我正在使用Audio API,第一步是将文件内容读入缓冲区。
我有以下代码,但是执行AudioFileReadPackets
时会得到返回代码-50,但我没有得到它,因为在文档中它不存在。
您能指出我正确的方向吗?任何想法将不胜感激!
//create url for file
CFURLRef myFileURL = CFURLCreateWithString(kCFAllocatorDefault, INPUT_FILE, NULL);
AudioFileID audioFile;
OSStatus error;
error = AudioFileOpenURL(myFileURL,kAudioFileReadPermission,0,&audioFile);
CFRelease(myFileURL);
if(error != noErr) {
printf("%d",(int)error);
exit(1);
}
AudioStreamBasicDescription dataFormat;
UInt32 size = sizeof(dataFormat);
error = AudioFileGetProperty(audioFile, kAudioFilePropertyDataFormat, &size, &dataFormat);
if(error != noErr) {
printf("%d",(int)error);
exit(1);
}
UInt32 dataSize;
error = AudioFileGetPropertyInfo(audioFile, kAudioFilePropertyAudioDataPacketCount, &dataSize, NULL);
if(error != noErr) {
printf("%d",(int)error);
exit(1);
}
UInt32 packetCount;
error = AudioFileGetProperty(audioFile, kAudioFilePropertyAudioDataPacketCount, &dataSize, &packetCount);
if(error != noErr) {
printf("%d",(int)error);
exit(1);
}
printf("File opened, packet count: %d\n", packetCount);
UInt32 packetsRead = packetCount;
UInt32 bytesRead = 0;
if(packetCount > 0) {
SInt16 audioData = *(SInt16 *)malloc(2 * packetCount);
error = AudioFileReadPackets(audioFile, false, &bytesRead, NULL, 0, &packetsRead, audioData);
if(error != noErr) {
printf("%d",(int)error);
exit(1);
}
printf("Read %d bytes, %d packets",bytesRead,packetsRead);
}
最佳答案
-50 = paramErr表示您传递了错误的参数。文档说,对于恒定比特率音频,AudioFileReadPackets的第四个参数只能为NULL。
https://stackoverflow.com/questions/28489918/