我正在使用 Flutter 构建一个应用程序，它允许我录制音频，然后再播放。我正在使用audio_recorder 0.4.0用于录制音频的包和stereo 1.0.0用于播放音频的包。
当我使用 iOS 模拟器录制时，一切正常。但是当我在物理设备（iPhone 6 Plus）上运行时，我总是在录制会话结束时得到一个 28 字节的文件——基本上只是 m4a 文件的标题。
我已经将此归结为两个库之间的某种干扰。如果我使用附带的示例应用程序，我可以在物理设备上进行录制audio_recorder 0.4.0。但我所要做的就是将这一行添加stereo: 1.0.0到同一个示例项目的 pubspec.yml 中的依赖项中，然后我突然开始在录制会话结束时在物理设备上获取 28 字节文件，而不是正常大小的 m4a 文件。
我有一个两部分的问题：
stereo图书馆可能会造成什么样的干扰，导致图书馆出现这种故障audio_recorder？我怀疑信道干扰，但我试图隔离它并没有产生任何结果。我怎样才能找到造成这种情况的原因？
我检查了两个会话的控制台输出。当它失败时，我在尝试开始录制后立即在控制台输出中看到其中的几 (8) 行：
mediaserverd 1111: AudioConverterNew returned -50
其他人建议当没有可用的麦克风时会发生此错误。
我还看到了输出之间的这种可疑差异。录音中断时：
default 11:36:57.098825 -0700 mediaserverd 4414: { "action":"set_play_state", "session":{"ID":"0x3315820","PID":14591,"name":"Runner"}, "details":"entry" }
default 11:36:57.100484 -0700 mediaserverd -CMSessionMgr- cmsSetIsPlaying: CMSession: 'sid:0x3315820, Runner(14591), 'prim'' with [MediaPlayback/Default] [NonMixable] [System Audio] starting playing.
default 11:36:57.104699 -0700 mediaserverd CAReportingClient.mm:328:-[CAReportingClient sendMessage:category:type:reporters:]: message {
Volume = "0.75";
VolumeCategory = "Audio/Video";
VolumeOperationProcess = "com.monkela.audioRecordSample";
VolumeOperationTime = 576708;
VolumePlayingState = 1;
}: (
857014545
)
default 11:36:57.105879 -0700 mediaserverd -CMVAEndptMgr- vaemSetDeviceVolume: CMSession: Setting cmsvolume = 0.750 for device ID: VirtualAudioDevice_Default
default 11:36:57.107295 -0700 mediaserverd VirtualAudio_Device.cpp:2046:SetPropertyData: [volm/outp/0] on device [ type: vdef; id: 354; addr: 0x1014e1ba0; hidden: 0; VA strms: { o/883/0x106fc5980 }; agg dev: [ id: 872; addr: 0x106f1a460; uid: "VAD [vdef] AggDev 52"; virt strms: { }; phys devs: { [ id: 292; addr: 0x104b0fdb0; uid: "Speaker"; streams: { i/294/0x104b11cd0, o/293/0x104b12790 } ] } ] ]: 0.750000.
default 11:36:57.108123 -0700 mediaserverd OutputVolumeControl_HAL_Common.cpp:662:CommitVolume: Setting Volume = -14.500000 dB, Final HW Volume = 0.000000 dB, Final SW Volume = -14.500000 dB, External Volume Handler: No
default 11:36:57.109008 -0700 mediaserverd OutputVolumeControl_HAL_Common.cpp:663:CommitVolume: PhysicalDevice UID = "Speaker"
default 11:36:57.109721 -0700 mediaserverd OutputVolumeControl_HAL_Common.cpp:664:CommitVolume: Scope = 1869968496 ("outp")
default 11:36:57.110704 -0700 mediaserverd OutputVolumeControl_HAL_Common.cpp:665:CommitVolume: Element = 0 ("0")
default 11:36:57.112062 -0700 mediaserverd OutputVolumeControl_HAL_Common.cpp:698:CommitVolume: SW Volume: 0.750000 scalar
default 11:36:57.114393 -0700 mediaserverd VirtualAudio_Device.cpp:2066:SetPropertyData: Client request to set nominal sample rate to 44100.000000 on VAD 354.
default 11:36:57.116038 -0700 assertiond [Runner:14591] Attempting to acquire assertion for Runner:14591: <BKProcessAssertion: 0x101349110; "CMSession.14591."com.monkela.audioRecordSample"."MediaPlayback".isPlayingProcessAssertion" (audio:inf); id:…C74721DE1F95>
default 11:36:57.116572 -0700 assertiond [Runner:14591] Add assertion: <BKProcessAssertion: 0x101349110; id: 13077-914DDDE2-35CE-4420-85ED-C74721DE1F95; name: CMSession.14591."com.monkela.audioRecordSample"."MediaPlayback".isPlayingProcessAssertion; state: active; reason: audio; duration: infs> {
owner = <BSProcessHandle: 0x101009be0; mediaserverd:13077; valid: YES>;
flags = preventSuspend, preventThrottleDownCPU, preventIdleSleep, preventSuspendOnSleep;
}
录制工作时：
default 11:39:19.865022 -0700 mediaserverd 2863: { "action":"activate", "session":{"ID":"0x3315826","PID":14609,"name":"Runner"}, "details":"entry" }
default 11:39:19.880637 -0700 mediaserverd CAReportingClient.mm:328:-[CAReportingClient sendMessage:category:type:reporters:]: message {
"active devices" = "[ { vdef, [ ], [ pspk ( 0 ) ] }, { vspd, [ pmbi ( 0 ) ], [ ] }, { vcal, [ pdln ( 0 ) ], [ puln ( 0 ) ] } ]";
category = csav;
"going_active" = 1;
mode = imdf;
"staying_active" = 0;
}: (
857014546
)
录制中断时的输出表明我尝试开始录制实际上开始播放某些内容（即调用错误的库）。