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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "EvsEnumerator.h"
#include "EvsV4lCamera.h"
#include "EvsGlDisplay.h"
#include <dirent.h>
namespace android {
namespace hardware {
namespace automotive {
namespace evs {
namespace V1_0 {
namespace implementation {
// NOTE: All members values are static so that all clients operate on the same state
// That is to say, this is effectively a singleton despite the fact that HIDL
// constructs a new instance for each client.
std::list<EvsEnumerator::CameraRecord> EvsEnumerator::sCameraList;
wp<EvsGlDisplay> EvsEnumerator::sActiveDisplay;
EvsEnumerator::EvsEnumerator() {
ALOGD("EvsEnumerator created");
unsigned videoCount = 0;
unsigned captureCount = 0;
// For every video* entry in the dev folder, see if it reports suitable capabilities
// WARNING: Depending on the driver implementations this could be slow, especially if
// there are timeouts or round trips to hardware required to collect the needed
// information. Platform implementers should consider hard coding this list of
// known good devices to speed up the startup time of their EVS implementation.
// For example, this code might be replaced with nothing more than:
// sCameraList.emplace_back("/dev/video0");
// sCameraList.emplace_back("/dev/video1");
ALOGI("Starting dev/video* enumeration");
DIR* dir = opendir("/dev");
if (!dir) {
LOG_FATAL("Failed to open /dev folder\n");
}
struct dirent* entry;
while ((entry = readdir(dir)) != nullptr) {
// We're only looking for entries starting with 'video'
if (strncmp(entry->d_name, "video", 5) == 0) {
std::string deviceName("/dev/");
deviceName += entry->d_name;
videoCount++;
if (qualifyCaptureDevice(deviceName.c_str())) {
sCameraList.emplace_back(deviceName.c_str());
captureCount++;
}
}
}
ALOGI("Found %d qualified video capture devices of %d checked\n", captureCount, videoCount);
}
// Methods from ::android::hardware::automotive::evs::V1_0::IEvsEnumerator follow.
Return<void> EvsEnumerator::getCameraList(getCameraList_cb _hidl_cb) {
ALOGD("getCameraList");
const unsigned numCameras = sCameraList.size();
// Build up a packed array of CameraDesc for return
hidl_vec<CameraDesc> hidlCameras;
hidlCameras.resize(numCameras);
unsigned i = 0;
for (const auto& cam : sCameraList) {
hidlCameras[i++] = cam.desc;
}
// Send back the results
ALOGD("reporting %zu cameras available", hidlCameras.size());
_hidl_cb(hidlCameras);
// HIDL convention says we return Void if we sent our result back via callback
return Void();
}
Return<sp<IEvsCamera>> EvsEnumerator::openCamera(const hidl_string& cameraId) {
ALOGD("openCamera");
// Is this a recognized camera id?
CameraRecord *pRecord = findCameraById(cameraId);
if (!pRecord) {
ALOGE("Requested camera %s not found", cameraId.c_str());
return nullptr;
}
// Has this camera already been instantiated by another caller?
sp<EvsV4lCamera> pActiveCamera = pRecord->activeInstance.promote();
if (pActiveCamera != nullptr) {
ALOGW("Killing previous camera because of new caller");
closeCamera(pActiveCamera);
}
// Construct a camera instance for the caller
pActiveCamera = new EvsV4lCamera(cameraId.c_str());
pRecord->activeInstance = pActiveCamera;
if (pActiveCamera == nullptr) {
ALOGE("Failed to allocate new EvsV4lCamera object for %s\n", cameraId.c_str());
}
return pActiveCamera;
}
Return<void> EvsEnumerator::closeCamera(const ::android::sp<IEvsCamera>& pCamera) {
ALOGD("closeCamera");
if (pCamera == nullptr) {
ALOGE("Ignoring call to closeCamera with null camera ptr");
return Void();
}
// Get the camera id so we can find it in our list
std::string cameraId;
pCamera->getCameraInfo([&cameraId](CameraDesc desc) {
cameraId = desc.cameraId;
}
);
// Find the named camera
CameraRecord *pRecord = findCameraById(cameraId);
// Is the display being destroyed actually the one we think is active?
if (!pRecord) {
ALOGE("Asked to close a camera whose name isn't recognized");
} else {
sp<EvsV4lCamera> pActiveCamera = pRecord->activeInstance.promote();
if (pActiveCamera == nullptr) {
ALOGE("Somehow a camera is being destroyed when the enumerator didn't know one existed");
} else if (pActiveCamera != pCamera) {
// This can happen if the camera was aggressively reopened, orphaning this previous instance
ALOGW("Ignoring close of previously orphaned camera - why did a client steal?");
} else {
// Drop the active camera
pActiveCamera->shutdown();
pRecord->activeInstance = nullptr;
}
}
return Void();
}
Return<sp<IEvsDisplay>> EvsEnumerator::openDisplay() {
ALOGD("openDisplay");
// If we already have a display active, then we need to shut it down so we can
// give exclusive access to the new caller.
sp<EvsGlDisplay> pActiveDisplay = sActiveDisplay.promote();
if (pActiveDisplay != nullptr) {
ALOGW("Killing previous display because of new caller");
closeDisplay(pActiveDisplay);
}
// Create a new display interface and return it
pActiveDisplay = new EvsGlDisplay();
sActiveDisplay = pActiveDisplay;
ALOGD("Returning new EvsGlDisplay object %p", pActiveDisplay.get());
return pActiveDisplay;
}
Return<void> EvsEnumerator::closeDisplay(const ::android::sp<IEvsDisplay>& pDisplay) {
ALOGD("closeDisplay");
// Do we still have a display object we think should be active?
sp<EvsGlDisplay> pActiveDisplay = sActiveDisplay.promote();
if (pActiveDisplay == nullptr) {
ALOGE("Somehow a display is being destroyed when the enumerator didn't know one existed");
} else if (sActiveDisplay != pDisplay) {
ALOGW("Ignoring close of previously orphaned display - why did a client steal?");
} else {
// Drop the active display
pActiveDisplay->forceShutdown();
sActiveDisplay = nullptr;
}
return Void();
}
Return<DisplayState> EvsEnumerator::getDisplayState() {
ALOGD("getDisplayState");
// Do we still have a display object we think should be active?
sp<IEvsDisplay> pActiveDisplay = sActiveDisplay.promote();
if (pActiveDisplay != nullptr) {
return pActiveDisplay->getDisplayState();
} else {
return DisplayState::NOT_OPEN;
}
}
bool EvsEnumerator::qualifyCaptureDevice(const char* deviceName) {
class FileHandleWrapper {
public:
FileHandleWrapper(int fd) { mFd = fd; }
~FileHandleWrapper() { if (mFd > 0) close(mFd); }
operator int() const { return mFd; }
private:
int mFd = -1;
};
FileHandleWrapper fd = open(deviceName, O_RDWR, 0);
if (fd < 0) {
return false;
}
v4l2_capability caps;
int result = ioctl(fd, VIDIOC_QUERYCAP, &caps);
if (result < 0) {
return false;
}
if (((caps.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) ||
((caps.capabilities & V4L2_CAP_STREAMING) == 0)) {
return false;
}
// Enumerate the available capture formats (if any)
v4l2_fmtdesc formatDescription;
formatDescription.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
for (int i=0; true; i++) {
formatDescription.index = i;
if (ioctl(fd, VIDIOC_ENUM_FMT, &formatDescription) == 0) {
switch (formatDescription.pixelformat)
{
case V4L2_PIX_FMT_YUYV: return true;
case V4L2_PIX_FMT_NV21: return true;
case V4L2_PIX_FMT_NV16: return true;
case V4L2_PIX_FMT_YVU420: return true;
case V4L2_PIX_FMT_RGB32: return true;
#ifdef V4L2_PIX_FMT_ARGB32 // introduced with kernel v3.17
case V4L2_PIX_FMT_ARGB32: return true;
case V4L2_PIX_FMT_XRGB32: return true;
#endif // V4L2_PIX_FMT_ARGB32
default: break;
}
} else {
// No more formats available
break;
}
}
// If we get here, we didn't find a usable output format
return false;
}
EvsEnumerator::CameraRecord* EvsEnumerator::findCameraById(const std::string& cameraId) {
// Find the named camera
for (auto &&cam : sCameraList) {
if (cam.desc.cameraId == cameraId) {
// Found a match!
return &cam;
}
}
// We didn't find a match
return nullptr;
}
} // namespace implementation
} // namespace V1_0
} // namespace evs
} // namespace automotive
} // namespace hardware
} // namespace android