我将Matt Gallagher's audio streamer 用于流式广播电台。但是如何录制音频？有没有办法将下载的数据包放入 NSData 并将其保存在 iPhone 上文档文件夹中的音频文件中？
谢谢
【问题讨论】：
标签： ios4 core-audio audio-streaming audio-recording
是的，有，我已经做到了。我的问题是能够在同一个流媒体中播放它（在别处询问）。它将使用 iOS 中的标准 AVAudioPlayer 播放。但是，这会通过将数据写入流媒体代码中来将数据保存到文件中。
这个例子缺少一些错误检查，但会给你主要的想法。
首先，从主线程调用开始和停止录制。当有人按下记录时，这是在我的 viewController 中：
//---------------------------------------------------------
// Record button was pressed (toggle on/off)
// writes a file to the documents directory using date and time for the name
//---------------------------------------------------------
-(IBAction)recordButton:(id)sender {
// only start if the streamer is playing (self.streamer is my streamer instance)
if ([self.streamer isPlaying]) {
NSDate *currentDateTime = [NSDate date]; // get current date and time
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:@"EEEE MMMM d YYYY 'at' HH:mm:ss"];
NSString *dateString = [dateFormatter stringFromDate:currentDateTime];
self.isRecording = !self.isRecording; // toggle recording state BOOL
if (self.isRecording)
{
// start recording here
// change the record button to show it is recording - this is an IBOutlet
[self.recordButtonImage setImage:[UIImage imageNamed:@"Record2.png"] forState:0];
// call AudioStreamer to start recording. It returns the file pointer back
//
self.recordFilePath = [self.streamer recordStream:TRUE fileName:dateString]; // start file stream and get file pointer
} else
{
//stop recording here
// change the button back
[self.recordButtonImage setImage:[UIImage imageNamed:@"Record.png"] forState:0];
// call streamer code, stop the recording. Also returns the file path again.
self.recordFilePath = [self.streamer recordStream:FALSE fileName:nil]; // stop stream and get file pointer
// add to "recorded files" for selecting a recorderd file later.
// first, add channel, date, time
dateString = [NSString stringWithFormat:@"%@ Recorded on %@",self.model.stationName, dateString]; // used to identify the item in a list laster
// the dictionary will be used to hold the data on this recording for display elsewhere
NSDictionary *row1 = [[[NSDictionary alloc] initWithObjectsAndKeys: self.recordFilePath, @"path", dateString, @"dateTime", nil] autorelease];
// save the stream info in an array of recorded Streams
if (self.model.recordedStreamsArray == nil) {
self.model.recordedStreamsArray = [[NSMutableArray alloc] init]// init the array
}
[self.model.recordedStreamsArray addObject:row1]; // dict for this recording
}
}
}
现在，在 AudioStreamer.m 中，我需要处理上面的记录设置调用
- (NSString*)recordStream:(BOOL)record fileName:(NSString *)fileName
{
// this will start/stop recording, and return the file pointer
if (record) {
if (state == AS_PLAYING)
{
// now open a file to save the data into
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
// will call this an mp3 file for now (this may need to change)
NSMutableString *temp = [NSMutableString stringWithString:[documentsDirectory stringByAppendingFormat:@"/%@.mp3",fileName]];
// remove the ':' in the time string, and create a file name w/ time & date
[temp replaceOccurrencesOfString:@":" withString:@"" options:NSLiteralSearch range:NSMakeRange(0, [temp length])];
self.filePath = temp; // file name is date time generated.
NSLog(@"Stream Save File Open = %@", self.filePath);
// open the recording file stream output
self.fileStream = [NSOutputStream outputStreamToFileAtPath:self.filePath append:NO];
[self.fileStream open];
NSLog(@"recording to %@", self.fileStream);
self.isRecording = TRUE;
return (self.filePath); // if started, send back the file path
}
return (nil); // if not started, return nil for error checking
} else {
// save the stream here to a file.
// we are done, close the stream.
if (self.fileStream != nil) {
[self.fileStream close];
self.fileStream = nil;
}
NSLog(@"stop recording");
self.isRecording = FALSE;
return (self.filePath); // when stopping, return nil
}
}
最后，我们需要修改流媒体的数据部分以实际保存字节。需要修改方法中的流代码：-(void)handleReadFromStream:(CFReadStreamRef)aStreameventType:(CFStreamEventType)eventType 在该方法中向下滚动，直到找到：
@synchronized(self)
{
if ([self isFinishing] || !CFReadStreamHasBytesAvailable(stream))
{
return;
}
//
// Read the bytes from the stream
//
length = CFReadStreamRead(stream, bytes, kAQDefaultBufSize);
if (length == -1)
{
[self failWithErrorCode:AS_AUDIO_DATA_NOT_FOUND];
return;
}
在length =行之后，添加如下代码：
//
// if recording, save the raw data to a file
//
if(self.isRecording && length != 0){
//
// write the data to a file
//
NSInteger bytesWritten;
NSInteger bytesWrittenSoFar;
bytesWrittenSoFar = 0;
do {
bytesWritten = [self.fileStream write:&bytes[bytesWrittenSoFar] maxLength:length - bytesWrittenSoFar];
NSLog(@"bytesWritten = %i",bytesWritten);
if (bytesWritten == -1) {
[self.fileStream close];
self.fileStream = nil;
NSLog(@"File write error");
break;
} else {
bytesWrittenSoFar += bytesWritten;
}
} while (bytesWrittenSoFar != length);
}
以下是 .h 声明：
添加到 AudioStreamer.h 的接口
// for recording and saving a stream
NSString* filePath;
NSOutputStream* fileStream;
BOOL isRecording;
BOOL isPlayingFile;
在您的视图控制器中，您将需要：
@property(nonatomic, assign) IBOutlet UIButton* recordButtonImage;
@property(nonatomic, assign) BOOL isRecording;
@property (nonatomic, copy) NSString* recordFilePath;
希望这对某人有所帮助。如果有问题请告诉我，并且总是很高兴听到有人可以改进这一点。
另外，有人问起 self.model.xxx 模型是我创建的一个数据对象，让我可以轻松地传递多个对象使用的数据，也可以被多个对象修改。我知道，全局数据的形式不好，但有时它只是让它更容易访问。我在调用时将数据模型传递给每个新对象。我在模型中保存了一组频道、歌曲名称、艺术家姓名和其他与流相关的数据。我还将我想通过启动保留的任何数据放在这里，例如设置，并在每次更改持久数据时将此数据模型写入文件。在此示例中，您可以将数据保存在本地。如果您在模型传递方面需要帮助，请告诉我。
【讨论】：
好的，这就是我播放录制文件的方式。播放文件时，站 URL 包含文件的路径。 self.model.playRecordedSong 包含我想要播放的流中的秒数的时间值。我保留了歌曲名称和时间索引的字典，因此我可以在任何歌曲的开头跳入录制的流。使用 0 从头开始。
NSError *error;
NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:self.model.stationURL, [[NSBundle mainBundle] resourcePath]]];
// get the file URL and then create an audio player if we don't already have one.
if (audioPlayer == nil) {
// set the seconds count to the proper start point (0, or some time into the stream)
// this will be 0 for start of stream, or some value passed back if they picked a song.
self.recordPlaySecondsCount = self.model.playRecordedSong;
//create a new player
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
// set self so we can catch the end of file.
[audioPlayer setDelegate: self];
// audio player needs an NSTimeInterval. Get it from the seconds start point.
NSTimeInterval interval = self.model.playRecordedSong;
// seek to the proper place in file.
audioPlayer.currentTime = interval;
}
audioPlayer.numberOfLoops = 0; // do not repeat
if (audioPlayer == nil)
NSLog(@"AVAudiolayer error: %@", error);
// I need to do more on the error of no player
else {
[audioPlayer play];
}
我希望这可以帮助您播放录制的文件。
【讨论】：
试试这个课程这有完整的解决方案所有广播流录音正在播放..
In Git Hub You Can Find This Use This Class Very Easy To Use
【讨论】：