LogoLogo
Buy SoftwareBuy HardwareOpen a ticket
Developer Ecosystem
Developer Ecosystem
  • 🚘Rekor CarCheck®
    • Rekor CarCheck® Overview
    • Countries and Regions Supported
    • Vehicle Characteristics Supported
    • Create an Account
    • Integration
    • Code Samples
    • Web Dashboard
  • ⚙️Vehicle Recognition SDK
    • Vehicle Recognition SDK Overview
    • Countries and Regions Supported
    • Vehicle Characteristics Supported
    • Request a License
    • Installation
      • Windows
      • Ubuntu Linux
    • Vehicle Recognition Image API
      • C++
      • C
      • Samples
    • Vehicle Recognition Stream API
      • C++
      • C
      • Samples
Powered by GitBook
LogoLogo

Platforms

  • Rekor Discover® for Urban Mobility
  • Rekor Command® for Transportation
  • Rekor Scout® for Public Safety

Systems

  • Rekor Edge Flex™ (Classificaiton)
  • Rekor Edge Max™ (Classification)
  • Rekor Edge Pro (ALPR)
  • Rekor Edge Max™ (ALPR)

Developers

  • Vehicle Recognition SDK
  • Rekor CarCheck®
  • Rekor AutoNotice™

Resources

  • About Us
  • Customer Stories
  • Newsroom
  • Help Center

© 2025 Rekor Systems, Inc. All Rights Reserved.

On this page

Was this helpful?

  1. Vehicle Recognition SDK
  2. Vehicle Recognition Stream API

C

PreviousC++NextSamples

Was this helpful?

Typedefs

typedefvoid ALPRSTREAM

void ALPRSTREAM

The instantiated AlprStream object. This is created by the function and should be passed into subsequent functions.

Functions

*alprstream_init(int framequeuesize, int usemotiondetection = 1)

Initializes the ALPRSTREAM instance. Each stream of video should have its own AlprStream instance. This object is threadsafe.

Returnan ALPRSTREAM instance that can be used in future calls. Call once you’re finished with the object. See also

int alprstreamgetqueue_size( *instance)

Check the size of the video buffer

See also

void alprstreamconnectvideostreamurl( *instance, const char *url)

See

void alprstreamdisconnectvideo_stream( *instance)

See

void alprstreamconnectvideo_file( *instance, const char *videofilepath, int64_t videostarttime)

See

Frees memory from an alprstreamprocess_frame() response.

Gets the completed groups from the list and performs vehicle make/model/color/type recognition before returning vehicle results. This is a CPU or GPU intensive operation so it may be best to perform on a separate thread.

  • vehicle_classifier: An initialized instance of the VehicleClassifier that AlprStream will use to perform vehicle recognition

void alprstreamfreeresponse_string(char *response)

Frees a char* response that was provided from a recognition request.

Parameters

  • response: A JSON character string from a previous pop/peek operation

structAlprStreamRecognizedFrameC #include <alprstream_c.h>

Public Members

bool image_available

char *jpeg_bytes

int64_t jpegbytessize

int64_t frameepochtime_ms

int64_t frame_number

char *results_str

structAlprStreamRecognizedBatchC

Public Members

size_t results_size

char *batch_results

void alprstreamdisconnectvideo_file( *instance)

See

int alprstreamvideofile_active( *instance)

See

int alprstreampushframe_encoded( *instance, unsigned char *bytes, long long length, int64_t frameepochtime = -1)

See

int alprstreampushframe( *instance, unsigned char *pixelData, int bytesPerPixel, int imgWidth, int imgHeight, int64_t frameepochtime = -1)

See

*alprstreamprocessframe( *instance, *alpr)

See . Each response must be freed with

void alprstreamfreeframe_response( *response)

void alprstreamfreebatch_response( *response)

Frees memory from an response.

*alprstreamskipframe( *instance, int return_image)

See

*alprstreamprocessbatch( *instance, *alpr)

See

char *alprstreampopcompleted_groups( *instance)

See

Returna JSON-formatted string describing the list of completed group results. Make sure to release the string memory using after using it

char *alprstreampeekactive_groups( *instance)

See

Returna JSON-formatted string describing the list of active group results. Make sure to release the string memory using after using it

char *alprstreampopcompletedgroupsandrecognizevehicle( *instance, VEHICLECLASSIFIER *vehicle_classifier)

Returna JSON-formatted string describing the list of completed group results. Each group result will contain vehicle information as well. Make sure to release the string memory using after using itParameters

void alprstreamcombinegrouping( *instance, *other_stream)

See

void alprstreamsetuuid_format( *instance, const char *format)

See

void alprstreamsetgroup_parameters( *instance, int minplatesto_group, int maxplatesper_group, float min_confidence, int maxdeltatime)

See

void alprstreamsetenv_parameters( *instance, const char *company_id, const char *agent_uid, int camera_id)

See

void alprstreamsetdetectionmaskencoded( *instance, unsigned char *bytes, long long length)

See

void alprstreamsetdetection_mask( *instance, unsigned char *pixelData, int bytesPerPixel, int imgWidth, int imgHeight)

See

void alprstreamsetjpeg_compression( *instance, int compression_level)

See

void alprstreamsetencode_jpeg( *instance, int alwaysreturnjpeg)

See

void alprstreamsetrecord_video( *instance, int enabled, int maxstoragesize_gb, char *rollingdbpath)

See

void alprstream_cleanup( *instance)

Free the memory for the OpenALPR instance created with

See .

**results_array

⚙️
alprstream_init()
ALPRSTREAM
alprstream_cleanup()
alpr::AlprStream::AlprStream()
ALPRSTREAM
alpr::AlprStream::get_queue_size()
ALPRSTREAM
alpr::AlprStream::connect_video_stream_url()
ALPRSTREAM
alpr::AlprStream::disconnect_video_stream()
ALPRSTREAM
alpr::AlprStream::connect_video_file()
ALPRSTREAM
alpr::AlprStream::disconnect_video_file()
ALPRSTREAM
alpr::AlprStream::video_file_active()
ALPRSTREAM
alpr::AlprStream::push_frame()
ALPRSTREAM
alpr::AlprStream::push_frame()
AlprStreamRecognizedFrameC
ALPRSTREAM
OPENALPR
alpr::AlprStream::process_frame()
alprstream_free_frame_response()
AlprStreamRecognizedFrameC
AlprStreamRecognizedBatchC
alprstream_process_batch()
AlprStreamRecognizedFrameC
ALPRSTREAM
alpr::AlprStream::skip_frame()
AlprStreamRecognizedBatchC
ALPRSTREAM
OPENALPR
alpr::AlprStream::process_batch()
ALPRSTREAM
alpr::AlprStream::pop_completed_groups()
alprstream_free_response_string()
ALPRSTREAM
alpr::AlprStream::peek_active_groups()
alprstream_free_response_string()
ALPRSTREAM
alprstream_free_response_string()
ALPRSTREAM
ALPRSTREAM
alpr::AlprStream::combine_grouping()
ALPRSTREAM
alpr::AlprStream::set_uuid_format()
ALPRSTREAM
alpr::AlprStream::set_group_parameters()
ALPRSTREAM
alpr::AlprStream::set_env_parameters()
ALPRSTREAM
alpr::AlprStream::set_detection_mask()
ALPRSTREAM
alpr::AlprStream::set_detection_mask()
ALPRSTREAM
alpr::AlprStream::set_jpeg_compression()
ALPRSTREAM
alpr::AlprStream::set_encode_jpeg()
ALPRSTREAM
alpr::AlprStream::set_record_video()
ALPRSTREAM
alprstream_init()
alpr::RecognizedFrame
AlprStreamRecognizedFrameC