Add TouchVideoDevice
TouchVideoDevice will represent a video device that reports heatmaps.
The heatmaps are strength of the signal at each point of the
touchscreen, taken at a particular time.
The only purpose of TouchVideoDevice is to read TouchVideoFrames.
Test: this is a partial cherry-pick of a standalone binary that was used
to pull heatmaps. Integration tested by observing the action of
InputClassifier HAL.
Bug: 111480215
Change-Id: Iba1b38114b156d4debb5966b803f3df6cdb1b91c
diff --git a/services/inputflinger/TouchVideoDevice.cpp b/services/inputflinger/TouchVideoDevice.cpp
new file mode 100644
index 0000000..ad70ccc
--- /dev/null
+++ b/services/inputflinger/TouchVideoDevice.cpp
@@ -0,0 +1,247 @@
+/*
+ * Copyright (C) 2018 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 "TouchVideoDevice.h"
+
+#define LOG_TAG "TouchVideoDevice"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/videodev2.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <iostream>
+
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <log/log.h>
+
+using android::base::StringPrintf;
+using android::base::unique_fd;
+
+namespace android {
+
+TouchVideoDevice::TouchVideoDevice(int fd, std::string&& name, std::string&& devicePath,
+ uint32_t width, uint32_t height,
+ const std::array<const int16_t*, NUM_BUFFERS>& readLocations) :
+ mFd(fd), mName(std::move(name)), mPath(std::move(devicePath)),
+ mWidth(width), mHeight(height),
+ mReadLocations(readLocations) {
+ mFrames.reserve(MAX_QUEUE_SIZE);
+};
+
+std::unique_ptr<TouchVideoDevice> TouchVideoDevice::create(std::string devicePath) {
+ unique_fd fd(open(devicePath.c_str(), O_RDWR | O_NONBLOCK));
+ if (fd.get() == INVALID_FD) {
+ ALOGE("Could not open video device %s: %s", devicePath.c_str(), strerror(errno));
+ return nullptr;
+ }
+
+ struct v4l2_capability cap;
+ int result = ioctl(fd.get(), VIDIOC_QUERYCAP, &cap);
+ if (result == -1) {
+ ALOGE("VIDIOC_QUERYCAP failed: %s", strerror(errno));
+ return nullptr;
+ }
+ if (!(cap.capabilities & V4L2_CAP_TOUCH)) {
+ ALOGE("Capability V4L2_CAP_TOUCH is not present, can't use device for heatmap data. "
+ "Make sure device specifies V4L2_CAP_TOUCH");
+ return nullptr;
+ }
+ ALOGI("Opening video device: driver = %s, card = %s, bus_info = %s, version = %i",
+ cap.driver, cap.card, cap.bus_info, cap.version);
+ std::string name = reinterpret_cast<const char*>(cap.card);
+
+ struct v4l2_input v4l2_input_struct;
+ result = ioctl(fd.get(), VIDIOC_ENUMINPUT, &v4l2_input_struct);
+ if (result == -1) {
+ ALOGE("VIDIOC_ENUMINPUT failed: %s", strerror(errno));
+ return nullptr;
+ }
+
+ if (v4l2_input_struct.type != V4L2_INPUT_TYPE_TOUCH) {
+ ALOGE("Video device does not provide touch data. "
+ "Make sure device specifies V4L2_INPUT_TYPE_TOUCH.");
+ return nullptr;
+ }
+
+ struct v4l2_format v4l2_fmt;
+ v4l2_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ result = ioctl(fd.get(), VIDIOC_G_FMT, &v4l2_fmt);
+ if (result == -1) {
+ ALOGE("VIDIOC_G_FMT failed: %s", strerror(errno));
+ return nullptr;
+ }
+ const uint32_t width = v4l2_fmt.fmt.pix.width;
+ const uint32_t height = v4l2_fmt.fmt.pix.height;
+ ALOGI("Frame dimensions: width = %" PRIu32 " height = %" PRIu32, width, height);
+
+ struct v4l2_requestbuffers req;
+ req.count = NUM_BUFFERS;
+ req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ req.memory = V4L2_MEMORY_MMAP;
+ result = ioctl(fd.get(), VIDIOC_REQBUFS, &req);
+ if (result == -1) {
+ ALOGE("VIDIOC_REQBUFS failed: %s", strerror(errno));
+ return nullptr;
+ }
+ if (req.count != NUM_BUFFERS) {
+ ALOGE("Requested %zu buffers, but driver responded with count=%i", NUM_BUFFERS, req.count);
+ return nullptr;
+ }
+
+ struct v4l2_buffer buf = {};
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ std::array<const int16_t*, NUM_BUFFERS> readLocations;
+ for (size_t i = 0; i < NUM_BUFFERS; i++) {
+ buf.index = i;
+ result = ioctl(fd.get(), VIDIOC_QUERYBUF, &buf);
+ if (result == -1) {
+ ALOGE("VIDIOC_QUERYBUF failed: %s", strerror(errno));
+ return nullptr;
+ }
+ if (buf.length != width * height * sizeof(int16_t)) {
+ ALOGE("Unexpected value of buf.length = %i (offset = %" PRIu32 ")",
+ buf.length, buf.m.offset);
+ return nullptr;
+ }
+
+ readLocations[i] = static_cast<const int16_t*>(mmap(nullptr /* start anywhere */,
+ buf.length, PROT_READ /* required */, MAP_SHARED /* recommended */,
+ fd.get(), buf.m.offset));
+ if (readLocations[i] == MAP_FAILED) {
+ ALOGE("%s: map failed: %s", __func__, strerror(errno));
+ return nullptr;
+ }
+ }
+
+ enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ result = ioctl(fd.get(), VIDIOC_STREAMON, &type);
+ if (result == -1) {
+ ALOGE("VIDIOC_STREAMON failed: %s", strerror(errno));
+ return nullptr;
+ }
+
+ for (size_t i = 0; i < NUM_BUFFERS; i++) {
+ buf.index = i;
+ result = ioctl(fd.get(), VIDIOC_QBUF, &buf);
+ if (result == -1) {
+ ALOGE("VIDIOC_QBUF failed for buffer %zu: %s", i, strerror(errno));
+ return nullptr;
+ }
+ }
+ // Using 'new' to access a non-public constructor.
+ return std::unique_ptr<TouchVideoDevice>(new TouchVideoDevice(
+ fd.release(), std::move(name), std::move(devicePath), width, height, readLocations));
+}
+
+size_t TouchVideoDevice::readAndQueueFrames() {
+ std::vector<TouchVideoFrame> frames = readFrames();
+ const size_t numFrames = frames.size();
+ if (numFrames == 0) {
+ // Likely an error occurred
+ return 0;
+ }
+ // Concatenate the vectors, then clip up to maximum size allowed
+ mFrames.insert(mFrames.end(), std::make_move_iterator(frames.begin()),
+ std::make_move_iterator(frames.end()));
+ if (mFrames.size() > MAX_QUEUE_SIZE) {
+ ALOGE("More than %zu frames have been accumulated. Dropping %zu frames", MAX_QUEUE_SIZE,
+ mFrames.size() - MAX_QUEUE_SIZE);
+ mFrames.erase(mFrames.begin(), mFrames.end() - MAX_QUEUE_SIZE);
+ }
+ return numFrames;
+}
+
+std::vector<TouchVideoFrame> TouchVideoDevice::consumeFrames() {
+ std::vector<TouchVideoFrame> frames = std::move(mFrames);
+ mFrames = {};
+ return frames;
+}
+
+std::optional<TouchVideoFrame> TouchVideoDevice::readFrame() {
+ struct v4l2_buffer buf = {};
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ int result = ioctl(mFd.get(), VIDIOC_DQBUF, &buf);
+ if (result == -1) {
+ // EAGAIN means we've reached the end of the read buffer, so it's expected.
+ if (errno != EAGAIN) {
+ ALOGE("VIDIOC_DQBUF failed: %s", strerror(errno));
+ }
+ return std::nullopt;
+ }
+ if ((buf.flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) != V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC) {
+ // We use CLOCK_MONOTONIC for input events, so if the clocks don't match,
+ // we can't compare timestamps. Just log a warning, since this is a driver issue
+ ALOGW("The timestamp %ld.%ld was not acquired using CLOCK_MONOTONIC",
+ buf.timestamp.tv_sec, buf.timestamp.tv_usec);
+ }
+ std::vector<int16_t> data(mWidth * mHeight);
+ const int16_t* readFrom = mReadLocations[buf.index];
+ std::copy(readFrom, readFrom + mWidth * mHeight, data.begin());
+ TouchVideoFrame frame(mWidth, mHeight, std::move(data), buf.timestamp);
+
+ result = ioctl(mFd.get(), VIDIOC_QBUF, &buf);
+ if (result == -1) {
+ ALOGE("VIDIOC_QBUF failed: %s", strerror(errno));
+ }
+ return std::make_optional(std::move(frame));
+}
+
+/*
+ * This function should not be called unless buffer is ready! This must be checked with
+ * select, poll, epoll, or some other similar api first.
+ * The oldest frame will be at the beginning of the array.
+ */
+std::vector<TouchVideoFrame> TouchVideoDevice::readFrames() {
+ std::vector<TouchVideoFrame> frames;
+ while (true) {
+ std::optional<TouchVideoFrame> frame = readFrame();
+ if (!frame) {
+ break;
+ }
+ frames.push_back(std::move(*frame));
+ }
+ return frames;
+}
+
+TouchVideoDevice::~TouchVideoDevice() {
+ enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ int result = ioctl(mFd.get(), VIDIOC_STREAMOFF, &type);
+ if (result == -1) {
+ ALOGE("VIDIOC_STREAMOFF failed: %s", strerror(errno));
+ }
+ for (const int16_t* buffer : mReadLocations) {
+ void* bufferAddress = static_cast<void*>(const_cast<int16_t*>(buffer));
+ result = munmap(bufferAddress, mWidth * mHeight * sizeof(int16_t));
+ if (result == -1) {
+ ALOGE("%s: Couldn't unmap: [%s]", __func__, strerror(errno));
+ }
+ }
+}
+
+std::string TouchVideoDevice::dump() const {
+ return StringPrintf("Video device %s (%s) : width=%" PRIu32 ", height=%" PRIu32
+ ", fd=%i, hasValidFd=%s",
+ mName.c_str(), mPath.c_str(), mWidth, mHeight, mFd.get(),
+ hasValidFd() ? "true" : "false");
+}
+
+} // namespace android