ESP32-CAM MJPEG Stream Decoder and Control Library | Details

# ESP32-CAM-MJPEG-Stream-Decoder-and-Control-Library

ESP32-CAM is an inexpensive MJPEG stream embedded device.
The library is MJPEG stream decoder based on libcurl and OpenCV, and written in C/C++.

## Firmware

Modify the following code in "CameraWebServer.ino" file, that is MJPEG stream boundary.

```cpp
#define PART_BOUNDARY "WINBONDBOUDARY"
static const char* _STREAM_CONTENT_TYPE = "multipart/x-mixed-replace;boundary=" PART_BOUNDARY;
static const char* _STREAM_BOUNDARY = "\r\n--" PART_BOUNDARY "\r\n";
static const char* _STREAM_PART = "Content-Type: image/jpeg\r\n\r\n";
```
## Easy-to-use

### Dependence
- OpenCV 3 or 4
- libcurl 7

- wxWidgets 2.8.12(for wxESP32-CAM example)

### Use
Include "ESP32-CAM MJPEG Library" folder into your project. </br>
- ESP32-CAM Library.h
- ESP32-CAM Library.cpp

```cpp
#include "./ESP32-CAM MJPEG Library/ESP32-CAM Library.h"

typedef enum {
FRAMESIZE_QQVGA, // 160x120
FRAMESIZE_QQVGA2, // 128x160
FRAMESIZE_QCIF, // 176x144
FRAMESIZE_HQVGA, // 240x176
FRAMESIZE_QVGA, // 320x240
FRAMESIZE_CIF, // 400x296
FRAMESIZE_VGA, // 640x480
FRAMESIZE_SVGA, // 800x600
FRAMESIZE_XGA, // 1024x768
FRAMESIZE_SXGA, // 1280x1024
FRAMESIZE_UXGA // 1600x1200
} framesize_t;

ESP32_CAM *esp32_cam = new ESP32_CAM(std::string( "192.168.1.254" )); //ESP32-CAM local IP address

esp32_cam->SetResolution(FRAMESIZE_SVGA); // Set mjpeg video stream resolution

esp32_cam->StartVideoStream(); // Start mjpeg video stream thread

cv::Mat frame = esp32_cam->GetFrame(); // Get mjpeg frame
if(!frame.empty()){
cv::imshow("Example",frame); //Show mjpeg video stream
}

```

### Command POST and ESP32-CAM GET

In cmd_handler, "var" is variable name, "val" is value of variable, curl POST command is:

```cpp
int ESP32_CAM::SendStream(CURL *curl_object)
{
long return_code;
CURLcode response;

curl_easy_setopt(curl_object,CURLOPT_URL,"192.168.1.254/control?var=framesize&val=7");

response = curl_easy_perform(curl_object);

response = curl_easy_getinfo(curl_object, CURLINFO_RESPONSE_CODE, &return_code);

return (int)return_code;
}
```

"192.168.1.254/control?var=framesize&val=8", "192.168.1.254" is ESP32-CAM IP address setting from:

```cpp
// Set your Static IP address
IPAddress local_IP(192, 168, 1, 254);
// Set your Gateway IP address
IPAddress gateway(192, 168, 1, 1);
WiFi.begin(ssid, password);
WiFi.config(local_IP, gateway, subnet);
```

In this example, "/control?var=framesize&val=8" POST /control API and set parameter "framesize" value is "7"(FRAMESIZE_SVGA 800x600).

API FlashControl(bool), Flash LED turn on or off "/led?var=flash&val=1", val=1 is on, val=0 is off.

### Receive ESP32-CAM Page Content

Set curl_easy_setopt parameter CURLOPT_WRITEFUNCTION and CURLOPT_WRITEDATA for writing received data.

```cpp
std::string ESP32_CAM::GetRSSI()
{
std::string buffer;

curl_easy_setopt(curl_command,CURLOPT_WRITEFUNCTION,WriteCallback);
curl_easy_setopt(curl_command,CURLOPT_WRITEDATA,&buffer);

if(SendStream(curl_command,std::string("/RSSI"))){
}

return buffer;
}
```

### MJPEG Stream Format

In this case MJPEG stream boundary is fixed length, for split into a MJPEG stream of JPEG binary(byte), each frame JPEG binary with cv::imdecode decode to RGB format. </br>

```cpp
const char VIDEO_STREAM_INTERLEAVE[] = "--WINBONDBOUDARY\r\nContent-Type: image/jpeg\r\n\r\n";

const char JPEG_SOI_MARKER_FIRST_BYTE = 0xFF;
const char JPEG_SOI_MARKER_SECOND_BYTE = 0xD8;
```

```cpp
Content-type: multipart/x-mixed-replace; boundary=WINBONDBOUDARY

--WINBONDBOUDARY\r\n
Content-Type: image/jpeg\r\n\r\n
JPEG Binary(0xFF,0xD8 ... 0xFF,0xD9)
--WINBONDBOUDARY\r\n
Content-Type: image/jpeg\r\n\r\n
JPEG Binary(0xFF,0xD8 ... 0xFF,0xD9)
...
...
...
--WINBONDBOUDARY\r\n
Content-Type: image/jpeg\r\n\r\n
JPEG Binary(0xFF,0xD8 ... 0xFF,0xD9)
```
## Examples

### wxESP32-CAM

#### Mac OS X or Linux
- "cd /examples/MAC/wxESP32-CAM/"
- make

#### Windows 10

Build x64 version wxWidgets and libcurl</br>
- 『x64 Native Tools Command Prompt for VS 2017/2019』, open the program as an administrator.
- Build x64 libcurl 7.67.0
- cd "./libcurl-7.67.0/winbuild"
- run "buildconf.bat"
- nmake /f Makefile.vc mode=static VC=15 MACHINE=x64 DEBUG=no
- static link libcurl_a.lib, Ws2_32.lib, Wldap32.lib, winmm.lib, Crypt32.lib, Normaliz.lib
- Build x64 wxWidgets 3.1.2
- cd "build/msw"
- nmake /f makefile.vc /ls RUNTIME_LIBS=static SHARED=0 COMPILER_VERSION=141 TARGET_CPU=X64 BUILD=release
- nmake /f makefile.vc /ls RUNTIME_LIBS=static SHARED=1 COMPILER_VERSION=141 TARGET_CPU=X64 BUILD=release
- Build wxESP32-CAM
- Open *.sln project
- Select "Release x64"
- Rebuild

#### DNN File

This example is wxWidgets GUI for the library demo, and integrate DNN Computer Vision use cases(YOLO V3, OpenPose). </br>

- YOLO V3
- Weights: https://pjreddie.com/media/files/yolov3.weights

- Model: https://github.com/pjreddie/darknet/blob/master/cfg/yolov3.cfg?raw=true

- COCO: https://github.com/pjreddie/darknet/blob/master/data/coco.names?raw=true

- OpenPose Caffe Model
- https://github.com/CMU-Perceptual-Computing-Lab/openpose/blob/master/models/pose/mpi/pose_deploy_linevec.prototxt

- http://posefs1.perception.cs.cmu.edu/Users/ZheCao/pose_iter_146000.caffemodel

### ESP32-CAM Opencv Example

OpenCV highgui MJPEG stream player.

#### Mac OS X or Linux
- cd /examples/MAC/ESP32-CAM Opencv Example/
- make

#### Windows 10
- Open *.sln project
- Select "Release x64"
- Rebuild

## Reference

- https://github.com/GCY/wxRovio

- https://github.com/tobybreckon/roviolib

- https://pjreddie.com/darknet/yolo/

- https://github.com/spmallick/learnopencv/tree/master/ObjectDetection-YOLO

- https://github.com/CMU-Perceptual-Computing-Lab/openpose

- https://github.com/spmallick/learnopencv/tree/master/OpenPose-Multi-Person

- https://randomnerdtutorials.com/esp32-cam-video-streaming-face-recognition-arduino-ide/

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