我們想查看camera 相關的一些基本配置信息，可以dump media.camera來查看：
adb shell dump media.camera > camera.txt
一. 查看相機支持的preview size和picture size
在dump結果中，搜索android.scaler.availableStreamConfigurations，出來的結果列表形式如下：
android.scaler.availableStreamConfigurations (d000a): int32[516]
[34 1920 1080 OUTPUT ]
其中，第1個參數為format，第2個參數為width，第3個參數為height，第4個參數為streamType（preview看OUTPUT類型）。
主要的format為：
HAL_PIXEL_FORMAT_RAW16 = 32;
HAL_PIXEL_FORMAT_BLOB = 33;
HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED = 34;
HAL_PIXEL_FORMAT_YCbCr_420_888 = 35;
HAL_PIXEL_FORMAT_RAW_OPAQUE = 36;
HAL_PIXEL_FORMAT_RAW10 = 37;
HAL_PIXEL_FORMAT_RAW12 = 38;
HAL_PIXEL_FORMAT_BLOB表示是jpeg stream，對應的size即平時所說的picture size; HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED表示preview stream，對應的size即平時所說的preview size.
例如，[34 1920 1080 OUTPUT ]表示preview size支持1920x1080. [33 1280 720 OUTPUT ]表示picture size支持1280x720.
所以availableStreamConfigurations的輸出結果中，所有format=34且streamType=OUTPUT的size即為相機支持的preview size.
同理，所有format=33且streamType=OUTPUT的size即為相機支持的picture size.
二、查看相機支持的FPS
在dump結果中，搜索android.control.aeAvailableTargetFpsRanges，出來的結果列表形式如下：
android.control.aeAvailableTargetFpsRanges (10014): int32[8]
[15 15 15 30 ]
[30 30 30 30 ]
數據中每2個一組構成一個FPSRange，其中第1個為FPSRange的下限，第2個為FPSRange的上限。
三.查看當前打開的相機及其設置
在dump結果，搜索CameraDeviceClient，出來的結果類似：
Number of camera devices: 7
Number of normal camera devices: 3
Device 0 maps to "0"
Device 1 maps to "1"
Device 2 maps to "2"
Active Camera Clients:
[
(Camera ID: 0, Cost: 100, PID: 13723, Score: 0, State: 2User Id: 0,
Client Package Name: com.jingdong.app.mall, Conflicting Client Devices: {6, })
]
Allowed user IDs: 0
要查看相機當前的設置，只需在該client的“Dumping camera metadata array”中根據對應的key搜索即可。
例如：查看相機當前設置的FPS
在dump結果中，搜索android.control.aeTargetFpsRange，出來的結果即為當前的FPSRange.
android.control.aeTargetFpsRange (10005): int32[2]
[15 30 ]
例如，[15 30 ]表示當前設定的FPSRange為[15 30 ].
四.查看相機當前設置的preview size和picture size
在dump結果中，搜索Stream configuration，Stream configuration的輸出類似：
Stream[0]: Output
Consumer name: SurfaceView - com.jingdong.app.mall/com.jd.lib.scan.lib.zxing.client.android.CaptureActivity#0
State: 4
Dims: 720 x 480, format 0x22, dataspace 0x0
Max size: 0
Combined usage: 133376, max HAL buffers: 8
Frames produced: 69, last timestamp: 850646358680 ns
Total buffers: 9, currently dequeued: 5
DequeueBuffer latency histogram: (74) samples
5 10 15 20 25 30 35 40 45 inf (max ms)
100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (%)
Stream[1]: Output
Consumer name: Camera2-JpegConsumer
State: 4
Dims: 720 x 480, format 0x21, dataspace 0x8c20000
Max size: 778507
Combined usage: 131075, max HAL buffers: 8
Frames produced: 0, last timestamp: 0 ns
Total buffers: 9, currently dequeued: 0
Stream[2]: Output
Consumer name: Camera2-CallbackConsumer
State: 4
Dims: 720 x 480, format 0x23, dataspace 0x8c20000
Max size: 0
Combined usage: 131075, max HAL buffers: 8
Frames produced: 66, last timestamp: 850613073471 ns
Total buffers: 14, currently dequeued: 6
DequeueBuffer latency histogram: (72) samples
其中stream 0的format為0x22=34，這個即為preview stream，其size為720 x 480.
其中stream 1的format為0x21=33，這個即為jpeg stream，其size為720 x 480.
附錄：
------- CameraService.cpp
status_t CameraService::dump(int fd, const Vector<String16>& args) {
ATRACE_CALL();
if (checkCallingPermission(String16("android.permission.DUMP")) == false) {
dprintf(fd, "Permission Denial: can't dump CameraService from pid=%d, uid=%d\n",
getCallingPid(),
getCallingUid());
return NO_ERROR;
}
bool locked = tryLock(mServiceLock);
// failed to lock - CameraService is probably deadlocked
if (!locked) {
dprintf(fd, "!! CameraService may be deadlocked !!\n");
}
if (!mInitialized) {
dprintf(fd, "!! No camera HAL available !!\n");
// Dump event log for error information
dumpEventLog(fd);
if (locked) mServiceLock.unlock();
return NO_ERROR;
}
dprintf(fd, "\n== Service global info: ==\n\n");
dprintf(fd, "Number of camera devices: %d\n", mNumberOfCameras);
dprintf(fd, "Number of normal camera devices: %zu\n", mNormalDeviceIds.size());
for (size_t i = 0; i < mNormalDeviceIds.size(); i++) {
dprintf(fd, " Device %zu maps to \"%s\"\n", i, mNormalDeviceIds[i].c_str());
}
String8 activeClientString = mActiveClientManager.toString();
dprintf(fd, "Active Camera Clients:\n%s", activeClientString.string());
dprintf(fd, "Allowed user IDs: %s\n", toString(mAllowedUsers).string());
dumpEventLog(fd);
bool stateLocked = tryLock(mCameraStatesLock);
if (!stateLocked) {
dprintf(fd, "CameraStates in use, may be deadlocked\n");
}
int argSize = args.size();
for (int i = 0; i < argSize; i++) {
if (args[i] == TagMonitor::kMonitorOption) {
if (i + 1 < argSize) {
mMonitorTags = String8(args[i + 1]);
}
break;
}
}
for (auto& state : mCameraStates) {
String8 cameraId = state.first;
dprintf(fd, "== Camera device %s dynamic info: ==\n", cameraId.string());
CameraParameters p = state.second->getShimParams();
if (!p.isEmpty()) {
dprintf(fd, " Camera1 API shim is using parameters:\n ");
p.dump(fd, args);
}
auto clientDescriptor = mActiveClientManager.get(cameraId);
if (clientDescriptor != nullptr) {
dprintf(fd, " Device %s is open. Client instance dump:\n",
cameraId.string());
dprintf(fd, " Client priority score: %d state: %d\n",
clientDescriptor->getPriority().getScore(),
clientDescriptor->getPriority().getState());
dprintf(fd, " Client PID: %d\n", clientDescriptor->getOwnerId());
auto client = clientDescriptor->getValue();
dprintf(fd, " Client package: %s\n",
String8(client->getPackageName()).string());
client->dumpClient(fd, args);
} else {
dprintf(fd, " Device %s is closed, no client instance\n",
cameraId.string());
}
}
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