视频分解图片,图片合成视频

转载自: http://blog.csdn.net/ioswyl88219/article/details/18152419

视频视频分解视频合成AVAssetImageGenerato

工作当中用到了相关的技术,现在特别记录一下

分解视频

[objc] view plaincopyprint?

1. <span style="font-size:18px;">
2. //分解视频
3. - (void)resolveMovWithUrl:(NSURL *)movUrl{
4. //得到url的资源,转为asset
5. AVAsset *myAsset = [[AVURLAsset alloc] initWithURL:movUrl options:nil];
6. NSParameterAssert(myAsset);
7. //初始化AVAssetImageGenerator
8. self.imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:myAsset] ;
9. self.imageGenerator.appliesPreferredTrackTransform = YES;//加这句话,取出的是正确方向的图片
10. self.imageGenerator.requestedTimeToleranceBefore = kCMTimeZero;
11. self.imageGenerator.requestedTimeToleranceAfter = kCMTimeZero;
12. //得到秒数
13. Float64 _durationSeconds = CMTimeGetSeconds([myAsset duration]);
14. __block float Second = 0.0;
15. __block int num = 0;
16. NSString *path = [self backPath];
17. NSLog(@"%@",path);
18. dispatch_semaphore_t sem = dispatch_semaphore_create(0);
19. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
20. dispatch_async(dispatch_get_main_queue(), ^{
21. [MBProgressHUD showHUDAddedTo:self.view animated:YES];
22. });
23. while ((_durationSeconds - Second)>0) {
24. NSLog(@"%f",_durationSeconds - Second);
25. CMTime rTime = CMTimeMakeWithSeconds(Second, NSEC_PER_SEC);
26. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
27. @autoreleasepool
28. {
29. //根据帧数取出图片
30. CGImageRef image= [self.imageGenerator copyCGImageAtTime:rTime actualTime:NULL error:NULL];
31. if (image)
32. {
33. UIImage *img = [[UIImage alloc] initWithCGImage:image];
34. NSData *imageData = UIImagePNGRepresentation(img);
35. NSString *pathNum = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"%d.png",num]];
36. [imageData writeToFile:pathNum atomically:NO];
37. CGImageRelease(image);
38. NSString *actualTimeString =CFBridgingRelease(CMTimeCopyDescription(NULL, rTime));
39. NSLog(@"photo:%d",num);
40. NSLog(@"%@",actualTimeString);
41. //调用dispatch_semaphore_signal函数，使计数器+1
42. dispatch_semaphore_signal(sem);
43. }else{
44. dispatch_async(dispatch_get_main_queue(), ^{
45. [MBProgressHUD hideAllHUDsForView:self.view animated:YES];
46. });
47. }
48. }
49. });
50. Second +=0.083;
51. //一直等待，直到信号量计数器大于等于1
52. dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
53. num+=1;
54. }
55. dispatch_async(dispatch_get_main_queue(), ^{
56. num = 0;
57. Second = 0.0;
58. [MBProgressHUD hideAllHUDsForView:self.view animated:YES];
59. });
60. });
61. }</span>

图片合成视频

[objc] view plaincopyprint?

1. <span style="font-size:18px;">
2. - (void)initRecord
3. {
4. //是否是第一次添加图片
5. self.firstImgAdded = FALSE;
6. //video路径
7. NSString* fileName = [NSString stringWithFormat:@"%d.mov", (int)[[NSDate date] timeIntervalSince1970]];
8. self.videoPath = [NSString stringWithFormat:@"%@/%@", [self getLibarayPath], fileName];
9. //设置一个gcd队列
10. writeQueue = dispatch_queue_create("recording_queue", DISPATCH_QUEUE_PRIORITY_DEFAULT);
11. CGSize frameSize = imageRect.size;
12. NSError* error = nil;
13. //创建写入对象
14. self.videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:self.videoPath] fileType:AVFileTypeQuickTimeMovie error:&error];
15. //如果出错,打印错误内容
16. if(error)
17. {
18. NSLog(@"error creating AssetWriter: %@",[error description]);
19. self.videoWriter = nil;
20. return;
21. }
22. //设置参数
23. NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
24. AVVideoCodecH264, AVVideoCodecKey,
25. [NSNumber numberWithInt:frameSize.width], AVVideoWidthKey,
26. [NSNumber numberWithInt:frameSize.height], AVVideoHeightKey,
27. nil nil];
28. //输入对象
29. self.writerInput = [AVAssetWriterInput
30. assetWriterInputWithMediaType:AVMediaTypeVideo
31. outputSettings:videoSettings];
32. //属性设置
33. NSMutableDictionary *attributes = [[NSMutableDictionary alloc] init];
34. [attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
35. [attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.width] forKey:(NSString*)kCVPixelBufferWidthKey];
36. [attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.height] forKey:(NSString*)kCVPixelBufferHeightKey];
37. //通过属性和writerInput 创建一个新的Adaptor
38. self.adaptor = [AVAssetWriterInputPixelBufferAdaptor
39. assetWriterInputPixelBufferAdaptorWithAssetWriterInput:self.writerInput
40. sourcePixelBufferAttributes:attributes];
41. //添加输入,必须在开始写入之前
42. [self.videoWriter addInput:self.writerInput];
43. self.writerInput.expectsMediaDataInRealTime = YES;
44. //开始写入
45. [self.videoWriter startWriting];
46. [self.videoWriter startSessionAtSourceTime:kCMTimeZero];
47. }
48. #pragma mark - 视频合成
49. static int count = 0;
50. - (void)startCamera
51. {
52. NSMutableArray *arr = [self allFilesAtPath:[self backPath]];
53. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
54. dispatch_async(dispatch_get_main_queue(), ^{
55. [MBProgressHUD showHUDAddedTo:self.view animated:YES];
56. });
57. while (arr.count -count) {
58. UIImage *image = [UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@/%d.png",[self backPath],count]];
59. CGImageRef image1 = image.CGImage;
60. [self writeImage:image1 withIndex:count];
61. NSLog(@"%d",count);
62. count ++;
63. }
64. [self.writerInput markAsFinished];
65. [self.videoWriter finishWriting];
66. //        [self combineWithAudio:num];
67. dispatch_async(dispatch_get_main_queue(), ^{
68. count = 0;
69. [MBProgressHUD hideAllHUDsForView:self.view animated:YES];
70. });
71. });
72. }
73. - (void)writeImage:(CGImageRef)img withIndex:(NSInteger)curCount
74. {
75. CVPixelBufferRef buffer = NULL;
76. if (self.videoWriter == nil)
77. {
78. NSLog(@"error~~~~~~~~~~~");
79. }
80. if (self.firstImgAdded == FALSE)
81. {
82. buffer = [self pixelBufferFromCGImage:img];
83. BOOL result = [self.adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
84. if (result == NO) //failes on 3GS, but works on iphone 4
85. {
86. NSLog(@"failed to append buffer");
87. }
88. if(buffer)
89. {
90. CVBufferRelease(buffer);
91. }
92. self.firstImgAdded = TRUE;
93. }
94. else
95. {
96. if (self.adaptor.assetWriterInput.readyForMoreMediaData)
97. {
98. CMTime frameTime = CMTimeMake(1, FramePerSec);
99. CMTime lastTime = CMTimeMake(curCount, FramePerSec);
100. CMTime presentTime = CMTimeAdd(lastTime, frameTime);
101. buffer = [self pixelBufferFromCGImage:img];
102. BOOL result = [self.adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
103. if (result == NO) //failes on 3GS, but works on iphone 4
104. {
105. NSLog(@"failed to append buffer");
106. NSLog(@"The error is %@", [self.videoWriter error]);
107. }
108. else
109. {
110. NSLog(@"write ok");
111. }
112. if(buffer)
113. {
114. CVBufferRelease(buffer);
115. }
116. }
117. else
118. {
119. NSLog(@"error");
120. }
121. }
122. }
123. - (CVPixelBufferRef)pixelBufferFromCGImage:(CGImageRef)image
124. {
125. NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
126. [NSNumber numberWithBool:TRUE], kCVPixelBufferCGImageCompatibilityKey,
127. [NSNumber numberWithBool:TRUE],kCVPixelBufferCGBitmapContextCompatibilityKey,
128. nil nil];//是否兼容
129. CVPixelBufferRef pxbuffer = NULL;
130. CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, imageRect.size.width,
131. imageRect.size.height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef) options,
132. &pxbuffer);//返回kCVReturnSuccess kCFAllocatorDefault = nil
133. status=status;
134. NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);//判断类型
135. CVPixelBufferLockBaseAddress(pxbuffer, 0);//访问地址
136. voidvoid *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
137. NSParameterAssert(pxdata != NULL);
138. CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
139. CGContextRef context = CGBitmapContextCreate(pxdata, imageRect.size.width,
140. imageRect.size.height, 8, 4*imageRect.size.width, rgbColorSpace,
141. kCGImageAlphaNoneSkipFirst);
142. NSParameterAssert(context);
143. CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
144. CGContextDrawImage(context, CGRectMake(0, 0, imageRect.size.width, imageRect.size.height), image);
145. CGColorSpaceRelease(rgbColorSpace);
146. CGContextRelease(context);
147. CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
148. return pxbuffer;
149. }</span>