/*
* 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 "EvsV4lCamera.h"
#include "EvsEnumerator.h"
#include "bufferCopy.h"
#include <ui/GraphicBufferAllocator.h>
#include <ui/GraphicBufferMapper.h>
namespace android {
namespace hardware {
namespace automotive {
namespace evs {
namespace V1_0 {
namespace implementation {
// Arbitrary limit on number of graphics buffers allowed to be allocated
// Safeguards against unreasonable resource consumption and provides a testable limit
static const unsigned MAX_BUFFERS_IN_FLIGHT = 100;
EvsV4lCamera::EvsV4lCamera(const char *deviceName) :
mFramesAllowed(0),
mFramesInUse(0) {
ALOGD("EvsV4lCamera instantiated");
mDescription.cameraId = deviceName;
// Initialize the video device
if (!mVideo.open(deviceName)) {
ALOGE("Failed to open v4l device %s\n", deviceName);
}
// Output buffer format.
// TODO: Does this need to be configurable?
mFormat = HAL_PIXEL_FORMAT_RGBA_8888;
// How we expect to use the gralloc buffers we'll exchange with our client
mUsage = GRALLOC_USAGE_HW_TEXTURE |
GRALLOC_USAGE_SW_READ_RARELY |
GRALLOC_USAGE_SW_WRITE_OFTEN;
}
EvsV4lCamera::~EvsV4lCamera() {
ALOGD("EvsV4lCamera being destroyed");
shutdown();
}
//
// This gets called if another caller "steals" ownership of the camera
//
void EvsV4lCamera::shutdown()
{
ALOGD("EvsV4lCamera shutdown");
// Make sure our output stream is cleaned up
// (It really should be already)
stopVideoStream();
// Note: Since stopVideoStream is blocking, no other threads can now be running
// Close our video capture device
mVideo.close();
// Drop all the graphics buffers we've been using
if (mBuffers.size() > 0) {
GraphicBufferAllocator& alloc(GraphicBufferAllocator::get());
for (auto&& rec : mBuffers) {
if (rec.inUse) {
ALOGW("Error - releasing buffer despite remote ownership");
}
alloc.free(rec.handle);
rec.handle = nullptr;
}
mBuffers.clear();
}
}
// Methods from ::android::hardware::automotive::evs::V1_0::IEvsCamera follow.
Return<void> EvsV4lCamera::getCameraInfo(getCameraInfo_cb _hidl_cb) {
ALOGD("getCameraInfo");
// Send back our self description
_hidl_cb(mDescription);
return Void();
}
Return<EvsResult> EvsV4lCamera::setMaxFramesInFlight(uint32_t bufferCount) {
ALOGD("setMaxFramesInFlight");
std::lock_guard<std::mutex> lock(mAccessLock);
// If we've been displaced by another owner of the camera, then we can't do anything else
if (!mVideo.isOpen()) {
ALOGW("ignoring setMaxFramesInFlight call when camera has been lost.");
return EvsResult::OWNERSHIP_LOST;
}
// We cannot function without at least one video buffer to send data
if (bufferCount < 1) {
ALOGE("Ignoring setMaxFramesInFlight with less than one buffer requested");
return EvsResult::INVALID_ARG;
}
// Update our internal state
if (setAvailableFrames_Locked(bufferCount)) {
return EvsResult::OK;
} else {
return EvsResult::BUFFER_NOT_AVAILABLE;
}
}
Return<EvsResult> EvsV4lCamera::startVideoStream(const ::android::sp<IEvsCameraStream>& stream) {
ALOGD("startVideoStream");
std::lock_guard<std::mutex> lock(mAccessLock);
// If we've been displaced by another owner of the camera, then we can't do anything else
if (!mVideo.isOpen()) {
ALOGW("ignoring startVideoStream call when camera has been lost.");
return EvsResult::OWNERSHIP_LOST;
}
if (mStream.get() != nullptr) {
ALOGE("ignoring startVideoStream call when a stream is already running.");
return EvsResult::STREAM_ALREADY_RUNNING;
}
// If the client never indicated otherwise, configure ourselves for a single streaming buffer
if (mFramesAllowed < 1) {
if (!setAvailableFrames_Locked(1)) {
ALOGE("Failed to start stream because we couldn't get a graphics buffer");
return EvsResult::BUFFER_NOT_AVAILABLE;
}
}
// Choose which image transfer function we need
// Map from V4L2 to Android graphic buffer format
const uint32_t videoSrcFormat = mVideo.getV4LFormat();
ALOGI("Configuring to accept %4.4s camera data and convert to 0x%X",
(char*)&videoSrcFormat, mFormat);
switch (mFormat) {
case HAL_PIXEL_FORMAT_YCRCB_420_SP:
switch (videoSrcFormat) {
case V4L2_PIX_FMT_NV21: mFillBufferFromVideo = fillNV21FromNV21; break;
case V4L2_PIX_FMT_YUYV: mFillBufferFromVideo = fillNV21FromYUYV; break;
default:
ALOGE("Unhandled camera output format %c%c%c%c (0x%8X)\n",
((char*)&videoSrcFormat)[0],
((char*)&videoSrcFormat)[1],
((char*)&videoSrcFormat)[2],
((char*)&videoSrcFormat)[3],
videoSrcFormat);
}
break;
case HAL_PIXEL_FORMAT_RGBA_8888:
switch (videoSrcFormat) {
case V4L2_PIX_FMT_YUYV: mFillBufferFromVideo = fillRGBAFromYUYV; break;
default:
ALOGE("Unhandled camera format %4.4s", (char*)&videoSrcFormat);
}
break;
case HAL_PIXEL_FORMAT_YCBCR_422_I:
switch (videoSrcFormat) {
case V4L2_PIX_FMT_YUYV: mFillBufferFromVideo = fillYUYVFromYUYV; break;
case V4L2_PIX_FMT_UYVY: mFillBufferFromVideo = fillYUYVFromUYVY; break;
default:
ALOGE("Unhandled camera format %4.4s", (char*)&videoSrcFormat);
}
break;
default:
ALOGE("Unhandled output format %4.4s", (char*)&mFormat);
}
// Record the user's callback for use when we have a frame ready
mStream = stream;
// Set up the video stream with a callback to our member function forwardFrame()
if (!mVideo.startStream([this](VideoCapture*, imageBuffer* tgt, void* data) {
this->forwardFrame(tgt, data);
})
) {
mStream = nullptr; // No need to hold onto this if we failed to start
ALOGE("underlying camera start stream failed");
return EvsResult::UNDERLYING_SERVICE_ERROR;
}
return EvsResult::OK;
}
Return<void> EvsV4lCamera::doneWithFrame(const BufferDesc& buffer) {
ALOGD("doneWithFrame");
std::lock_guard <std::mutex> lock(mAccessLock);
// If we've been displaced by another owner of the camera, then we can't do anything else
if (!mVideo.isOpen()) {
ALOGW("ignoring doneWithFrame call when camera has been lost.");
} else {
if (buffer.memHandle == nullptr) {
ALOGE("ignoring doneWithFrame called with null handle");
} else if (buffer.bufferId >= mBuffers.size()) {
ALOGE("ignoring doneWithFrame called with invalid bufferId %d (max is %zu)",
buffer.bufferId, mBuffers.size()-1);
} else if (!mBuffers[buffer.bufferId].inUse) {
ALOGE("ignoring doneWithFrame called on frame %d which is already free",
buffer.bufferId);
} else {
// Mark the frame as available
mBuffers[buffer.bufferId].inUse = false;
mFramesInUse--;
// If this frame's index is high in the array, try to move it down
// to improve locality after mFramesAllowed has been reduced.
if (buffer.bufferId >= mFramesAllowed) {
// Find an empty slot lower in the array (which should always exist in this case)
for (auto&& rec : mBuffers) {
if (rec.handle == nullptr) {
rec.handle = mBuffers[buffer.bufferId].handle;
mBuffers[buffer.bufferId].handle = nullptr;
break;
}
}
}
}
}
return Void();
}
Return<void> EvsV4lCamera::stopVideoStream() {
ALOGD("stopVideoStream");
// Tell the capture device to stop (and block until it does)
mVideo.stopStream();
if (mStream != nullptr) {
std::unique_lock <std::mutex> lock(mAccessLock);
// Send one last NULL frame to signal the actual end of stream
BufferDesc nullBuff = {};
auto result = mStream->deliverFrame(nullBuff);
if (!result.isOk()) {
ALOGE("Error delivering end of stream marker");
}
// Drop our reference to the client's stream receiver
mStream = nullptr;
}
return Void();
}
Return<int32_t> EvsV4lCamera::getExtendedInfo(uint32_t /*opaqueIdentifier*/) {
ALOGD("getExtendedInfo");
// Return zero by default as required by the spec
return 0;
}
Return<EvsResult> EvsV4lCamera::setExtendedInfo(uint32_t /*opaqueIdentifier*/,
int32_t /*opaqueValue*/) {
ALOGD("setExtendedInfo");
std::lock_guard<std::mutex> lock(mAccessLock);
// If we've been displaced by another owner of the camera, then we can't do anything else
if (!mVideo.isOpen()) {
ALOGW("ignoring setExtendedInfo call when camera has been lost.");
return EvsResult::OWNERSHIP_LOST;
}
// We don't store any device specific information in this implementation
return EvsResult::INVALID_ARG;
}
bool EvsV4lCamera::setAvailableFrames_Locked(unsigned bufferCount) {
if (bufferCount < 1) {
ALOGE("Ignoring request to set buffer count to zero");
return false;
}
if (bufferCount > MAX_BUFFERS_IN_FLIGHT) {
ALOGE("Rejecting buffer request in excess of internal limit");
return false;
}
// Is an increase required?
if (mFramesAllowed < bufferCount) {
// An increase is required
unsigned needed = bufferCount - mFramesAllowed;
ALOGI("Allocating %d buffers for camera frames", needed);
unsigned added = increaseAvailableFrames_Locked(needed);
if (added != needed) {
// If we didn't add all the frames we needed, then roll back to the previous state
ALOGE("Rolling back to previous frame queue size");
decreaseAvailableFrames_Locked(added);
return false;
}
} else if (mFramesAllowed > bufferCount) {
// A decrease is required
unsigned framesToRelease = mFramesAllowed - bufferCount;
ALOGI("Returning %d camera frame buffers", framesToRelease);
unsigned released = decreaseAvailableFrames_Locked(framesToRelease);
if (released != framesToRelease) {
// This shouldn't happen with a properly behaving client because the client
// should only make this call after returning sufficient outstanding buffers
// to allow a clean resize.
ALOGE("Buffer queue shrink failed -- too many buffers currently in use?");
}
}
return true;
}
unsigned EvsV4lCamera::increaseAvailableFrames_Locked(unsigned numToAdd) {
// Acquire the graphics buffer allocator
GraphicBufferAllocator &alloc(GraphicBufferAllocator::get());
unsigned added = 0;
while (added < numToAdd) {
unsigned pixelsPerLine;
buffer_handle_t memHandle = nullptr;
status_t result = alloc.allocate(mVideo.getWidth(), mVideo.getHeight(),
mFormat, 1,
mUsage,
&memHandle, &pixelsPerLine, 0, "EvsV4lCamera");
if (result != NO_ERROR) {
ALOGE("Error %d allocating %d x %d graphics buffer",
result,
mVideo.getWidth(),
mVideo.getHeight());
break;
}
if (!memHandle) {
ALOGE("We didn't get a buffer handle back from the allocator");
break;
}
if (mStride) {
if (mStride != pixelsPerLine) {
ALOGE("We did not expect to get buffers with different strides!");
}
} else {
// Gralloc defines stride in terms of pixels per line
mStride = pixelsPerLine;
}
// Find a place to store the new buffer
bool stored = false;
for (auto&& rec : mBuffers) {
if (rec.handle == nullptr) {
// Use this existing entry
rec.handle = memHandle;
rec.inUse = false;
stored = true;
break;
}
}
if (!stored) {
// Add a BufferRecord wrapping this handle to our set of available buffers
mBuffers.emplace_back(memHandle);
}
mFramesAllowed++;
added++;
}
return added;
}
unsigned EvsV4lCamera::decreaseAvailableFrames_Locked(unsigned numToRemove) {
// Acquire the graphics buffer allocator
GraphicBufferAllocator &alloc(GraphicBufferAllocator::get());
unsigned removed = 0;
for (auto&& rec : mBuffers) {
// Is this record not in use, but holding a buffer that we can free?
if ((rec.inUse == false) && (rec.handle != nullptr)) {
// Release buffer and update the record so we can recognize it as "empty"
alloc.free(rec.handle);
rec.handle = nullptr;
mFramesAllowed--;
removed++;
if (removed == numToRemove) {
break;
}
}
}
return removed;
}
// This is the async callback from the video camera that tells us a frame is ready
void EvsV4lCamera::forwardFrame(imageBuffer* /*pV4lBuff*/, void* pData) {
bool readyForFrame = false;
size_t idx = 0;
// Lock scope for updating shared state
{
std::lock_guard<std::mutex> lock(mAccessLock);
// Are we allowed to issue another buffer?
if (mFramesInUse >= mFramesAllowed) {
// Can't do anything right now -- skip this frame
ALOGW("Skipped a frame because too many are in flight\n");
} else {
// Identify an available buffer to fill
for (idx = 0; idx < mBuffers.size(); idx++) {
if (!mBuffers[idx].inUse) {
if (mBuffers[idx].handle != nullptr) {
// Found an available record, so stop looking
break;
}
}
}
if (idx >= mBuffers.size()) {
// This shouldn't happen since we already checked mFramesInUse vs mFramesAllowed
ALOGE("Failed to find an available buffer slot\n");
} else {
// We're going to make the frame busy
mBuffers[idx].inUse = true;
mFramesInUse++;
readyForFrame = true;
}
}
}
if (!readyForFrame) {
// We need to return the vide buffer so it can capture a new frame
mVideo.markFrameConsumed();
} else {
// Assemble the buffer description we'll transmit below
BufferDesc buff = {};
buff.width = mVideo.getWidth();
buff.height = mVideo.getHeight();
buff.stride = mStride;
buff.format = mFormat;
buff.usage = mUsage;
buff.bufferId = idx;
buff.memHandle = mBuffers[idx].handle;
// Lock our output buffer for writing
void *targetPixels = nullptr;
GraphicBufferMapper &mapper = GraphicBufferMapper::get();
mapper.lock(buff.memHandle,
GRALLOC_USAGE_SW_WRITE_OFTEN | GRALLOC_USAGE_SW_READ_NEVER,
android::Rect(buff.width, buff.height),
(void **) &targetPixels);
// If we failed to lock the pixel buffer, we're about to crash, but log it first
if (!targetPixels) {
ALOGE("Camera failed to gain access to image buffer for writing");
}
// Transfer the video image into the output buffer, making any needed
// format conversion along the way
mFillBufferFromVideo(buff, (uint8_t*)targetPixels, pData, mVideo.getStride());
// Unlock the output buffer
mapper.unlock(buff.memHandle);
// Give the video frame back to the underlying device for reuse
// Note that we do this before making the client callback to give the underlying
// camera more time to capture the next frame.
mVideo.markFrameConsumed();
// Issue the (asynchronous) callback to the client -- can't be holding the lock
auto result = mStream->deliverFrame(buff);
if (result.isOk()) {
ALOGD("Delivered %p as id %d", buff.memHandle.getNativeHandle(), buff.bufferId);
} else {
// This can happen if the client dies and is likely unrecoverable.
// To avoid consuming resources generating failing calls, we stop sending
// frames. Note, however, that the stream remains in the "STREAMING" state
// until cleaned up on the main thread.
ALOGE("Frame delivery call failed in the transport layer.");
// Since we didn't actually deliver it, mark the frame as available
std::lock_guard<std::mutex> lock(mAccessLock);
mBuffers[idx].inUse = false;
mFramesInUse--;
}
}
}
} // namespace implementation
} // namespace V1_0
} // namespace evs
} // namespace automotive
} // namespace hardware
} // namespace android