Deprecation warning

Please note that this is outdated documentation for an older release of the Scandit Barcode Scanner SDK.

We are deprecating the 5.x API on all platforms (except Linux). Release 5.19 in April 2021 will be our final. Applications running 5.x will continue to work, and we will continue to release critical bug fixes and security patches only, for one year. We encourage you to migrate to 6.x and take advantage of our latest / advanced features and improved performance.

You'll find the updated documentation at: Data Capture SDK Documentation for Android


MatrixScan Sample Without User Interface

This example uses the Scandit SDK to run MatrixScan (Tracking) using frames from a camera.

This demo is currently limited to GNU/Linux systems with a Video4Linux 2 camera.

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
// Please insert your app key here:
// Please insert the desired default camera resolution here:
static volatile ScBool process_frames;
static void catch_exit(int signo) {
printf("SIGINT received.\n");
process_frames = SC_FALSE;
static void print_all_discrete_resolutions(const ScCamera *cam) {
printf("This camera uses discrete resolutions:\n");
ScSize resolution_array[20];
ScFramerate framerate_array[10];
const int32_t resolution_count = sc_camera_query_supported_resolutions(cam, &resolution_array[0], 20);
for (int32_t i = 0; i < resolution_count; i++) {
const int32_t framerate_count = sc_camera_query_supported_framerates(cam, resolution_array[i], framerate_array, 10);
for (int32_t j = 0; j < framerate_count; j++) {
const float fps = sc_framerate_get_fps(&framerate_array[j]);
printf("\t%u:%u @ %.2f FPS\n", resolution_array[i].width, resolution_array[i].height, fps);
void on_appeared(const ScTrackedObject* obj, void *user_data) {
// This callback gets emitted when a new object appears in the camera feed.
// Use this callback to start to draw a location.
const uint32_t id = sc_tracked_object_get_id(obj);
const ScBarcode* barcode = (const ScBarcode*) obj;
if (sc_barcode_is_recognized(barcode)) {
printf("Barcode #%u: %s '%s' appeared.\n", id, sc_symbology_to_string(sc_barcode_get_symbology(barcode)), data.str);
} else {
printf("Object #%u appeared.\n", id);
void on_updated(const ScTrackedObject* obj, void *user_data) {
// This callback gets emitted when an existing object has been found
// in a new location.
const uint32_t id = sc_tracked_object_get_id(obj);
const ScBarcode* barcode = (const ScBarcode*) obj;
if (sc_barcode_is_recognized(barcode)) {
printf("Barcode #%u: %s '%s' was updated.\n", id, sc_symbology_to_string(sc_barcode_get_symbology(barcode)), data.str);
} else {
printf("Object #%u was updated.\n", id);
void on_lost(ScTrackedObjectType type, uint32_t tracking_id, void *user_data) {
// This callback gets emitted when an object was no longer found.
// Use this callback to disable your drawing task.
// Be aware that it also gets triggered on objects that have not been recognized.
printf("Object #%u was lost.\n", tracking_id);
void on_predicted(uint32_t tracking_id, ScQuadrilateral quadrilateral,
float dt, void *user_data) {
// Use this callback to update the drawing location of an object. Predictions
// are made even if the object was not found for a certain time.
int main(int argc, const char *argv[]) {
// Handle ctrl+c events.
if (signal(SIGINT, catch_exit) == SIG_ERR) {
printf("Could not set up signal handler.\n");
return -1;
// Create the camera object.
ScCamera *camera = NULL;
if (argc > 1) {
// Setup the camera from a device path. E.g. /dev/video1
// We use 4 image buffers.
camera = sc_camera_new_from_path(argv[1], 4);
} else {
// When no parameters are given, the camera is automatically detected.
camera = sc_camera_new();
if (camera == NULL) {
printf("No camera available.\n");
return -1;
uint32_t resolution_width = DEFAULT_RESOLUTION_WIDTH;
uint32_t resolution_height = DEFAULT_RESOLUTION_HEIGHT;
// Read the desired resolution form the command line.
if (argc == 4) {
resolution_width = atoi(argv[2]);
resolution_height = atoi(argv[3]);
// Get the supported resolutions and check
// if the desired resolution is supported
ScBool supported = SC_FALSE;
const uint32_t resolutions_size = 30;
ScSize resolutions[resolutions_size];
int32_t resolutions_found;
switch (resm) {
// The camera supports a small set of predefined resolutions
resolutions_found = sc_camera_query_supported_resolutions(camera, &resolutions[0], resolutions_size);
if (!resolutions_found) {
printf("There was an error getting the discrete resolution capabilities of the camera.\n");
return -1;
for (int i = 0; i < resolutions_found; i++) {
if (resolutions[i].width == resolution_width &&
resolutions[i].height == resolution_height) {
supported = SC_TRUE;
// The camera supports a wide range of resolutions that are
// generated step-wise. Refer to documentation for further
// explanation.
printf("There was an error getting the stepwise resolution capabilities of the camera.\n");
return -1;
printf("This camera uses step-wise resolutions:\n");
printf("\tx: %u:%u:%u\n", swres.min_width, swres.step_width, swres.max_width);
printf("\ty: %u:%u:%u\n", swres.min_height, swres.step_height, swres.max_height);
if (swres.min_width <= resolution_width &&
resolution_width <= swres.max_width &&
swres.min_height <= resolution_height &&
resolution_height <= swres.max_height &&
resolution_width % swres.step_width == 0 &&
resolution_height % swres.step_height == 0) {
supported = SC_TRUE;
printf("Could not get camera resolution mode.\n");
return -1;
// Set the resolution
if (!supported) {
printf("%dx%d is not supported by this camera.\nPlease specify a supported resolution on the command line or in the source code.\n", resolution_width, resolution_height);
return -1;
ScSize desired_resolution;
desired_resolution.width = resolution_width;
desired_resolution.height = resolution_height;
if (!sc_camera_request_resolution(camera, desired_resolution)) {
printf("Setting resolution failed.\n");
return -1;
// Start streaming.
if (!sc_camera_start_stream(camera)) {
printf("Start the camera failed.\n");
return -1;
// Create a recognition context. Files created by the recognition context and the
// attached scanners will be written to this directory. In production environment,
// it should be replaced with writable path which does not get removed between reboots
sc_recognition_context_new(SCANDIT_SDK_LICENSE_KEY, "/tmp", NULL);
if (context == NULL) {
printf("Could not initialize context.\n");
return -1;
// Create barcode scanner with EAN13/UPCA and QR code scanning enabled.
// The default preset is optimized for real-time frame processing using a
// camera.
if (settings == NULL) {
return -1;
// We want to track at most one so that the command line output remains readable.
// In a more realistic MatrixScan scenario this number should be set to the number of
// expected codes that have to be tracked at the same time.
// We disable looking at a default scan area to get a smother MatrixScan experience
// Our camera has no auto-focus.
// Codes are most likely oriented from left to right.
// Only keep codes for one frame and do not accumulate anything.
// Accumulating many codes over a long scan session can slow down the scanning speed significantly.
// Create a barcode scanner for our context and settings.
if (scanner == NULL) {
return -1;
// The scanner is setup asynchronous.
// We could wait here using sc_barcode_scanner_wait_for_setup_completed if needed.
// Setup the object tracker and it's callbacks used for MatrixScan.
// We don't pass custom data to the callbacks in this simple example.
// The tracker is enabled by default.
ScObjectTracker *tracker = sc_object_tracker_new(context, &callbacks, NULL);
// ... but it can be disabled on demand.
//sc_object_tracker_set_enabled(tracker, SC_FALSE);
// Signal a new frame sequence to the context.
// Create an image description that is reused for every frame.
process_frames = SC_TRUE;
while (process_frames) {
// Get the latest camera frame data and description
const uint8_t *image_data = sc_camera_get_frame(camera, image_descr);
if (image_data == NULL) {
printf("Frame access failed. Exiting.\n");
// Process the frame.
ScProcessFrameResult result = sc_recognition_context_process_frame(context, image_descr, image_data);
printf("Processing frame failed with error %d: '%s'\n", result.status,
// Signal the camera that we are done reading the image buffer.
sc_camera_enqueue_frame_data(camera, image_data);
// Signal to the context that the frame sequence is finished.
// Cleanup all objects.