ApsaraVideo VOD:FAQ about ApsaraVideo Player SDK for iOS

Problem description: After an app is packaged and submitted to the App Store by using Xcode 14, a bitcode-related error is returned during the review. Example:

 ITMS-90482: Invalid Executable - The executable 'xxx.app/Frameworks/alivcffmpeg.framework/alivcffmpeg' contains bitcode.

Solution: Use xcrun bitcode_strip to remove bitcode from your framework. In the following sample code, ${framework_path} indicates the binary file path of the framework.

xcrun bitcode_strip ${framework_path} -r -o ${framework_path}

Problem description: After an app is packaged and submitted to the App Store by using Xcode 14, a cURL error is returned during the review. Example:

ITMS-90338: Non-public API usage - The app references non-public symbols in Frameworks/AliyunPlayer.framework/AliyunPlayer: _curl_multi_poll, _curl_multi_wakeup. If method names in your source code match the private Apple APIs listed above, altering your method names will help prevent this app from being flagged in future submissions. In addition, note that one or more of the above APIs may be located in a static library that was included with your app. If so, they must be removed. For further information, visit the Technical Support Information at http://developer.apple.com/support/technical/

Solution:

• If you integrate only ApsaraVideo Player SDK for iOS into your project, we recommend that you update the SDK to V5.4.9.2 or later.

• If you integrate ApsaraVideo Player SDK for iOS and the short video SDK into your project, we recommend that you update ApsaraVideo Player SDK to V5.4.9.2 or later, AlivcFFmpeg (QuCore-ThirdParty) to V4.3.6, and the short video SDK to V3.26 or later.

Problem description: After an app is packaged and submitted to the App Store by using Xcode 14, an error related to non-public selectors is returned during the review. The following figure shows a sample error.

Problem description: After an app is packaged and submitted to the App Store by using Xcode 14, the following errors about mpf_filter.framework for frame insertion and vfi_filter.framework for post-processing after image sharpening are returned.

Solution:

• If you do not need to use the plug-ins that are listed in the error message, we recommend that you delete the plug-ins from your project. This reduces the size of the package, and does not compromise the performance of the player.

• If your project relies on these plug-ins, remove the "_" from the value of the "Bundle identifier" key-value pair in the Info.plist file. This file can be found in the directory where the framework is stored. Then, re-compile and build your project.

• Update ApsaraVideo Player SDK to V5.5.2.0 or later. In ApsaraVideo Player SDK V5.5.2.0 or later, the issue related to plug-in names has been fixed.

Solution: Set AVAudioSession of all audio players to the same value in your project. For example, set the audio session of your application to the playback mode and allow audio mixing with other applications. You can also set the audio session of your application to PlayAndRecord if you want to record and play videos at the same time. If errors occur when you perform the operation, the error messages are stored in the err variable.

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryOptionMixWithOthers error:&err];

Then, configure a custom delegate for AVAudioSession in ApsaraVideo Player SDK for iOS. This circumvents the preset AVAudioSession logic and prevents audio preemption. Sample configurations:

1. Configure the delegate.

   [AliPlayer setAudioSessionDelegate:self];

2. Configure listeners for the delegate.

   return TRUE indicates that no preset AVAudioSession logic is configured in the SDK.

   #pragma mark CicadaAudioSessionDelegate
   - (BOOL)setActive:(BOOL)active error:(NSError **)outError
   {
       return YES;
   }
   
   - (BOOL)setCategory:(NSString *)category withOptions:(AVAudioSessionCategoryOptions)options error:(NSError **)outError
   {
         return YES;
   }
   
   - (BOOL)setCategory:(AVAudioSessionCategory)category mode:(AVAudioSessionMode)mode routeSharingPolicy:(AVAudioSessionRouteSharingPolicy)policy options:(AVAudioSessionCategoryOptions)options error:(NSError **)outError
   {
       return YES;
   }

If the stack that points to ApsaraVideo Player SDK for iOS crashes, you can use one of the following methods to resolve the issue:

1. Update ApsaraVideo Player SDK for iOS to the latest version. ApsaraVideo Player SDK for iOS keeps updating to improve stability. For more information about how to obtain the latest version of ApsaraVideo Player SDK, see SDK overview and download.

2. If the problem persists after you update the SDK to the latest version, we recommend that you provide all the crash information to Alibaba Cloud technical support for troubleshooting. For more information about how to contact technical support, see Contact technical support.

By default, ApsaraVideo Player SDK returns a callback about the playback position every 500 milliseconds. You can reduce the interval at which callbacks are returned to obtain playback positions more frequently. Sample code:

AVPConfig *config = [self.player getConfig];
config.positionTimerIntervalMs = 100; // Change the callback interval. Unit: milliseconds. 
[self.player setConfig:config];

/**
 @brief: The callback for the current playback position. 
 @param player: The pointer for the player. 
 @param position: The current playback position. 
 */
- (void)onCurrentPositionUpdate:(AliPlayer*)player position:(int64_t)position {
    // The current playback position. 
    long currentPosition = position;
}

You can use one of the following methods to obtain the height and width of a video:

• Method 1: Call the prepare method in the AliPlayer instance. After the AVPEventPrepareDone event is complete, obtain the height and width of the AliPlayer instance.

  -(void)onPlayerEvent:(AliPlayer*)player eventType:(AVPEventType)eventType {
      if (eventType == AVPEventPrepareDone) {
        NSLog(@"Width:%d,Height:%d", player.width, player.height);
      }
  }

• Method 2: Listen to the event that is triggered when the video size is changed.

  - (void)onVideoSizeChanged:(AliPlayer*)player width:(int)width height:(int)height rotation:(int)rotation {
      NSLog(@"Width:%d,Height:%d", width, height);
  }

• Method 3: Configure callbacks to obtain the track information. You can obtain the width and height of the video from AVPTrackInfo in the returned array.

  Note

  This method depends heavily on network quality because requests are sent over the Internet to obtain data. We recommend that you use Method 1 or Method 2 to obtain the width and height of a video.

  - (void)onTrackReady:(AliPlayer*)player info:(NSArray<AVPTrackInfo*>*)info {
      for (int i=0; i<info.count; i++) {
        AVPTrackInfo *trackInfo = info[i];
        NSLog(@"Width:%d,Height:%d", trackInfo.videoWidth, trackInfo.videoHeight);
    }
  }

Perform the following steps to troubleshoot the issue:

1. Check whether the crash occurs on ApsaraVideo Player SDK.

   If a crash stack name prefixed with AliyunPlayer exists, the crash occurs on ApsaraVideo Player SDK.

2. Update ApsaraVideo Player SDK to the latest version and check whether the issue is fixed.

3. If the issue persists, contact Alibaba Cloud technical support. Prepare the files about all threads and crash logs and describe the crash scenario when you contact technical support. For more information, see How do I obtain the error log?

Sample code:

UIInterfaceOrientation orientation = UIInterfaceOrientationLandscapeLeft; // Rotate the view to enable full-screen playback.
......

// The following sample code applies to iOS 16.0 or later.
if (@available(iOS 16.0, *)) {
    @try {
            NSArray *array = [[[UIApplication sharedApplication] connectedScenes] allObjects];
      UIWindowScene *ws = (UIWindowScene *)array[0];
        Class GeometryPreferences = NSClassFromString(@"UIWindowSceneGeometryPreferencesIOS");
      id geometryPreferences = [[GeometryPreferences alloc]init];
      UIInterfaceOrientationMask orientationMask = UIInterfaceOrientationMaskLandscapeRight;
      if (orientation == UIInterfaceOrientationPortrait) {
          orientationMask = UIInterfaceOrientationMaskPortrait;
      }
      [geometryPreferences setValue:@(orientationMask) forKey:@"interfaceOrientations"];
      SEL sel_method = NSSelectorFromString(@"requestGeometryUpdateWithPreferences:errorHandler:");
      void (^ErrorBlock)(NSError *err) = ^(NSError *err){
            NSLog(@"Rotation error:%@", [err debugDescription]);
      };
      if ([ws respondsToSelector:sel_method]) {
          (((void (*)(id, SEL,id,id))[ws methodForSelector:sel_method])(ws, sel_method,geometryPreferences,ErrorBlock));
      }
  } @catch (NSException *exception) {
      NSLog(@"Rotation error:%@", exception.reason);
  } @finally {
  }
} else { // The following sample code applies to iOS versions earlier than 16.0.
  if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {
      SEL selector = NSSelectorFromString(@"setOrientation:");
      NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]];
      [invocation setSelector:selector];
      [invocation setTarget:[UIDevice currentDevice]];
      [invocation setArgument:&Orientation atIndex:2];
      invocation invoke];
  }
  [[UIApplication sharedApplication]setStatusBarOrientation:orientation animated:YES];
}

Perform the following steps to troubleshoot the issue:

1. Check if black bars appear on your video source.

2. Call the following operations to change the scaling mode of the player:

   /*
   AVP_SCALINGMODE_SCALEASPECTFILL: crops the video to fit the view based on the aspect ratio of the video. 
   AVP_SCALINGMODE_SCALEASPECTFIT: scales in the video based on the aspect ratio of the video. Black bars are displayed in the view. 
   AVP_SCALINGMODE_SCALETOFILL: stretches the video to fill in the view. Image distortion may occur. 
   */
   self.player.scalingMode = AVP_SCALINGMODE_SCALETOFILL;

3. If the issue persists after you change the scaling mode, call self.player.playerView and specify the frame parameter to customize the width and height of the view.

Perform the following steps to troubleshoot the issue:

1. Play the video in another player and check whether the video contains only audio.

2. If the video can be played in another player and the aspect ratio of the video is different from that of the video source, use software decoding:

   player.enableHardwareDecoder = NO

If you use ApsaraVideo Player SDK V5.4.5.0 or earlier, you cannot use AliListPlayer to play HLS (M3U8) videos. If you use ApsaraVideo Player SDK V5.4.5.0 or later, you must enable local caching to play HLS (M3U8) videos. For more information, see Configure local caching.

Solution:

1. Enable the background data collection feature in Xcode. The following figure shows an example.

2. If you have specified methods for listening to foreground and background events, comment out the pause and start methods.

   // Add a method to listen to the event that the app enters the background.
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationEnterBackground) name: UIApplicationWillResignActiveNotification object:nil];
   // Call this method when the app is switched to the foreground from the background.
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationDidBecomeActive) name: UIApplicationDidBecomeActiveNotification object:nil];
   
   // Comment out the pause method.
   - (void)applicationEnterBackground {
      // [self.player pause];
   }
   // Comment out the start method.
   - (void)applicationDidBecomeActive {
      // [self.player start];
   }

The following sample code provides an example on how to switch the seeking mode:

// Switch to the inaccurate seeking mode. 
[self.player seekToTime:1000 seekMode:AVP_SEEKMODE_INACCURATE];
// Switch to the accurate seeking mode. 
[self.player seekToTime:1000 seekMode:AVP_SEEKMODE_ACCURATE];

Solution: Call the setMaxAccurateSeekDelta operation to set the maximum interval between the seeking position and the nearest keyframe allowed for the accurate seeking mode. This way, the seeking accuracy is improved but the response time is longer. We recommend that you set the maximum interval based on your business requirements. Sample code:

// Unit: milliseconds. 
[self.player setMaxAccurateSeekDelta:100];

Obtain the cause of the caching failure in the onPlayerEvent callback. The following sample code provides an example on how to configure the onPlayerEvent callback:

/**
 @brief: The callback for player events. 
 @param player: The pointer for the player. 
 @param eventWithString: The type of the player event. 
 @param description: The description of the player event. 
 @see AVPEventType
 */
-(void)onPlayerEvent:(AliPlayer*)player eventWithString:(AVPEventWithString)eventWithString description:(NSString *)description {
    if (eventWithString == EVENT_PLAYER_CACHE_SUCCESS) { // Caching during playback succeeded. 

    } else if (eventWithString == EVENT_PLAYER_CACHE_ERROR) { // Caching during playback failed. 
        NSString *errorMsg = description;
    }
}

The following items list the common causes for caching failures:

• The size and duration specified in CacheConfig do not match those of the video.

• The position where you stop or seek during playback is outside the buffer.

The following sample code provides an example on how to obtain media source data:

// Configure the rendering callback. 
self.player.renderingDelegate = self;

// Listen to the rendering callback. 
- (BOOL)onRenderingFrame:(CicadaFrameInfo*) frameInfo {
    if (frameInfo.frameType == Cicada_FrameType_Video) { // The underlying video data. 

    } else if (frameInfo.frameType == Cicada_FrameType_Audio) { // The underlying audio data. 

    }
    return NO;
}

After you call [self.player selectTrack:SELECT_AVPTRACK_TYPE_VIDEO_AUTO] to enable the automatic bitrate switching feature, ApsaraVideo Player SDK monitors the network speed. The bitrate of the video is switched between higher and lower bitrates based on the 10-second average network speed. If the 10-second average network speed does not fulfill the conditions, the video bitrate is not switched.

• If the 10-second average network speed meets the conditions for a lower bitrate, the video is switched to a lower bitrate after the playback for cached content is complete.

• If the 10-second average network speed meets the conditions for a higher bitrate, the video is immediately switched to a higher bitrate.

You can customize the retry logic and receive notifications when retry events occur. Sample code:

AVPConfig *config = [self.player getConfig];
config.networkRetryCount = 0; // The number of retries. In this example, this parameter is set to 0. 
[self.player setConfig:config];

/**
 @brief: The callback for player events. 
 @param player: The pointer for the player. 
 @param eventWithString: The type of the player event. 
 @param description: The description of the player event. 
 @see AVPEventType
 */
-(void)onPlayerEvent:(AliPlayer*)player eventWithString:(AVPEventWithString)eventWithString description:(NSString *)description {
    if (eventWithString == EVENT_PLAYER_NETWORK_RETRY) { // The network connection fails. Try again. 
        // Configure the retry logic. 
    }
}

Perform the following steps to troubleshoot the issue:

1. Check whether the AliPlayerSDK_iOS, AliPlayerSDK_iOS_ARTC, and RtsSDK dependencies are added.

   You must add AliPlayerSDK_iOS, AliPlayerSDK_iOS_ARTC, and RtsSDK dependencies before you can use ApsaraVideo Player to play Real-Time Streaming (RTS) streams. For more information, see Native RTS SDK for iOS.

2. Check whether the versions of the RTS SDK and ApsaraVideo Player SDK match.

   You must use a version of ApsaraVideo Player SDK that is supported by the RTS SDK. For more information, see Download SDKs.

3. Check whether the versions of AliPlayerSDK_iOS and AliPlayerSDK_iOS_ARTC are the same. You must use the same version for AliPlayerSDK_iOS and AliPlayerSDK_iOS_ARTC.

The following sample code provides an example on how to configure a default resolution:

// Video playback based on VidSts is used in this example. 
AVPVidStsSource *stsSource = [[AVPVidStsSource alloc] init];
stsSource.vid = @"<vid>";
stsSource.accessKeyId = @"<accessKeyId>";
stsSource.securityToken = @"<securityToken>";
stsSource.accessKeySecret = @"<accessKeySecret>";
stsSource.quality = @""; // The resolution in which you want to play videos. Valid values: FD, LD, SD, HD, 2K, 4K, and OD. 
stsSource.forceQuality = NO; // Specifies whether to forcibly use the specified resolution to play videos. NO: ApsaraVideo Player SDK uses the first resolution that is available in the preceding order for video playback. Yes: ApsaraVideo Player SDK forcibly uses the specified resolution to play videos. If a video in the specified resolution is not available, the video is not played.