# AudioSampleProvider > Provides access to the audio samples generated by Unity objects such as VideoPlayer. ## Definition * **Type:** Class * **Namespace:** [UnityEngine.Experimental.Audio](/engine/6000.7/script-reference/unityengine/experimental/audio.md) * **Assembly:** UnityEngine.AudioModule * **Implements:** [IDisposable](https://learn.microsoft.com/dotnet/api/system.idisposable) ```csharp public class AudioSampleProvider : IDisposable ``` ## Remarks This class is meant to be usable outside the main thread and the implementation assumes a single consumer at a time invoking [AudioSampleProvider.ConsumeSampleFrames](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/consumesampleframes.md). Audio data can be accessed both from C# and from C++, depending on what has to be done with this data. The following is an example of how to access samples from C# using an accessor obtained from the [VideoPlayer](/engine/6000.7/script-reference/unityengine/video/videoplayer.md): The following is an example of how to access samples from C++. The setup has to be done in C# and then Unity's core and the native plug-in can call into each other without having to go through managed code. And here is the accompanying C++ plug-in: ## Examples ```csharp using UnityEngine; using Unity.Collections; using UnityEngine.Experimental.Video; using UnityEngine.Experimental.Audio; using UnityEngine.Video; public class ManagedAudioOutput : MonoBehaviour { AudioSampleProvider provider; void Start() { VideoPlayer vp = GetComponent(); vp.audioOutputMode = VideoAudioOutputMode.APIOnly; vp.prepareCompleted += Prepared; vp.Prepare(); } void Prepared(VideoPlayer vp) { provider = vp.GetAudioSampleProvider(0); provider.sampleFramesAvailable += SampleFramesAvailable; provider.enableSampleFramesAvailableEvents = true; provider.freeSampleFrameCountLowThreshold = provider.maxSampleFrameCount / 4; vp.Play(); } void SampleFramesAvailable(AudioSampleProvider provider, uint sampleFrameCount) { using (NativeArray buffer = new NativeArray( (int)sampleFrameCount * provider.channelCount, Allocator.Temp)) { var sfCount = provider.ConsumeSampleFrames(buffer); Debug.LogFormat("SetupSoftwareAudioOut.Available got {0} sample frames.", sfCount); // Do something with the samples here... } } } ``` ```csharp using System; using System.Runtime.InteropServices; using UnityEngine; using UnityEngine.Experimental.Video; using UnityEngine.Experimental.Audio; using UnityEngine.Video; public class NativeAudioOutput : MonoBehaviour { AudioSampleProvider provider; AudioSampleProvider.SampleFramesEventNativeFunction sampleFramesAvailableNativeHandler = SampleFramesAvailable; void Start() { VideoPlayer vp = GetComponent(); vp.audioOutputMode = VideoAudioOutputMode.APIOnly; vp.prepareCompleted += Prepared; vp.Prepare(); } void Prepared(VideoPlayer vp) { provider = vp.GetAudioSampleProvider(0); provider.freeSampleFrameCountLowThreshold = provider.maxSampleFrameCount - 1024; SetConsumeSampleFramesFunction( AudioSampleProvider.consumeSampleFramesNativeFunction, provider.id, provider.channelCount, provider.sampleRate); provider.SetSampleFramesAvailableNativeHandler( sampleFramesAvailableNativeHandler, (IntPtr)0); vp.Play(); } private const string pluginName = #if UNITY_IPHONE "__Internal" #else "NativeAudioOutputPlugin" #endif ; [DllImport(pluginName, ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)] private static extern void SetConsumeSampleFramesFunction( AudioSampleProvider.ConsumeSampleFramesNativeFunction cb, uint id, ushort channelCount, uint sampleRate); [AOT.MonoPInvokeCallback(typeof(AudioSampleProvider.SampleFramesEventNativeFunction))] [DllImport(pluginName, ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)] private static extern void SampleFramesAvailable(IntPtr userData, uint id, uint sampleFrameCount); } ``` ```csharp #include #include typedef uint32_t(__cdecl *ConsumeSampleFramesFunction)( uint32_t providerId, float* interleavedSampleFrames, uint32_t sampleFrameCount); ConsumeSampleFramesFunction ConsumeSampleFrames = NULL; uint32_t providerId = -1; float* buffer = NULL; uint32_t bufferSampleFrameCount = 0; uint32_t availableSampleFrameCount = 0; extern "C" __cdecl void SetConsumeSampleFramesFunction( ConsumeSampleFramesFunction function, uint32_t id, uint16_t channelCount, uint32_t sampleRate) { ConsumeSampleFrames = function; providerId = id; delete[] buffer; buffer = new float[channelCount * sampleRate]; // 1s worth of sample frames. bufferSampleFrameCount = sampleRate; } extern "C" __cdecl void SampleFramesAvailable(void* userData, uint32_t id, uint32_t sampleFrameCount) { if (ConsumeSampleFrames == NULL) return; // We consume the sample frames from the handler that tells us that there are some available. // But we could also invoke this regularly from another thread, for example the thread providing // samples to an audio device. const uint32_t consumedSampleFrameCount = ConsumeSampleFrames( providerId, buffer, std::min(bufferSampleFrameCount, sampleFrameCount)); // Do something with the samples here... } ``` ## Properties | Property | Description | | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [availableSampleFrameCount](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/availablesampleframecount.md) | Number of sample frames available for consuming with [AudioSampleProvider.ConsumeSampleFrames](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/consumesampleframes.md). | | [channelCount](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/channelcount.md) | The number of audio channels per sample frame. | | [enableSampleFramesAvailableEvents](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/enablesampleframesavailableevents.md) | Enables the [\_sampleFramesAvailable](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframesavailable.md) events. | | [enableSilencePadding](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/enablesilencepadding.md) | If true, buffers produced by ConsumeSampleFrames will get padded when silence if there are less available than asked for. Otherwise, the extra sample frames in the buffer will be left unchanged. | | [freeSampleFrameCount](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/freesampleframecount.md) | Number of sample frames that can still be written to by the sample producer before overflowing. | | [freeSampleFrameCountLowThreshold](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/freesampleframecountlowthreshold.md) | When the free sample count falls below this threshold, the [\_sampleFramesAvailable](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframesavailable.md) event and associated native is emitted. | | [id](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/id.md) | Unique identifier for this instance. | | [maxSampleFrameCount](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/maxsampleframecount.md) | The maximum number of sample frames that can be accumulated inside the internal buffer before an overflow event is emitted. | | [owner](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/owner.md) | Object where this provider came from. | | [sampleRate](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/samplerate.md) | The expected playback rate for the sample frames produced by this class. | | [trackIndex](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/trackindex.md) | Index of the track in the object that created this provider. | | [valid](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/valid.md) | True if the object is valid. | ## Static Properties | Property | Description | | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------- | | [consumeSampleFramesNativeFunction](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/consumesampleframesnativefunction-1.md) | Pointer to the native function that provides access to audio sample frames. | ## Methods | Method | Description | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [ClearSampleFramesAvailableNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/clearsampleframesavailablenativehandler.md) | Clear the native handler set with [AudioSampleProvider.SetSampleFramesAvailableNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/setsampleframesavailablenativehandler.md). | | [ClearSampleFramesOverflowNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/clearsampleframesoverflownativehandler.md) | Clear the native handler set with [AudioSampleProvider.SetSampleFramesOverflowNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/setsampleframesoverflownativehandler.md). | | [ConsumeSampleFrames](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/consumesampleframes.md) | Consume sample frames from the internal buffer. | | [Dispose](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/dispose.md) | Release internal resources. Inherited from IDisposable. | | [SetSampleFramesAvailableNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/setsampleframesavailablenativehandler.md) | Set the native event handler for events emitted when the number of available sample frames crosses the threshold. | | [SetSampleFramesOverflowNativeHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/setsampleframesoverflownativehandler.md) | Set the native event handler for events emitted when the internal sample frame buffer overflows. | ## Events | Member | Description | | ------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [sampleFramesAvailable](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframesavailable.md) | Invoked when the number of available sample frames goes beyond the threshold set with [\_freeSampleFrameCountLowThreshold](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/freesampleframecountlowthreshold.md). | | [sampleFramesOverflow](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframesoverflow.md) | Invoked when the number of available sample frames goes beyond the maximum that fits in the internal buffer. | ## Delegates | Delegate | Description | | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | | [AudioSampleProvider.ConsumeSampleFramesNativeFunction](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/consumesampleframesnativefunction.md) | Type that represents the native function pointer for consuming sample frames. | | [AudioSampleProvider.SampleFramesEventNativeFunction](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframeseventnativefunction.md) | Type that represents the native function pointer for handling sample frame events. | | [AudioSampleProvider.SampleFramesHandler](/engine/6000.7/script-reference/unityengine/experimental/audio/audiosampleprovider/sampleframeshandler.md) | Delegate for sample frame events. |