1#include "camera.h"
  2#include "common/debug.h"
  3
  4#include <camera/NdkCameraManager.h>
  5#include <camera/NdkCameraMetadata.h>
  6#include <camera/NdkCameraMetadataTags.h>
  7
  8// HAL_PIXEL_FORMAT_JPEG, the still capture format the stream configurations are keyed by. It is
  9// defined in <system/graphics.h>, which the NDK does not ship, and shares its value with
 10// AHardwareBuffer's BLOB format.
 11#define FF_ANDROID_PIXEL_FORMAT_JPEG 0x21
 12
 13// Records the largest size the camera can stream in the given pixel format. The stream configurations
 14// are a flat array of (format, width, height, isInput) quads; a negative format matches any of them.
 15static void getMaxStreamSize(const ACameraMetadata* metadata, int32_t format, uint32_t* width, uint32_t* height) {
 16    ACameraMetadata_const_entry entry;
 17    if (ACameraMetadata_getConstEntry(metadata, ACAMERA_SCALER_AVAILABLE_STREAM_CONFIGURATIONS, &entry) != ACAMERA_OK) {
 18        return;
 19    }
 20    if (entry.type != ACAMERA_TYPE_INT32) {
 21        return;
 22    }
 23
 24    uint64_t maxArea = 0;
 25    for (uint32_t i = 0; i + 3 < entry.count; i += 4) {
 26        if (entry.data.i32[i + 3] != ACAMERA_SCALER_AVAILABLE_STREAM_CONFIGURATIONS_OUTPUT) {
 27            continue;
 28        }
 29        if (format >= 0 && entry.data.i32[i] != format) {
 30            continue;
 31        }
 32
 33        uint32_t w = (uint32_t) entry.data.i32[i + 1];
 34        uint32_t h = (uint32_t) entry.data.i32[i + 2];
 35        if ((uint64_t) w * h > maxArea) {
 36            maxArea = (uint64_t) w * h;
 37            *width = w;
 38            *height = h;
 39        }
 40    }
 41}
 42
 43const char* ffDetectCamera(FFlist* result) {
 44    // The camera2 NDK and every entry point below were introduced in API 24, which is the API level
 45    // this build targets, so nothing here is newer than the minimum supported version and
 46    // common/android/api.h has nothing to guard. That header covers the opposite case: entry points
 47    // the NDK marks unavailable because they postdate the target, such as AImageDecoder (30) or
 48    // AMediaCodec_getName (28). It also only ever makes *symbols* weak -- libcamera2ndk.so itself is
 49    // API 24, so linking it unconditionally in CMakeLists.txt is fine on every supported device.
 50    ACameraManager* manager = ACameraManager_create();
 51    if (!manager) {
 52        FF_DEBUG("ACameraManager_create() failed");
 53        return "ACameraManager_create() failed";
 54    }
 55
 56    ACameraIdList* idList = nullptr;
 57    if (ACameraManager_getCameraIdList(manager, &idList) != ACAMERA_OK || !idList) {
 58        FF_DEBUG("ACameraManager_getCameraIdList() failed");
 59        ACameraManager_delete(manager);
 60        return "ACameraManager_getCameraIdList() failed";
 61    }
 62
 63    for (int32_t i = 0; i < idList->numCameras; ++i) {
 64        const char* id = idList->cameraIds[i];
 65
 66        ACameraMetadata* metadata = nullptr;
 67        if (ACameraManager_getCameraCharacteristics(manager, id, &metadata) != ACAMERA_OK || !metadata) {
 68            continue;
 69        }
 70
 71        FFCameraResult* camera = FF_LIST_ADD(FFCameraResult, *result);
 72        ffStrbufInit(&camera->vendor);
 73        ffStrbufInit(&camera->colorspace);
 74        ffStrbufInitS(&camera->id, id);
 75
 76        ACameraMetadata_const_entry facing;
 77        if (ACameraMetadata_getConstEntry(metadata, ACAMERA_LENS_FACING, &facing) == ACAMERA_OK && facing.type == ACAMERA_TYPE_BYTE && facing.count >= 1) {
 78            switch (facing.data.u8[0]) {
 79                case ACAMERA_LENS_FACING_FRONT:
 80                    ffStrbufInitStatic(&camera->name, "builtin-front");
 81                    break;
 82                case ACAMERA_LENS_FACING_BACK:
 83                    ffStrbufInitStatic(&camera->name, "builtin-back");
 84                    break;
 85                case ACAMERA_LENS_FACING_EXTERNAL:
 86                    ffStrbufInitStatic(&camera->name, "builtin-external");
 87                    break;
 88                default:
 89                    ffStrbufInitStatic(&camera->name, "Unknown");
 90                    break;
 91            }
 92        } else {
 93            ffStrbufInitStatic(&camera->name, "Unknown");
 94        }
 95
 96        camera->width = camera->height = 0;
 97        getMaxStreamSize(metadata, FF_ANDROID_PIXEL_FORMAT_JPEG, &camera->width, &camera->height);
 98        if (camera->width == 0) {
 99            // Not every camera HAL lists a JPEG format. The largest size of any output format is the
100            // same resolution on those devices.
101            getMaxStreamSize(metadata, -1, &camera->width, &camera->height);
102        }
103
104        ACameraMetadata_free(metadata);
105    }
106
107    ACameraManager_deleteCameraIdList(idList);
108    ACameraManager_delete(manager);
109
110    return nullptr;
111}