标签：generate hat 信息 char session methods mil 摄像头 dde
一、camera_metadata简介
Camera API2/HAL3架构下使用了全新的CameraMetadata结构取代了之前的SetParameter/Paramters等操作，实现了Java到native到HAL3的参数传递。引入了管道的概念将安卓设备和摄像头之间联系起来，系统向摄像头发送 Capture 请求，而摄像头会返回 CameraMetadata，这一切建立在一个叫作 CameraCaptureSession 的会话中。和Camera_metadata数据结构相关的主要有以下几个文件：
system/media/camera/include/system/camera_metadata_tags.h(不允许直接引用该头文件，如需引用，可以引用camera_metadata.h)
system/media/camera/include/system/camera_metadata.h
system/media/camera/include/system/camera_vendor_tags.h(给各个芯片厂商扩展的tag)
system/media/camera/src/camera_metadata_tag_info.c(不允许直接调用该文件中的函数，如需调用，调用camera_metadata.c中包装函数)
system/media/camera/src/camera_metadata.c
framework/av/camera/CameraMetadata.cpp
framework/av/include/camera/CameraMetadata.h
frameworks/base/core/jni/android_hardware_camera2_CameraMetadata.cpp
二、Framework到HAL层的转换
Camera2Client 使用 API1 传递参数采用的逻辑是还是在Java层预留了setParameters接口，只是当Parameter在设置时比起CameraClient而言，是将这个Parameter根据不同的TAG形式直接绑定到CameraMetadata mPreviewRequest/mRecordRequest/mCaptureRequest中，这些数据会由Capture_Request转为camera3_capture_request中的camera_metadata_t settings完成参数从Java到native到HAL3的传递。
但是在Camera API2下，不再需要那么复杂的转换过程，在Java层中直接对参数进行设置并将其封装到Capture_Request即可，即参数控制由Java层来完成。这也体现了API2中Request和Result在APP中就大量存在的原因。对此为了和Framework Native层相关TAG数据的统一，在Java层中大量出现的参数设置是通过Section Tag的name来交由Native完成转换生成在Java层的TAG。
（1）Java层对应代码位置：frameworks/base/core/java/android/hardware/camera2/impl/CameraMetadataNative.java
1 private <T> T getBase(Key<T> key) { 2 int tag = nativeGetTagFromKeyLocal(key.getName()); 3 byte[] values = readValues(tag); 4 if (values == null) { 5 // If the key returns null, use the fallback key if exists. 6 // This is to support old key names for the newly published keys. 7 if (key.mFallbackName == null) { 8 return null; 9 } 10 tag = nativeGetTagFromKeyLocal(key.mFallbackName); 11 values = readValues(tag); 12 if (values == null) { 13 return null; 14 } 15 } 16 17 int nativeType = nativeGetTypeFromTagLocal(tag); 18 Marshaler<T> marshaler = getMarshalerForKey(key, nativeType); 19 ByteBuffer buffer = ByteBuffer.wrap(values).order(ByteOrder.nativeOrder()); 20 return marshaler.unmarshal(buffer); 21 }
（2）Native层对应代码位置：frameworks/base/core/jni/android_hardware_camera2_CameraMetadata.cpp
1 static const JNINativeMethod gCameraMetadataMethods[] = { 2 // static methods 3 { "nativeGetTagFromKey", 4 "(Ljava/lang/String;J)I", 5 (void *)CameraMetadata_getTagFromKey }, 6 { "nativeGetTypeFromTag", 7 "(IJ)I", 8 (void *)CameraMetadata_getTypeFromTag }, 9 { "nativeSetupGlobalVendorTagDescriptor", 10 "()I", 11 (void*)CameraMetadata_setupGlobalVendorTagDescriptor }, 12 // instance methods 13 { "nativeAllocate", 14 "()J", 15 (void*)CameraMetadata_allocate }, 16 { "nativeAllocateCopy", 17 "(L" CAMERA_METADATA_CLASS_NAME ";)J", 18 (void *)CameraMetadata_allocateCopy }, 19 { "nativeIsEmpty", 20 "()Z", 21 (void*)CameraMetadata_isEmpty }, 22 { "nativeGetEntryCount", 23 "()I", 24 (void*)CameraMetadata_getEntryCount }, 25 { "nativeClose", 26 "()V", 27 (void*)CameraMetadata_close }, 28 { "nativeSwap", 29 "(L" CAMERA_METADATA_CLASS_NAME ";)V", 30 (void *)CameraMetadata_swap }, 31 { "nativeGetTagFromKeyLocal", 32 "(Ljava/lang/String;)I", 33 (void *)CameraMetadata_getTagFromKeyLocal }, 34 { "nativeGetTypeFromTagLocal", 35 "(I)I", 36 (void *)CameraMetadata_getTypeFromTagLocal }, 37 ... 38 };
其中CameraMetadata_getTagFromKey是实现将一个Java层的string转为一个tag的值，如：android.control.mode。对比最初不同的Section name就可以发现前面两个x.y的字符串就是代表是Section name.而后面mode即是在该section下的tag数值，所以通过对这个string的分析可知，就可以定位对应的section以及tag值，这样返回到Java层的就是key相应的tag值了。继续追踪到 \system\media\camera\src\camera_metadata.c：
1 // Declared in system/media/private/camera/include/camera_metadata_hidden.h 2 const char *get_local_camera_metadata_tag_name_vendor_id(uint32_t tag, 3 metadata_vendor_id_t id) { 4 uint32_t tag_section = tag >> 16; 5 if (tag_section >= VENDOR_SECTION && vendor_cache_ops != NULL && 6 id != CAMERA_METADATA_INVALID_VENDOR_ID) { 7 return vendor_cache_ops->get_tag_name(tag, id); 8 } else if (tag_section >= VENDOR_SECTION && vendor_tag_ops != NULL) { 9 return vendor_tag_ops->get_tag_name( 10 vendor_tag_ops, 11 tag); 12 } 13 if (tag_section >= ANDROID_SECTION_COUNT || 14 tag >= camera_metadata_section_bounds[tag_section][1] ) { // 关键是camera_metadata_section_bounds这个数组，保存了各个tag的绑定信息 15 return NULL; 16 } 17 uint32_t tag_index = tag & 0xFFFF; 18 return tag_info[tag_section][tag_index].tag_name; 19 }
相关文件调用关系如下：
其中 camera_metadata_tags.h 包含了所有的基本宏，每一个section的大小是64K（每个section_start 由section偏移16位，也就是2^16=65536，即64K）。tag也就是又section_start偏移而来，比如android.control.mode，由camera_metadata_section--->ANDROID_CONTROL找到对应的camera_metadata_section_start--->ANDROID_CONTROL_START，然后在camera_metadata_tag找到对应的ANDROID_CONTROL_MODE，也就是tag值。
1 /** 2 * !! Do not include this file directly !! 3 * 4 * Include camera_metadata.h instead. 5 */ 6 7 /** 8 * ! Do not edit this file directly ! 9 * 10 * Generated automatically from camera_metadata_tags.mako 11 */ 12 13 /** TODO: Nearly every enum in this file needs a description */ 14 15 /** 16 * Top level hierarchy definitions for camera metadata. *_INFO sections are for 17 * the static metadata that can be retrived without opening the camera device. 18 * New sections must be added right before ANDROID_SECTION_COUNT to maintain 19 * existing enumerations. 20 */ 21 typedef enum camera_metadata_section { 22 ANDROID_COLOR_CORRECTION, 23 ANDROID_CONTROL, 24 ANDROID_DEMOSAIC, 25 ANDROID_EDGE, 26 ANDROID_FLASH, 27 ANDROID_FLASH_INFO, 28 ANDROID_HOT_PIXEL, 29 ANDROID_JPEG, 30 ANDROID_LENS, 31 ANDROID_LENS_INFO, 32 ANDROID_NOISE_REDUCTION, 33 ANDROID_QUIRKS, 34 ANDROID_REQUEST, 35 ANDROID_SCALER, 36 ANDROID_SENSOR, 37 ANDROID_SENSOR_INFO, 38 ANDROID_SHADING, 39 ANDROID_STATISTICS, 40 ANDROID_STATISTICS_INFO, 41 ANDROID_TONEMAP, 42 ANDROID_LED, 43 ANDROID_INFO, 44 ANDROID_BLACK_LEVEL, 45 ANDROID_SYNC, 46 ANDROID_REPROCESS, 47 ANDROID_DEPTH, 48 ANDROID_LOGICAL_MULTI_CAMERA, 49 ANDROID_DISTORTION_CORRECTION, 50 ANDROID_HEIC, 51 ANDROID_HEIC_INFO, 52 ANDROID_H264, 53 ANDROID_H265, 54 ANDROID_SECTION_COUNT, 55 56 VENDOR_SECTION = 0x8000 57 } camera_metadata_section_t; 58 59 /** 60 * Hierarchy positions in enum space. All vendor extension tags must be 61 * defined with tag >= VENDOR_SECTION_START 62 */ 63 typedef enum camera_metadata_section_start { 64 ANDROID_COLOR_CORRECTION_START = ANDROID_COLOR_CORRECTION << 16, 65 ANDROID_CONTROL_START = ANDROID_CONTROL << 16, 66 ANDROID_DEMOSAIC_START = ANDROID_DEMOSAIC << 16, 67 ANDROID_EDGE_START = ANDROID_EDGE << 16, 68 ANDROID_FLASH_START = ANDROID_FLASH << 16, 69 ANDROID_FLASH_INFO_START = ANDROID_FLASH_INFO << 16, 70 ANDROID_HOT_PIXEL_START = ANDROID_HOT_PIXEL << 16, 71 ANDROID_JPEG_START = ANDROID_JPEG << 16, 72 ANDROID_LENS_START = ANDROID_LENS << 16, 73 ANDROID_LENS_INFO_START = ANDROID_LENS_INFO << 16, 74 ANDROID_NOISE_REDUCTION_START = ANDROID_NOISE_REDUCTION << 16, 75 ANDROID_QUIRKS_START = ANDROID_QUIRKS << 16, 76 ANDROID_REQUEST_START = ANDROID_REQUEST << 16, 77 ANDROID_SCALER_START = ANDROID_SCALER << 16, 78 ANDROID_SENSOR_START = ANDROID_SENSOR << 16, 79 ANDROID_SENSOR_INFO_START = ANDROID_SENSOR_INFO << 16, 80 ANDROID_SHADING_START = ANDROID_SHADING << 16, 81 ANDROID_STATISTICS_START = ANDROID_STATISTICS << 16, 82 ANDROID_STATISTICS_INFO_START = ANDROID_STATISTICS_INFO << 16, 83 ANDROID_TONEMAP_START = ANDROID_TONEMAP << 16, 84 ANDROID_LED_START = ANDROID_LED << 16, 85 ANDROID_INFO_START = ANDROID_INFO << 16, 86 ANDROID_BLACK_LEVEL_START = ANDROID_BLACK_LEVEL << 16, 87 ANDROID_SYNC_START = ANDROID_SYNC << 16, 88 ANDROID_REPROCESS_START = ANDROID_REPROCESS << 16, 89 ANDROID_DEPTH_START = ANDROID_DEPTH << 16, 90 ANDROID_LOGICAL_MULTI_CAMERA_START 91 = ANDROID_LOGICAL_MULTI_CAMERA 92 << 16, 93 ANDROID_DISTORTION_CORRECTION_START 94 = ANDROID_DISTORTION_CORRECTION 95 << 16, 96 ANDROID_HEIC_START = ANDROID_HEIC << 16, 97 ANDROID_HEIC_INFO_START = ANDROID_HEIC_INFO << 16, 98 ANDROID_H264_START = ANDROID_H264 << 16, 99 ANDROID_H265_START = ANDROID_H265 << 16, 100 VENDOR_SECTION_START = VENDOR_SECTION << 16 101 } camera_metadata_section_start_t;
1 /** 2 * Main enum for defining camera metadata tags. New entries must always go 3 * before the section _END tag to preserve existing enumeration values. In 4 * addition, the name and type of the tag needs to be added to 5 * system/media/camera/src/camera_metadata_tag_info.c 6 */ 7 typedef enum camera_metadata_tag { 8 ANDROID_COLOR_CORRECTION_MODE = // enum | public | HIDL v3.2 9 ANDROID_COLOR_CORRECTION_START, 10 ANDROID_COLOR_CORRECTION_TRANSFORM, // rational[] | public | HIDL v3.2 11 ANDROID_COLOR_CORRECTION_GAINS, // float[] | public | HIDL v3.2 12 ANDROID_COLOR_CORRECTION_ABERRATION_MODE, // enum | public | HIDL v3.2 13 ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES, 14 // byte[] | public | HIDL v3.2 15 ANDROID_COLOR_CORRECTION_END, 16 17 ANDROID_CONTROL_AE_ANTIBANDING_MODE = // enum | public | HIDL v3.2 18 ANDROID_CONTROL_START, 19 ANDROID_CONTROL_AE_EXPOSURE_COMPENSATION, // int32 | public | HIDL v3.2 20 ANDROID_CONTROL_AE_LOCK, // enum | public | HIDL v3.2 21 ANDROID_CONTROL_AE_MODE, // enum | public | HIDL v3.2 22 ANDROID_CONTROL_AE_REGIONS, // int32[] | public | HIDL v3.2 23 ANDROID_CONTROL_AE_TARGET_FPS_RANGE, // int32[] | public | HIDL v3.2 24 ANDROID_CONTROL_AE_PRECAPTURE_TRIGGER, // enum | public | HIDL v3.2 25 ANDROID_CONTROL_AF_MODE, // enum | public | HIDL v3.2 26 ANDROID_CONTROL_AF_REGIONS, // int32[] | public | HIDL v3.2 27 ANDROID_CONTROL_AF_TRIGGER, // enum | public | HIDL v3.2 28 ANDROID_CONTROL_AWB_LOCK, // enum | public | HIDL v3.2 29 ANDROID_CONTROL_AWB_MODE, // enum | public | HIDL v3.2 30 ANDROID_CONTROL_AWB_REGIONS, // int32[] | public | HIDL v3.2 31 ANDROID_CONTROL_CAPTURE_INTENT, // enum | public | HIDL v3.2 32 ANDROID_CONTROL_EFFECT_MODE, // enum | public | HIDL v3.2 33 ANDROID_CONTROL_MODE, // enum | public | HIDL v3.2 34 ANDROID_CONTROL_SCENE_MODE, // enum | public | HIDL v3.2 35 ANDROID_CONTROL_VIDEO_STABILIZATION_MODE, // enum | public | HIDL v3.2 36 ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES, // byte[] | public | HIDL v3.2 37 ANDROID_CONTROL_AE_AVAILABLE_MODES, // byte[] | public | HIDL v3.2 38 ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES, // int32[] | public | HIDL v3.2 39 ANDROID_CONTROL_AE_COMPENSATION_RANGE, // int32[] | public | HIDL v3.2 40 ANDROID_CONTROL_AE_COMPENSATION_STEP, // rational | public | HIDL v3.2 41 ANDROID_CONTROL_AF_AVAILABLE_MODES, // byte[] | public | HIDL v3.2 42 ANDROID_CONTROL_AVAILABLE_EFFECTS, // byte[] | public | HIDL v3.2 43 ANDROID_CONTROL_AVAILABLE_SCENE_MODES, // byte[] | public | HIDL v3.2 44 ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES, 45 // byte[] | public | HIDL v3.2 46 ANDROID_CONTROL_AWB_AVAILABLE_MODES, // byte[] | public | HIDL v3.2 47 ANDROID_CONTROL_MAX_REGIONS, // int32[] | ndk_public | HIDL v3.2 48 ANDROID_CONTROL_SCENE_MODE_OVERRIDES, // byte[] | system | HIDL v3.2 49 ANDROID_CONTROL_AE_PRECAPTURE_ID, // int32 | system | HIDL v3.2 50 ANDROID_CONTROL_AE_STATE, // enum | public | HIDL v3.2 51 ANDROID_CONTROL_AF_STATE, // enum | public | HIDL v3.2 52 ANDROID_CONTROL_AF_TRIGGER_ID, // int32 | system | HIDL v3.2 53 ANDROID_CONTROL_AWB_STATE, // enum | public | HIDL v3.2 54 ANDROID_CONTROL_AVAILABLE_HIGH_SPEED_VIDEO_CONFIGURATIONS, 55 // int32[] | hidden | HIDL v3.2 56 ANDROID_CONTROL_AE_LOCK_AVAILABLE, // enum | public | HIDL v3.2 57 ANDROID_CONTROL_AWB_LOCK_AVAILABLE, // enum | public | HIDL v3.2 58 ANDROID_CONTROL_AVAILABLE_MODES, // byte[] | public | HIDL v3.2 59 ANDROID_CONTROL_POST_RAW_SENSITIVITY_BOOST_RANGE, // int32[] | public | HIDL v3.2 60 ANDROID_CONTROL_POST_RAW_SENSITIVITY_BOOST, // int32 | public | HIDL v3.2 61 ANDROID_CONTROL_ENABLE_ZSL, // enum | public | HIDL v3.2 62 ANDROID_CONTROL_AF_SCENE_CHANGE, // enum | public | HIDL v3.3 63 ANDROID_CONTROL_END, 64 65 ......
对应关系如图所示：
然后在 camera_metadata_tag_info.c 中进行了映射和绑定，前面Native层CameraMetadata_getTagFromKey--->getTagFromName--->camera_metadata_section_bounds调用的camera_metadata_section_bounds实现在这里：
1 /** 2 * ! Do not edit this file directly ! 3 * 4 * Generated automatically from camera_metadata_tag_info.mako 5 */ 6 7 const char *camera_metadata_section_names[ANDROID_SECTION_COUNT] = { 8 [ANDROID_COLOR_CORRECTION] = "android.colorCorrection", 9 [ANDROID_CONTROL] = "android.control", 10 [ANDROID_DEMOSAIC] = "android.demosaic", 11 [ANDROID_EDGE] = "android.edge", 12 [ANDROID_FLASH] = "android.flash", 13 [ANDROID_FLASH_INFO] = "android.flash.info", 14 [ANDROID_HOT_PIXEL] = "android.hotPixel", 15 [ANDROID_JPEG] = "android.jpeg", 16 [ANDROID_LENS] = "android.lens", 17 [ANDROID_LENS_INFO] = "android.lens.info", 18 [ANDROID_NOISE_REDUCTION] = "android.noiseReduction", 19 [ANDROID_QUIRKS] = "android.quirks", 20 [ANDROID_REQUEST] = "android.request", 21 [ANDROID_SCALER] = "android.scaler", 22 [ANDROID_SENSOR] = "android.sensor", 23 [ANDROID_SENSOR_INFO] = "android.sensor.info", 24 [ANDROID_SHADING] = "android.shading", 25 [ANDROID_STATISTICS] = "android.statistics", 26 [ANDROID_STATISTICS_INFO] = "android.statistics.info", 27 [ANDROID_TONEMAP] = "android.tonemap", 28 [ANDROID_LED] = "android.led", 29 [ANDROID_INFO] = "android.info", 30 [ANDROID_BLACK_LEVEL] = "android.blackLevel", 31 [ANDROID_SYNC] = "android.sync", 32 [ANDROID_REPROCESS] = "android.reprocess", 33 [ANDROID_DEPTH] = "android.depth", 34 [ANDROID_LOGICAL_MULTI_CAMERA] = "android.logicalMultiCamera", 35 [ANDROID_DISTORTION_CORRECTION] 36 = "android.distortionCorrection", 37 }; 38 39 unsigned int camera_metadata_section_bounds[ANDROID_SECTION_COUNT][2] = { 40 [ANDROID_COLOR_CORRECTION] = { ANDROID_COLOR_CORRECTION_START, 41 ANDROID_COLOR_CORRECTION_END }, 42 [ANDROID_CONTROL] = { ANDROID_CONTROL_START, 43 ANDROID_CONTROL_END }, 44 [ANDROID_DEMOSAIC] = { ANDROID_DEMOSAIC_START, 45 ANDROID_DEMOSAIC_END }, 46 [ANDROID_EDGE] = { ANDROID_EDGE_START, 47 ANDROID_EDGE_END }, 48 [ANDROID_FLASH] = { ANDROID_FLASH_START, 49 ANDROID_FLASH_END }, 50 [ANDROID_FLASH_INFO] = { ANDROID_FLASH_INFO_START, 51 ANDROID_FLASH_INFO_END }, 52 [ANDROID_HOT_PIXEL] = { ANDROID_HOT_PIXEL_START, 53 ANDROID_HOT_PIXEL_END }, 54 [ANDROID_JPEG] = { ANDROID_JPEG_START, 55 ANDROID_JPEG_END }, 56 [ANDROID_LENS] = { ANDROID_LENS_START, 57 ANDROID_LENS_END }, 58 [ANDROID_LENS_INFO] = { ANDROID_LENS_INFO_START, 59 ANDROID_LENS_INFO_END }, 60 [ANDROID_NOISE_REDUCTION] = { ANDROID_NOISE_REDUCTION_START, 61 ANDROID_NOISE_REDUCTION_END }, 62 [ANDROID_QUIRKS] = { ANDROID_QUIRKS_START, 63 ANDROID_QUIRKS_END }, 64 [ANDROID_REQUEST] = { ANDROID_REQUEST_START, 65 ANDROID_REQUEST_END }, 66 [ANDROID_SCALER] = { ANDROID_SCALER_START, 67 ANDROID_SCALER_END }, 68 [ANDROID_SENSOR] = { ANDROID_SENSOR_START, 69 ANDROID_SENSOR_END }, 70 [ANDROID_SENSOR_INFO] = { ANDROID_SENSOR_INFO_START, 71 ANDROID_SENSOR_INFO_END }, 72 [ANDROID_SHADING] = { ANDROID_SHADING_START, 73 ANDROID_SHADING_END }, 74 [ANDROID_STATISTICS] = { ANDROID_STATISTICS_START, 75 ANDROID_STATISTICS_END }, 76 [ANDROID_STATISTICS_INFO] = { ANDROID_STATISTICS_INFO_START, 77 ANDROID_STATISTICS_INFO_END }, 78 [ANDROID_TONEMAP] = { ANDROID_TONEMAP_START, 79 ANDROID_TONEMAP_END }, 80 [ANDROID_LED] = { ANDROID_LED_START, 81 ANDROID_LED_END }, 82 [ANDROID_INFO] = { ANDROID_INFO_START, 83 ANDROID_INFO_END }, 84 [ANDROID_BLACK_LEVEL] = { ANDROID_BLACK_LEVEL_START, 85 ANDROID_BLACK_LEVEL_END }, 86 [ANDROID_SYNC] = { ANDROID_SYNC_START, 87 ANDROID_SYNC_END }, 88 [ANDROID_REPROCESS] = { ANDROID_REPROCESS_START, 89 ANDROID_REPROCESS_END }, 90 [ANDROID_DEPTH] = { ANDROID_DEPTH_START, 91 ANDROID_DEPTH_END }, 92 [ANDROID_LOGICAL_MULTI_CAMERA] = { ANDROID_LOGICAL_MULTI_CAMERA_START, 93 ANDROID_LOGICAL_MULTI_CAMERA_END }, 94 [ANDROID_DISTORTION_CORRECTION] 95 = { ANDROID_DISTORTION_CORRECTION_START, 96 ANDROID_DISTORTION_CORRECTION_END }, 97 };
由 tag_info 结构体统一管理：
1 static tag_info_t android_color_correction[ANDROID_COLOR_CORRECTION_END - 2 ANDROID_COLOR_CORRECTION_START] = { 3 [ ANDROID_COLOR_CORRECTION_MODE - ANDROID_COLOR_CORRECTION_START ] = 4 { "mode", TYPE_BYTE }, 5 [ ANDROID_COLOR_CORRECTION_TRANSFORM - ANDROID_COLOR_CORRECTION_START ] = 6 { "transform", TYPE_RATIONAL 7 }, 8 [ ANDROID_COLOR_CORRECTION_GAINS - ANDROID_COLOR_CORRECTION_START ] = 9 { "gains", TYPE_FLOAT }, 10 [ ANDROID_COLOR_CORRECTION_ABERRATION_MODE - ANDROID_COLOR_CORRECTION_START ] = 11 { "aberrationMode", TYPE_BYTE }, 12 [ ANDROID_COLOR_CORRECTION_AVAILABLE_ABERRATION_MODES - ANDROID_COLOR_CORRECTION_START ] = 13 { "availableAberrationModes", TYPE_BYTE }, 14 }; 15 16 ------------------------------------------------------------- 17 18 tag_info_t *tag_info[ANDROID_SECTION_COUNT] = { 19 android_color_correction, 20 android_control, 21 android_demosaic, 22 android_edge, 23 android_flash, 24 android_flash_info, 25 android_hot_pixel, 26 android_jpeg, 27 android_lens, 28 android_lens_info, 29 android_noise_reduction, 30 android_quirks, 31 android_request, 32 android_scaler, 33 android_sensor, 34 android_sensor_info, 35 android_shading, 36 android_statistics, 37 android_statistics_info, 38 android_tonemap, 39 android_led, 40 android_info, 41 android_black_level, 42 android_sync, 43 android_reprocess, 44 android_depth, 45 android_logical_multi_camera, 46 android_distortion_correction, 47 };
下图是Camera Metadata对不同section以及相应section下不同tag的布局图，以最常见的android.control Section为例进行描述：
标签：generate hat 信息 char session methods mil 摄像头 dde
原文地址：https://www.cnblogs.com/SaraMoring/p/14385967.html
