1	//创建转场效果实例，这里以读取本地配置文件为例
2	NSString *name = [NSString stringWithFormat:@"bundle/%@.zip",转场唯一签名];
3
4    NSString *path = [[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:name];
5
6    BOOL isExist = [[NSFileManager defaultManager] fileExistsAtPath:path];
7
8    //解压
9
10    if (isExist) {
11
12        NSString *destPath = [self localPath];
13
14        destPath = [destPath stringByAppendingPathComponent:item.sign];
15
16        BOOL bSucess = [self unzipStickerPackage:path destPath:destPath];
17
18        if (bSucess) {
19
20            // 读取json文件
21
22            NSString *jsonPath =  [destPath stringByAppendingPathComponent:@"transition_config.json"];
23
24            BOOL isJsonExist = [[NSFileManager defaultManager] fileExistsAtPath:jsonPath];
25
26            if (isJsonExist) {
27
28                NSData *data=[NSData dataWithContentsOfFile:jsonPath];
29
30                NSError *error;
31
32                NSDictionary *jsonDict =[NSJSONSerialization JSONObjectWithData:data
33
34                                                                        options:NSJSONReadingAllowFragments
35
36                                                                          error:&error];                
37
38                if(jsonDict != nil && jsonDict.count > 0) {
39
40                    NSString *library_name      = @"library_name";
41
42                    NSString *vertex_function   = @"vertex_function";
43
44                    NSString *fragment_function = @"fragment_function";
45
46                    NSString *durationKey       = @"duration";
47                    
48                    NSString *library = [jsonDict objectForKey:library_name];
49
50                    NSString *libraryPath = [destPath stringByAppendingPathComponent:library];
51                    
52                    if (![[NSFileManager defaultManager] fileExistsAtPath:libraryPath]) {
53
54                        return nil;
55
56                    }                    
57
58                    NSString *vertexShaderName = [jsonDict objectForKey:vertex_function];
59
60                    NSString *fragmentShaderName = [jsonDict objectForKey:fragment_function];
61
62                    CGFloat defaultDuration = 0.5 * 1000;
63
64                    CGFloat duration = [jsonDict hk_floatForKey:durationKey];
65
66                    if (duration <0.01) {
67
68                        duration = defaultDuration;
69
70                    }
71					//创建转场效果实例
72                    RMVPMediaVideoTransitionItem *mediaItem = [[RMVPMediaVideoTransitionItem alloc] initWithType:RMVPMediaVideoTransitionItemTypeDual transitionType:RMVPMediaVideoTransitionItemTypeTransitionTypeDefault libraryPath:libraryPath vertexFunctionName:vertexShaderName fragmentFunctionName:fragmentShaderName];
73
74                    mediaItem.duration = CMTimeMakeWithSeconds(duration / 1000, NSEC_PER_SEC);
75
76                    mediaItem.transitionId = item.transition_id;             
77
78                }
79
80            }
81
82        }
83
84    }
85
86
87	//删除原有转场效果
88	[self.videoTrack removeTransitionItemAtIndex:index];
89
90
91	//绑定最新转场效果
92	[self.videoTrack bindTransitionItem:mediaItem atIndex:index];