1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_CAMERA_CAMERA_CAPTURE_H 18 #define ANDROID_CAMERA_CAMERA_CAPTURE_H 19 20 /* 21 * Contains declarations for video capturing API that is used by the camera 22 * emulator. 23 */ 24 25 #include "camera-common.h" 26 27 /* Initializes camera device descriptor, and connects to the camera device. 28 * Param: 29 * name - On Linux contains name of the device to be used to capture video. 30 * On Windows contains name to assign to the capturing window. This parameter 31 * can be NULL, in which case '/dev/video0' will be used as device name on 32 * Linux, or 'AndroidEmulatorVC' on Windows. 33 * inp_channel - On Linux defines input channel to use when communicating with 34 * the camera driver. On Windows contains an index (up to 10) of the driver 35 * to use to communicate with the camera device. 36 * Return: 37 * Initialized camera device descriptor on success, or NULL on failure. 38 */ 39 extern CameraDevice* camera_device_open(const char* name, int inp_channel); 40 41 /* Starts capturing frames from the camera device. 42 * Param: 43 * cd - Camera descriptor representing a camera device opened in 44 * camera_device_open routine. 45 * pixel_format - Defines pixel format for the captured frames. Must be one of 46 * the formats, supported by the camera device. 47 * width, height - Frame dimensions for the captured video frame. Must match 48 * dimensions supported by the camera for the pixel format defined by the 49 * 'pixel_format' parameter. 50 * Return: 51 * 0 on success, or non-zero value on failure. 52 */ 53 extern int camera_device_start_capturing(CameraDevice* cd, 54 uint32_t pixel_format, 55 int frame_width, 56 int frame_height); 57 58 /* Stops capturing frames from the camera device. 59 * Param: 60 * cd - Camera descriptor representing a camera device opened in 61 * camera_device_open routine. 62 * Return: 63 * 0 on success, or non-zero value on failure. 64 */ 65 extern int camera_device_stop_capturing(CameraDevice* cd); 66 67 /* Captures a frame from the camera device. 68 * Param: 69 * cd - Camera descriptor representing a camera device opened in 70 * camera_device_open routine. 71 * framebuffers - Array of framebuffers where to read the frame. Size of this 72 * array is defined by the 'fbs_num' parameter. Note that the caller must 73 * make sure that buffers are large enough to contain entire frame captured 74 * from the device. 75 * fbs_num - Number of entries in the 'framebuffers' array. 76 * r_scale, g_scale, b_scale - White balance scale. 77 * exp_comp - Expsoure compensation. 78 * Return: 79 * 0 on success, or non-zero value on failure. There is a special vaule 1 80 * returned from this routine which indicates that frames were not available in 81 * the device. This value is returned on Linux implementation when frame ioctl 82 * has returned EAGAIN error. The client should respond to this value by 83 * repeating the read, rather than reporting an error. 84 */ 85 extern int camera_device_read_frame(CameraDevice* cd, 86 ClientFrameBuffer* framebuffers, 87 int fbs_num, 88 float r_scale, 89 float g_scale, 90 float b_scale, 91 float exp_comp); 92 93 /* Closes camera device, opened in camera_device_open routine. 94 * Param: 95 * cd - Camera descriptor representing a camera device opened in 96 * camera_device_open routine. 97 */ 98 extern void camera_device_close(CameraDevice* cd); 99 100 /* Enumerates camera devices connected to the host, and collects information 101 * about each device. 102 * Apparently, camera framework in the guest will only accept the the YV12 103 * (V4L2_PIX_FMT_YVU420) pixel format. So, we don't really need to report all the 104 * pixel formats, supported by the camera device back to the guest. We can simpy 105 * pick any format that is supported by the device, and collect frame dimensions 106 * available for it. The only thing we can do is to specifically check, if camera 107 * support YV12, and choose it, in order to spare some CPU cycles on the 108 * conversion. 109 * Param: 110 * cis - An allocated array where to store informaion about found camera 111 * devices. For each found camera device an entry will be initialized in the 112 * array. It's responsibility of the caller to free the memory allocated for 113 * the entries. 114 * max - Maximum number of entries that can fit into the array. 115 * Return: 116 * Number of entries added to the 'cis' array on success, or < 0 on failure. 117 */ 118 extern int enumerate_camera_devices(CameraInfo* cis, int max); 119 120 #endif /* ANDROID_CAMERA_CAMERA_CAPTURE_H */ 121
