camera-streamer/buffer.c
Kamil Trzcinski 0322dc920a WIP
2022-04-04 19:19:42 +02:00

82 lines
1.8 KiB
C

#include "buffer.h"
#include "buffer_list.h"
#include "device.h"
buffer_t *buffer_open(const char *name, buffer_list_t *buf_list, int index) {
buffer_t *buf = calloc(1, sizeof(buffer_t));
device_t *dev = buf_list->device;
buf->name = strdup(name);
buf->index = index;
buf->buf_list = buf_list;
buf->dma_fd = -1;
buf->mmap_reflinks = 1;
buf->used = 0;
buf->v4l2_buffer.type = buf_list->type;
buf->v4l2_buffer.index = index;
if (buf_list->do_mplanes) {
buf->v4l2_buffer.length = 1;
buf->v4l2_buffer.m.planes = &buf->v4l2_plane;
}
if (!buf_list->do_mmap) {
// nothing to do here
buf->v4l2_buffer.memory = V4L2_MEMORY_DMABUF;
return buf;
}
buf->v4l2_buffer.memory = V4L2_MEMORY_MMAP;
E_XIOCTL(buf_list, dev->fd, VIDIOC_QUERYBUF, &buf->v4l2_buffer, "Cannot query buffer %d", index);
if (buf_list->do_mplanes) {
buf->offset = buf->v4l2_plane.m.mem_offset;
buf->length = buf->v4l2_plane.length;
} else {
buf->offset = buf->v4l2_buffer.m.offset;
buf->length = buf->v4l2_buffer.length;
}
buf->start = mmap(NULL, buf->length, PROT_READ | PROT_WRITE, MAP_SHARED, dev->fd, buf->offset);
if (buf->start == MAP_FAILED) {
goto error;
}
if (buf_list->do_dma) {
struct v4l2_exportbuffer v4l2_exp = {0};
v4l2_exp.type = buf_list->type;
v4l2_exp.index = index;
v4l2_exp.plane = 0;
E_XIOCTL(buf_list, dev->fd, VIDIOC_EXPBUF, &v4l2_exp, "Can't export queue buffer=%u to DMA", index);
buf->dma_fd = v4l2_exp.fd;
}
if (buf_list->do_capture) {
buffer_consumed(buf);
}
return buf;
error:
buffer_close(buf);
return NULL;
}
void buffer_close(buffer_t *buf)
{
if (buf == NULL) {
return;
}
if (buf->start && buf->start != MAP_FAILED) {
munmap(buf->start, buf->length);
}
if (buf->dma_fd >= 0) {
close(buf->dma_fd);
}
free(buf->name);
free(buf);
}