一、导览
本文介绍了使用rk mpp 库的demo 程序，对一帧 nv12的yuv 图像进行jpeg 编码，最后输出jpeg图像的过程。作为学习mpp 入门的教程。
rk mpp 的源码仓库地址是：https://github.com/rockchip-linux/mpp/
参考文档在：https://github.com/rockchip-linux/mpp/blob/develop/doc/Rockchip_Developer_Guide_MPP_CN.md
二、编译程序
下载源码后，mpp 框架是使用CMake 进行编译的，首先需要配置好交叉编译工具，我是在linux 平台，aarch64 架构下使用的，所以编辑 mpp/build/linux/aarch64/arm.linux.cross.cmake
将CMAKE_C_COMPILER、CMAKE_CXX_COMPILER 设置成项目所使用的工具链
然后执行 make-Makefiles.bash ，将自动调用cmake 生成makefile 文件，最后直接make 就能编译整个mpp 以及demo
编译生成的文件如下：
- librockchip_mpp.so:mpp的运行时动态库
- test/* :test 目录下存放所有的demo app
三、执行
首先将librockchip_mpp.so 添加到链接路径，准备好一张yuv图像，以及mpi_enc_test 程序
bash
# 将ov5648.yuv 编码成jpeg图像，-t 表示编码类型为jpeg
root@RK356X:/mnt/nfs/output# ./mpi_enc_test -w 800 -h 600 -t 8 -i ./ov5648.yuv -o tmp.jpegdemo输出的log需要通过 /var/sys/message 查看：
bash
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: cmd parse result:
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: input file name: ./ov5648.yuv
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: output file name: tmp.jpeg
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: width : 800
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: height : 600
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: format : 0
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_utils: type : 8
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: ./mpi_enc_test start
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: jpege default encode only one frame. Use -n [num] for rc case
Dec 9 03:02:08 RK356X user.info mpp[392]: mpp_info: mpp version: unknown mpp version for missing VCS info
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: 0x7fac001e20 encoder test start w 800 h 600 type 8
Dec 9 03:02:08 RK356X user.info mpp[392]: mpp_enc: MPP_ENC_SET_RC_CFG bps 1800000 [112500 : 1912500] fps [30:30] gop 60
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: chn 0 encoded frame 0 size 41650
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: chn 0 encode 1 frames time 11 ms delay 6 ms fps 89.27 bps 9996000
Dec 9 03:02:08 RK356X user.info mpp[392]: mpi_enc_test: ./mpi_enc_test average frame rate 89.27可以看到编码了一帧图像，耗时11ms+6ms
直接运行/mpi_enc_test可以打印help信息：
bash
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: usage: ./mpi_enc_test [options]
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -i input_file input frame file
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -o output_file output encoded bitstream file
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -w width the width of input picture
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -h height the height of input picture
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -hstride hor_stride the horizontal stride of input picture
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -vstride ver_stride the vertical stride of input picture
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -f format the format of input picture
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -t type output stream coding type
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -tsrc source type input file source coding type
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -n max frame number max encoding frame number
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -g gop reference mode gop_mode:gop_len:vi_len
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -rc rate control mode set rc_mode
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -bps bps target:min:max set tareget/min/max bps and rc_mode
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -fps in/output fps set input and output frame rate
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -qc quality control set qp_init/min/max/min_i/max_i
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -s instance_nb number of instances
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -v trace option q - quiet f - show fps
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -l loop count loop encoding times for each frame
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -ini ini file encoder extra ini config file
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi_enc_utils: -slt slt file slt verify data file
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: mpp coding type support list:
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: mpeg2 id 2
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: mpeg4 id 4
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: h.263 id 3
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: h.264/AVC id 7
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: h.265/HEVC id 16777220
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: vp8 id 9
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: VP9 id 10
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: avs+ id 16777221
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: jpeg id 8
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: dec id 0 coding: av1 id 16777224
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: enc id 1 coding: h.264/AVC id 7
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: enc id 1 coding: jpeg id 8
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: enc id 1 coding: h265 id 16777220
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: type: enc id 1 coding: vp8 id 9
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: mpp color support list:
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 0 0x00000 YUV420SP, NV12
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 1 0x00001 YUV420SP-10bit
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 2 0x00002 YUV422SP, NV24
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 3 0x00003 YUV422SP-10bit
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 4 0x00004 YUV420P, I420
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 5 0x00005 YUV420SP, NV21
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 6 0x00006 YUV422P, 422P
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 7 0x00007 YUV422SP, NV42
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 8 0x00008 YUV422-YUYV, YUY2
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 10 0x0000a YUV422-UYVY, UYVY
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 12 0x0000c YUV400-Y8, Y800
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 15 0x0000f YUV444SP
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 16 0x00010 YUV444P
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65536 0x10000 RGB565
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65537 0x10001 BGR565
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65538 0x10002 RGB555
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65539 0x10003 BGR555
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65542 0x10006 RGB888
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65543 0x10007 BGR888
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65546 0x1000a ARGB8888
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65547 0x1000b ABGR8888
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65548 0x1000c BGRA8888
Dec 9 03:06:05 RK356X user.info mpp[399]: mpi: color: id 65549 0x1000d RGBA8888