This will be a short post where I introduce a new addition to the Arduino Eloquent library aimed to make video streaming from an ESP32 camera over HTTP super easy. It will be the first component of a larger project I'm going to implement.

If you Google "esp32 video streaming" you will get a bunch of results that are essentialy copy-pasted from the official Espressif repo: many of them neither copy-pasted the code, just tell you to load the example sketch.

And if you try to read it and try to modify just a bit for your own use-case, you won't understand much.

This is the exact environment for an Eloquent component to live: make it painfully easy what's messy.

I still have to find a good naming scheme for my libraries since Arduino IDE doesn't allow nested imports, so forgive me if "ESP32CameraHTTPVideoStreamingServer.h" was the best that came to mind.

How easy is it to use?

1 line of code if used in conjuction with my other library EloquentVision.

#define CAMERA_MODEL_M5STACK_WIDE
#include "WiFi.h"
#include "EloquentVision.h"
#include "ESP32CameraHTTPVideoStreamingServer.h"

using namespace Eloquent::Vision;
using namespace Eloquent::Vision::Camera;

ESP32Camera camera;
HTTPVideoStreamingServer server(81);

/**
 *
 */
void setup() {
    Serial.begin(115200);
    WiFi.softAP("ESP32", "12345678");

    camera.begin(FRAMESIZE_QVGA, PIXFORMAT_JPEG);
    server.start();

    Serial.print("Camera Ready! Use 'http://");
    Serial.print(WiFi.softAPIP());
    Serial.println(":81' to stream");
}

void loop() {
}

HTTPVideoStreamingServer assumes you already initialized your camera. You can achieve this task in the way you prefer: ESP32Camera class makes this a breeze.

81 in the server constructor is the port you want the server to be listening to.

Once connected to WiFi or started in AP mode, all you have to do is call start(): that's it!

Want to learn more?

What else is it good for?

The main reason I wrote this piece of library is because one of you reader commented on the motion detection post asking if it would be possible to start the video streaming once motion is detected.

Of course it is.

It's just a matter of composing the Eloquent pieces.

// not workings AS-IS, needs refactoring

#define CAMERA_MODEL_M5STACK_WIDE
#include "WiFi.h"
#include "EloquentVision.h"
#include "ESP32CameraHTTPVideoStreamingServer.h"

#define FRAME_SIZE FRAMESIZE_QVGA
#define SOURCE_WIDTH 320
#define SOURCE_HEIGHT 240
#define CHANNELS 1
#define DEST_WIDTH 32
#define DEST_HEIGHT 24
#define BLOCK_VARIATION_THRESHOLD 0.3
#define MOTION_THRESHOLD 0.2

// we're using the Eloquent::Vision namespace a lot!
using namespace Eloquent::Vision;
using namespace Eloquent::Vision::Camera;
using namespace Eloquent::Vision::ImageProcessing;
using namespace Eloquent::Vision::ImageProcessing::Downscale;
using namespace Eloquent::Vision::ImageProcessing::DownscaleStrategies;

ESP32Camera camera;
HTTPVideoStreamingServer server(81);
// the buffer to store the downscaled version of the image
uint8_t resized[DEST_HEIGHT][DEST_WIDTH];
// the downscaler algorithm
// for more details see https://eloquentarduino.github.io/2020/05/easier-faster-pure-video-esp32-cam-motion-detection
Cross<SOURCE_WIDTH, SOURCE_HEIGHT, DEST_WIDTH, DEST_HEIGHT> crossStrategy;
// the downscaler container
Downscaler<SOURCE_WIDTH, SOURCE_HEIGHT, CHANNELS, DEST_WIDTH, DEST_HEIGHT> downscaler(&crossStrategy);
// the motion detection algorithm
MotionDetection<DEST_WIDTH, DEST_HEIGHT> motion;

/**
 *
 */
void setup() {
    Serial.begin(115200);
    WiFi.softAP("ESP32", "12345678");

    camera.begin(FRAMESIZE_QVGA, PIXFORMAT_GRAYSCALE);
    motion.setBlockVariationThreshold(BLOCK_VARIATION_THRESHOLD);

    Serial.print("Camera Ready! Use 'http://");
    Serial.print(WiFi.softAPIP());
    Serial.println(":81' to stream");
}

void loop() {
    camera_fb_t *frame = camera.capture();

    // resize image and detect motion
    downscaler.downscale(frame->buf, resized);
    motion.update(resized);
    motion.detect();

    if (motion.ratio() > MOTION_THRESHOLD) {
        Serial.print("Motion detected");
        // start the streaming server when motion is detected
        // shutdown after 20 seconds if no one connects
        camera.begin(FRAMESIZE_QVGA, PIXFORMAT_JPEG);
        delay(2000);
        Serial.print("Camera Server ready! Use 'http://");
        Serial.print(WiFi.softAPIP());
        Serial.println(":81' to stream");
        server.start();
        delay(20000);
        server.stop();
        camera.begin(FRAMESIZE_QVGA, PIXFORMAT_GRAYSCALE);
        delay(2000);
    }

    // probably we don't need 30 fps, save some power
    delay(300);
}

Does it look good?

Now the rationale behind Eloquent components should be starting to be clear to you: easy to use objects you can compose the way it fits to achieve the result you want.

Would you suggest me more piece of functionality you would like to see wrapped in an Eloquent component?

You can find the class code and the example sketch on the Github repo.

Help the blow grow