pa_mac_core_utilities.c

一个开源的sip源代码

   mab->once = TRUE;
   pthread_mutex_unlock( &(mab->mutex) );
   return noErr;
}

/* sets the value of the given property and waits for the change to 
   be acknowledged, and returns the final value, which is not guaranteed
   by this function to be the same as the desired value. Obviously, this
   function can only be used for data whose input and output are the
   same size and format, and their size and format are known in advance.*/
PaError AudioDeviceSetPropertyNowAndWaitForChange(
    AudioDeviceID inDevice,
    UInt32 inChannel, 
    Boolean isInput, 
    AudioDevicePropertyID inPropertyID,
    UInt32 inPropertyDataSize, 
    const void *inPropertyData,
    void *outPropertyData )
{
   OSStatus macErr;
   int unixErr;
   MutexAndBool mab;
   UInt32 outPropertyDataSize = inPropertyDataSize;

   /* First, see if it already has that value. If so, return. */
   macErr = AudioDeviceGetProperty( inDevice, inChannel,
                                 isInput, inPropertyID, 
                                 &outPropertyDataSize, outPropertyData );
   if( macErr )
      goto failMac2;
   if( inPropertyDataSize!=outPropertyDataSize )
      return paInternalError;
   if( 0==memcmp( outPropertyData, inPropertyData, outPropertyDataSize ) )
      return paNoError;

   /* setup and lock mutex */
   mab.once = FALSE;
   unixErr = pthread_mutex_init( &mab.mutex, NULL );
   if( unixErr )
      goto failUnix2;
   unixErr = pthread_mutex_lock( &mab.mutex );
   if( unixErr )
      goto failUnix;

   /* add property listener */
   macErr = AudioDeviceAddPropertyListener( inDevice, inChannel, isInput,
                                   inPropertyID, propertyProc,
                                   &mab ); 
   if( macErr )
      goto failMac;
   /* set property */
   macErr  = AudioDeviceSetProperty( inDevice, NULL, inChannel,
                                 isInput, inPropertyID,
                                 inPropertyDataSize, inPropertyData );
   if( macErr ) {
      /* we couldn't set the property, so we'll just unlock the mutex
         and move on. */
      pthread_mutex_unlock( &mab.mutex );
   }

   /* wait for property to change */                      
   unixErr = pthread_mutex_lock( &mab.mutex );
   if( unixErr )
      goto failUnix;

   /* now read the property back out */
   macErr = AudioDeviceGetProperty( inDevice, inChannel,
                                 isInput, inPropertyID, 
                                 &outPropertyDataSize, outPropertyData );
   if( macErr )
      goto failMac;
   /* cleanup */
   AudioDeviceRemovePropertyListener( inDevice, inChannel, isInput,
                                      inPropertyID, propertyProc );
   unixErr = pthread_mutex_unlock( &mab.mutex );
   if( unixErr )
      goto failUnix2;
   unixErr = pthread_mutex_destroy( &mab.mutex );
   if( unixErr )
      goto failUnix2;

   return paNoError;

 failUnix:
   pthread_mutex_destroy( &mab.mutex );
   AudioDeviceRemovePropertyListener( inDevice, inChannel, isInput,
                                      inPropertyID, propertyProc );

 failUnix2:
   DBUG( ("Error #%d while setting a device property: %s\n", unixErr, strerror( unixErr ) ) );
   return paUnanticipatedHostError;

 failMac:
   pthread_mutex_destroy( &mab.mutex );
   AudioDeviceRemovePropertyListener( inDevice, inChannel, isInput,
                                      inPropertyID, propertyProc );
 failMac2:
   return ERR( macErr );
}

/*
 * Sets the sample rate the HAL device.
 * if requireExact: set the sample rate or fail.
 *
 * otherwise      : set the exact sample rate.
 *             If that fails, check for available sample rates, and choose one
 *             higher than the requested rate. If there isn't a higher one,
 *             just use the highest available.
 */
PaError setBestSampleRateForDevice( const AudioDeviceID device,
                                    const bool isOutput,
                                    const bool requireExact,
                                    const Float64 desiredSrate )
{
   /*FIXME: changing the sample rate is disruptive to other programs using the
            device, so it might be good to offer a custom flag to not change the
            sample rate and just do conversion. (in my casual tests, there is
            no disruption unless the sample rate really does need to change) */
   const bool isInput = isOutput ? 0 : 1;
   Float64 srate;
   UInt32 propsize = sizeof( Float64 );
   OSErr err;
   AudioValueRange *ranges;
   int i=0;
   Float64 max  = -1; /*the maximum rate available*/
   Float64 best = -1; /*the lowest sample rate still greater than desired rate*/
   VDBUG(("Setting sample rate for device %ld to %g.\n",device,(float)desiredSrate));

   /* -- try setting the sample rate -- */
   err = AudioDeviceSetPropertyNowAndWaitForChange(
                                 device, 0, isInput,
                                 kAudioDevicePropertyNominalSampleRate,
                                 propsize, &desiredSrate, &srate );
   if( err )
      return err;

   /* -- if the rate agrees, and we got no errors, we are done -- */
   if( !err && srate == desiredSrate )
      return paNoError;
   /* -- we've failed if the rates disagree and we are setting input -- */
   if( requireExact )
      return paInvalidSampleRate;

   /* -- generate a list of available sample rates -- */
   err = AudioDeviceGetPropertyInfo( device, 0, isInput,
                                kAudioDevicePropertyAvailableNominalSampleRates,
                                &propsize, NULL );
   if( err )
      return ERR( err );
   ranges = (AudioValueRange *)calloc( 1, propsize );
   if( !ranges )
      return paInsufficientMemory;
   err = AudioDeviceGetProperty( device, 0, isInput,
                                kAudioDevicePropertyAvailableNominalSampleRates,
                                &propsize, ranges );
   if( err )
   {
      free( ranges );
      return ERR( err );
   }
   VDBUG(("Requested sample rate of %g was not available.\n", (float)desiredSrate));
   VDBUG(("%lu Available Sample Rates are:\n",propsize/sizeof(AudioValueRange)));
#ifdef MAC_CORE_VERBOSE_DEBUG
   for( i=0; i<propsize/sizeof(AudioValueRange); ++i )
      VDBUG( ("\t%g-%g\n",
              (float) ranges[i].mMinimum,
              (float) ranges[i].mMaximum ) );
#endif
   VDBUG(("-----\n"));
   
   /* -- now pick the best available sample rate -- */
   for( i=0; i<propsize/sizeof(AudioValueRange); ++i )
   {
      if( ranges[i].mMaximum > max ) max = ranges[i].mMaximum;
      if( ranges[i].mMinimum > desiredSrate ) {
         if( best < 0 )
            best = ranges[i].mMinimum;
         else if( ranges[i].mMinimum < best )
            best = ranges[i].mMinimum;
      }
   }
   if( best < 0 )
      best = max;
   VDBUG( ("Maximum Rate %g. best is %g.\n", max, best ) );
   free( ranges );

   /* -- set the sample rate -- */
   propsize = sizeof( best );
   err = AudioDeviceSetPropertyNowAndWaitForChange(
                                 device, 0, isInput,
                                 kAudioDevicePropertyNominalSampleRate,
                                 propsize, &best, &srate );
   if( err )
      return err;

   if( err )
      return ERR( err );
   /* -- if the set rate matches, we are done -- */
   if( srate == best )
      return paNoError;

   /* -- otherwise, something wierd happened: we didn't set the rate, and we got no errors. Just bail. */
   return paInternalError;
}


/*
   Attempts to set the requestedFramesPerBuffer. If it can't set the exact
   value, it settles for something smaller if available. If nothing smaller
   is available, it uses the smallest available size.
   actualFramesPerBuffer will be set to the actual value on successful return.
   OK to pass NULL to actualFramesPerBuffer.
   The logic is very simmilar too setBestSampleRate only failure here is
   not usually catastrophic.
*/
PaError setBestFramesPerBuffer( const AudioDeviceID device,
                                       const bool isOutput,
                                       unsigned long requestedFramesPerBuffer, 
                                       unsigned long *actualFramesPerBuffer )
{
   UInt32 afpb;
   const bool isInput = !isOutput;
   UInt32 propsize = sizeof(UInt32);
   OSErr err;
   Float64 min  = -1; /*the min blocksize*/
   Float64 best = -1; /*the best blocksize*/
   int i=0;
   AudioValueRange *ranges;

   if( actualFramesPerBuffer == NULL )
      actualFramesPerBuffer = &afpb;


   /* -- try and set exact FPB -- */
   err = AudioDeviceSetProperty( device, NULL, 0, isInput,
                                 kAudioDevicePropertyBufferFrameSize,
                                 propsize, &requestedFramesPerBuffer);
   err = AudioDeviceGetProperty( device, 0, isInput,
                           kAudioDevicePropertyBufferFrameSize,
                           &propsize, actualFramesPerBuffer);
   if( err )
      return ERR( err );
   if( *actualFramesPerBuffer == requestedFramesPerBuffer )
      return paNoError; /* we are done */

   /* -- fetch available block sizes -- */
   err = AudioDeviceGetPropertyInfo( device, 0, isInput,
                           kAudioDevicePropertyBufferSizeRange,
                           &propsize, NULL );
   if( err )
      return ERR( err );
   ranges = (AudioValueRange *)calloc( 1, propsize );
   if( !ranges )
      return paInsufficientMemory;
   err = AudioDeviceGetProperty( device, 0, isInput,
                                kAudioDevicePropertyBufferSizeRange,
                                &propsize, ranges );
   if( err )
   {
      free( ranges );
      return ERR( err );
   }
   VDBUG(("Requested block size of %lu was not available.\n",
          requestedFramesPerBuffer ));
   VDBUG(("%lu Available block sizes are:\n",propsize/sizeof(AudioValueRange)));
#ifdef MAC_CORE_VERBOSE_DEBUG
   for( i=0; i<propsize/sizeof(AudioValueRange); ++i )
      VDBUG( ("\t%g-%g\n",
              (float) ranges[i].mMinimum,
              (float) ranges[i].mMaximum ) );
#endif
   VDBUG(("-----\n"));
   
   /* --- now pick the best available framesPerBuffer -- */
   for( i=0; i<propsize/sizeof(AudioValueRange); ++i )
   {
      if( min == -1 || ranges[i].mMinimum < min ) min = ranges[i].mMinimum;
      if( ranges[i].mMaximum < requestedFramesPerBuffer ) {
         if( best < 0 )
            best = ranges[i].mMaximum;
         else if( ranges[i].mMaximum > best )
            best = ranges[i].mMaximum;
      }
   }
   if( best == -1 )
      best = min;
   VDBUG( ("Minimum FPB  %g. best is %g.\n", min, best ) );
   free( ranges );

   /* --- set the buffer size (ignore errors) -- */
   requestedFramesPerBuffer = (UInt32) best ;
   propsize = sizeof( UInt32 );
   err = AudioDeviceSetProperty( device, NULL, 0, isInput,
                                 kAudioDevicePropertyBufferSize,
                                 propsize, &requestedFramesPerBuffer );
   /* --- read the property to check that it was set -- */
   err = AudioDeviceGetProperty( device, 0, isInput,
                                 kAudioDevicePropertyBufferSize,
                                 &propsize, actualFramesPerBuffer );

   if( err )
      return ERR( err );

   return paNoError;
}