ApsaraVideo VOD:FAQ for ApsaraVideo Player SDK for iOS

Symptom: When you package an app with Xcode 14 and submit it to the App Store for review, a bitcode-related error occurs. The following code shows an example of the error message:

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

Solution: You can run the xcrun bitcode_strip command to manually remove bitcode from the framework. In the following example, ${framework_path} is the path of the binary file of the framework.

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

Symptom: When you package an app with Xcode 14 and submit it to the App Store for review, a cURL-related error occurs. The following code shows an example of the error message:

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 your project integrates only the ApsaraVideo Player SDK (AliPlayerSDK_iOS), upgrade the SDK to a version later than 5.4.9.2.

• If your project integrates both the ApsaraVideo Player SDK (AliPlayerPartSDK_iOS) and the short video SDK, upgrade the ApsaraVideo Player SDK to a version later than 5.4.9.2, alivcffmpeg (QuCore-ThirdParty) to version 4.3.6, and the short video SDK to a version later than 3.26.

Symptom: When you package an app with Xcode 14 and submit it to the App Store for review, an error about non-public APIs occurs. The following figure shows an example of the error message:

Symptom: When you package an app with Xcode 14 and submit it to the App Store for review, an error related to post-processing plugins such as mpf_filter.framework and vfi_filter.framework for frame interpolation and sharpening occurs. The following figure shows an example of the error message:

Solution:

• If your project does not use the plugin that is mentioned in the error message, you can delete the plugin. This does not affect the player's features and can reduce the package size.

• If your project must use the plugin mentioned in the error, you can temporarily remove the "_" from the value string in the "Bundle identifier" key-value pair in the Info.plist file under the framework path, and then compile and build the project.

• You can upgrade to version 5.5.2.0 or later, in which the naming is corrected.

By default, the ApsaraVideo Player SDK calls back the playback progress every 500 ms. You can change the callback interval. Shorten the interval to obtain the current playback progress more frequently. The following code provides an example:

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

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

You can use one of the following three methods:

• Method 1: After the prepare method is called for the AliPlayer instance for iOS and the player is prepared (AVPEventPrepareDone), you can directly obtain the width and height of the AliPlayer instance.

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

• Method 2: Listen for the callback that is returned when the video size changes. This callback directly returns the width and height of the video.

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

• Method 3: Listen for the callback that is returned when track information is obtained. Obtain the videoWidth and videoHeight from the AVPTrackInfo returned in the info array.

  Note

  Listening for the track information callback involves a network request. The success of obtaining the video width and height depends on the network quality. Use Method 1 or Method 2 to obtain the video width and height for better reliability.

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

The following code provides an example of how to switch the seek mode:

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

Solution: You can call an API to set a larger maximum interval for accurate seek. This reduces the frequency at which the player switches from accurate seek to inaccurate seek and improves seek accuracy. However, if the distance from the seek point to the nearest keyframe is too large, the seek operation takes longer. Set the maximum interval for accurate seek as needed. The following code provides an example:

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

The following code provides an example of how to obtain audio and video source data:

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

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

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

    }
    return NO;
}

After you enable adaptive bitrate switching by calling the [self.player selectTrack:SELECT_AVPTRACK_TYPE_VIDEO_AUTO]; API, the ApsaraVideo Player SDK collects statistics on the current network speed. If the network speed reaches the next bitrate level within 10 seconds, the player switches to that bitrate. If the network speed does not reach the next bitrate level within 10 seconds, the player does not switch.

• When switching from a high bitrate to a low bitrate, if the network speed reaches the next bitrate level within 10 seconds, the player switches after the cached content at the high bitrate is played.

• When switching from a low bitrate to a high bitrate, if the network speed reaches the next bitrate level within 10 seconds, the player switches immediately.

You can customize the retry logic. When a retry is triggered, a retry event is sent to an external module, which determines the specific retry logic. The following code provides an example:

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

/**
 @brief: The callback for player events.
 @param player: The player pointer.
 @param eventWithString: The player event type.
 @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) { // Network error. A retry is required.
        // TODO: Add the processing logic.
    }
}

Solution: You can configure AVAudioSession in a unified manner at an appropriate location in your project. For example, you can configure the audio session of the app as the playback category and allow mixing with other apps. You can also configure the audio session of the app as the PlayAndRecord category for recording and playback scenarios. If an error occurs during the operation, the error message is stored in the err variable.

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

At the same time, on the ApsaraVideo Player SDK for iOS side, you can customize the proxy for AVAudioSession and not use the AVAudioSession logic defined inside the SDK. This helps avoid the risk of audio preemption that might be caused by the ApsaraVideo Player SDK for iOS. The following code shows an example of the configuration on the ApsaraVideo Player SDK for iOS side:

1. Set the proxy.

   [AliPlayer setAudioSessionDelegate:self];

2. Set the listener for the proxy.

   return TRUE indicates that the SDK no longer configures 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 a stack crash that points to the SDK occurs when you use ApsaraVideo Player SDK for iOS, you can use the following methods to resolve the issue:

1. If you are not using the latest version of ApsaraVideo Player SDK for iOS, upgrade to the latest version. ApsaraVideo Player SDK for iOS is continuously updated to improve stability. For more information about how to obtain the latest SDK, see SDK introduction.

2. If the crash persists after you upgrade to the latest version, provide the complete crash information to Alibaba Cloud technical support. For more information about how to get technical support, see Get technical support.

You can follow these steps to identify the cause of the issue:

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

   Check whether the crash stack contains the AliyunPlayer prefix. If it does, the issue occurs in the ApsaraVideo Player SDK.

2. Upgrade to the latest version of the ApsaraVideo Player SDK and verify whether the issue is resolved.

3. If the issue persists, prepare the relevant crash files (including all threads), crash logs, and crash scenarios. For more information, see How to obtain logs.

The following code provides an example of how to implement this feature:

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

// For iOS 16.0 and 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(@"Screen 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(@"Screen rotation error:%@", exception.reason);
  } @finally {
  }
} else { // For systems earlier than iOS 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];
}

You can follow these steps to identify the cause of the issue:

1. Check whether the video source itself has black bars.

2. You can call the following API to adjust the scaling mode of the player.

   /*
   AVP_SCALINGMODE_SCALEASPECTFILL: The video is scaled to fill the screen. The video may be cropped.
   AVP_SCALINGMODE_SCALEASPECTFIT: The video is scaled to fit the screen. Black bars may appear.
   AVP_SCALINGMODE_SCALETOFILL: The video is scaled to fill the screen without preserving the aspect ratio. The video may be distorted.
   */
   self.player.scalingMode = AVP_SCALINGMODE_SCALETOFILL;

3. If the scaling mode does not meet your requirements, you can adjust the width and height of the custom view for self.player.playerView by modifying the frame of self.player.playerView.

You can follow these steps to identify the cause of the issue:

1. Use another player to play the video and check whether it is an audio-only file.

2. If the video plays normally on another player and the video dimensions change, you can switch to software decoding. The following code shows how to switch to software decoding:

   player.enableHardwareDecoder = NO

Versions of the ApsaraVideo Player SDK earlier than V5.4.5.0 do not support using the list player AliListPlayer to play HLS (m3u8) videos. Versions V5.4.5.0 and later support playing HLS (m3u8) videos, but you must enable local caching. For more information about how to enable local caching, see Local caching.

The following code provides an example:

// The following code provides an example of playback using VidSts.
AVPVidStsSource *stsSource = [[AVPVidStsSource alloc] init];
stsSource.vid = @"<vid>";
stsSource.accessKeyId = @"<accessKeyId>";
stsSource.securityToken = @"<securityToken>";
stsSource.accessKeySecret = @"<accessKeySecret>";
stsSource.quality = @""; // The expected definition for playback. Valid values: FD, LD, SD, HD, 2K, 4K, and OD.
stsSource.forceQuality = NO; // Specifies whether to forcibly play the video in the expected definition. NO: The video is not forcibly played in the expected definition. The player searches for definitions in the default order and plays the video in the first definition that it finds. YES: The video is forcibly played in the expected definition. If the expected definition is not found, the video is not played.