pa_jack.c

一个开源的sip源代码

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

    framesProcessed = PaUtil_EndBufferProcessing( &stream->bufferProcessor,
            &stream->callbackResult );
    /* We've specified a host buffer size mode where every frame should be consumed by the buffer processor */
    assert( framesProcessed == frames );

    PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesProcessed );

end:
    return result;
}

/* Alter the processing queue if necessary */
static PaError UpdateQueue( PaJackHostApiRepresentation *hostApi )
{
    PaError result = paNoError;
    int queueModified = 0;
    const double jackSr = jack_get_sample_rate( hostApi->jack_client );
    int err;

    if( (err = pthread_mutex_trylock( &hostApi->mtx )) != 0 )
    {
        assert( err == EBUSY );
        return paNoError;
    }

    if( hostApi->toAdd )
    {
        if( hostApi->processQueue )
        {
            PaJackStream *node = hostApi->processQueue;
            /* Advance to end of queue */
            while( node->next )
                node = node->next;

            node->next = hostApi->toAdd;
        }
        else
            hostApi->processQueue = (PaJackStream *)hostApi->toAdd;

        /* If necessary, update stream state */
        if( hostApi->toAdd->streamRepresentation.streamInfo.sampleRate != jackSr )
            UpdateSampleRate( hostApi->toAdd, jackSr );

        hostApi->toAdd = NULL;
        queueModified = 1;
    }
    if( hostApi->toRemove )
    {
        int removed = 0;
        PaJackStream *node = hostApi->processQueue, *prev = NULL;
        assert( hostApi->processQueue );

        while( node )
        {
            if( node == hostApi->toRemove )
            {
                if( prev )
                    prev->next = node->next;
                else
                    hostApi->processQueue = (PaJackStream *)node->next;

                removed = 1;
                break;
            }

            prev = node;
            node = node->next;
        }
        UNLESS( removed, paInternalError );
        hostApi->toRemove = NULL;
        PA_DEBUG(( "%s: Removed stream from processing queue\n", __FUNCTION__ ));
        queueModified = 1;
    }

    if( queueModified )
    {
        /* Signal that we've done what was asked of us */
        ASSERT_CALL( pthread_cond_signal( &hostApi->cond ), 0 );
    }

error:
    ASSERT_CALL( pthread_mutex_unlock( &hostApi->mtx ), 0 );

    return result;
}

static int JackCallback( jack_nframes_t frames, void *userData )
{
    PaError result = paNoError;
    PaJackHostApiRepresentation *hostApi = (PaJackHostApiRepresentation *)userData;
    PaJackStream *stream = NULL;
    int xrun = hostApi->xrun;
    hostApi->xrun = 0;

    assert( hostApi );

    ENSURE_PA( UpdateQueue( hostApi ) );

    /* Process each stream */
    stream = hostApi->processQueue;
    for( ; stream; stream = stream->next )
    {
        if( xrun )  /* Don't override if already set */
            stream->xrun = 1;

        /* See if this stream is to be started */
        if( stream->doStart )
        {
            /* If we can't obtain a lock, we'll try next time */
            int err = pthread_mutex_trylock( &stream->hostApi->mtx );
            if( !err )
            {
                if( stream->doStart )   /* Could potentially change before obtaining the lock */
                {
                    stream->is_active = 1;
                    stream->doStart = 0;
                    PA_DEBUG(( "%s: Starting stream\n", __FUNCTION__ ));
                    ASSERT_CALL( pthread_cond_signal( &stream->hostApi->cond ), 0 );
                    stream->callbackResult = paContinue;
                    stream->isSilenced = 0;
                }

                ASSERT_CALL( pthread_mutex_unlock( &stream->hostApi->mtx ), 0 );
            }
            else
                assert( err == EBUSY );
        }
        else if( stream->doStop || stream->doAbort )    /* Should we stop/abort stream? */
        {
            if( stream->callbackResult == paContinue )     /* Ok, make it stop */
            {
                PA_DEBUG(( "%s: Stopping stream\n", __FUNCTION__ ));
                stream->callbackResult = stream->doStop ? paComplete : paAbort;
            }
        }

        if( stream->is_active )
            ENSURE_PA( RealProcess( stream, frames ) );
        /* If we have just entered inactive state, silence output */
        if( !stream->is_active && !stream->isSilenced )
        {
            int i;

            /* Silence buffer after entering inactive state */
            PA_DEBUG(( "Silencing the output\n" ));
            for( i = 0; i < stream->num_outgoing_connections; ++i )
            {
                jack_default_audio_sample_t *buffer = jack_port_get_buffer( stream->local_output_ports[i], frames );
                memset( buffer, 0, sizeof (jack_default_audio_sample_t) * frames );
            }

            stream->isSilenced = 1;
        }

        if( stream->doStop || stream->doAbort )
        {
            /* See if RealProcess has acted on the request */
            if( !stream->is_active )   /* Ok, signal to the main thread that we've carried out the operation */
            {
                /* If we can't obtain a lock, we'll try next time */
                int err = pthread_mutex_trylock( &stream->hostApi->mtx );
                if( !err )
                {
                    stream->doStop = stream->doAbort = 0;
                    ASSERT_CALL( pthread_cond_signal( &stream->hostApi->cond ), 0 );
                    ASSERT_CALL( pthread_mutex_unlock( &stream->hostApi->mtx ), 0 );
                }
                else
                    assert( err == EBUSY );
            }
        }
    }

    return 0;
error:
    return -1;
}

static PaError StartStream( PaStream *s )
{
    PaError result = paNoError;
    PaJackStream *stream = (PaJackStream*)s;
    int i;

    /* Ready the processor */
    PaUtil_ResetBufferProcessor( &stream->bufferProcessor );

    /* connect the ports */

    /* NOTE: I would rather use jack_port_connect which uses jack_port_t's
     * instead of port names, but it is not implemented yet. */
    if( stream->num_incoming_connections > 0 )
    {
        for( i = 0; i < stream->num_incoming_connections; i++ )
            UNLESS( jack_connect( stream->jack_client,
                    jack_port_name( stream->remote_output_ports[i] ),
                    jack_port_name( stream->local_input_ports[i] ) ) == 0, paUnanticipatedHostError );
    }

    if( stream->num_outgoing_connections > 0 )
    {
        for( i = 0; i < stream->num_outgoing_connections; i++ )
            UNLESS( jack_connect( stream->jack_client,
                    jack_port_name( stream->local_output_ports[i] ),
                    jack_port_name( stream->remote_input_ports[i] ) ) == 0, paUnanticipatedHostError );
    }

    stream->xrun = FALSE;

    /* Enable processing */

    ASSERT_CALL( pthread_mutex_lock( &stream->hostApi->mtx ), 0 );
    stream->doStart = 1;

    /* Wait for stream to be started */
    result = WaitCondition( stream->hostApi );
    /*
    do
    {
        err = pthread_cond_timedwait( &stream->hostApi->cond, &stream->hostApi->mtx, &ts );
    } while( !stream->is_active && !err );
    */
    if( result != paNoError )   /* Something went wrong, call off the stream start */
    {
        stream->doStart = 0;
        stream->is_active = 0;  /* Cancel any processing */
    }
    ASSERT_CALL( pthread_mutex_unlock( &stream->hostApi->mtx ), 0 );

    ENSURE_PA( result );

    stream->is_running = TRUE;
    PA_DEBUG(( "%s: Stream started\n", __FUNCTION__ ));

error:
    return result;
}

static PaError RealStop( PaJackStream *stream, int abort )
{
    PaError result = paNoError;
    int i;

    if( stream->isBlockingStream )
        BlockingWaitEmpty ( stream );

    ASSERT_CALL( pthread_mutex_lock( &stream->hostApi->mtx ), 0 );
    if( abort )
        stream->doAbort = 1;
    else
        stream->doStop = 1;

    /* Wait for stream to be stopped */
    result = WaitCondition( stream->hostApi );
    ASSERT_CALL( pthread_mutex_unlock( &stream->hostApi->mtx ), 0 );
    ENSURE_PA( result );

    UNLESS( !stream->is_active, paInternalError );
    
    PA_DEBUG(( "%s: Stream stopped\n", __FUNCTION__ ));

error:
    stream->is_running = FALSE;

    /* Disconnect ports belonging to this stream */

    if( !stream->hostApi->jackIsDown )  /* XXX: Well? */
    {
        for( i = 0; i < stream->num_incoming_connections; i++ )
        {
            UNLESS( !jack_port_lock( stream->jack_client, stream->local_input_ports[i] ),
                    paUnanticipatedHostError );
            if( jack_port_connected( stream->local_input_ports[i] ) )
            {
                UNLESS( !jack_port_disconnect( stream->jack_client, stream->local_input_ports[i] ),
                        paUnanticipatedHostError );
            }
            UNLESS( !jack_port_unlock( stream->jack_client, stream->local_input_ports[i] ),
                    paUnanticipatedHostError );
        }
        for( i = 0; i < stream->num_outgoing_connections; i++ )
        {
            UNLESS( !jack_port_lock( stream->jack_client, stream->local_output_ports[i] ),
                    paUnanticipatedHostError );
            if( jack_port_connected( stream->local_output_ports[i] ) )
            {
                UNLESS( !jack_port_disconnect( stream->jack_client, stream->local_output_ports[i] ),
                        paUnanticipatedHostError );
            }
            UNLESS( !jack_port_unlock( stream->jack_client, stream->local_output_ports[i] ),
                    paUnanticipatedHostError );
        }
    }

    return result;
}

static PaError StopStream( PaStream *s )
{
    assert(s);
    return RealStop( (PaJackStream *)s, 0 );
}

static PaError AbortStream( PaStream *s )
{
    assert(s);
    return RealStop( (PaJackStream *)s, 1 );
}

static PaError IsStreamStopped( PaStream *s )
{
    PaJackStream *stream = (PaJackStream*)s;
    return !stream->is_running;
}


static PaError IsStreamActive( PaStream *s )
{
    PaJackStream *stream = (PaJackStream*)s;
    return stream->is_active;
}


static PaTime GetStreamTime( PaStream *s )
{
    PaJackStream *stream = (PaJackStream*)s;

    /* A: Is this relevant?? --> TODO: what if we're recording-only? */
    return (jack_frame_time( stream->jack_client ) - stream->t0) / (PaTime)jack_get_sample_rate( stream->jack_client );
}


static double GetStreamCpuLoad( PaStream* s )
{
    PaJackStream *stream = (PaJackStream*)s;
    return PaUtil_GetCpuLoad( &stream->cpuLoadMeasurer );
}