我正在尝试在 iPhone4 上使用 AVQueuePlayer 播放 .m4a 声音文件,但没有声音。
如果我使用相同的文件尝试 AudioServicesPlaySystemSound,则一切正常。
这是代码。
(AVFoundation framework is installed.)
#import <AVFoundation/AVFoundation.h>
-(void) play_sound_file: (NSString *) sound_file_m4a
{
printf("\n play_sound_file 1: '%s' ", [sound_file_m4a UTF8String] );
AVPlayerItem *sound_file = [[AVPlayerItem alloc] initWithURL:[NSURL URLWithString:[[NSBundle mainBundle] pathForResource:sound_file_m4a ofType:@"m4a"]]];
AVQueuePlayer *player = [AVQueuePlayer queuePlayerWithItems:[NSArray arrayWithObjects:sound_file, nil]];
[player play];
return;
}
2012 年 8 月 28 日的最新代码.......
(注意:两个声音文件都适用于 AudioServicesPlaySystemSound)
AVPlayerItem *sound_file1 = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[[NSString alloc] initWithFormat:@"Hold still"] ofType:@"m4a"]]];
AVPlayerItem *sound_file2 = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[[NSString alloc] initWithFormat:@"Press go"] ofType:@"m4a"]]];
AVQueuePlayer *player = [AVQueuePlayer queuePlayerWithItems: [NSArray arrayWithObjects:sound_file1, sound_file2, nil]];
[player play];
最佳答案
我在你上一篇文章中对我的回答的评论中解释了如何解决这个问题。这可能不起作用的原因之一是因为您将一项传递给 arrayWithObjects:
这需要不止一项。另一个可能导致它不起作用的事情是,如果您试图在模拟器中运行它,AVQueuePlayer
之间存在已知的兼容性问题。和模拟器。
还:
代替
AVPlayerItem *sound_file = [[AVPlayerItem alloc] initWithURL:[NSURL URLWithString:[[NSBundle mainBundle] pathForResource:sound_file_m4a ofType:@"m4a"]]];
和
AVPlayerItem *sound_file = [[AVPlayerItem alloc] initWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[[NSString alloc] initWithFormat:@"sound_file_m4a"] ofType:@"m4a"]]];
编辑:下面是如何按顺序播放音频文件的示例。
在你的头文件中:
#import <AVFoundation/AVFoundation.h>
AVAudioPlayer *data;
NSArray *arrayOfTracks;
NSUInteger currentTrackNumber;
然后在您的实现文件中:
- (void)viewDidLoad
{
[super viewDidLoad];
arrayOfTracks = [[NSArray alloc] initWithObjects:@"1",@"2",@"3", nil];//Do NOT include file extension here
currentTrackNumber = 0;
}
- (void)startPlaying
{
if (data) {
[data stop];
//[data release]; if project isn't using Automatic Reference Counting
data = nil;
}
data = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[[NSString alloc] initWithString:[arrayOfTracks objectAtIndex:currentTrackNumber]] ofType:@"m4a"]] error:NULL];
data.delegate = self;
[data play];
}
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
if (flag) {
if (currentTrackNumber < [arrayOfTracks count] - 1) {
currentTrackNumber ++;
if (data) {
[data stop];
//[data release]; if project isn't using Automatic Reference Counting
data = nil;
}
data = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[[NSString alloc] initWithString:[arrayOfTracks objectAtIndex:currentTrackNumber]] ofType:@"m4a"]] error:NULL];
data.delegate = self;
[data play];
}
}
}
关于iphone - iOS xcode4 AVQueuePlayer 不播放声音,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12160774/