ApsaraVideo VOD:FAQ about ApsaraVideo Player SDK for iOS

Problem description: After an app is packaged and submitted to the App Store 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 example, ${framework_path} is the path to the binary file 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 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 (AliPlayerSDK_iOS) in your project, we recommend that you update the SDK to V5.4.9.2 or later.

• If you integrate ApsaraVideo Player SDK for iOS (AliPlayerPartSDK_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 using Xcode 14, an error related to non-public methods is returned during the review:

Problem description: After an app is packaged and submitted to the App Store using Xcode 14, errors related to frame interpolation and sharpening post-processing plugins such as mpf_filter.framework and vfi_filter.framework are returned during the review:

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 must use the plugins mentioned in the error message, you can temporarily remove the "_" from the value of the "Bundle identifier" key in the framework's Info.plist file, and then compile and build the project.

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

By default, ApsaraVideo Player SDK returns a callback about the current 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 obtain it in the following three ways:

• 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 for 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);
    }
  }

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 increase 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 as needed. Sample code:

// Unit: milliseconds.
[self.player setMaxAccurateSeekDelta:10000];

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 of 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:

// Set 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;
}

When automatic bitrate switching is enabled by calling the [self.player selectTrack:SELECT_AVPTRACK_TYPE_VIDEO_AUTO]; interface, the player SDK internally monitors the current network speed. If the network speed reaches the threshold for the next bitrate within 10 seconds, the player switches to that bitrate. If the network speed does not reach the threshold within 10 seconds, no switching occurs.

• When switching from a higher bitrate to a lower bitrate, if the 10-second average network speed meets the conditions for a lower bitrate, the video switches to a lower bitrate after the playback of cached content completes.

• When switching from a lower bitrate to a higher bitrate, if the 10-second average network speed meets the conditions for a higher bitrate, the video immediately switches to a higher bitrate.

You can customize the retry logic to receive notifications when retry events occur. Then, you can configure the retry logic. The following sample code provides an example:

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.
    }
}

Solution: You can configure AVAudioSession uniformly at an appropriate location in your project. For example, set the audio session of your application to the playback mode and allow audio mixing with other applications. Another example is to set the audio session of your application to the PlayAndRecord category for recording and playback scenarios. If any errors occur during this operation, the error message will be stored in the err variable.

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

Additionally, you can customize the delegate of AVAudioSession on the ApsaraVideo Player SDK for iOS side without using the predefined AVAudioSession logic in the SDK. This helps avoid the risk of audio preemption that might be caused by ApsaraVideo Player SDK for iOS. Sample configurations:

1. Configure the delegate.

   [AliPlayer setAudioSessionDelegate:self];

2. Configure listeners for the delegate.

   return TRUE indicates that the SDK will no longer configure AVAudioSession internally.

   #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 the following methods to resolve the issue:

1. Update ApsaraVideo Player SDK for iOS to the latest version. The iOS Player SDK continuously releases new versions to optimize and improve stability. To obtain the latest version of the SDK, see SDK introduction.

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, see Obtain technical support.

You can perform the following steps to troubleshoot the issue:

1. Check whether the crash occurs on the player SDK.

   Check if there is a crash stack with the AliyunPlayer prefix. If yes, the issue occurs on the player SDK.

2. Update to the latest version of the player SDK and verify whether the issue is fixed.

3. If the issue persists, prepare relevant crash files (including all threads), crash logs, crash scenario, and other information. How to obtain problem logs.

Sample code:

UIInterfaceOrientation orientation = UIInterfaceOrientationLandscapeLeft; // Rotate to full screen
......

// 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 whether the black bars appear on your video source.

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

   /*
   AVP_SCALINGMODE_SCALEASPECTFILL: scales the image to fill the view while maintaining the aspect ratio. The image may be cropped as a result.
   AVP_SCALINGMODE_SCALEASPECTFIT: scales the image to fit the view while maintaining the aspect ratio. This leads to black bars in the view.
   AVP_SCALINGMODE_SCALETOFILL: stretches the image to fill the view. This does not preserve the aspect ratio, and may cause the image to be distorted.
   */
   self.player.scalingMode = AVP_SCALINGMODE_SCALETOFILL;

3. If the scaling mode still cannot meet your requirements, you can adjust the width and height of the custom view of self.player.playerView (by modifying the self.player.playerView's frame).

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 its aspect ratio differs from that of the video source, use the following method to adopt software decoding:

   player.enableHardwareDecoder = NO

Player SDK versions V5.4.5.0 and earlier do not support using AliListPlayer to play HLS (M3U8) videos. Support for playing HLS (M3U8) videos is available starting from version V5.4.5.0, but you need to enable local caching. For information about how to enable local caching, see Local cache.

The following sample code provides an example:

//Take VidSts playback as an 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: The specified resolution is not forcibly used. The SDK searches for available resolutions based on the default resolution playback order. YES: The specified resolution is forcibly used. If the specified resolution is not found, the video cannot be played.