在iOS上以编程方式将flv转换为mp4

Question

在我们的iOS应用程序中，我们将收到带有视频和音频流的flv**(容器(**文件，类似于

Input #0, flv, from 'test.flv':
Metadata:
streamName      : flvLiveStream
encoder         : Lavf55.12.100
Duration: 00:00:48.00, start: 66064.401000, bitrate: 632 kb/s
Stream #0:0, 41, 1/1000: **Video: h264 (Baseline)**, 1 reference frame, yuv420p(progressive, left), 1280x720, 0/1, 15 fps, 1k tbr, 1k tbn
Stream #0:1, 14, 1/1000: **Audio: pcm_alaw,** 8000 Hz, mono, s16, 64 kb/s

这也需要转换为mp4容器和格式，我正在尝试使用ffmpeg，我相信这只是一种方法，使用转码.c文件，但在现阶段失败

Impossible to convert between the formats supported by the filter 'in' and the filter 'auto_scaler_0'

我正在尝试学习像ffmpeg这样的OSX命令-I test.flv test.mp4，

移植到iOS可行吗，它能在所有不同的场景中工作吗

总结

---在iOS设备上将flv转换为mp4的最佳方式是什么h264中的视频将在哪里，swf编解码器中的音频将在哪里？

Answer 1

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"MyVideo.mp4"];
NSURL *outputURL = [NSURL fileURLWithPath:filePath];
[self convertVideoToLowQuailtyWithInputURL:localUrl outputURL:outputURL handler:^(AVAssetExportSession *exportSession)
{
if (exportSession.status == AVAssetExportSessionStatusCompleted) {
// Video conversation completed
}          
}];
- (void)convertVideoToLowQuailtyWithInputURL:(NSURL*)inputURL outputURL:(NSURL*)outputURL handler:(void (^)(AVAssetExportSession*))handler {
[[NSFileManager defaultManager] removeItemAtURL:outputURL error:nil];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:inputURL options:nil];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetPassthrough];
exportSession.outputURL = outputURL;
exportSession.outputFileType = AVFileTypeMPEG4;
[exportSession exportAsynchronouslyWithCompletionHandler:^(void) {
handler(exportSession);
}];
}