Step 2: Write and examine the code - Amazon Kinesis Video Streams
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Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Step 2: Write and examine the code

In this section, you examine the code of the sample application KvsVideoOnlyStreamingSample.c in the samples folder of the https://github.com/awslabs/amazon-kinesis-video-streams-producer-c repo on GitHub. You downloaded this code in the previous step. This sample demonstrates how to use the C Producer Library to send H.264-encoded video frames inside the folder samples/h264SampleFrames to your Kinesis video stream.

This sample application has three sections:

  • Initialization and configuration:

    • Initializing and configuring the platform-specific media pipeline.

    • Initializing and configuring KinesisVideoClient and KinesisVideoStream for the pipeline, setting the callbacks, integrating scenario-specific authentication, extracting and submitting codec private data, and getting the stream to READY state.

  • Main loop:

    • Getting the frame from the media pipeline with the timestamps and flags.

    • Submitting the frame to the KinesisVideoStream.

  • Teardown:

    • Stopping (sync) KinesisVideoStream, freeing KinesisVideoStream, freeing KinesisVideoClient.

This sample application completes the following tasks:

  • Call the createDefaultDeviceInfo API to create the deviceInfo object that contains information about the device or storage configuration.

    
// default storage size is 128MB. Use setDeviceInfoStorageSize after create to change storage size.
CHK_STATUS(createDefaultDeviceInfo(&pDeviceInfo));
// adjust members of pDeviceInfo here if needed
    pDeviceInfo->clientInfo.loggerLogLevel = LOG_LEVEL_DEBUG;

  • Call the createRealtimeVideoStreamInfoProvider API to create the StreamInfo object.

    
CHK_STATUS(createRealtimeVideoStreamInfoProvider(streamName, DEFAULT_RETENTION_PERIOD, DEFAULT_BUFFER_DURATION, &pStreamInfo));
// adjust members of pStreamInfo here if needed

  • Call the createDefaultCallbacksProviderWithAwsCredentials API to create the default callbacks provider based on static Amazon credentials.

    
CHK_STATUS(createDefaultCallbacksProviderWithAwsCredentials(accessKey,
                                                                secretKey,
                                                                sessionToken,
                                                                MAX_UINT64,
                                                                region,
                                                                cacertPath,
                                                                NULL,
                                                                NULL,
                                                                FALSE,
                                                                &pClientCallbacks));

  • Call the createKinesisVideoClient API to create the KinesisVideoClient object that contains information about your device storage and maintains callbacks to report on Kinesis Video Streams events.

    
CHK_STATUS(createKinesisVideoClient(pDeviceInfo, pClientCallbacks, &clientHandle));

  • Call the createKinesisVideoStreamSync API to create the KinesisVideoStream object.

    
CHK_STATUS(createKinesisVideoStreamSync(clientHandle, pStreamInfo, &streamHandle));

  • Set up a sample frame and call PutKinesisVideoFrame API to send that frame to the KinesisVideoStream object.

    
 // setup sample frame
    MEMSET(frameBuffer, 0x00, frameSize);
    frame.frameData = frameBuffer;
    frame.version = FRAME_CURRENT_VERSION;
    frame.trackId = DEFAULT_VIDEO_TRACK_ID;
    frame.duration = HUNDREDS_OF_NANOS_IN_A_SECOND / DEFAULT_FPS_VALUE;
    frame.decodingTs = defaultGetTime(); // current time
    frame.presentationTs = frame.decodingTs;

    while(defaultGetTime() > streamStopTime) {
        frame.index = frameIndex;
        frame.flags = fileIndex % DEFAULT_KEY_FRAME_INTERVAL == 0 ? FRAME_FLAG_KEY_FRAME : FRAME_FLAG_NONE;
        frame.size = SIZEOF(frameBuffer);

        CHK_STATUS(readFrameData(&frame, frameFilePath));

        CHK_STATUS(putKinesisVideoFrame(streamHandle, &frame));
        defaultThreadSleep(frame.duration);

        frame.decodingTs += frame.duration;
        frame.presentationTs = frame.decodingTs;
        frameIndex++;
        fileIndex++;
        fileIndex = fileIndex % NUMBER_OF_FRAME_FILES;
    }

  • Teardown:

    
CHK_STATUS(stopKinesisVideoStreamSync(streamHandle));
CHK_STATUS(freeKinesisVideoStream(&streamHandle));
CHK_STATUS(freeKinesisVideoClient(&clientHandle));

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Step 3: Run and verify the code