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Wwise SDK 2023.1.9
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Offline Rendering with Wwise
Offline Rendering
The Wwise Sound Engine offers offline rendering that allows for non-real-time, compute-intensive audio generation and the synchronization of audio processing with compute-intensive video generation.
 | Caution: Care must be taken when enabling offline rendering in applications that use the synchronous AK::SoundEngine::LoadBank and AK::SoundEngine::UnloadBank APIs. See Audio Rendering Thread for details. |
An audio capture callback can be registered using AK::SoundEngine::RegisterCaptureCallback, which provides a mechanism for accessing the rendered audio buffers.
The following is an example that illustrates one possible implementation of offline rendering:
/// Video capture services accessible in the game code
namespace VideoCaptureServices
{
/// Possibly allocates buffers for video capture
void Initialize();
/// Possibly outputs captured video and audio as a movie file
void Finalize();
/// Possibly captures a single video frame buffer to a file.
void CaptureSingleFrame();
}
/// Audio capture services accessible in the game code
namespace AudioCaptureServices
{
/// Allocates buffers or opens files for the eventual capture of audio samples.
void Initialize(unsigned in_uSampleRate, unsigned in_uChannels);
/// Releases buffers or file handles once audio sample capture is completed.
void Finalize();
/// Adds audio samples to the allocated buffers
void CaptureInterleavedSamples(float* in_pfSamples, unsigned in_uSampleCount);
}
class GameInterface
{
// ...
public:
/// Function called once per game frame
virtual void UpdateCallback(float deltaTime //< elapsed wall clock time in real-time, inverse of the desired frame rate in offline mode
) = 0;
};
class Game : public GameInterface
{
// ...
private:
/// True when offline rendering is enabled.
bool m_bIsOfflineRendering{ false };
/// Output device ID for registration/unregistration of capture callback.
AkOutputDeviceID m_defaultOutputDeviceId{ AK_INVALID_OUTPUT_DEVICE_ID };
/// Wwise audio capture callback.
static void CaptureCallback(AkAudioBuffer& in_CaptureBuffer, AkOutputDeviceID /*in_idOutput*/, void* /*in_pCookie*/)
{
const unsigned uSampleCount = static_cast<unsigned>(in_CaptureBuffer.uValidFrames) * in_CaptureBuffer.NumChannels();
if (!uSampleCount)
return;
AudioCaptureServices::CaptureInterleavedSamples(in_CaptureBuffer.GetInterleavedData(), uSampleCount);
}
public:
/// Function called to enable/disable offline rendering
void SetOfflineRendering(bool bIsOfflineRendering //< true for offline rendering, and false for real-time rendering
)
{
const bool bWasOfflineRendering{ m_bIsOfflineRendering };
m_bIsOfflineRendering = bIsOfflineRendering;
// Posts a message on the message queue to enable/disable offline rendering
AK::SoundEngine::SetOfflineRendering(m_bIsOfflineRendering);
if (m_bIsOfflineRendering == bWasOfflineRendering)
return;
// Posts a message on the message queue to set the offline rendering frame time to zero ensuring that the subsequent call to RenderAudio() will not generate more audio samples.
// Call RenderAudio() to flush the message queue. After this call, offline rendering will be enabled/disabled.
if (m_bIsOfflineRendering)
{
VideoCaptureServices::Initialize();
// When engaging offline rendering, the output configuration will switch to Stereo output by default
// In order to render to a different output speaker layout, replace the output with an explicitly defined one.
// In this example, switch to 7.1.4
AkChannelConfig surroundConfig;
surroundConfig.SetStandard(AK_SPEAKER_SETUP_DOLBY_7_1_4);
// Post a mesage to replace the output device.
AkOutputSettings newSettings;
newSettings.audioDeviceShareset = AK::AUDIO_DEVICES::SYSTEM;
newSettings.idDevice = 0;
newSettings.ePanningRule = AkPanningRule_Speakers;
newSettings.channelConfig = surroundConfig;
AK::SoundEngine::ReplaceOutput(newSettings, 0, &m_defaultOutputDeviceId);
// Flush the message queue again to make sure ReplaceOutput is processed, before registering the capture callback on the offline device
AK::SoundEngine::RenderAudio(true);
// Provide the sample rate and number of channels to allocate the appropriate buffers.
AudioCaptureServices::Initialize(uSampleRate, surroundConfig.uNumChannels);
AK::SoundEngine::RegisterCaptureCallback(&CaptureCallback, m_defaultOutputDeviceId, this);
}
else
{
AK::SoundEngine::UnregisterCaptureCallback(&CaptureCallback, m_defaultOutputDeviceId, this);
AudioCaptureServices::Finalize();
VideoCaptureServices::Finalize();
}
}
void UpdateCallback(float deltaTime) override
{
if (m_bIsOfflineRendering)
AK::SoundEngine::SetOfflineRenderingFrameTime(deltaTime);
if (m_bIsOfflineRendering)
VideoCaptureServices::CaptureSingleFrame();
}
};
AKSOUNDENGINE_API AkUInt32 GetSampleRate()
Definition: AkSpeakerConfig.h:497
Platform-independent initialization settings of output devices.
Definition: AkSoundEngine.h:123
AKSOUNDENGINE_API AKRESULT SetOfflineRenderingFrameTime(AkReal32 in_fFrameTimeInSeconds)
AKSOUNDENGINE_API AKRESULT ReplaceOutput(const AkOutputSettings &in_Settings, AkOutputDeviceID in_outputDeviceId, AkOutputDeviceID *out_pOutputDeviceId=NULL)
AkUInt16 uValidFrames
Number of valid sample frames in the audio buffer.
Definition: AkCommonDefs.h:657
#define AK_SPEAKER_SETUP_DOLBY_7_1_4
Dolby 7.1.4 setup channel mask.
Definition: AkSpeakerConfig.h:109
AKSOUNDENGINE_API AKRESULT RegisterCaptureCallback(AkCaptureCallbackFunc in_pfnCallback, AkOutputDeviceID in_idOutput=AK_INVALID_OUTPUT_DEVICE_ID, void *in_pCookie=NULL)
AKSOUNDENGINE_API AKRESULT RenderAudio(bool in_bAllowSyncRender=true)
AKSOUNDENGINE_API AKRESULT UnregisterCaptureCallback(AkCaptureCallbackFunc in_pfnCallback, AkOutputDeviceID in_idOutput=AK_INVALID_OUTPUT_DEVICE_ID, void *in_pCookie=NULL)
@ AkPanningRule_Speakers
Left and right positioned 60 degrees apart (by default - see AK::SoundEngine::GetSpeakerAngles()).
Definition: AkTypes.h:1139
AKSOUNDENGINE_API AKRESULT SetOfflineRendering(bool in_bEnableOfflineRendering)
AkForceInline void SetStandard(AkUInt32 in_uChannelMask)
Set channel config as a standard configuration specified with given channel mask.
Definition: AkSpeakerConfig.h:564
Definition: AkCommonDefs.h:465
AkForceInline void * GetInterleavedData()
Definition: AkCommonDefs.h:514
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