Jetson Linux API Reference32.5 Release |
The video_encode sample application demonstrates how to encode H.264/H.265 video streams.
The application YUV reads input buffers from a file, performs H.264 or H.265 video encoding, and saves the encoded bitstream to an elementary .264
or .265
file.
The application runs on file source simulated input buffers, and so does not require a camera.
Supported video formats are:
$ cd /usr/src/jetson_multimedia_api/samples/01_video_encode $ make
$ video_encode <in-file> <in-width> <in-height> <encoder-type> <out-file> [OPTIONS]
Enter:
$ ./video_encode --help
$ ./video_encode ../../data/Video/sample_outdoor_car_1080p_10fps.yuv 1920 1080 H264 sample_outdoor_car_1080p_10fps.h264
The following diagram shows the flow through this sample.
The sample uses the following key structures and classes.
Element | Description |
---|---|
NvVideoEncoder | Contains all video encoding-related elements and functions. |
Enc_pollthread | A pointer to the thread handler for the encoding capture loop. |
The NvVideoEncoder class packages all video encoding-related elements and functions. Key members used in the sample are:
Member | Description |
---|---|
output_plane | Specifies the V4L2 output plane. |
capture_plane | Specifies the V4L2 capture plane. |
createVideoEncoder | Static function to create video encode object. |
subscribeEvent | Subscribe event. |
setOutputPlaneFormat | Set output plane format. |
setCapturePlaneFormat | Set capture plane format. |
dqEvent | Dqueue the event which reports by the V4L2 device. |
isInError | Checks if under error state. |
Class NvVideoEncoder contains two key elements: output_plane
and capture_plane
. These objects are derived from class type NvV4l2ElementPlane. The sample uses the following key members:
Element | Description |
---|---|
setupPlane | Sets up the plane of V4L2 element. |
deinitPlane | Destroys the plane of the V4L2 element. |
setStreamStatus | Starts/stops the stream. |
setDQThreadCallback | Sets the callback function of the dqueue buffer thread. |
startDQThread | Starts the thread of the dqueue buffer. |
stopDQThread | Stops the thread of the dqueue buffer. |
qBuffer | Queues the V4L2 buffer. |
dqBuffer | Dequeues the V4L2 buffer. |
getNumBuffers | Gets the number of V4L2 buffers. |
getNumQueuedBuffers | Gets the number of buffers currently queued on the plane. |