Question

我创建了一个带有示例项目的GitHub仓库，它显示了我在这里询问的以下问题：
https://github.com/paulpv/audio-loopback/tree/simplified/src/com/twistpair/wave/experimental/loopback
（请坚持使用“简化”分支并忽略“主”分支）

两个主要文件是：

免责声明：我目前只使用运行CyanogenMod 10 Jelly Bean的单个三星Epic SPH-D700进行编码和测试。我没有在其他设备上试过这个，但也许这可能有助于阻止我拔掉头发并疯狂。

我一直在努力让Android蓝牙SCO 可靠启动和停止以及捕获/播放音频 FOR MONTHS ！一旦我可以将手机转入SCO模式，通过AudioRecord和AudioTrack（分别）进行捕获和回放可以正常工作。我遇到的问题是我无法可靠地将手机送入SCO模式！

使用startBluetoothSco（）和setBluetoothScoOn（true）的“互联网”的例子看起来都很简单直接，但是当我在我的设备上使用它们时，它们几乎从不可靠地工作。
我创建了自己的测试应用程序，除了启动和停止SCO之外什么都不做，我甚至无法让它可靠地工作！

我的代码会侦听BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED EXTRA_STATE==CONNECTED. 我可以可靠地检测何时连接或断开任何耳机。

当检测到连接时，我的处理程序立即调用startBluetoothSco（） A可能会发誓至少一次将SCO_AUDIO_STATE踢到C O NNECTED，但99％的时间只会导致从DISCONNECTED->CONNECTING->DISCONNECTED过渡。

以下是我的GitHub示例应用程序的带注释日志输出：

10-03 17:00:13.970: I/dalvikvm(29487): Debugger is active
10-03 17:00:14.158: I/System.out(29487): Debugger has connected
10-03 17:00:15.779: I/System.out(29487): waiting for debugger to settle...
10-03 17:00:15.978: I/System.out(29487): debugger has settled (1325)

我的应用程序启动时关闭了Jawbone耳机并更新了用户界面...

10-03 17:00:16.568: D/MainActivity(29487): updateScreen()...
10-03 17:00:16.572: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false

...完成了UI更新
粘贴广播告诉我当前的SCO_AUDIO_STATE ...

10-03 17:00:16.689: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.media.ACTION_SCO_AUDIO_STATE_UPDATED flg=0x10 (has extras) }
10-03 17:00:16.689: D/AudioStateManager(29487): extras={"android.media.extra.SCO_AUDIO_PREVIOUS_STATE"=2, "android.media.extra.SCO_AUDIO_STATE"=0}
10-03 17:00:16.689: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED
10-03 17:00:16.693: D/AudioStateManager(29487): ==> scoAudioStatePrevious=SCO_AUDIO_STATE_CONNECTING(2)
10-03 17:00:16.693: D/AudioStateManager(29487): ==> scoAudioState=SCO_AUDIO_STATE_DISCONNECTED(0)
10-03 17:00:16.693: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED: SCO_AUDIO_STATE_DISCONNECTED

...当前SCO_AUDIO_STATE == DISCONNECTED;预计，因为我的耳机已关闭。
我的SCO Disconnected事件监听器被调用并用两个sendMessages更新UI ...

10-03 17:00:16.693: I/MainActivity(29487): onAudioManagerScoAudioDisconnected()
10-03 17:00:16.755: D/libEGL(29487): loaded /vendor/lib/egl/libEGL_POWERVR_SGX540_120.so
10-03 17:00:16.787: D/libEGL(29487): loaded /vendor/lib/egl/libGLESv1_CM_POWERVR_SGX540_120.so
10-03 17:00:16.791: D/libEGL(29487): loaded /vendor/lib/egl/libGLESv2_POWERVR_SGX540_120.so
10-03 17:00:16.888: D/OpenGLRenderer(29487): Enabling debug mode 0
10-03 17:00:16.912: D/MainActivity(29487): MSG_UPDATE_BLUETOOTH_INDICATION
10-03 17:00:16.912: D/MainActivity(29487): updateScreen()...
10-03 17:00:16.912: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false
10-03 17:00:16.927: D/MainActivity(29487): MSG_UPDATE_AUDIO_OUTPUT_STREAM_TYPE
10-03 17:00:16.927: D/MainActivity(29487): updateScreen()...
10-03 17:00:16.931: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false

...完成了UI更新

约20秒后，我打开我的Jawbone耳机......

10-03 17:00:37.572: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.bluetooth.headset.profile.action.CONNECTION_STATE_CHANGED flg=0x10 (has extras) }
10-03 17:00:37.583: D/AudioStateManager(29487): extras={"android.bluetooth.device.extra.DEVICE"=00:21:3C:00:3E:02, "android.bluetooth.profile.extra.PREVIOUS_STATE"=0, "android.bluetooth.profile.extra.STATE"=1}
10-03 17:00:37.587: D/AudioStateManager(29487): mReceiver: BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED
10-03 17:00:37.587: D/AudioStateManager(29487): ==> bluetoothDevice=00:21:3C:00:3E:02
10-03 17:00:37.587: D/AudioStateManager(29487): ==> bluetoothHeadsetStatePrevious=STATE_DISCONNECTED(0)
10-03 17:00:37.587: D/AudioStateManager(29487): ==> bluetoothHeadsetState=STATE_CONNECTING(1)
10-03 17:00:37.619: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.bluetooth.headset.profile.action.CONNECTION_STATE_CHANGED flg=0x10 (has extras) }
10-03 17:00:37.623: D/AudioStateManager(29487): extras={"android.bluetooth.device.extra.DEVICE"=00:21:3C:00:3E:02, "android.bluetooth.profile.extra.PREVIOUS_STATE"=1, "android.bluetooth.profile.extra.STATE"=2}
10-03 17:00:37.623: D/AudioStateManager(29487): mReceiver: BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED
10-03 17:00:37.623: D/AudioStateManager(29487): ==> bluetoothDevice=00:21:3C:00:3E:02
10-03 17:00:37.626: D/AudioStateManager(29487): ==> bluetoothHeadsetStatePrevious=STATE_CONNECTING(1)
10-03 17:00:37.626: D/AudioStateManager(29487): ==> bluetoothHeadsetState=STATE_CONNECTED(2)

Jawbone连接;我的事件监听器被称为...

10-03 17:00:37.626: I/MainActivity(29487): onBluetoothHeadsetConnected()

......看到我们可以上SCO ......

10-03 17:00:37.626: D/AudioStateManager(29487): mAudioManager.isBluetoothScoAvailableOffCall()=true

...并自动调用startBluetoothSco（）
这里的问题是什么！为什么调用startBluetoothSco不会导致SCO_AUDIO_STATE == CONNECTED？！？！

10-03 17:00:37.626: D/AudioStateManager(29487): startBluetoothSco()
10-03 17:00:37.626: I/AudioStateManager(29487): mAudioManager.startBluetoothSco();

我的事件监听器完成w / sendMessage以更新当前BT状态的UI ...

10-03 17:00:37.646: D/MainActivity(29487): MSG_UPDATE_BLUETOOTH_INDICATION
10-03 17:00:37.650: D/MainActivity(29487): updateScreen()...
10-03 17:00:37.650: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false

...完成了UI更新
startBluetoothSco的第一个结果来自...

10-03 17:00:37.681: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.media.ACTION_SCO_AUDIO_STATE_UPDATED flg=0x10 (has extras) }
10-03 17:00:37.681: D/AudioStateManager(29487): extras={"android.media.extra.SCO_AUDIO_STATE"=2, "android.media.extra.SCO_AUDIO_PREVIOUS_STATE"=0}
10-03 17:00:37.681: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED
10-03 17:00:37.685: D/AudioStateManager(29487): ==> scoAudioStatePrevious=SCO_AUDIO_STATE_DISCONNECTED(0)
10-03 17:00:37.685: D/AudioStateManager(29487): ==> scoAudioState=SCO_AUDIO_STATE_CONNECTING(2)

...从DISCONNECTED转移到CONNECTING
startBluetoothSco的第二个结果是......

10-03 17:00:37.759: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.media.ACTION_SCO_AUDIO_STATE_UPDATED flg=0x10 (has extras) }
10-03 17:00:37.763: D/AudioStateManager(29487): extras={"android.media.extra.SCO_AUDIO_STATE"=0, "android.media.extra.SCO_AUDIO_PREVIOUS_STATE"=2}
10-03 17:00:37.763: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED
10-03 17:00:37.763: D/AudioStateManager(29487): ==> scoAudioStatePrevious=SCO_AUDIO_STATE_CONNECTING(2)
10-03 17:00:37.763: D/AudioStateManager(29487): ==> scoAudioState=SCO_AUDIO_STATE_DISCONNECTED(0)
10-03 17:00:37.763: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED: SCO_AUDIO_STATE_DISCONNECTED

...从CONNECTING转移到 DISCONNECTED
我原本希望SCO从CONNECTING转到 CONNECTED ！
调用我的事件监听器并使用两个sendMessages ...

更新UI

10-03 17:00:37.763: I/MainActivity(29487): onAudioManagerScoAudioDisconnected()
10-03 17:00:37.767: D/MainActivity(29487): MSG_UPDATE_BLUETOOTH_INDICATION
10-03 17:00:37.767: D/MainActivity(29487): updateScreen()...
10-03 17:00:37.767: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false
10-03 17:00:37.783: D/MainActivity(29487): MSG_UPDATE_AUDIO_OUTPUT_STREAM_TYPE
10-03 17:00:37.783: D/MainActivity(29487): updateScreen()...
10-03 17:00:37.783: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=false

...完成了UI更新

我等待~20秒连接SCO，但它永远不会来。
我按我的应用程序＆＃34; startBluetoothSco＆＃34;按钮。
请注意，这导致完全相同的呼吁启动蓝牙科技（）17：00：37.626

10-03 17:01:01.689: D/AudioStateManager(29487): startBluetoothSco()
10-03 17:01:01.689: I/AudioStateManager(29487): mAudioManager.startBluetoothSco();

startBluetoothSco的第一个结果是...

10-03 17:01:01.708: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.media.ACTION_SCO_AUDIO_STATE_UPDATED flg=0x10 (has extras) }
10-03 17:01:01.712: D/AudioStateManager(29487): extras={"android.media.extra.SCO_AUDIO_STATE"=2, "android.media.extra.SCO_AUDIO_PREVIOUS_STATE"=0}
10-03 17:01:01.712: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED
10-03 17:01:01.712: D/AudioStateManager(29487): ==> scoAudioStatePrevious=SCO_AUDIO_STATE_DISCONNECTED(0)
10-03 17:01:01.712: D/AudioStateManager(29487): ==> scoAudioState=SCO_AUDIO_STATE_CONNECTING(2)

...从DISCONNECTED转移到CONNECTING
这里的内容与startBluetoothSco（）在17：00：37.626 的自动调用有所不同 我们收到 BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED 事件......

10-03 17:01:01.716: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.bluetooth.headset.profile.action.AUDIO_STATE_CHANGED flg=0x10 (has extras) }
10-03 17:01:01.720: D/AudioStateManager(29487): extras={"android.bluetooth.device.extra.DEVICE"=00:21:3C:00:3E:02, "android.bluetooth.profile.extra.PREVIOUS_STATE"=10, "android.bluetooth.profile.extra.STATE"=11}
10-03 17:01:01.720: D/AudioStateManager(29487): mReceiver: BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED
10-03 17:01:01.720: D/AudioStateManager(29487): ==> bluetoothDevice=00:21:3C:00:3E:02
10-03 17:01:01.720: D/AudioStateManager(29487): ==> bluetoothHeadsetAudioStatePrevious=STATE_AUDIO_DISCONNECTED(10)
10-03 17:01:01.720: D/AudioStateManager(29487): ==> bluetoothHeadsetAudioState=STATE_AUDIO_CONNECTING(11)

...从DISCONNECTED转移到CONNECTING
我们获得了另一个BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED事件......

10-03 17:01:02.572: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.bluetooth.headset.profile.action.AUDIO_STATE_CHANGED flg=0x10 (has extras) }
10-03 17:01:02.576: D/AudioStateManager(29487): extras={"android.bluetooth.device.extra.DEVICE"=00:21:3C:00:3E:02, "android.bluetooth.profile.extra.PREVIOUS_STATE"=11, "android.bluetooth.profile.extra.STATE"=12}
10-03 17:01:02.576: D/AudioStateManager(29487): mReceiver: BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED
10-03 17:01:02.576: D/AudioStateManager(29487): ==> bluetoothDevice=00:21:3C:00:3E:02
10-03 17:01:02.576: D/AudioStateManager(29487): ==> bluetoothHeadsetAudioStatePrevious=STATE_AUDIO_CONNECTING(11)
10-03 17:01:02.580: D/AudioStateManager(29487): ==> bluetoothHeadsetAudioState=STATE_AUDIO_CONNECTED(12)

...从CONNECTING转移到CONNECTED
事件使用一个sendMessage

更新UI

10-03 17:01:02.580: I/MainActivity(29487): onBluetoothHeadsetAudioConnected()
10-03 17:01:02.580: D/MainActivity(29487): MSG_UPDATE_BLUETOOTH_INDICATION
10-03 17:01:02.580: D/MainActivity(29487): updateScreen()...
10-03 17:01:02.583: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=true

...完成了UI更新（说实话，我不确定第二次调用isBluetoothScoOn是什么时候）

10-03 17:01:02.603: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=true

startBluetoothSco的第二个结果是...

10-03 17:01:02.603: D/AudioStateManager(29487): onReceive: intent=Intent { act=android.media.ACTION_SCO_AUDIO_STATE_UPDATED flg=0x10 (has extras) }
10-03 17:01:02.607: D/AudioStateManager(29487): extras={"android.media.extra.SCO_AUDIO_STATE"=1, "android.media.extra.SCO_AUDIO_PREVIOUS_STATE"=2}
10-03 17:01:02.607: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED
10-03 17:01:02.607: D/AudioStateManager(29487): ==> scoAudioStatePrevious=SCO_AUDIO_STATE_CONNECTING(2)
10-03 17:01:02.607: D/AudioStateManager(29487): ==> scoAudioState=.SCO_AUDIO_STATE_CONNECTED(1)
10-03 17:01:02.607: D/AudioStateManager(29487): android.media.ACTION_SCO_AUDIO_STATE_UPDATED: SCO_AUDIO_STATE_CONNECTED

...已从CONNECTING移至CONNECTED

最后！
调用我的事件监听器并使用两个sendMessages ...

更新UI

10-03 17:01:02.611: I/MainActivity(29487): onAudioManagerScoAudioConnected()
10-03 17:01:02.630: D/MainActivity(29487): MSG_UPDATE_BLUETOOTH_INDICATION
10-03 17:01:02.630: D/MainActivity(29487): updateScreen()...
10-03 17:01:02.634: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=true
10-03 17:01:02.650: D/MainActivity(29487): MSG_UPDATE_AUDIO_OUTPUT_STREAM_TYPE
10-03 17:01:02.650: D/MainActivity(29487): updateScreen()...
10-03 17:01:02.650: D/AudioStateManager(29487): mAudioManager.isBluetoothScoOn()=true

...完成了UI更新

一切（这次）在我＆＃34;手动＆＃34;一段时间后启动SCO，但如果我在连接耳机后立即自动启动SCO则不行。

更糟糕的是，当事情没有按预期发挥作用时，我会在SCO状态中看到奇怪的行为：

将startBluetoothSco（）延迟合理的3-5秒似乎没有任何区别。我没有尝试过延迟5秒钟。等待超过5秒钟让音频开始流入你的BT耳机是荒谬的。
有时调用isBluetoothScoOn（）会返回true，即使我从未收到广播事件，因为上次DISCONNECTED状态表明状态已更改为CONNECTED。
有时＆＃34;手动＆＃34;从UI调用startBluetoothSco（）不会做任何事情，就像SCO已经打开一样，但是自上次DISCONNECTED状态以来状态变为CONNECTED后我从未收到任何广播事件。
尝试打开AudioTrack或AudioRecord导致没有声音（当SCO没有行为时，同样的代码工作正常。即：问题是SCO状态，而不是AudioTrack / AudioRecord调用。）
调用stopBluetoothSco（）不会导致任何事件报告状态为DISCONNECTED。
setBluetoothScoOn（false / true）没有区别。说实话，我不明白看似多余的＆＃34; startBluetoothSco（）/ stopBluetoothSco（）＆＃34;和＆＃34; setBluetoothScoOn（boolean）＆＃34;。当事情有效时，我的调用startBluetoothSco（）会导致isBluetoothScoOn（）返回true，这让我觉得我不需要调用setBluetoothScoOn（true）。
重新启动手机没有任何区别。
重新启动耳机没有任何区别。
换到另一个耳机没什么区别。
有时耳机失去配对，必须重新配对。

考虑到谷歌/ Android在蓝牙支持方面的记录，这一点让我感到惊讶。

有人可以让我摆脱困境，明确解释如何在Android中可靠地启动和停止蓝牙SCO吗？

PS：是否有正式渠道来升级此类问题[w / Google？三星？]？或者，StackOverflow是我找到实际答案的最佳机会吗？

Answer 1

Android文档中缺少许多内容，但是，如果您在音频路由期间每次调用startBluetoothSco（）和stopBluetoothSco（），则应该没有问题正确地路由音频。即使我已经看到连接长时间处于空闲状态并且我们启动StartBluetoothSco（），我们直接断开连接。为了解决这个问题，我写了一个解决方法：https://github.com/kodered/Bluetooth-Refresh-Logic

希望这有帮助。

Android startBluetoothSco没有启动sco但isBluetoothScoOn返回true

1 个答案: