我制作了一个使用OpenAL播放许多声音的iphone应用程序。 这些声音是mp3,非常重(超过1百万),我流式传输(每个声音2个缓冲区),以便使用更少的内存。 要管理中断,我使用以下代码:
在OpenALSupport.c文件中:
//used to disable openAL during a call
void openALInterruptionListener ( void *inClientData, UInt32 inInterruptionState)
{
if (inInterruptionState == kAudioSessionBeginInterruption)
{
alcMakeContextCurrent (NULL);
}
}
//used to restore openAL after a call
void restoreOpenAL(void* a_context)
{
alcMakeContextCurrent(a_context);
}
在我的SoundManager.m文件中:
- (void) restoreOpenAL
{
restoreOpenAL(mContext);
}
//OPENAL initialization
- (bool) initOpenAL
{
// Initialization
mDevice = alcOpenDevice(NULL);
if (mDevice) {
...
// use the device to make a context
mContext=alcCreateContext(mDevice,NULL);
// set my context to the currently active one
alcMakeContextCurrent(mContext);
AudioSessionInitialize (NULL, NULL, openALInterruptionListener, mContext);
NSError *activationError = nil;
[[AVAudioSession sharedInstance] setActive: YES error: &activationError];
NSError *setCategoryError = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryAmbient error: &setCategoryError];
...
}
最后在我的AppDelegate中:
- (void)applicationDidBecomeActive:(UIApplication *)application
{
[[CSoundManager getInstance] restoreOpenAL];
...
}
使用此方法,声音在通话后恢复,但流似乎是随机播放的。 是否有一种特定的方法来管理流媒体声音的中断?我没有找到任何关于此的文章。
感谢您的帮助。
答案 0 :(得分:1)
好的,我回答了我自己的问题。
我通过管理流媒体方法的错误解决了这个问题:
- (void) updateStream
{
ALint processed;
alGetSourcei(sourceID, AL_BUFFERS_PROCESSED, &processed);
while(processed--)
{
oldPosition = position;
NSUInteger buffer;
alSourceUnqueueBuffers(sourceID, 1, &buffer);
////////////////////
//code freshly added
ALint err = alGetError();
if (err != 0)
{
NSLog(@"Error Calling alSourceUnQueueBuffers: %d",err);
processed++;
//restore old position for the next buffer
position = oldPosition;
usleep(10000);
continue;
}
////////////////////
[self stream:buffer];
alSourceQueueBuffers(sourceID, 1, &buffer);
////////////////////
//code freshly added
err = alGetError();
if (err != 0)
{
NSLog(@"Error Calling alSourceQueueBuffers: %d",err);
processed++;
usleep(10000);
//restore old position for the next buffer
position = oldPosition;
}
///////////////////
}
}