124 lines
3.0 KiB
C
124 lines
3.0 KiB
C
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/*
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Copyright (C) 2014 by Leonhard Oelke <leonhard@in-verted.de>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <sys/mman.h>
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#include <util/bmem.h>
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#include "v4l2-helpers.h"
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#define blog(level, msg, ...) blog(level, "v4l2-helpers: " msg, ##__VA_ARGS__)
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int_fast32_t v4l2_start_capture(int_fast32_t dev, struct v4l2_buffer_data *buf)
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{
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enum v4l2_buf_type type;
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struct v4l2_buffer enq;
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memset(&enq, 0, sizeof(enq));
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enq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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enq.memory = V4L2_MEMORY_MMAP;
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for (enq.index = 0; enq.index < buf->count; ++enq.index) {
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if (v4l2_ioctl(dev, VIDIOC_QBUF, &enq) < 0) {
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blog(LOG_ERROR, "unable to queue buffer");
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return -1;
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}
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}
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type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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if (v4l2_ioctl(dev, VIDIOC_STREAMON, &type) < 0) {
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blog(LOG_ERROR, "unable to start stream");
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return -1;
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}
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return 0;
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}
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int_fast32_t v4l2_stop_capture(int_fast32_t dev)
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{
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enum v4l2_buf_type type;
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type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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if (v4l2_ioctl(dev, VIDIOC_STREAMOFF, &type) < 0) {
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blog(LOG_ERROR, "unable to stop stream");
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return -1;
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}
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return 0;
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}
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int_fast32_t v4l2_create_mmap(int_fast32_t dev, struct v4l2_buffer_data *buf)
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{
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struct v4l2_requestbuffers req;
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struct v4l2_buffer map;
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memset(&req, 0, sizeof(req));
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req.count = 4;
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req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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req.memory = V4L2_MEMORY_MMAP;
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if (v4l2_ioctl(dev, VIDIOC_REQBUFS, &req) < 0) {
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blog(LOG_ERROR, "Request for buffers failed !");
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return -1;
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}
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if (req.count < 2) {
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blog(LOG_ERROR, "Device returned less than 2 buffers");
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return -1;
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}
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buf->count = req.count;
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buf->info = bzalloc(req.count * sizeof(struct v4l2_mmap_info));
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memset(&map, 0, sizeof(map));
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map.type = req.type;
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map.memory = req.memory;
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for (map.index = 0; map.index < req.count; ++map.index) {
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if (v4l2_ioctl(dev, VIDIOC_QUERYBUF, &map) < 0) {
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blog(LOG_ERROR, "Failed to query buffer details");
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return -1;
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}
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buf->info[map.index].length = map.length;
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buf->info[map.index].start = v4l2_mmap(NULL, map.length,
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PROT_READ | PROT_WRITE, MAP_SHARED,
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dev, map.m.offset);
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if (buf->info[map.index].start == MAP_FAILED) {
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blog(LOG_ERROR, "mmap for buffer failed");
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return -1;
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}
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}
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return 0;
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}
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int_fast32_t v4l2_destroy_mmap(struct v4l2_buffer_data *buf)
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{
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for(uint_fast32_t i = 0; i < buf->count; ++i) {
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if (buf->info[i].start != MAP_FAILED)
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v4l2_munmap(buf->info[i].start, buf->info[i].length);
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}
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buf->count = 0;
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bfree(buf->info);
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return 0;
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}
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