StreamWAVFormatDecoder.h

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//  
// Copyright (C) 2006 SIPez LLC. 
// Licensed to SIPfoundry under a Contributor Agreement. 
//
// Copyright (C) 2004-2006 SIPfoundry Inc.
// Licensed by SIPfoundry under the LGPL license.
//
// Copyright (C) 2004-2006 Pingtel Corp.  All rights reserved.
// Licensed to SIPfoundry under a Contributor Agreement.
//
// $$

#ifndef DISABLE_STREAM_PLAYER // [

#ifndef _StreamWAVFormatDecoder_h_
#define _StreamWAVFormatDecoder_h_

// SYSTEM INCLUDES
// APPLICATION INCLUDES
#include "mp/StreamQueueingFormatDecoder.h"
#include "os/OsDefs.h"
#include "os/OsStatus.h"
#include "os/OsTask.h"
#include "os/OsBSem.h"

// DEFINES
// MACROS
// EXTERNAL FUNCTIONS
// EXTERNAL VARIABLES
// CONSTANTS
// STRUCTS
struct WAVChunkID
{
        char     ckID[4];               // chunk id 'RIFF'
   unsigned long ckSize;           // chunk size
};

struct FORMATChunkInfo
{
   unsigned short formatTag;       // format tag currently pcm
   unsigned short nChannels;       // number of channels
   unsigned long nSamplesPerSec;   // sample rate in hz
   unsigned long nAvgBytesPerSec;  // average bytes per second
   unsigned short nBlockAlign;     // number of bytes per sample
   unsigned short nBitsPerSample;  // number of bits in a sample
};


// TYPEDEFS
// FORWARD DECLARATIONS

//:A WAV format Decoder
class StreamWAVFormatDecoder : public StreamQueueingFormatDecoder, public OsTask
{
/* //////////////////////////// PUBLIC //////////////////////////////////// */
public:

/* ============================ CREATORS ================================== */

   StreamWAVFormatDecoder(StreamDataSource* pDataSource);
     //:Default constructor

   virtual
   ~StreamWAVFormatDecoder();
     //:Destructor


/* ============================ MANIPULATORS ============================== */

   virtual OsStatus init();
     //:Initializes the decoder

   virtual OsStatus free();
     //:Frees all resources consumed by the decoder

   virtual OsStatus begin();
     //:Begins decoding

   virtual OsStatus end();
     //:Ends decoding


/* ============================ ACCESSORS ================================= */


   virtual OsStatus toString(UtlString& string);
     //:Renders a string describing this decoder.  
     // This is often used for debugging purposes.


/* ============================ INQUIRY =================================== */


   virtual UtlBoolean isDecoding();
     //:Gets the decoding status.  TRUE indicates decoding activity, false
     //:indicates the decoder has completed.

   virtual UtlBoolean validDecoder();
     //:Determines if this is a valid decoder given the associated data 
     //:source.
     // The data source is "peeked" for data, so that the stream's
     // data is not disturbed.


/* //////////////////////////// PROTECTED ///////////////////////////////// */
protected:

   StreamWAVFormatDecoder(const StreamWAVFormatDecoder& rStreamWAVFormatDecoder);
     //:Copy constructor (not supported)

   StreamWAVFormatDecoder& operator=(const StreamWAVFormatDecoder& rhs);
     //:Assignment operator (not supported)

   int run(void* pArgs);
     //:Thread entry point

   UtlBoolean nextDataChunk(int& iLength);
     //:Advances the mCurrentChunk to the next data chunk within the stream

/* //////////////////////////// PRIVATE /////////////////////////////////// */
private:
   UtlBoolean mbEnd ;    // Has the decoder completed?
   OsBSem    mSemExited ;  // Have we successfully exited?
   struct FORMATChunkInfo mFormatChunk ;
};

/* ============================ INLINE METHODS ============================ */

#endif  // _StreamWAVFormatDecoder_h_

#endif // DISABLE_STREAM_PLAYER ]