app_httpd.cpp

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "esp_http_server.h"
#include "esp_timer.h"
#include "esp_camera.h"
#include "img_converters.h"
#include "fb_gfx.h"
#include "driver/ledc.h"
#include "sdkconfig.h"
#include "camera_index.h"

#if defined(ARDUINO_ARCH_ESP32) && defined(CONFIG_ARDUHAL_ESP_LOG)
#include "esp32-hal-log.h"
#define TAG ""
#else
#include "esp_log.h"
static const char *TAG = "camera_httpd";
#endif

//#define CONFIG_LED_ILLUMINATOR_ENABLED
//#define CONFIG_LED_LEDC_LOW_SPEED_MODE

#ifdef CONFIG_LED_ILLUMINATOR_ENABLED
int led_duty = 0;
bool isStreaming = false;
#ifdef CONFIG_LED_LEDC_LOW_SPEED_MODE
#define CONFIG_LED_LEDC_SPEED_MODE LEDC_LOW_SPEED_MODE
#else
#define CONFIG_LED_LEDC_SPEED_MODE LEDC_HIGH_SPEED_MODE
#endif
#endif

typedef struct
{
    httpd_req_t *req;
    size_t len;
} jpg_chunking_t;

#define PART_BOUNDARY "123456789000000000000987654321"
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\nContent-Length: %u\r\nX-Timestamp: %d.%06d\r\n\r\n";

httpd_handle_t stream_httpd = NULL;
httpd_handle_t camera_httpd = NULL;

typedef struct
{
    size_t size;  //number of values used for filtering
    size_t index; //current value index
    size_t count; //value count
    int sum;
    int *values; //array to be filled with values
} ra_filter_t;

static ra_filter_t ra_filter;

static ra_filter_t *ra_filter_init(ra_filter_t *filter, size_t sample_size)
{
    memset(filter, 0, sizeof(ra_filter_t));

    filter->values = (int *)malloc(sample_size * sizeof(int));
    if (!filter->values)
    {
        return NULL;
    }
    memset(filter->values, 0, sample_size * sizeof(int));

    filter->size = sample_size;
    return filter;
}

#ifdef CONFIG_LED_ILLUMINATOR_ENABLED
void enable_led(bool en)
{ // Turn LED On or Off
    int duty = en ? led_duty : 0;
    if (en && isStreaming && (led_duty > CONFIG_LED_MAX_INTENSITY))
    {
        duty = CONFIG_LED_MAX_INTENSITY;
    }
    ledc_set_duty(CONFIG_LED_LEDC_SPEED_MODE, CONFIG_LED_LEDC_CHANNEL, duty);
    ledc_update_duty(CONFIG_LED_LEDC_SPEED_MODE, CONFIG_LED_LEDC_CHANNEL);
    ESP_LOGI(TAG, "Set LED intensity to %d", duty);
}
#endif


static size_t jpg_encode_stream(void *arg, size_t index, const void *data, size_t len)
{
    jpg_chunking_t *j = (jpg_chunking_t *)arg;
    if (!index)
    {
        j->len = 0;
    }
    if (httpd_resp_send_chunk(j->req, (const char *)data, len) != ESP_OK)
    {
        return 0;
    }
    j->len += len;
    return len;
}

static esp_err_t capture_handler(httpd_req_t *req)
{
    camera_fb_t *fb = NULL;
    esp_err_t res = ESP_OK;
    int64_t fr_start = esp_timer_get_time();

#ifdef CONFIG_LED_ILLUMINATOR_ENABLED
    enable_led(true);
    vTaskDelay(150 / portTICK_PERIOD_MS); // The LED needs to be turned on ~150ms before the call to esp_camera_fb_get()
    fb = esp_camera_fb_get();             // or it won't be visible in the frame. A better way to do this is needed.
    enable_led(false);
#else
    fb = esp_camera_fb_get();
#endif

    if (!fb)
    {
        ESP_LOGE(TAG, "Camera capture failed");
        httpd_resp_send_500(req);
        return ESP_FAIL;
    }

    httpd_resp_set_type(req, "image/jpeg");
    httpd_resp_set_hdr(req, "Content-Disposition", "inline; filename=capture.jpg");
    httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");

    char ts[32];
    snprintf(ts, 32, "%ld.%06ld", fb->timestamp.tv_sec, fb->timestamp.tv_usec);
    httpd_resp_set_hdr(req, "X-Timestamp", (const char *)ts);

        size_t fb_len = 0;
        if (fb->format == PIXFORMAT_JPEG)
        {
            fb_len = fb->len;
            res = httpd_resp_send(req, (const char *)fb->buf, fb->len);
        }
        else
        {
            jpg_chunking_t jchunk = {req, 0};
            res = frame2jpg_cb(fb, 80, jpg_encode_stream, &jchunk) ? ESP_OK : ESP_FAIL;
            httpd_resp_send_chunk(req, NULL, 0);
            fb_len = jchunk.len;
        }
        esp_camera_fb_return(fb);
        int64_t fr_end = esp_timer_get_time();
        ESP_LOGI(TAG, "JPG: %uB %ums", (uint32_t)(fb_len), (uint32_t)((fr_end - fr_start) / 1000));
        return res;
}

void startCameraServer()
{
    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
    config.max_uri_handlers = 16;

    httpd_uri_t capture_uri = {
        .uri = "/capture",
        .method = HTTP_GET,
        .handler = capture_handler,
        .user_ctx = NULL};

    ra_filter_init(&ra_filter, 20);

    ESP_LOGI(TAG, "Starting web server on port: '%d'", config.server_port);
    if (httpd_start(&camera_httpd, &config) == ESP_OK)
    {
        httpd_register_uri_handler(camera_httpd, &capture_uri);
    }

    config.server_port += 1;
    config.ctrl_port += 1;
}