/* $Id: DrvHostAudioNull.cpp $ */ /** @file * Host audio driver - NULL (bitbucket). * * This also acts as a fallback if no other backend is available. */ /* * Copyright (C) 2006-2022 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * SPDX-License-Identifier: GPL-3.0-only */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include /* For PDMIBASE_2_PDMDRV. */ #define LOG_GROUP LOG_GROUP_DRV_HOST_AUDIO #include #include #include #include "VBoxDD.h" /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ /** Null audio stream. */ typedef struct DRVHSTAUDNULLSTREAM { /** Common part. */ PDMAUDIOBACKENDSTREAM Core; /** The stream's acquired configuration. */ PDMAUDIOSTREAMCFG Cfg; } DRVHSTAUDNULLSTREAM; /** Pointer to a null audio stream. */ typedef DRVHSTAUDNULLSTREAM *PDRVHSTAUDNULLSTREAM; /** * @interface_method_impl{PDMIHOSTAUDIO,pfnGetConfig} */ static DECLCALLBACK(int) drvHstAudNullHA_GetConfig(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDCFG pBackendCfg) { NOREF(pInterface); AssertPtrReturn(pBackendCfg, VERR_INVALID_POINTER); /* * Fill in the config structure. */ RTStrCopy(pBackendCfg->szName, sizeof(pBackendCfg->szName), "NULL audio"); pBackendCfg->cbStream = sizeof(DRVHSTAUDNULLSTREAM); pBackendCfg->fFlags = 0; pBackendCfg->cMaxStreamsOut = 1; /* Output */ pBackendCfg->cMaxStreamsIn = 2; /* Line input + microphone input. */ return VINF_SUCCESS; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnGetStatus} */ static DECLCALLBACK(PDMAUDIOBACKENDSTS) drvHstAudNullHA_GetStatus(PPDMIHOSTAUDIO pInterface, PDMAUDIODIR enmDir) { RT_NOREF(pInterface, enmDir); return PDMAUDIOBACKENDSTS_RUNNING; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamCreate} */ static DECLCALLBACK(int) drvHstAudNullHA_StreamCreate(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream, PCPDMAUDIOSTREAMCFG pCfgReq, PPDMAUDIOSTREAMCFG pCfgAcq) { RT_NOREF(pInterface); PDRVHSTAUDNULLSTREAM pStreamNull = (PDRVHSTAUDNULLSTREAM)pStream; AssertPtrReturn(pStreamNull, VERR_INVALID_POINTER); AssertPtrReturn(pCfgReq, VERR_INVALID_POINTER); AssertPtrReturn(pCfgAcq, VERR_INVALID_POINTER); PDMAudioStrmCfgCopy(&pStreamNull->Cfg, pCfgAcq); return VINF_SUCCESS; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamDestroy} */ static DECLCALLBACK(int) drvHstAudNullHA_StreamDestroy(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream, bool fImmediate) { RT_NOREF(pInterface, pStream, fImmediate); return VINF_SUCCESS; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamEnable} */ static DECLCALLBACK(int) drvHstAudNullHA_StreamControlStub(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream) { RT_NOREF(pInterface, pStream); return VINF_SUCCESS; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamGetState} */ static DECLCALLBACK(PDMHOSTAUDIOSTREAMSTATE) drvHstAudNullHA_StreamGetState(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream) { RT_NOREF(pInterface); AssertPtrReturn(pStream, PDMHOSTAUDIOSTREAMSTATE_INVALID); #if 0 /* Bit bucket appraoch where we ignore the output and silence the input buffers. */ return PDMHOSTAUDIOSTREAMSTATE_OKAY; #else /* Approach where the mixer in the devices skips us and saves a few CPU cycles. */ return PDMHOSTAUDIOSTREAMSTATE_INACTIVE; #endif } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamGetPending} */ static DECLCALLBACK(uint32_t) drvHstAudNullHA_StreamGetPending(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream) { RT_NOREF(pInterface, pStream); return 0; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamGetWritable} */ static DECLCALLBACK(uint32_t) drvHstAudNullHA_StreamGetWritable(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream) { RT_NOREF(pInterface, pStream); return UINT32_MAX; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamPlay} */ static DECLCALLBACK(int) drvHstAudNullHA_StreamPlay(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream, const void *pvBuf, uint32_t cbBuf, uint32_t *pcbWritten) { RT_NOREF(pInterface, pStream, pvBuf); /* The bitbucket never overflows. */ *pcbWritten = cbBuf; return VINF_SUCCESS; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamGetReadable} */ static DECLCALLBACK(uint32_t) drvHstAudNullHA_StreamGetReadable(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream) { RT_NOREF(pInterface, pStream); /** @todo rate limit this? */ return UINT32_MAX; } /** * @interface_method_impl{PDMIHOSTAUDIO,pfnStreamCapture} */ static DECLCALLBACK(int) drvHstAudNullHA_StreamCapture(PPDMIHOSTAUDIO pInterface, PPDMAUDIOBACKENDSTREAM pStream, void *pvBuf, uint32_t cbBuf, uint32_t *pcbRead) { RT_NOREF(pInterface); PDRVHSTAUDNULLSTREAM pStreamNull = (PDRVHSTAUDNULLSTREAM)pStream; /** @todo rate limit this? */ /* Return silence. */ PDMAudioPropsClearBuffer(&pStreamNull->Cfg.Props, pvBuf, cbBuf, PDMAudioPropsBytesToFrames(&pStreamNull->Cfg.Props, cbBuf)); *pcbRead = cbBuf; return VINF_SUCCESS; } /** * This is used directly by DrvAudio when a backend fails to initialize in a * non-fatal manner. */ DECL_HIDDEN_CONST(PDMIHOSTAUDIO) const g_DrvHostAudioNull = { /* .pfnGetConfig =*/ drvHstAudNullHA_GetConfig, /* .pfnGetDevices =*/ NULL, /* .pfnSetDevice =*/ NULL, /* .pfnGetStatus =*/ drvHstAudNullHA_GetStatus, /* .pfnDoOnWorkerThread =*/ NULL, /* .pfnStreamConfigHint =*/ NULL, /* .pfnStreamCreate =*/ drvHstAudNullHA_StreamCreate, /* .pfnStreamInitAsync =*/ NULL, /* .pfnStreamDestroy =*/ drvHstAudNullHA_StreamDestroy, /* .pfnStreamNotifyDeviceChanged =*/ NULL, /* .pfnStreamEnable =*/ drvHstAudNullHA_StreamControlStub, /* .pfnStreamDisable =*/ drvHstAudNullHA_StreamControlStub, /* .pfnStreamPause =*/ drvHstAudNullHA_StreamControlStub, /* .pfnStreamResume =*/ drvHstAudNullHA_StreamControlStub, /* .pfnStreamDrain =*/ drvHstAudNullHA_StreamControlStub, /* .pfnStreamGetState =*/ drvHstAudNullHA_StreamGetState, /* .pfnStreamGetPending =*/ drvHstAudNullHA_StreamGetPending, /* .pfnStreamGetWritable =*/ drvHstAudNullHA_StreamGetWritable, /* .pfnStreamPlay =*/ drvHstAudNullHA_StreamPlay, /* .pfnStreamGetReadable =*/ drvHstAudNullHA_StreamGetReadable, /* .pfnStreamCapture =*/ drvHstAudNullHA_StreamCapture, }; /** * @interface_method_impl{PDMIBASE,pfnQueryInterface} */ static DECLCALLBACK(void *) drvHstAudNullQueryInterface(PPDMIBASE pInterface, const char *pszIID) { PPDMDRVINS pDrvIns = PDMIBASE_2_PDMDRV(pInterface); PPDMIHOSTAUDIO pThis = PDMINS_2_DATA(pDrvIns, PPDMIHOSTAUDIO); PDMIBASE_RETURN_INTERFACE(pszIID, PDMIBASE, &pDrvIns->IBase); PDMIBASE_RETURN_INTERFACE(pszIID, PDMIHOSTAUDIO, pThis); return NULL; } /** * Constructs a Null audio driver instance. * * @copydoc FNPDMDRVCONSTRUCT */ static DECLCALLBACK(int) drvHstAudNullConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags) { PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns); PPDMIHOSTAUDIO pThis = PDMINS_2_DATA(pDrvIns, PPDMIHOSTAUDIO); RT_NOREF(pCfg, fFlags); LogRel(("Audio: Initializing NULL driver\n")); /* * Init the static parts. */ /* IBase */ pDrvIns->IBase.pfnQueryInterface = drvHstAudNullQueryInterface; /* IHostAudio */ *pThis = g_DrvHostAudioNull; return VINF_SUCCESS; } /** * Char driver registration record. */ const PDMDRVREG g_DrvHostNullAudio = { /* u32Version */ PDM_DRVREG_VERSION, /* szName */ "NullAudio", /* szRCMod */ "", /* szR0Mod */ "", /* pszDescription */ "NULL audio host driver", /* fFlags */ PDM_DRVREG_FLAGS_HOST_BITS_DEFAULT, /* fClass. */ PDM_DRVREG_CLASS_AUDIO, /* cMaxInstances */ ~0U, /* cbInstance */ sizeof(PDMIHOSTAUDIO), /* pfnConstruct */ drvHstAudNullConstruct, /* pfnDestruct */ NULL, /* pfnRelocate */ NULL, /* pfnIOCtl */ NULL, /* pfnPowerOn */ NULL, /* pfnReset */ NULL, /* pfnSuspend */ NULL, /* pfnResume */ NULL, /* pfnAttach */ NULL, /* pfnDetach */ NULL, /* pfnPowerOff */ NULL, /* pfnSoftReset */ NULL, /* u32EndVersion */ PDM_DRVREG_VERSION };