v4l2导出的dmabuf可以导入mpp缓存池吗

[cht851]

我把v4l2 expbuf得到的dmabuf导入的缓存池报错：
mpp[3436]: mpp_log: allocator_ext_dma_import The ext_dma is not used for userptr
mpp[3436]: mpp_buffer: mpp_buffer_create failed to create buffer with size 3133440
是我的代码有问题吗？

BufInfo保存了v4l2导出dmabuf的信息

[cht851]

要把外部缓冲区导入mpp缓存池，外部缓冲区只能是drm申请的buffer吗

[HermanChen]

看 camera_source.c 里的例子，要加加一个 export fd 的过程

[cht851]

看 camera_source.c 里的例子，要加加一个 export fd 的过程

我加了也报错
mpp[3436]: mpp_log: allocator_ext_dma_import The ext_dma is not used for userptr
mpp[3436]: mpp_buffer: mpp_buffer_create failed to create buffer with size 3133440
是为什么呢？导出fd代码如下：
` struct v4l2_buffer buf;
struct v4l2_plane planes;
memset(&buf, 0, sizeof(struct v4l2_buffer));
memset(&planes, 0, sizeof(struct v4l2_plane));
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
buf.memory = V4L2_MEMORY_MMAP;
buf.m.planes = &planes;
buf.length = 1;
struct v4l2_exportbuffer expbuf;
memset(&expbuf, 0, sizeof(expbuf));
expbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;

for(int i = 0; i < VI_BUFF_NUM; i++){
    expbuf.index = i;
    ret = ioctl(fd, VIDIOC_EXPBUF, &expbuf);
    if(ret < 0)
    {
        perror("export buf error\n");
        return -1;
    }
    bufferInfo[i].fd = expbuf.fd;
    bufferInfo[i].index = i;
    // 查询缓冲区长度
    buf.index = i;
    ret = ioctl(fd, VIDIOC_QUERYBUF, &buf);
    if(ret < 0)
    {
        perror("query buffer length error\n");
        return -1;
    }
    bufferInfo[i].length = buf.m.planes[0].length;
    // 将内核内存映射到用户空间
    bufferInfo[i].addr = (uint8_t*)mmap(NULL, buf.m.planes[0].length, PROT_READ | PROT_WRITE, MAP_SHARED, 
                                fd, buf.m.planes[0].m.mem_offset);
    if(!bufferInfo[i].addr)
    {
        perror("mmap buffers error\n");
        return -1;
    }
}

`