Skip to content

CANON_C200_API.md

Latest commit

 

History

History
943 lines (746 loc) · 23.7 KB

CANON_C200_API.md

File metadata and controls

943 lines (746 loc) · 23.7 KB

Canon C200 Browser Remote API Documentation

Camera IP: 10.10.11.35 Base Path: /wpd/VNCX02/ Auth: HTTP Basic (admin:admin) Product ID: VNCX02

VERIFIED WORKING - Your Camera's Current Settings

These were queried live from your C200 at 10.10.11.35:

Exposure

Setting Current Options Enabled
Aperture (av) F5.6 F1.8-F16 (20 steps) Yes
Aperture Type (atype) T-stop F, T Yes
Aperture Step (avst) 3fine 2, 3, 2fine, 3fine Yes
Iris Mode (am) --- autoiris, maniris No (disabled)
ISO/Gain Mode (gcm) ISO iso, gain Yes
ISO Value (gcv) 1000 160-25600 (23 steps) Yes
Gain Step (gcvst) 1/3 1, 1/3 Yes
Gain Extended (gcext) off off, on Yes
Shutter Mode (ssm) angle speed, angle, cls, slow, off Yes
Shutter Value (ssv) 180.00° 11.25°-360° (15 steps) Yes
Shutter Step (ssvst) --- 3, 4 No (disabled)
AE Shift (aesv) 0 -2.0 to +2.0 (17 steps) Yes

ND Filter

Setting Current Options Enabled
ND Value (ndv) 2 stops 0, 2, 4, 6, 8, 10 Yes
ND Extended (ndext) on off, on Yes

White Balance

Setting Current Options Enabled
WB Mode (wbm) user1 awb, seta, setb, daylight, tungsten, user1-5 Yes
WB Kelvin (wbvk) 4760K 2000K-15000K (88 steps) Yes
WB Color Comp (wbvc) -2 -20 to +20 (41 steps) Yes

Focus

Setting Current Options Enabled
AF Mode (afm) oneshot oneshot, afboostedmf, continuous No
AF Position (fpos) selectable selectable, center No
Face Detection (fdat) off off, on Yes
Face AF (faf) only priority, only No
Focus Speed (fsv) --- +2 to -7 (10 steps) No
Focus Guide (fguide) on off, on Yes

Authentication

Login

GET /api/acnt/login

Returns: {"res":"ok"} or {"res":"errsession"} (another client connected)

Important: Only ONE client can be connected at a time. The ESP32 will be the sole client.

Get Device Info

GET /api/sys/getdevinfo

Returns: modelName, manufacturer, serialNum, lang, mode, productId

Status Polling

Get Current Properties

GET /api/cam/getcurprop?seq={N}
  • Poll this endpoint every ~1 second
  • seq starts at 0, camera returns next sequence number
  • Returns JSON with all current camera state

Response Properties:

Property Description Values
res Result ok, busy, errsession
seq Next sequence number integer
mode Camera mode ctrl, nonctrl, ctrlnonlv
rec Recording status stby, rec, sf_stby, sf_rec, frm_stby, frm_rec, int_stby, int_rec, pre_rec, pre_rec_stby, pre_rec_rec
extrec External recording off, stby, rec
contrec Continuous recording off, stby, rec
tc Timecode string HH:MM:SS:FF
recfmt Recording format mp4, xf-avc, raw, non
camid Camera ID string string
msg Warning/error message string

Nested Status Objects:

Object Contents
Opower Battery: Obatt.percent, Obatt.rtime
Omedia Cards: Ocfa, Osda, Osdb with state, rtime
Owbinfo White balance mode, kelvin, CC values
Ondinfo ND filter value, extended range
Oirisinfo Iris mode, step, value
Oisogaininfo ISO/Gain mode, step, value, extended range
Oshutterinfo Shutter mode, step, value
Oaesinfo AE shift value
Ofocusinfo AF mode, position, face detection, speed
Olensinfo Lens name, type
Opz Power zoom step

Recording Control

Toggle Recording

GET /api/cam/rec?cmd=trig

Starts recording if stopped, stops if recording.

Switch Recording Slot

GET /api/cam/rec?cmd=slot

Switches between SD card slots.

Clip Markers

Mark Clip OK

GET /api/cam/markclip?type=ok

Mark Clip Check

GET /api/cam/markclip?type=check

Mark Shot 1

GET /api/cam/markclip?type=shot1

White Balance

Set White Balance Mode

GET /api/cam/setprop?wbm={mode}
Mode Description
awb Auto White Balance
seta Preset A
setb Preset B
daylight Daylight (~5600K)
tungsten Tungsten (~3200K)
user1 User Preset 1

AWB Hold (Lock current AWB)

GET /api/cam/cmdwb?awbhold=trig

Execute Set A/B (capture white balance)

GET /api/cam/cmdwb?wbset=a
GET /api/cam/cmdwb?wbset=b

ND Filter

Adjust ND Filter

GET /api/cam/drivelens?nd=plus
GET /api/cam/drivelens?nd=minus

Iris / Aperture

Adjust Iris

GET /api/cam/drivelens?iris=plus
GET /api/cam/drivelens?iris=minus

Push Auto Iris (momentary auto exposure)

GET /api/cam/drivelens?ai=push

ISO / Gain

Adjust ISO

GET /api/cam/drivelens?iso=plus
GET /api/cam/drivelens?iso=minus

Adjust Gain

GET /api/cam/drivelens?gain=plus
GET /api/cam/drivelens?gain=minus

Shutter

Adjust Shutter

GET /api/cam/drivelens?shutter=plus
GET /api/cam/drivelens?shutter=minus

AE Shift

Adjust AE Shift

GET /api/cam/drivelens?aes=plus
GET /api/cam/drivelens?aes=minus

Focus Control

One-Shot AF

GET /api/cam/drivelens?focus=oneshotaf

AF Lock

GET /api/cam/drivelens?focus=aflock

Face/Subject Tracking AF

GET /api/cam/drivelens?focus=track

Cancel Tracking

GET /api/cam/drivelens?focus=trackcancel

Manual Focus Adjustment

For continuous focus movement (hold button):

GET /api/cam/drivelens?fl=near1start   # Start slow near
GET /api/cam/drivelens?fl=near2start   # Start medium near
GET /api/cam/drivelens?fl=near3start   # Start fast near
GET /api/cam/drivelens?fl=far1start    # Start slow far
GET /api/cam/drivelens?fl=far2start    # Start medium far
GET /api/cam/drivelens?fl=far3start    # Start fast far
GET /api/cam/drivelens?fl=near1stop    # Stop movement

For single-step focus (tap):

GET /api/cam/drivelens?fl=near1   # Step slow near
GET /api/cam/drivelens?fl=near2   # Step medium near
GET /api/cam/drivelens?fl=near3   # Step fast near
GET /api/cam/drivelens?fl=far1    # Step slow far
GET /api/cam/drivelens?fl=far2    # Step medium far
GET /api/cam/drivelens?fl=far3    # Step fast far

Status Property Details

Recording Status (rec)

Value Description
stby Standby (ready to record)
rec Recording
sf_stby Slow/Fast standby
sf_rec Slow/Fast recording
frm_stby Frame recording standby
frm_rec Frame recording
int_stby Interval recording standby
int_rec Interval recording
pre_rec Pre-recording enabled
pre_rec_stby Pre-recording standby
pre_rec_rec Pre-recording active

White Balance Info (Owbinfo)

{
  "Omode": {"pv": "awb", "en": 1},
  "Oawb": {"kelvinvalue": "5500", "ccvalue": "0", "en": 1},
  "Oseta": {"Ovalue": {...}, "Osts": {"pv": "comp"}},
  "Osetb": {"Ovalue": {...}, "Osts": {"pv": "comp"}},
  "Odaylight": {"kelvinvalue": "5600", "ccvalue": "0"},
  "Otungsten": {"kelvinvalue": "3200", "ccvalue": "0"},
  "Ouser1": {"kelvinvalue": "5500", "ccvalue": "0"},
  "Oawbhold": {"pv": "off", "en": 1}
}

Iris Info (Oirisinfo)

{
  "Omode": {"pv": "maniris", "en": 1},     // maniris or autoiris
  "Ostep": {"pv": "1/3", "en": 1},         // 1/2, 1/3, fine
  "Ovalue": {"pv": "F2.8", "en": 1},       // F-stop or T-stop
  "Odisp": {"pv": "F", "en": 1},           // Display type F or T
  "Opushai": {"pv": "stop", "en": 1}       // Push auto iris state
}

ISO/Gain Info (Oisogaininfo)

{
  "Omode": {"pv": "iso", "en": 1},         // iso or gain
  "Ostep": {"pv": "1/3", "en": 1},         // 1/3, normal, fine
  "Ovalue": {"pv": "800", "en": 1},        // ISO value or dB
  "Oextrange": {"pv": "off", "en": 1}      // Extended range
}

Shutter Info (Oshutterinfo)

{
  "Omode": {"pv": "speed", "en": 1},       // speed, angle, cls, slow, off
  "Ostep": {"pv": "1/3", "en": 1},
  "Ovalue": {"pv": "1/50", "en": 1}        // Speed or angle value
}

ND Filter Info (Ondinfo)

{
  "Ovalue": {"pv": "1/4", "en": 1},        // off, 1/4, 1/16, 1/64, etc.
  "Oextrange": {"pv": "off", "en": 1}      // Extended range
}

Focus Info (Ofocusinfo)

{
  "Oafmode": {"pv": "continuous", "en": 1},  // oneshot, continuous
  "Oafpos": {"pv": "center", "en": 1},       // center, selectable
  "Ofacedat": {"pv": "on", "en": 1},         // Face detection
  "Ofaceaf": {"pv": "priority", "en": 1},    // priority, only
  "Oafspeed": {"pv": "0", "en": 1},          // AF speed 0-7
  "Ofguide": {"pv": "on", "en": 1},          // Focus guide
  "afctrlen": 1,                              // AF control enabled
  "trctrlen": 0,                              // Tracking control
  "tcctrlen": 0,                              // Track cancel control
  "Ofctrl": {"pv": "", "en": 1}              // Focus control state
}

Media Info (Omedia)

{
  "Ocfa": {"state": "n", "rtime": -1},       // CFast: n=none, sel=selected
  "Osda": {"state": "sel", "rtime": 120},    // SD A: minutes remaining
  "Osdb": {"state": "n", "rtime": -1}        // SD B
}

Battery Info (Opower)

{
  "Obatt": {"percent": "75", "rtime": "120"}  // Battery % and minutes
}

Common Property Patterns

All status values follow a pattern:

{"pv": "value", "en": 1}
  • pv = present value
  • en = enabled (1) or disabled (0)

When en is 0, the control is locked/unavailable.

Error Responses

Response Meaning
{"res":"ok"} Success
{"res":"busy"} Camera busy, retry
{"res":"errsession"} Another client connected
{"res":"failparam"} Invalid parameter
{"res":"failid"} Invalid ID
{"res":"rootredirect"} Redirect to root

Live View Stream

The live view is MJPEG served from:

GET /lv/lv.mjpg

Requires authenticated session.

Reading Individual Properties (VERIFIED WORKING)

The getcurprop endpoint may return "busy", but individual properties work reliably:

GET /api/cam/getprop?r={property_name}

Working Property Names

Property Description
wbm White balance mode
wbvk White balance kelvin
wbvc White balance color compensation
av Aperture value
avst Aperture step
atype Aperture display type (F/T)
am Iris mode (auto/manual)
gcm ISO/Gain mode
gcv ISO/Gain value
gcvst ISO/Gain step
gcext ISO/Gain extended range
ssm Shutter mode
ssv Shutter value
ssvst Shutter step
aesv AE shift value
ndv ND filter value
ndext ND extended range
afm AF mode
fpos AF position
fdat Face detection
faf Face AF mode
fsv Focus speed
fguide Focus guide

Response Format

{
  "res": "ok",
  "O{property}": {
    "pv": "current_value",     // Present value
    "en": 1,                   // Enabled (1) or disabled (0)
    "rvn": 10,                 // Number of options
    "rv": ["opt1", "opt2"]     // Array of valid options
  }
}

Live View

Start Live View

GET /api/cam/lv?cmd=start&sz=l
  • sz = size: l (large), s (small)

Stop Live View

GET /api/cam/lv?cmd=stop

Get Live View Frame (JPEG)

GET /api/cam/lvgetimg?d={timestamp}
  • Poll every 100ms for smooth video
  • Returns JPEG image

Touch to Focus (during live view)

GET /api/cam/drivelens?xcoord={X}&ycoord={Y}
  • Coordinates relative to center of frame
  • X range: -543 to 543 (DCI) or -511 to 511 (HD)
  • Y range: -287 to 287

Usage Notes

  1. Single Client: Only one Browser Remote session at a time
  2. Polling: Use getcurprop for status polling (returns everything including rec field)
  3. Authentication: Use HTTP Basic Auth with every request
  4. Cookies: See CRITICAL COOKIE REQUIREMENTS section below - this is essential!
  5. Live View: Must start LV session for getcurprop to return data
  6. Poll Interval: Camera expects ~1 second between status polls

CRITICAL: Cookie Requirements (The "Busy" Fix)

The Problem We Solved

For weeks, getcurprop returned {"res":"busy"} 90%+ of the time when accessed from ESP32 or curl, but worked perfectly in the browser. This made external recording detection impossible.

Root Cause: The camera requires 4 specific cookies to return full data from getcurprop. The browser sent all 4, but we were only sending 2.

Required Cookies

Cookie Value Source Purpose
acid Session ID (e.g., 6f55) Set by camera on login Session identifier
authlevel full Set by camera on login Authorization level
brlang 0 Must add manually Browser language setting
productId VNCX02 Must add manually Camera product identifier

The Fix

After login, append the missing cookies:

// After successful login
strcat(camera_cookies, "; brlang=0; productId=VNCX02");

How We Discovered This

  1. Camera on main network (10.10.11.36) - could test with curl directly
  2. Used curl with only acid + authlevel cookies → {"res":"busy"}
  3. Checked browser DevTools → saw 4 cookies being sent
  4. Added all 4 cookies to curl → FULL DATA RETURNED!

Working curl command:

curl -s -b "acid=6f55; authlevel=full; brlang=0; productId=VNCX02" \
  "http://10.10.11.36/api/cam/getcurprop?seq=1"

Response with correct cookies:

{
  "res": "ok",
  "seq": 3,
  "com": 6,
  "mode": "ctrl",
  "camid": "C200    ",
  "rec": "stby",           // ← Recording status!
  "tc": "15:32:00.12",     // ← Timecode!
  "Opower": {"Obatt": {"percent": "25", "rtime": "35"}},
  "Omedia": {...},
  "Owbinfo": {...},
  // ... full camera state
}

Where Does productId Come From?

The productId cookie value (VNCX02) comes from the camera's URL path:

  • Camera serves pages from: /wpd/VNCX02/...
  • This is the Canon C200's internal product identifier
  • It's embedded in the URL when you access Browser Remote

Browser Cookie Analysis (Chrome DevTools)

When examining Chrome's Network tab → Cookies:

Cookie Value Domain Path
acid 6f55 camera IP /
authlevel full camera IP /
brlang 0 camera IP /
productId VNCX02 camera IP /

The browser JavaScript sets brlang and productId cookies automatically. We need to set them manually.

ESP32 Recording Detection

Current State (WORKING - 2026-02-12)

  • ✅ Dashboard-triggered recording - Works perfectly
  • ✅ Physical button detection - NOW WORKS with cookie fix!
  • ✅ rec field available - Returns "stby" or "rec"
  • ✅ Timecode available - Returns "HH:MM:SS.FF"

Network Architecture

ESP32 (1.1.1.1) <--Ethernet--> Camera (1.1.1.2)
       |
       WiFi
       |
   Dashboard/Companion
  • ESP32 Ethernet IP: 1.1.1.1
  • Camera Ethernet IP: 1.1.1.2
  • Direct Ethernet connection between ESP32 and camera
  • ESP32 exposes API over WiFi for external control

Recording State Detection

The rec field in getcurprop response indicates recording state:

rec Value Meaning
stby Standby (not recording)
rec Recording
sf_stby Slow/Fast standby
sf_rec Slow/Fast recording
frm_stby Frame recording standby
frm_rec Frame recording
int_stby Interval recording standby
int_rec Interval recording

ESP32 Detection Logic

cJSON *rec = cJSON_GetObjectItem(json, "rec");
if (rec && cJSON_IsString(rec)) {
    if (strcmp(rec->valuestring, "rec") == 0) {
        camera_recording = true;
    } else if (strcmp(rec->valuestring, "stby") == 0) {
        camera_recording = false;
    }
}

Full getcurprop Response (When Recording)

{
  "res": "ok",
  "seq": 1,
  "com": 1,
  "mode": "ctrl",
  "camid": "C200    ",
  "rec": "rec",
  "extrec": "off",
  "tc": "15:32:20.23",
  "lvactfarea": "hd_80x80",
  "Opower": {
    "Obatt": {"percent": "25", "rtime": "32"}
  },
  "Omedia": {
    "Ocfa": {"state": "n", "rtime": -1},
    "Osda": {"state": "sel", "rtime": 93},
    "Osdb": {"state": "n", "rtime": -1}
  },
  "Owbinfo": {
    "Omode": {"pv": "user1", "en": 1},
    "Oawb": {"kelvinvalue": "non", "ccvalue": "non", "en": 1},
    "Oseta": {"Ovalue": {"kelvinvalue": "5600", "ccvalue": "0", "en": 1}},
    "Osetb": {"Ovalue": {"kelvinvalue": "5600", "ccvalue": "0", "en": 1}},
    "Odaylight": {"kelvinvalue": "5600", "ccvalue": "0", "en": 1},
    "Otungsten": {"kelvinvalue": "3200", "ccvalue": "0", "en": 1},
    "Ouser1": {"kelvinvalue": "4760", "ccvalue": "-2", "en": 1},
    "Oawbhold": {"pv": "off", "en": 1}
  },
  "Ondinfo": {
    "Ovalue": {"pv": "0", "en": 1},
    "Oextrange": {"pv": "on", "en": 1}
  },
  "Oirisinfo": {
    "Omode": {"pv": "---", "en": 0},
    "Ostep": {"pv": "3fine", "en": 1},
    "Ovalue": {"pv": "F2.2", "en": 1},
    "Opushai": {"pv": "stop", "en": 1}
  }
  // ... additional fields truncated
}

Timecode Behavior

  • When recording: tc field shows running timecode (e.g., "15:32:20.23")
  • When stopped: tc field still present with last recorded timecode
  • Format: HH:MM:SS.FF (hours:minutes:seconds.frames)

Session Initialization Sequence

Complete Login Flow (ESP32)

  1. Login to camera

    GET /api/acnt/login

    Response: {"res":"ok"} Camera sets: acid=XXXX; authlevel=full

  2. Add required cookies manually

    strcat(camera_cookies, "; brlang=0; productId=VNCX02");

    Full cookie string: acid=XXXX; authlevel=full; brlang=0; productId=VNCX02

  3. Start Live View session

    GET /api/cam/lv?cmd=start&sz=s

    Response: {"res":"ok"} This enables getcurprop to return data.

  4. Poll for status

    GET /api/cam/getcurprop?seq=0

    Now returns full camera state including rec field!

Why Live View is Required

Without an active Live View session, getcurprop returns minimal data or {"res":"busy"}. The camera needs to know a client is actively viewing before it reports full status.

Investigation History

What We Tried (Before Cookie Discovery)

Approach Result Why It Failed
getcurprop?seq=N {"res":"busy"} Missing cookies
getprop?r=rec {"res":"failparam"} "rec" is not a property, it's a status field
Start LV first Still busy Missing cookies
Fetch HTML first Still busy Missing cookies
Different seq values Still busy Missing cookies
Longer delays Still busy Missing cookies
Timecode detection Worked but not ideal tc present even when not recording

The Breakthrough (2026-02-12)

  1. Moved camera from ESP32 Ethernet to main network (10.10.11.36)
  2. Used curl to test directly (no ESP32 in the middle)
  3. Compared browser's cookies to our cookies
  4. Found browser sends 4 cookies, we sent 2
  5. Added missing brlang=0 and productId=VNCX02
  6. getcurprop now returns full data including rec field!

ESP32 Implementation Details

Cookie Storage

// Session cookies from camera login
static char camera_cookies[256] = "";

Login Function (with Cookie Fix)

static esp_err_t camera_login(void)
{
    // Clear old cookies before login
    camera_cookies[0] = 0;

    char response[512];
    esp_err_t err = camera_request("/api/acnt/login", response, sizeof(response));

    if (err == ESP_OK) {
        cJSON *json = cJSON_Parse(response);
        if (json) {
            cJSON *res = cJSON_GetObjectItem(json, "res");
            if (res && strcmp(res->valuestring, "ok") == 0) {
                camera_logged_in = true;
                cJSON_Delete(json);

                // CRITICAL: Add required cookies for getcurprop to work
                // Without these, camera returns {"res":"busy"}
                if (strlen(camera_cookies) + 30 < sizeof(camera_cookies)) {
                    strcat(camera_cookies, "; brlang=0; productId=VNCX02");
                }

                // Start live view session
                char lv_response[256];
                camera_request("/api/cam/lv?cmd=start&sz=s", lv_response, sizeof(lv_response));

                return ESP_OK;
            }
        }
    }
    return ESP_FAIL;
}

HTTP Request with Cookies

// Add session cookies if we have them
if (strlen(camera_cookies) > 0) {
    esp_http_client_set_header(client, "Cookie", camera_cookies);
}

Recording Detection Function

static void update_recording_state(void)
{
    if (!camera_logged_in) return;

    char path[64];
    char response[1024];

    snprintf(path, sizeof(path), "/api/cam/getcurprop?seq=%d", getcurprop_seq);
    esp_err_t err = camera_request(path, response, sizeof(response));

    if (err != ESP_OK) return;

    cJSON *json = cJSON_Parse(response);
    if (!json) return;

    // Update seq from response
    cJSON *seq = cJSON_GetObjectItem(json, "seq");
    if (seq && cJSON_IsNumber(seq)) {
        getcurprop_seq = seq->valueint;
    }

    // Check for session error
    cJSON *res = cJSON_GetObjectItem(json, "res");
    if (res && cJSON_IsString(res) && strcmp(res->valuestring, "errsession") == 0) {
        camera_logged_in = false;
        cJSON_Delete(json);
        return;
    }

    // Check "rec" field for recording state
    cJSON *rec = cJSON_GetObjectItem(json, "rec");
    bool was_recording = camera_recording;

    if (rec && cJSON_IsString(rec)) {
        if (strcmp(rec->valuestring, "rec") == 0) {
            camera_recording = true;
        } else if (strcmp(rec->valuestring, "stby") == 0) {
            camera_recording = false;
        }
    }

    cJSON_Delete(json);
}

ESP32 API Endpoints

Status Endpoint

GET /api/status

Response:

{
  "wifi_connected": true,
  "eth_connected": true,
  "camera_connected": true,
  "is_recording": false,
  "wifi_ip": "10.10.11.229",
  "eth_ip": "1.1.1.1",
  "camera_ip": "1.1.1.2"
}

Proxy Endpoint (for Testing)

GET /api/proxy/{camera_path}

Forwards requests to camera and returns response. Useful for testing camera APIs from a computer.

Example:

curl "http://10.10.11.229/api/proxy/api/cam/getcurprop?seq=1"

Troubleshooting

getcurprop Returns {"res":"busy"}

Cause: Missing cookies

Fix: Ensure all 4 cookies are sent:

  • acid (from login)
  • authlevel (from login)
  • brlang=0 (add manually)
  • productId=VNCX02 (add manually)

getcurprop Returns {"res":"errsession"}

Cause: Another client connected (browser, etc.)

Fix: Close other Browser Remote sessions. Only one client at a time.

Recording State Not Updating

Causes:

  1. Live View not started
  2. Cookies missing
  3. Session expired

Fix: Re-login and ensure LV session is started.

Camera Returns 401 Unauthorized

Cause: Basic Auth credentials wrong

Fix: Check username/password (default: admin/admin)

Key Learnings

  1. Cookies are CRITICAL - The camera requires specific cookies beyond just session auth
  2. Browser DevTools reveals all - Compare what browser sends vs. what you send
  3. Live View enables status - Must start LV session for full getcurprop data
  4. rec is NOT a property - It's a status field in getcurprop, not queryable via getprop
  5. Product ID from URL - The VNCX02 value comes from the camera's URL path structure