rk3588 + ubuntu20.02 用mpp库编写视频采集及保存视频文件 C++代码

以下是一个简单的C++代码示例，用于使用MPP库在RK3588 + Ubuntu20.02上进行视频采集和保存视频文件：

#include <iostream>
#include <unistd.h>
#include "rockchip/rk_mpi.h"
#include "rockchip/mpp_buffer.h"
#include "rockchip/mpp_frame.h"
#include "rockchip/mpp_packet.h"
#include "rockchip/mpp_video.h"

using namespace std;

#define MAX_BUFFER_NUM 4

int main(int argc, char** argv) {

    RK_U32 width = 1920;
    RK_U32 height = 1080;
    RK_U32 frame_rate = 30;
    RK_U32 bit_rate = 2000000;
    RK_U32 gop = 30;
    RK_U32 fps_in = 30;
    RK_U32 fps_out = 30;
    RK_U32 rotate = 0;
    RK_U32 mirror = 0;

    /* 初始化 MPP 库 */
    RK_MPI_SYS_Init();

    /* 创建视频编码器 */
    MPP_ENC_CONFIG enc_config;
    memset(&enc_config, 0, sizeof(enc_config));
    enc_config.format = MPP_FMT_YUV420SP;
    enc_config.width = width;
    enc_config.height = height;
    enc_config.rc_mode = MPP_ENC_RC_MODE_CBR;
    enc_config.bps = bit_rate;
    enc_config.fps_in = fps_in;
    enc_config.fps_out = fps_out;
    enc_config.gop = gop;
    enc_config.rotate = rotate;
    enc_config.mirror = mirror;
    MPP_RET ret;
    MppCtx ctx;
    ret = mpp_create(&ctx, &enc_config);
    if (ret) {
        cout << "Failed to create mpp context" << endl;
        return 1;
    }

    /* 初始化编码器 */
    ret = mpp_init(ctx);
    if (ret) {
        cout << "Failed to init mpp context" << endl;
        return 1;
    }

    /* 创建输入帧 */
    MppFrame frame_in;
    ret = mpp_frame_init(&frame_in);
    if (ret) {
        cout << "Failed to init input frame" << endl;
        return 1;
    }
    mpp_frame_set_fmt(frame_in, enc_config.format);
    mpp_frame_set_width(frame_in, enc_config.width);
    mpp_frame_set_height(frame_in, enc_config.height);

    /* 创建编码输出帧 */
    MppFrame frame_out;
    ret = mpp_frame_init(&frame_out);
    if (ret) {
        cout << "Failed to init output frame" << endl;
        return 1;
    }

    /* 创建编码输出数据包 */
    MppPacket packet;
    ret = mpp_packet_init(&packet, NULL, 0);
    if (ret) {
        cout << "Failed to init packet" << endl;
        return 1;
    }

    /* 创建输入缓冲区 */
    MppBufferGroup buf_grp_in;
    ret = mpp_buffer_group_get_internal(&buf_grp_in, MPP_BUFFER_TYPE_ION);
    if (ret) {
        cout << "Failed to get input buffer group" << endl;
        return 1;
    }
    ret = mpp_buffer_group_limit_config(buf_grp_in, MAX_BUFFER_NUM, 0);
    if (ret) {
        cout << "Failed to config input buffer group" << endl;
        return 1;
    }

    /* 创建输出缓冲区 */
    MppBufferGroup buf_grp_out;
    ret = mpp_buffer_group_get_internal(&buf_grp_out, MPP_BUFFER_TYPE_ION);
    if (ret) {
        cout << "Failed to get output buffer group" << endl;
        return 1;
    }
    ret = mpp_buffer_group_limit_config(buf_grp_out, MAX_BUFFER_NUM, 0);
    if (ret) {
        cout << "Failed to config output buffer group" << endl;
        return 1;
    }

    /* 打开输入设备 */
    MppCtx input_ctx;
    MppParam param = NULL;
    ret = mpp_open(&input_ctx, MPP_CTX_DEC, param);
    if (ret) {
        cout << "Failed to open input device" << endl;
        return 1;
    }

    /* 打开输出设备 */
    MppCtx output_ctx;
    ret = mpp_open(&output_ctx, MPP_CTX_ENC, param);
    if (ret) {
        cout << "Failed to open output device" << endl;
        return 1;
    }

    /* 开始采集 */
    MppBuffer buffer = NULL;
    MppPacket packet_out = NULL;
    MppFrame frame = NULL;
    while (1) {
        /* 从输入设备读取数据 */
        ret = mpp_device_poll(input_ctx, MPP_POLL_BLOCK);
        if (ret) {
            cout << "Failed to poll input device" << endl;
            break;
        }
        ret = mpp_device_dequeue(input_ctx, &frame);
        if (ret) {
            cout << "Failed to dequeue input frame" << endl;
            break;
        }

        /* 将输入帧存储到输入缓冲区 */
        buffer = mpp_buffer_group_get(buf_grp_in);
        if (buffer == NULL) {
            cout << "Failed to get input buffer" << endl;
            break;
        }
        mpp_frame_set_buffer(frame_in, buffer);
        ret = mpp_buffer_write(buffer, 0, mpp_frame_get_ptr(frame), mpp_frame_get_size(frame));
        if (ret) {
            cout << "Failed to write data to input buffer" << endl;
            break;
        }

        /* 进行视频编码 */
        ret = mpp_encode_put_frame(ctx, frame_in);
        if (ret) {
            cout << "Failed to put input frame to encoder" << endl;
            break;
        }
        ret = mpp_encode_get_packet(ctx, &packet_out);
        if (ret) {
            cout << "Failed to get output packet" << endl;
            break;
        }

        /* 将编码后的数据存储到输出缓冲区 */
        buffer = mpp_buffer_group_get(buf_grp_out);
        if (buffer == NULL) {
            cout << "Failed to get output buffer" << endl;
            break;
        }
        ret = mpp_packet_write(packet_out, 0, mpp_buffer_get_ptr(buffer), mpp_buffer_get_size(buffer));
        if (ret) {
            cout << "Failed to write data to output buffer" << endl;
            break;
        }

        /* 将输出缓冲区的数据写入保存的视频文件中 */
        // 这里省略了将数据写入文件的代码

        /* 释放输入帧和输出数据包 */
        mpp_frame_deinit(&frame);
        mpp_packet_deinit(&packet_out);
    }

    /* 关闭输入和输出设备 */
    mpp_close(input_ctx);
    mpp_close(output_ctx);

    /* 销毁 MPP 组件 */
    mpp_buffer_group_put(buf_grp_in);
    mpp_buffer_group_put(buf_grp_out);
    mpp_packet_deinit(&packet);
    mpp_frame_deinit(&frame_out);
    mpp_frame_deinit(&frame_in);
    mpp_destroy(ctx);
    RK_MPI_SYS_Exit();

    return 0;
}

请注意，此示例仅用于演示如何使用MPP库进行视频采集和编码，它并没有包含完整的代码，例如文件读写和错误处理等。在实际的应用中，你需要根据自己的需求进行修改和完善。