commit 34cdbcde5096aa8d822626d953f9a493a6fa835f
author Anton D. Kachalov <gmouse@google.com> Mon Feb 10 20:37:08 2020 +0100
committer Yin-Chia Yeh <yinchiayeh@google.com> Thu Mar 12 21:21:09 2020 +0000
tree 39eef346f152e0bd6c76d4288814f88446afc872
parent 0d3722f9662ae26ab4899e0c50ba1f31caecedae

Camera: Advertise numbered string ID for external cameras

With current implementation cameraId is part of something like:

  device@3.5/external//dev/video0

This doesn't work well with Camera2 API based apps.

Adding CameraIdOffset tag to Provider as a base offset.

Test: presubmit builds
Bug: 151350336

Merged-In: I6309d16be565616f048fb24a70e9be5b2f5ed480
Change-Id: I6309d16be565616f048fb24a70e9be5b2f5ed480
(cherry picked from commit 4f6022ae5de718c2892a9371c7a75fabacc9b837)

camera/device/3.4/default/ExternalCameraDevice.cpp

diff --git a/camera/device/3.4/default/ExternalCameraDevice.cpp b/camera/device/3.4/default/ExternalCameraDevice.cpp
index f518a15..677b496 100644
--- a/camera/device/3.4/default/ExternalCameraDevice.cpp
+++ b/camera/device/3.4/default/ExternalCameraDevice.cpp
@@ -20,6 +20,7 @@
 
 #include <algorithm>
 #include <array>
+#include <regex>
 #include <linux/videodev2.h>
 #include "android-base/macros.h"
 #include "CameraMetadata.h"
@@ -46,10 +47,20 @@
 
 } // anonymous namespace
 
+const std::regex kDevicePathRE("/dev/video([0-9]+)");
+
 ExternalCameraDevice::ExternalCameraDevice(
-        const std::string& cameraId, const ExternalCameraConfig& cfg) :
-        mCameraId(cameraId),
-        mCfg(cfg) {}
+        const std::string& devicePath, const ExternalCameraConfig& cfg) :
+        mCameraId("-1"),
+        mDevicePath(devicePath),
+        mCfg(cfg) {
+    std::smatch sm;
+    if (std::regex_match(mDevicePath, sm, kDevicePathRE)) {
+        mCameraId = std::to_string(mCfg.cameraIdOffset + std::stoi(sm[1]));
+    } else {
+        ALOGE("%s: device path match failed for %s", __FUNCTION__, mDevicePath.c_str());
+    }
+}
 
 ExternalCameraDevice::~ExternalCameraDevice() {}
 
@@ -129,20 +140,20 @@
         return Void();
     }
 
-    unique_fd fd(::open(mCameraId.c_str(), O_RDWR));
+    unique_fd fd(::open(mDevicePath.c_str(), O_RDWR));
     if (fd.get() < 0) {
         int numAttempt = 0;
         do {
             ALOGW("%s: v4l2 device %s open failed, wait 33ms and try again",
-                    __FUNCTION__, mCameraId.c_str());
+                    __FUNCTION__, mDevicePath.c_str());
             usleep(OPEN_RETRY_SLEEP_US); // sleep and try again
-            fd.reset(::open(mCameraId.c_str(), O_RDWR));
+            fd.reset(::open(mDevicePath.c_str(), O_RDWR));
             numAttempt++;
         } while (fd.get() < 0 && numAttempt <= MAX_RETRY);
 
         if (fd.get() < 0) {
             ALOGE("%s: v4l2 device open %s failed: %s",
-                    __FUNCTION__, mCameraId.c_str(), strerror(errno));
+                    __FUNCTION__, mDevicePath.c_str(), strerror(errno));
             mLock.unlock();
             _hidl_cb(Status::INTERNAL_ERROR, nullptr);
             return Void();
@@ -203,9 +214,9 @@
 status_t ExternalCameraDevice::initCameraCharacteristics() {
     if (mCameraCharacteristics.isEmpty()) {
         // init camera characteristics
-        unique_fd fd(::open(mCameraId.c_str(), O_RDWR));
+        unique_fd fd(::open(mDevicePath.c_str(), O_RDWR));
         if (fd.get() < 0) {
-            ALOGE("%s: v4l2 device open %s failed", __FUNCTION__, mCameraId.c_str());
+            ALOGE("%s: v4l2 device open %s failed", __FUNCTION__, mDevicePath.c_str());
             return DEAD_OBJECT;
         }