fune/dom/media/systemservices/objc_video_capture/device_info_objc.mm

/*
 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#if !defined(__has_feature) || !__has_feature(objc_arc)
#  error "This file requires ARC support."
#endif

#import <AVFoundation/AVFoundation.h>

#import "device_info_objc.h"

@implementation DeviceInfoIosObjC

- (id)init {
  self = [super init];
  if (nil != self) {
    _lock = [[NSLock alloc] init];
  }
  return self;
}

- (void)dealloc {
}

- (void)registerOwner:(webrtc::VideoCaptureModule::DeviceInfo*)owner {
  [_lock lock];
  if (!_owner && owner) {
    [self configureObservers];
  } else if (_owner && !owner) {
    NSNotificationCenter* notificationCenter =
        [NSNotificationCenter defaultCenter];
    for (id observer in _observers) {
      [notificationCenter removeObserver:observer];
    }
    _observers = nil;
  }
  _owner = owner;
  [_lock unlock];
}

+ (int)captureDeviceCount {
  int cnt = 0;
  @try {
    for (AVCaptureDevice* device in
         [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]) {
      if ([device isSuspended]) {
        continue;
      }
      cnt++;
    }
  } @catch (NSException* exception) {
    cnt = 0;
  }
  return cnt;
}

+ (AVCaptureDevice*)captureDeviceForIndex:(int)index {
  int cnt = 0;
  @try {
    for (AVCaptureDevice* device in
         [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]) {
      if ([device isSuspended]) {
        continue;
      }
      if (cnt == index) {
        return device;
      }
      cnt++;
    }
  } @catch (NSException* exception) {
    cnt = 0;
  }

  return nil;
}

+ (AVCaptureDevice*)captureDeviceForUniqueId:(NSString*)uniqueId {
  for (AVCaptureDevice* device in
       [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]) {
    if ([device isSuspended]) {
      continue;
    }
    if ([uniqueId isEqual:device.uniqueID]) {
      return device;
    }
  }

  return nil;
}

+ (NSString*)deviceNameForIndex:(int)index {
  return [DeviceInfoIosObjC captureDeviceForIndex:index].localizedName;
}

+ (NSString*)deviceUniqueIdForIndex:(int)index {
  return [DeviceInfoIosObjC captureDeviceForIndex:index].uniqueID;
}

+ (NSString*)deviceNameForUniqueId:(NSString*)uniqueId {
  return [[AVCaptureDevice deviceWithUniqueID:uniqueId] localizedName];
}

+ (webrtc::VideoCaptureCapability)capabilityForPreset:(NSString*)preset {
  webrtc::VideoCaptureCapability capability;

  // TODO(tkchin): Maybe query AVCaptureDevice for supported formats, and
  // then get the dimensions / frame rate from each supported format
  if ([preset isEqualToString:AVCaptureSessionPreset352x288]) {
    capability.width = 352;
    capability.height = 288;
    capability.maxFPS = 30;
    capability.videoType = webrtc::VideoType::kNV12;
    capability.interlaced = false;
  } else if ([preset isEqualToString:AVCaptureSessionPreset640x480]) {
    capability.width = 640;
    capability.height = 480;
    capability.maxFPS = 30;
    capability.videoType = webrtc::VideoType::kNV12;
    capability.interlaced = false;
  } else if ([preset isEqualToString:AVCaptureSessionPreset1280x720]) {
    capability.width = 1280;
    capability.height = 720;
    capability.maxFPS = 30;
    capability.videoType = webrtc::VideoType::kNV12;
    capability.interlaced = false;
  }

  return capability;
}

- (void)configureObservers {
  // register device connected / disconnected event
  NSNotificationCenter* notificationCenter =
      [NSNotificationCenter defaultCenter];

  id deviceWasConnectedObserver = [notificationCenter
      addObserverForName:AVCaptureDeviceWasConnectedNotification
                  object:nil
                   queue:[NSOperationQueue mainQueue]
              usingBlock:^(NSNotification* note) {
                [_lock lock];
                AVCaptureDevice* device = [note object];
                BOOL isVideoDevice = [device hasMediaType:AVMediaTypeVideo];
                if (isVideoDevice && _owner) _owner->DeviceChange();
                [_lock unlock];
              }];

  id deviceWasDisconnectedObserver = [notificationCenter
      addObserverForName:AVCaptureDeviceWasDisconnectedNotification
                  object:nil
                   queue:[NSOperationQueue mainQueue]
              usingBlock:^(NSNotification* note) {
                [_lock lock];
                AVCaptureDevice* device = [note object];
                BOOL isVideoDevice = [device hasMediaType:AVMediaTypeVideo];
                if (isVideoDevice && _owner) _owner->DeviceChange();
                [_lock unlock];
              }];

  _observers =
      [[NSArray alloc] initWithObjects:deviceWasConnectedObserver,
                                       deviceWasDisconnectedObserver, nil];
}

@end