the 00_video_decode application only decode one frame after ffmpeg

I use ffmpeg to read rtsp url of one camera,then use av_read_frame to get one frame.
And now i want to put the frame data to NvVideoDecoder to decode.But i do not know how to decode.
I want to know, ret = ctx.dec->output_plane.setupPlane(V4L2_MEMORY_MMAP, 10, true, false);why the second parameter is 10,not other numbers?
pthread_create(&ctx.dec_capture_loop, NULL, dec_capture_loop_fcn, &ctx);this thread only one,or every frame should create one this thread?
If you know,please tell me,thank you!

Please refer to tegra_multimedia_api\samples\00_video_decode
There are two modes of feeding stream:

static int
read_decoder_input_nalu(ifstream * stream, NvBuffer * buffer,
        char *parse_buffer, streamsize parse_buffer_size, context_t * ctx);
static int
read_decoder_input_chunk(ifstream * stream, NvBuffer * buffer);

You may try other values.

Only create once.

Dear DaneLLL,
Thany you very much for your help!