The multivideo_encode sample application demonstrates how to encode multiple video streams in parallel.
The application reads input buffers from a YUV file, performs H.264, H.265, VP8 or VP9 video encoding, and saves the encoded bitstream to an elementary file. It can do this in parallel for multiple inputs and corresponding outputs.
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/15_multivideo_encode $ make
$ multivideo_encode num_files <number_of_files> <in-file1> <in-width1> <in-height1> <encoder-type1> <out-file1> <in-file2> <in-width2> <in-height2> <encoder-type2> <out-file2> [OPTIONS]
Enter:
$ ./multivideo_encode --help
$ ./multivideo_encode num_files 2 ../../data/Video/sample_outdoor_car_1080p_10fps.yuv 1920 1080 H264 sample_outdoor_car_1080p_10fps.h264 ../../data/Video/sample_outdoor_car_1080p_10fps.yuv 1920 1080 H264 sample_outdoor_car_1080p_10fps_second.h264
The following diagram shows the flow through this sample.
For the Output Plane the application supports MMAP, DMABUF, and USRPTR memory types. For the Capture Plane, it supports MMAP memory type.
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 | Subscribes to event. |
setOutputPlaneFormat | Set output plane format. |
setCapturePlaneFormat | Set capture plane format. |
dqEvent | Dequeues the event reported 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. |