AUGraph - 动态重新配置？(AUGraph - reconfigure on the fly?)

 我想在播放（渲染）期间重新排列AUGraph中的节点。 特别是，我试图在这两个设置之间切换： 
 
 
 
 多通道混音器 - >远程I / O. 
 
 
 多通道混频器 - >转换器＃0 - >带通滤波器 - >转换器＃1 - >远程I / O. 
 
 
 （需要流转换器，因为带通滤波器使用浮点格式） 
 
 两种设置均经过测试并独立工作 ; 即，如果我从给定的设置（节点连接）开始，图表将正确呈现。 但是当我在播放过程中尝试重新排列节点时，出现了问题。 
 
 我的连接代码是这样的： 
 
void enableBandpassFilter(Boolean enable)
{
    OSStatus result;

    if (enable) {

        // [ A ] Enable

        // Connect mixer to converter0
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         mixerNode,             // (in) src node
                                         0,                     // (in) src output number
                                         converterNode0,        // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for mixer->converter0");
        }

        // Connect converter0 to bandpass
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         converterNode0,        // (in) src node
                                         0,                     // (in) src output number
                                         bandpassNode,          // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for converter0->bandpass");
        }

        // Connect bandpass to converter1
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         bandpassNode,          // (in) src node
                                         0,                     // (in) src output number
                                         converterNode1,        // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for bandpass->converter1");
        }

        // Connect converter1 to i/o
        result = AUGraphConnectNodeInput(processingGraph,
                                         converterNode1,
                                         0,
                                         remoteIONode,
                                         0);
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for converter1->output");
        }
    }
    else{
        // [ B ] Disable


        result = AUGraphDisconnectNodeInput(processingGraph,
                                            remoteIONode,
                                            0);
        if ( result != noErr ){
            DLog(@"AUGraphDisconnectNodeInput() Failed for output");
        }

        // Connect mixer to remote I/O
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         mixerNode,             // (in) src node
                                         0,                     // (in) src output number
                                         remoteIONode,          // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for mixer->output");
        }
    }
}
 
 （图形和节点是文件范围的全局变量。这个C函数在与我的Obj-C声音管理器类相同的文件中定义）。 我在图初始化和之后用于切换都使用相同的功能。 
 
 我尝试了两种方法： 
 
 
 
 立即调用enableBandpassFilter() （从Obj-C方法中），和 
 
 
 使用AUGraphAddRenderNotify() （在“实时优先级线程”中运行AUGraphAddRenderNotify()注册通知回调，并在回调中调用enableBandpassFilter() 。 
 
 
 两种方法都惨遭失败。 为了简化操作并避免在图形启动时没有初始化的断开连接的音频单元的缺陷，我从上面的5节点配置＃2开始（带通滤波器：打开）并从那里尝试切换到上面的旁路配置＃1（带通滤波器：关闭）。 
 
 启动时，音频图如下所示： 
 
AudioUnitGraph 0x1E9B000:
  Member Nodes:
    node 1: 'aumx' 'mcmx' 'appl', instance 0x170820fe0 O  
    node 2: 'aufc' 'conv' 'appl', instance 0x178424040 O  
    node 3: 'aufx' 'bpas' 'appl', instance 0x1784241a0 O  
    node 4: 'aufc' 'conv' 'appl', instance 0x1708295a0 O  
    node 5: 'auou' 'rioc' 'appl', instance 0x17082b020 O  
  Connections:
    node   1 bus   0 => node   2 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000C2C) 8.24-bit little-endian signed integer, deinterleaved]
    node   2 bus   0 => node   3 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   3 bus   0 => node   4 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   4 bus   0 => node   5 bus   0  [ 2 ch,      0 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
  Input Callbacks:
    {0x10000d17c, 0x10004ea90} => node   1 bus   0  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   1  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   2  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   3  [2 ch, 44100 Hz]
  CurrentState:
    mLastUpdateError=0, eventsToProcess=F, isInitialized=F, isRunning=F
 
 （最后一次连接中的“0Hz”部分有点警报，但此时声音正常流动） 
 
 当我尝试使用回调绕过过滤器时，在将混音器连接到输出时，我得到了可怕的-10861错误（ kAUGraphErr_InvalidConnection ）。 
 
 当我尝试绕过主线程上的过滤器（Obj-C方法）时，我没有得到错误结果代码但是过滤器没有被停用。 
 
 在这两种情况下，切换后图形日志变为： 
 
AudioUnitGraph 0x1EA2000:
  Member Nodes:
    node 1: 'aumx' 'mcmx' 'appl', instance 0x178228d80 O I
    node 2: 'aufc' 'conv' 'appl', instance 0x17062c760 O I
    node 3: 'aufx' 'bpas' 'appl', instance 0x17062dfe0 O I
    node 4: 'aufc' 'conv' 'appl', instance 0x170636d00 O I
    node 5: 'auou' 'rioc' 'appl', instance 0x170637200 O I
  Connections:
    node   1 bus   0 => node   2 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000C2C) 8.24-bit little-endian signed integer, deinterleaved]
    node   2 bus   0 => node   3 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   3 bus   0 => node   4 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
  Input Callbacks:
    {0x1000452fc, 0x100086a40} => node   1 bus   0  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   1  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   2  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   3  [2 ch, 44100 Hz]
  Problem Events when updated:
    connect:source=1,bus=0,dest=5,bus=0
  CurrentState:
    mLastUpdateError=0, eventsToProcess=F, isInitialized=T, isRunning=T (1)
 
 （注意更新时的问题事件：部分详细说明了连接Multichannel Mixer和Remote I/O的可能性。另外，每个节点之后的O变为OI 。） 
 
 我无法相信这些节点是不兼容的，因为如果我开始构建该配置，它就可以工作。 
 
 那么，动态重新连接节点的正确方法是什么？ 我错过了什么？ 
 
 *很抱歉这个问题很长。 
 
 EDIT（解决方案？）：正如我在评论中提到的，事实证明图形重新布线必须在主线程中完成 ，而不是在Core Audio线程中完成（相关对象在该上下文中被锁定）。 我将重新布线的代码移动到主线程（实例方法），并在调用AUGraphClearConnections() 之前添加了对AUGraphClearConnections()调用，现在它可以工作， 即使我没有停止/重新启动图形 。 
 
 现在唯一的问题是，每当我重新连接时，所有声音都会停止播放（渲染回调停止被调用），直到我再次停止/启动这些声音。 我必须检查调音台的每个总线，看看是否附加了回调，总线启用等等......我现在就做。 

I am trying to rearrange the nodes in an AUGraph during playback (render). In particular, I am trying to switch between these two setups:
 
 
 
Multichannel Mixer -> Remote I/O
 
 
Multichannel Mixer -> Converter #0 -> Bandpass Filter -> Converter #1 -> Remote I/O
 
 
(The stream converters are needed because the bandpass filter uses a floating point format)
 
Both setups atre tested and work on their own; i.e., if I start with a given setup (node connections), the graph renders properly. But when I try to rearrange the nodes during playback, something goes wrong.
 
My connection code is this:
 
void enableBandpassFilter(Boolean enable)
{
    OSStatus result;

    if (enable) {

        // [ A ] Enable

        // Connect mixer to converter0
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         mixerNode,             // (in) src node
                                         0,                     // (in) src output number
                                         converterNode0,        // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for mixer->converter0");
        }

        // Connect converter0 to bandpass
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         converterNode0,        // (in) src node
                                         0,                     // (in) src output number
                                         bandpassNode,          // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for converter0->bandpass");
        }

        // Connect bandpass to converter1
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         bandpassNode,          // (in) src node
                                         0,                     // (in) src output number
                                         converterNode1,        // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for bandpass->converter1");
        }

        // Connect converter1 to i/o
        result = AUGraphConnectNodeInput(processingGraph,
                                         converterNode1,
                                         0,
                                         remoteIONode,
                                         0);
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for converter1->output");
        }
    }
    else{
        // [ B ] Disable


        result = AUGraphDisconnectNodeInput(processingGraph,
                                            remoteIONode,
                                            0);
        if ( result != noErr ){
            DLog(@"AUGraphDisconnectNodeInput() Failed for output");
        }

        // Connect mixer to remote I/O
        result = AUGraphConnectNodeInput(processingGraph,       // (in) graph
                                         mixerNode,             // (in) src node
                                         0,                     // (in) src output number
                                         remoteIONode,          // (in) dst node
                                         0);                    // (in) dst input number
        if ( result != noErr ){
            DLog(@"AUGraphConnectNodeInput() Failed for mixer->output");
        }
    }
}
 
(The graph and nodes are file-scope globals. This C function is defined in the same file as my Obj-C sound manager class). I use this same function both at graph initialization and afterwards for switching.
 
I've tried two approaches: 
 
 
 
Calling the enableBandpassFilter() right away (from within an Obj-C method), and
 
 
Register a notification callback with AUGraphAddRenderNotify() (which runs in the 'real time priority thread') and calling enableBandpassFilter() from within the callback.
 
 
Both approaches fail miserably. To make thing simple and avoid the pitfall of disconnected audio units not being initialized when the graph starts, I start with the 5 node configuration #2 above (bandpass filter: on) and from there try to switch to the bypass configuration #1 above (bandpass filter: off).
 
On startup, the audio graph looks like this:
 
AudioUnitGraph 0x1E9B000:
  Member Nodes:
    node 1: 'aumx' 'mcmx' 'appl', instance 0x170820fe0 O  
    node 2: 'aufc' 'conv' 'appl', instance 0x178424040 O  
    node 3: 'aufx' 'bpas' 'appl', instance 0x1784241a0 O  
    node 4: 'aufc' 'conv' 'appl', instance 0x1708295a0 O  
    node 5: 'auou' 'rioc' 'appl', instance 0x17082b020 O  
  Connections:
    node   1 bus   0 => node   2 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000C2C) 8.24-bit little-endian signed integer, deinterleaved]
    node   2 bus   0 => node   3 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   3 bus   0 => node   4 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   4 bus   0 => node   5 bus   0  [ 2 ch,      0 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
  Input Callbacks:
    {0x10000d17c, 0x10004ea90} => node   1 bus   0  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   1  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   2  [2 ch, 44100 Hz]
    {0x10000d17c, 0x10004ea90} => node   1 bus   3  [2 ch, 44100 Hz]
  CurrentState:
    mLastUpdateError=0, eventsToProcess=F, isInitialized=F, isRunning=F
 
(The "0Hz" part in the last connection is a bit alarming, but sound flows properly at this point)
 
When I try to bypass the filter using callbacks, I get the dreaded -10861 error (kAUGraphErr_InvalidConnection) when connection the mixer to the output.
 
When I try to bypass the filter on the main thread (Obj-C method), I get no error result codes but the filter is not deactivated. 
 
In both cases, after the switch the graph log becomes this:
 
AudioUnitGraph 0x1EA2000:
  Member Nodes:
    node 1: 'aumx' 'mcmx' 'appl', instance 0x178228d80 O I
    node 2: 'aufc' 'conv' 'appl', instance 0x17062c760 O I
    node 3: 'aufx' 'bpas' 'appl', instance 0x17062dfe0 O I
    node 4: 'aufc' 'conv' 'appl', instance 0x170636d00 O I
    node 5: 'auou' 'rioc' 'appl', instance 0x170637200 O I
  Connections:
    node   1 bus   0 => node   2 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000C2C) 8.24-bit little-endian signed integer, deinterleaved]
    node   2 bus   0 => node   3 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
    node   3 bus   0 => node   4 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved]
  Input Callbacks:
    {0x1000452fc, 0x100086a40} => node   1 bus   0  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   1  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   2  [2 ch, 44100 Hz]
    {0x1000452fc, 0x100086a40} => node   1 bus   3  [2 ch, 44100 Hz]
  Problem Events when updated:
    connect:source=1,bus=0,dest=5,bus=0
  CurrentState:
    mLastUpdateError=0, eventsToProcess=F, isInitialized=T, isRunning=T (1)
 
(Notice the Problem Events when updated: part detailing the impossibility to connect Multichannel Mixer and Remote I/O. Also, the O after each node changes into O I.)
 
I can't believe the nodes are incompatible, because if I start form that configuration, it works.
 
So, what is the proper way to reconnect nodes on the fly? What am I missing?
 
*Sorry for the long question.
 
EDIT (Solution?): As I mentioned in the comments, it turns out the graph rewiring must be done in the main thread, and not in the Core Audio thread (the relevant objects are locked in that context). I moved the rewiring code to the main thread (instance method), and also added a call to AUGraphClearConnections() before any call to AUGraphConnectNodeInput(), and now it works, even if I don't stop/restart the graph. 
 
The only problem right now is, whenever I rewire, all sounds playing stop (render callbacks stop being called) until I stop/start those sounds again. I must inspect each bus of the mixer to see if the callback is attached, bus enabled, etc... I'll do just that right now.

原文：https://stackoverflow.com/questions/23039319