pa_jack.c

一个开源的sip源代码

        /* Unlock mutex and await signal from processing thread */
        result = WaitCondition( stream->hostApi );
    }
    ASSERT_CALL( pthread_mutex_unlock( &hostApi->mtx ), 0 );
    ENSURE_PA( result );

error:
    return result;
}

/* Add stream to processing queue */
static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
                           PaStream** s,
                           const PaStreamParameters *inputParameters,
                           const PaStreamParameters *outputParameters,
                           double sampleRate,
                           unsigned long framesPerBuffer,
                           PaStreamFlags streamFlags,
                           PaStreamCallback *streamCallback,
                           void *userData )
{
    PaError result = paNoError;
    PaJackHostApiRepresentation *jackHostApi = (PaJackHostApiRepresentation*)hostApi;
    PaJackStream *stream = NULL;
    char *port_string = PaUtil_GroupAllocateMemory( jackHostApi->deviceInfoMemory, jack_port_name_size() );
    unsigned long regexSz = jack_client_name_size() + 3;
    char *regex_pattern = PaUtil_GroupAllocateMemory( jackHostApi->deviceInfoMemory, regexSz );
    const char **jack_ports = NULL;
    /* int jack_max_buffer_size = jack_get_buffer_size( jackHostApi->jack_client ); */
    int i;
    int inputChannelCount, outputChannelCount;
    const double jackSr = jack_get_sample_rate( jackHostApi->jack_client );
    PaSampleFormat inputSampleFormat = 0, outputSampleFormat = 0;
    int bpInitialized = 0, srInitialized = 0;   /* Initialized buffer processor and stream representation? */
    unsigned long ofs;

    /* validate platform specific flags */
    if( (streamFlags & paPlatformSpecificFlags) != 0 )
        return paInvalidFlag; /* unexpected platform specific flag */
    if( (streamFlags & paPrimeOutputBuffersUsingStreamCallback) != 0 )
    {
        streamFlags &= ~paPrimeOutputBuffersUsingStreamCallback;
        /*return paInvalidFlag;*/   /* This implementation does not support buffer priming */
    }

    if( framesPerBuffer != paFramesPerBufferUnspecified )
    {
        /* Jack operates with power of two buffers, and we don't support non-integer buffer adaption (yet) */
        /*UNLESS( !(framesPerBuffer & (framesPerBuffer - 1)), paBufferTooBig );*/  /* TODO: Add descriptive error code? */
    }

    /* Preliminary checks */

    if( inputParameters )
    {
        inputChannelCount = inputParameters->channelCount;
        inputSampleFormat = inputParameters->sampleFormat;

        /* unless alternate device specification is supported, reject the use of
            paUseHostApiSpecificDeviceSpecification */

        if( inputParameters->device == paUseHostApiSpecificDeviceSpecification )
            return paInvalidDevice;

        /* check that input device can support inputChannelCount */
        if( inputChannelCount > hostApi->deviceInfos[ inputParameters->device ]->maxInputChannels )
            return paInvalidChannelCount;

        /* validate inputStreamInfo */
        if( inputParameters->hostApiSpecificStreamInfo )
            return paIncompatibleHostApiSpecificStreamInfo; /* this implementation doesn't use custom stream info */
    }
    else
    {
        inputChannelCount = 0;
    }

    if( outputParameters )
    {
        outputChannelCount = outputParameters->channelCount;
        outputSampleFormat = outputParameters->sampleFormat;

        /* unless alternate device specification is supported, reject the use of
            paUseHostApiSpecificDeviceSpecification */

        if( outputParameters->device == paUseHostApiSpecificDeviceSpecification )
            return paInvalidDevice;

        /* check that output device can support inputChannelCount */
        if( outputChannelCount > hostApi->deviceInfos[ outputParameters->device ]->maxOutputChannels )
            return paInvalidChannelCount;

        /* validate outputStreamInfo */
        if( outputParameters->hostApiSpecificStreamInfo )
            return paIncompatibleHostApiSpecificStreamInfo; /* this implementation doesn't use custom stream info */
    }
    else
    {
        outputChannelCount = 0;
    }

    /* ... check that the sample rate exactly matches the ONE acceptable rate
     * A: This rate isn't necessarily constant though? */

#define ABS(x) ( (x) > 0 ? (x) : -(x) )
    if( ABS(sampleRate - jackSr) > 1 )
       return paInvalidSampleRate;
#undef ABS

    UNLESS( stream = (PaJackStream*)PaUtil_AllocateMemory( sizeof(PaJackStream) ), paInsufficientMemory );
    ENSURE_PA( InitializeStream( stream, jackHostApi, inputChannelCount, outputChannelCount ) );

    /* the blocking emulation, if necessary */
    stream->isBlockingStream = !streamCallback;
    if( stream->isBlockingStream )
    {
        float latency = 0.001; /* 1ms is the absolute minimum we support */
        int   minimum_buffer_frames = 0;

        if( inputParameters && inputParameters->suggestedLatency > latency )
            latency = inputParameters->suggestedLatency;
        else if( outputParameters && outputParameters->suggestedLatency > latency )
            latency = outputParameters->suggestedLatency;

        /* the latency the user asked for indicates the minimum buffer size in frames */
        minimum_buffer_frames = (int) (latency * jack_get_sample_rate( jackHostApi->jack_client ));

        /* we also need to be able to store at least three full jack buffers to avoid dropouts */
        if( jackHostApi->jack_buffer_size * 3 > minimum_buffer_frames )
            minimum_buffer_frames = jackHostApi->jack_buffer_size * 3;

        /* setup blocking API data structures (FIXME: can fail) */
	BlockingBegin( stream, minimum_buffer_frames );

        /* install our own callback for the blocking API */
        streamCallback = BlockingCallback;
        userData = stream;

        PaUtil_InitializeStreamRepresentation( &stream->streamRepresentation,
                                               &jackHostApi->blockingStreamInterface, streamCallback, userData );
    }
    else
    {
        PaUtil_InitializeStreamRepresentation( &stream->streamRepresentation,
                                               &jackHostApi->callbackStreamInterface, streamCallback, userData );
    }
    srInitialized = 1;
    PaUtil_InitializeCpuLoadMeasurer( &stream->cpuLoadMeasurer, jackSr );

    /* create the JACK ports.  We cannot connect them until audio
     * processing begins */

    /* Register a unique set of ports for this stream
     * TODO: Robust allocation of new port names */

    ofs = jackHostApi->inputBase;
    for( i = 0; i < inputChannelCount; i++ )
    {
        snprintf( port_string, jack_port_name_size(), "in_%lu", ofs + i );
        UNLESS( stream->local_input_ports[i] = jack_port_register(
              jackHostApi->jack_client, port_string,
              JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0 ), paInsufficientMemory );
    }
    jackHostApi->inputBase += inputChannelCount;

    ofs = jackHostApi->outputBase;
    for( i = 0; i < outputChannelCount; i++ )
    {
        snprintf( port_string, jack_port_name_size(), "out_%lu", ofs + i );
        UNLESS( stream->local_output_ports[i] = jack_port_register(
             jackHostApi->jack_client, port_string,
             JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0 ), paInsufficientMemory );
    }
    jackHostApi->outputBase += outputChannelCount;

    /* look up the jack_port_t's for the remote ports.  We could do
     * this at stream start time, but doing it here ensures the
     * name lookup only happens once. */

    if( inputChannelCount > 0 )
    {
        int err = 0;
        
        /* ... remote output ports (that we input from) */
        snprintf( regex_pattern, regexSz, "%s:.*", hostApi->deviceInfos[ inputParameters->device ]->name );
        UNLESS( jack_ports = jack_get_ports( jackHostApi->jack_client, regex_pattern,
                                     NULL, JackPortIsOutput ), paUnanticipatedHostError );
        for( i = 0; i < inputChannelCount && jack_ports[i]; i++ )
        {
            if( (stream->remote_output_ports[i] = jack_port_by_name(
                 jackHostApi->jack_client, jack_ports[i] )) == NULL ) 
            {
                err = 1;
                break;
            }
        }
        free( jack_ports );
        UNLESS( !err, paInsufficientMemory );

        /* Fewer ports than expected? */
        UNLESS( i == inputChannelCount, paInternalError );
    }

    if( outputChannelCount > 0 )
    {
        int err = 0;

        /* ... remote input ports (that we output to) */
        snprintf( regex_pattern, regexSz, "%s:.*", hostApi->deviceInfos[ outputParameters->device ]->name );
        UNLESS( jack_ports = jack_get_ports( jackHostApi->jack_client, regex_pattern,
                                     NULL, JackPortIsInput ), paUnanticipatedHostError );
        for( i = 0; i < outputChannelCount && jack_ports[i]; i++ )
        {
            if( (stream->remote_input_ports[i] = jack_port_by_name(
                 jackHostApi->jack_client, jack_ports[i] )) == 0 )
            {
                err = 1;
                break;
            }
        }
        free( jack_ports );
        UNLESS( !err , paInsufficientMemory );

        /* Fewer ports than expected? */
        UNLESS( i == outputChannelCount, paInternalError );
    }

    ENSURE_PA( PaUtil_InitializeBufferProcessor(
                  &stream->bufferProcessor,
                  inputChannelCount,
                  inputSampleFormat,
                  paFloat32,            /* hostInputSampleFormat */
                  outputChannelCount,
                  outputSampleFormat,
                  paFloat32,            /* hostOutputSampleFormat */
                  jackSr,
                  streamFlags,
                  framesPerBuffer,
                  0,                            /* Ignored */
                  paUtilUnknownHostBufferSize,  /* Buffer size may vary on JACK's discretion */
                  streamCallback,
                  userData ) );
    bpInitialized = 1;

    if( stream->num_incoming_connections > 0 )
        stream->streamRepresentation.streamInfo.inputLatency = (jack_port_get_latency( stream->remote_output_ports[0] )
                - jack_get_buffer_size( jackHostApi->jack_client )  /* One buffer is not counted as latency */
            + PaUtil_GetBufferProcessorInputLatency( &stream->bufferProcessor )) / sampleRate;
    if( stream->num_outgoing_connections > 0 )
        stream->streamRepresentation.streamInfo.outputLatency = (jack_port_get_latency( stream->remote_input_ports[0] )
                - jack_get_buffer_size( jackHostApi->jack_client )  /* One buffer is not counted as latency */
            + PaUtil_GetBufferProcessorOutputLatency( &stream->bufferProcessor )) / sampleRate;

    stream->streamRepresentation.streamInfo.sampleRate = jackSr;
    stream->t0 = jack_frame_time( jackHostApi->jack_client );   /* A: Time should run from Pa_OpenStream */

    ENSURE_PA( AddStream( stream ) );  /* Add to queue over opened streams */
    
    *s = (PaStream*)stream;

    return result;

error:
    if( stream )
        CleanUpStream( stream, srInitialized, bpInitialized );

    return result;
}

/*
    When CloseStream() is called, the multi-api layer ensures that
    the stream has already been stopped or aborted.
*/
static PaError CloseStream( PaStream* s )
{
    PaError result = paNoError;
    PaJackStream *stream = (PaJackStream*)s;

    /* Remove this stream from the processing queue */
    ENSURE_PA( RemoveStream( stream ) );

error:
    CleanUpStream( stream, 1, 1 );
    return result;
}

static PaError RealProcess( PaJackStream *stream, jack_nframes_t frames )
{
    PaError result = paNoError;
    PaStreamCallbackTimeInfo timeInfo = {0,0,0};
    int chn;
    int framesProcessed;
    const double sr = jack_get_sample_rate( stream->jack_client );    /* Shouldn't change during the process callback */
    PaStreamCallbackFlags cbFlags = 0;

    /* If the user has returned !paContinue from the callback we'll want to flush the internal buffers,
     * when these are empty we can finally mark the stream as inactive */
    if( stream->callbackResult != paContinue &&
            PaUtil_IsBufferProcessorOutputEmpty( &stream->bufferProcessor ) )
    {
        stream->is_active = 0;
        if( stream->streamRepresentation.streamFinishedCallback )
            stream->streamRepresentation.streamFinishedCallback( stream->streamRepresentation.userData );
        PA_DEBUG(( "%s: Callback finished\n", __FUNCTION__ ));

        goto end;
    }

    timeInfo.currentTime = (jack_frame_time( stream->jack_client ) - stream->t0) / sr;
    if( stream->num_incoming_connections > 0 )
        timeInfo.inputBufferAdcTime = timeInfo.currentTime - jack_port_get_latency( stream->remote_output_ports[0] )
            / sr;
    if( stream->num_outgoing_connections > 0 )
        timeInfo.outputBufferDacTime = timeInfo.currentTime + jack_port_get_latency( stream->remote_input_ports[0] )
            / sr;

    PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer );

    if( stream->xrun )
    {
        /* XXX: Any way to tell which of these occurred? */
        cbFlags = paOutputUnderflow | paInputOverflow;
        stream->xrun = FALSE;
    }
    PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo,
            cbFlags );

    if( stream->num_incoming_connections > 0 )
        PaUtil_SetInputFrameCount( &stream->bufferProcessor, frames );
    if( stream->num_outgoing_connections > 0 )
        PaUtil_SetOutputFrameCount( &stream->bufferProcessor, frames );

    for( chn = 0; chn < stream->num_incoming_connections; chn++ )
    {
        jack_default_audio_sample_t *channel_buf = (jack_default_audio_sample_t*)
            jack_port_get_buffer( stream->local_input_ports[chn],
                    frames );

        PaUtil_SetNonInterleavedInputChannel( &stream->bufferProcessor,
                chn,
                channel_buf );
    }

    for( chn = 0; chn < stream->num_outgoing_connections; chn++ )
    {
        jack_default_audio_sample_t *channel_buf = (jack_default_audio_sample_t*)
            jack_port_get_buffer( stream->local_output_ports[chn],
                    frames );