Mac Video Capture Device: split VCD into VCD and Factory.

media/video/capture/mac/video_capture_device_factory_mac.mm

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/video/capture/mac/video_capture_device_factory_mac.h"
+
+#import "media/video/capture/mac/avfoundation_glue.h"
+#include "media/video/capture/mac/video_capture_device_mac.h"
+#import "media/video/capture/mac/video_capture_device_avfoundation_mac.h"
+#import "media/video/capture/mac/video_capture_device_qtkit_mac.h"
+
+namespace media {
+
+// Some devices are not correctly supported in AVFoundation, f.i. Blackmagic,
+// see http://crbug.com/347371. The devices are identified by USB Vendor ID and
+// by a characteristic substring of the name, usually the vendor's name.
+const struct NameAndVid {
+  const char* vid;
+  const char* name;
+} kBlacklistedCameras[] = { { "a82c", "Blackmagic" } };
+
+// In device identifiers, the USB VID and PID are stored in 4 bytes each.
+const size_t kVidPidSize = 4;
+
+VideoCaptureDeviceFactoryMac::VideoCaptureDeviceFactoryMac() {
+  thread_checker_.DetachFromThread();
+}
+
+scoped_ptr<VideoCaptureDevice> VideoCaptureDeviceFactoryMac::Create(
+    const VideoCaptureDevice::Name& device_name) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  VideoCaptureDeviceMac* capture_device =
+      new VideoCaptureDeviceMac(device_name);
+
+  // TODO(mcasas): The following check might not be necessary; if the device has
+  // disappeared after enumeration and before coming here, opening would just
+  // fail but not necessarily produce a crash.
+  VideoCaptureDevice::Names device_names;
+  GetDeviceNames(&device_names);
+  VideoCaptureDevice::Names::const_iterator it = device_names.begin();
+  for (; it != device_names.end(); ++it) {
+    if (it->id() == device_name.id())
+      break;
+  }
+  if (it == device_names.end())
+    return scoped_ptr<VideoCaptureDevice>();
+  DCHECK_NE(it->capture_api_type(), VideoCaptureDevice::Name::API_TYPE_UNKNOWN);
+
+  if (!capture_device->Init(it->capture_api_type())) {
+    LOG(ERROR) << "Could not initialize VideoCaptureDevice.";
+    delete capture_device;
+    capture_device = NULL;
+  }
+  return scoped_ptr<VideoCaptureDevice>(capture_device);
+}
+
+void VideoCaptureDeviceFactoryMac::GetDeviceNames(
+    VideoCaptureDevice::Names* const device_names) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // Loop through all available devices and add to |device_names|.
+  NSDictionary* capture_devices;
+  if (AVFoundationGlue::IsAVFoundationSupported()) {

[perkj_chrome, 2014/05/06 06:44:46]

How about we do this check already in VideoCaptureDeviceFactory::Create and
create separate factories depending on AVFoundation or QTKit?

Then you don't need to check in each method.

[mcasas, 2014/05/06 07:26:30]

I'd rather do that in a later CL, so this one is concerned with
moving this around without modifying the functionality.

Performance-wise the IsAVFoundationSupported() returns a
static bool, so shouldn't be too bad.

+    bool is_any_device_blacklisted = false;
+    DVLOG(1) << "Enumerating video capture devices using AVFoundation";
+    capture_devices = [VideoCaptureDeviceAVFoundation deviceNames];
+    std::string device_vid;
+    // Enumerate all devices found by AVFoundation, translate the info for each
+    // to class Name and add it to |device_names|.
+    for (NSString* key in capture_devices) {
+      VideoCaptureDevice::Name name(
+          [[capture_devices valueForKey:key] UTF8String],
+          [key UTF8String], VideoCaptureDevice::Name::AVFOUNDATION);
+      device_names->push_back(name);
+      // Extract the device's Vendor ID and compare to all blacklisted ones.
+      device_vid = name.GetModel().substr(0, kVidPidSize);
+      for (size_t i = 0; i < arraysize(kBlacklistedCameras); ++i) {
+        is_any_device_blacklisted |=
+            !strcasecmp(device_vid.c_str(), kBlacklistedCameras[i].vid);
+        if (is_any_device_blacklisted)
+          break;
+      }
+    }
+    // If there is any device blacklisted in the system, walk the QTKit device
+    // list and add those devices with a blacklisted name to the |device_names|.
+    // AVFoundation and QTKit device lists partially overlap, so add a "QTKit"
+    // prefix to the latter ones to distinguish them from the AVFoundation ones.
+    if (is_any_device_blacklisted) {
+      capture_devices = [VideoCaptureDeviceQTKit deviceNames];
+      for (NSString* key in capture_devices) {
+        NSString* device_name = [capture_devices valueForKey:key];
+        for (size_t i = 0; i < arraysize(kBlacklistedCameras); ++i) {
+          if ([device_name rangeOfString:@(kBlacklistedCameras[i].name)
+                                 options:NSCaseInsensitiveSearch].length != 0) {
+            DVLOG(1) << "Enumerated blacklisted " << [device_name UTF8String];
+            VideoCaptureDevice::Name name(
+                "QTKit " + std::string([device_name UTF8String]),
+                [key UTF8String], VideoCaptureDevice::Name::QTKIT);
+            device_names->push_back(name);
+          }
+        }
+      }
+    }
+  } else {
+    DVLOG(1) << "Enumerating video capture devices using QTKit";
+    capture_devices = [VideoCaptureDeviceQTKit deviceNames];
+    for (NSString* key in capture_devices) {
+      VideoCaptureDevice::Name name(
+          [[capture_devices valueForKey:key] UTF8String],
+          [key UTF8String], VideoCaptureDevice::Name::QTKIT);
+      device_names->push_back(name);
+    }
+  }
+}
+
+void VideoCaptureDeviceFactoryMac::GetDeviceSupportedFormats(
+    const VideoCaptureDevice::Name& device,
+    VideoCaptureFormats* supported_formats) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (device.capture_api_type() == VideoCaptureDevice::Name::AVFOUNDATION) {
+    DVLOG(1) << "Enumerating video capture capabilities, AVFoundation";
+    [VideoCaptureDeviceAVFoundation getDevice:device
+                             supportedFormats:supported_formats];
+  } else {
+    NOTIMPLEMENTED();
+  }
+}
+
+}  // namespace media