buffers for frames
bufs = client.request_buffers(65536, 50)
for b in bufs:
    client.enqueue_buffer(b)
    
# Start the client in a background thread
client.start()
# grab 4 frames from stream
i = 4
while i > 0:
    buf = client.dequeue_buffer()
    data = memoryview(buf.data)[:buf.used]
    f = open('rat.jpg', 'wb')
    f.write(data)
    f.close()
    client.enqueue_buffer(buf)
    i = i - 4
client.print_stats()

EXPECTED BEHAVIOUR

A clear and concise description of what you expected to happen.
stream is processed without error.

SCREENSHOTS

If applicable, add screenshots to help explain your problem.

python3 
Traceback (most recent call last):
  File "/Users/martin/Library/Python/3.7/lib/python/site-packages/mjpeg/client.py", line 151, in run
    self.process_stream(s)
  File "/Users/martin/Library/Python/3.7/lib/python/site-packages/mjpeg/client.py", line 120, in process_stream
    timestamp, clen = read_mjpeg_frame(stream, boundary, mem, length)
  File "/Users/martin/Library/Python/3.7/lib/python/site-packages/mjpeg/__init__.py", line 152, in read_mjpeg_frame
    hdr = read_headers(stream, boundary)
  File "/Users/martin/Library/Python/3.7/lib/python/site-packages/mjpeg/__init__.py", line 38, in read_headers
    raise ProtoError('Boundary string expected, but not found')
mjpeg.ProtoError: Boundary string expected, but not found

ADDITIONAL CONTEXT

Add any other context about the problem here.

(Please, remember to close the issue when the problem has been addressed)

[Jason2866]

Try with latest commit 99d303c

[mnsuk]

I just tried it with 41db97e (9.5.0.1) and it works for me. Testing with a client program using py-mjpeg, I was able to successfully decode and save individual images from the stream. All good thanks.