sdla_render.h

这是在PCA下的基于IPP库示例代码例子,在网上下了IPP的库之后,设置相关参数就可以编译该代码.

/*//////////////////////////////////////////////////////////////////////////////
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 2003-2005 Intel Corporation. All Rights Reserved.
//
*/

#ifndef __SDLAUDIO_RENDER_H__
#define __SDLAUDIO_RENDER_H__

#if defined(SDL_ON) && (defined(LINUX32) || defined(WIN32))

#include <SDL/SDL.h>
#include "uimc_structures.h"
#include "uimc_audio_render.h"
#include "vm_semaphore.h"
#include "vm_time.h"

#define NUM_SND_BUFFER 32

class SDLAudioRender :public AudioRender {
public:
    /* Initialize the audio device. The playback is paused */
    UMC_Status Init(AudioRenderParams* pInit);

    /* Write sound data to sound buffer */
    UMC_Status SendFrame(sMediaData* in);

    /* Send EOF to sound buffer */
    void SendEOF(void);

    /* Toggle pause mode. Return current pts */
    UMC_Status Pause(bool pause);

    /* Close the sound device */
    UMC_Status Close(void);

    float SetVolume(float volume) { return volume;};   /* 0-silence 1-max, return previous volume */
    float GetVolume() { return 0.;};

    UMC_Status Reset(void) { return UMC_OPERATION_FAILED; };

    SDLAudioRender(void);
    ~SDLAudioRender(void);

    // Audio Reference Clock
    double GetTime(void);
    // Estimated value of device latency
    double GetDelay(void);

    // Estimated value of difference between independent ref clock and pts
    double GetClockOffset(void);

    void   AudioThreadFunc(Uint8 *stream, int nbytes);

protected:

    bool    m_bInitSemaphore;

    struct SndBuffer {
        unsigned char *buffer;
        int nbytes;
        double pts;
    };

    SDL_AudioSpec spec;
    SndBuffer buffers[NUM_SND_BUFFER];
    int read_index, read_position, write_index, nbuffer;
    vm_semaphore sm_read_buffer, sm_write_buffer;
    double prev_rpts, prev_pts, offset;

    double    GetPTS(void);

};

#endif    //    defined(SDL_ON) && (defined(LINUX32) || defined(WIN32))
#endif    //    __SDLAUDIO_RENDER_H__