rdpsnd_pulse.c

 
#include <freerdp/config.h>
 
#include <errno.h>
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
 
#include <winpr/crt.h>
#include <winpr/assert.h>
#include <winpr/stream.h>
#include <winpr/cmdline.h>
 
#include <pulse/pulseaudio.h>
 
#include <freerdp/types.h>
#include <freerdp/codec/dsp.h>
 
#include "rdpsnd_main.h"
 
typedef struct
{
  rdpsndDevicePlugin device;
 
  char* device_name;
  pa_threaded_mainloop* mainloop;
  pa_context* context;
  pa_sample_spec sample_spec;
  pa_stream* stream;
  UINT32 latency;
  UINT32 volume;
  time_t reconnect_delay_seconds;
  time_t reconnect_time;
} rdpsndPulsePlugin;
 
static BOOL rdpsnd_check_pulse(rdpsndPulsePlugin* pulse, BOOL haveStream)
{
  BOOL rc = TRUE;
  WINPR_ASSERT(pulse);
 
  if (!pulse->context)
  {
    WLog_WARN(TAG, "pulse->context=%p", pulse->context);
    rc = FALSE;
  }
 
  if (haveStream)
  {
    if (!pulse->stream)
    {
      WLog_WARN(TAG, "pulse->stream=%p", pulse->stream);
      rc = FALSE;
    }
  }
 
  if (!pulse->mainloop)
  {
    WLog_WARN(TAG, "pulse->mainloop=%p", pulse->mainloop);
    rc = FALSE;
  }
 
  return rc;
}
 
static BOOL rdpsnd_pulse_format_supported(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format);
 
static void rdpsnd_pulse_get_sink_info(pa_context* c, const pa_sink_info* i, int eol,
                                       void* userdata)
{
  UINT16 dwVolumeLeft = ((50 * 0xFFFF) / 100);  /* 50% */
  UINT16 dwVolumeRight = ((50 * 0xFFFF) / 100); /* 50% */
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)userdata;
 
  WINPR_ASSERT(c);
  if (!rdpsnd_check_pulse(pulse, FALSE) || !i)
    return;
 
  for (uint8_t x = 0; x < i->volume.channels; x++)
  {
    pa_volume_t volume = i->volume.values[x];
 
    if (volume >= PA_VOLUME_NORM)
      volume = PA_VOLUME_NORM - 1;
 
    switch (x)
    {
      case 0:
        dwVolumeLeft = (UINT16)volume;
        break;
 
      case 1:
        dwVolumeRight = (UINT16)volume;
        break;
 
      default:
        break;
    }
  }
 
  pulse->volume = ((UINT32)dwVolumeLeft << 16U) | dwVolumeRight;
}
 
static void rdpsnd_pulse_context_state_callback(pa_context* context, void* userdata)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)userdata;
 
  WINPR_ASSERT(context);
  WINPR_ASSERT(pulse);
 
  pa_context_state_t state = pa_context_get_state(context);
 
  switch (state)
  {
    case PA_CONTEXT_READY:
      pa_threaded_mainloop_signal(pulse->mainloop, 0);
      break;
 
    case PA_CONTEXT_FAILED:
      // Destroy context now, create new one for next connection attempt
      pa_context_unref(pulse->context);
      pulse->context = NULL;
      if (pulse->reconnect_delay_seconds >= 0)
        pulse->reconnect_time = time(NULL) + pulse->reconnect_delay_seconds;
      pa_threaded_mainloop_signal(pulse->mainloop, 0);
      break;
 
    case PA_CONTEXT_TERMINATED:
      pa_threaded_mainloop_signal(pulse->mainloop, 0);
      break;
 
    default:
      break;
  }
}
 
static BOOL rdpsnd_pulse_connect(rdpsndDevicePlugin* device)
{
  BOOL rc = 0;
  pa_operation* o = NULL;
  pa_context_state_t state = PA_CONTEXT_FAILED;
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
    return FALSE;
 
  pa_threaded_mainloop_lock(pulse->mainloop);
 
  if (pa_context_connect(pulse->context, NULL, 0, NULL) < 0)
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    return FALSE;
  }
 
  for (;;)
  {
    state = pa_context_get_state(pulse->context);
 
    if (state == PA_CONTEXT_READY)
      break;
 
    if (!PA_CONTEXT_IS_GOOD(state))
    {
      break;
    }
 
    pa_threaded_mainloop_wait(pulse->mainloop);
  }
 
  o = pa_context_get_sink_info_by_index(pulse->context, 0, rdpsnd_pulse_get_sink_info, pulse);
 
  if (o)
    pa_operation_unref(o);
 
  if (state == PA_CONTEXT_READY)
  {
    rc = TRUE;
  }
  else
  {
    pa_context_disconnect(pulse->context);
    rc = FALSE;
  }
 
  pa_threaded_mainloop_unlock(pulse->mainloop);
  return rc;
}
 
static void rdpsnd_pulse_stream_success_callback(pa_stream* stream, int success, void* userdata)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)userdata;
 
  if (!rdpsnd_check_pulse(pulse, TRUE))
    return;
 
  pa_threaded_mainloop_signal(pulse->mainloop, 0);
}
 
static void rdpsnd_pulse_wait_for_operation(rdpsndPulsePlugin* pulse, pa_operation* operation)
{
  if (!rdpsnd_check_pulse(pulse, TRUE))
    return;
 
  if (!operation)
    return;
 
  while (pa_operation_get_state(operation) == PA_OPERATION_RUNNING)
  {
    pa_threaded_mainloop_wait(pulse->mainloop);
  }
 
  pa_operation_unref(operation);
}
 
static void rdpsnd_pulse_stream_state_callback(pa_stream* stream, void* userdata)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)userdata;
 
  WINPR_ASSERT(stream);
  if (!rdpsnd_check_pulse(pulse, TRUE))
    return;
 
  pa_stream_state_t state = pa_stream_get_state(stream);
 
  switch (state)
  {
    case PA_STREAM_READY:
      pa_threaded_mainloop_signal(pulse->mainloop, 0);
      break;
 
    case PA_STREAM_FAILED:
    case PA_STREAM_TERMINATED:
      // Stream object is about to be destroyed, clean up our pointer
      pulse->stream = NULL;
      pa_threaded_mainloop_signal(pulse->mainloop, 0);
      break;
 
    default:
      break;
  }
}
 
static void rdpsnd_pulse_stream_request_callback(pa_stream* stream, size_t length, void* userdata)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)userdata;
 
  WINPR_ASSERT(stream);
  if (!rdpsnd_check_pulse(pulse, TRUE))
    return;
 
  pa_threaded_mainloop_signal(pulse->mainloop, 0);
}
 
static void rdpsnd_pulse_close(rdpsndDevicePlugin* device)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  WINPR_ASSERT(pulse);
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
    return;
 
  pa_threaded_mainloop_lock(pulse->mainloop);
  if (pulse->stream)
  {
    rdpsnd_pulse_wait_for_operation(
        pulse, pa_stream_drain(pulse->stream, rdpsnd_pulse_stream_success_callback, pulse));
    pa_stream_disconnect(pulse->stream);
    pa_stream_unref(pulse->stream);
    pulse->stream = NULL;
  }
  pa_threaded_mainloop_unlock(pulse->mainloop);
}
 
static BOOL rdpsnd_pulse_set_format_spec(rdpsndPulsePlugin* pulse, const AUDIO_FORMAT* format)
{
  pa_sample_spec sample_spec = { 0 };
 
  WINPR_ASSERT(format);
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
    return FALSE;
 
  if (!rdpsnd_pulse_format_supported(&pulse->device, format))
    return FALSE;
 
  sample_spec.rate = format->nSamplesPerSec;
  sample_spec.channels = format->nChannels;
 
  switch (format->wFormatTag)
  {
    case WAVE_FORMAT_PCM:
      switch (format->wBitsPerSample)
      {
        case 8:
          sample_spec.format = PA_SAMPLE_U8;
          break;
 
        case 16:
          sample_spec.format = PA_SAMPLE_S16LE;
          break;
 
        default:
          return FALSE;
      }
 
      break;
 
    default:
      return FALSE;
  }
 
  pulse->sample_spec = sample_spec;
  return TRUE;
}
 
static BOOL rdpsnd_pulse_context_connect(rdpsndDevicePlugin* device)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  pulse->context = pa_context_new(pa_threaded_mainloop_get_api(pulse->mainloop), "freerdp");
 
  if (!pulse->context)
    return FALSE;
 
  pa_context_set_state_callback(pulse->context, rdpsnd_pulse_context_state_callback, pulse);
 
  if (!rdpsnd_pulse_connect((rdpsndDevicePlugin*)pulse))
    return FALSE;
 
  return TRUE;
}
 
static BOOL rdpsnd_pulse_open_stream(rdpsndDevicePlugin* device)
{
  pa_stream_state_t state = PA_STREAM_FAILED;
  int flags = PA_STREAM_NOFLAGS;
  pa_buffer_attr buffer_attr = { 0 };
  char ss[PA_SAMPLE_SPEC_SNPRINT_MAX] = { 0 };
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (pa_sample_spec_valid(&pulse->sample_spec) == 0)
  {
    pa_sample_spec_snprint(ss, sizeof(ss), &pulse->sample_spec);
    return FALSE;
  }
 
  pa_threaded_mainloop_lock(pulse->mainloop);
  if (!pulse->context)
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    if (pulse->reconnect_delay_seconds >= 0 && time(NULL) - pulse->reconnect_time >= 0)
      rdpsnd_pulse_context_connect(device);
    pa_threaded_mainloop_lock(pulse->mainloop);
  }
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    return FALSE;
  }
 
  pulse->stream = pa_stream_new(pulse->context, "freerdp", &pulse->sample_spec, NULL);
 
  if (!pulse->stream)
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    return FALSE;
  }
 
  /* register essential callbacks */
  pa_stream_set_state_callback(pulse->stream, rdpsnd_pulse_stream_state_callback, pulse);
  pa_stream_set_write_callback(pulse->stream, rdpsnd_pulse_stream_request_callback, pulse);
  flags = PA_STREAM_INTERPOLATE_TIMING | PA_STREAM_AUTO_TIMING_UPDATE;
 
  if (pulse->latency > 0)
  {
    const size_t val = pa_usec_to_bytes(1000ULL * pulse->latency, &pulse->sample_spec);
    buffer_attr.maxlength = UINT32_MAX;
    buffer_attr.tlength = (val > UINT32_MAX) ? UINT32_MAX : (UINT32)val;
    buffer_attr.prebuf = UINT32_MAX;
    buffer_attr.minreq = UINT32_MAX;
    buffer_attr.fragsize = UINT32_MAX;
    flags |= PA_STREAM_ADJUST_LATENCY;
  }
 
  // NOLINTNEXTLINE(clang-analyzer-optin.core.EnumCastOutOfRange)
  pa_stream_flags_t eflags = (pa_stream_flags_t)flags;
  if (pa_stream_connect_playback(pulse->stream, pulse->device_name,
                                 pulse->latency > 0 ? &buffer_attr : NULL, eflags, NULL,
                                 NULL) < 0)
  {
    WLog_ERR(TAG, "error connecting playback stream");
    pa_stream_unref(pulse->stream);
    pulse->stream = NULL;
    pa_threaded_mainloop_unlock(pulse->mainloop);
    return FALSE;
  }
 
  while (pulse->stream)
  {
    state = pa_stream_get_state(pulse->stream);
 
    if (state == PA_STREAM_READY)
      break;
 
    if (!PA_STREAM_IS_GOOD(state))
    {
      break;
    }
 
    pa_threaded_mainloop_wait(pulse->mainloop);
  }
 
  pa_threaded_mainloop_unlock(pulse->mainloop);
 
  if (state == PA_STREAM_READY)
    return TRUE;
 
  rdpsnd_pulse_close(device);
  return FALSE;
}
 
static BOOL rdpsnd_pulse_open(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format,
                              UINT32 latency)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  WINPR_ASSERT(format);
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
    return TRUE;
 
  if (!rdpsnd_pulse_set_format_spec(pulse, format))
    return FALSE;
 
  pulse->latency = latency;
 
  return rdpsnd_pulse_open_stream(device);
}
 
static void rdpsnd_pulse_free(rdpsndDevicePlugin* device)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!pulse)
    return;
 
  rdpsnd_pulse_close(device);
 
  if (pulse->mainloop)
    pa_threaded_mainloop_stop(pulse->mainloop);
 
  if (pulse->context)
  {
    pa_context_disconnect(pulse->context);
    pa_context_unref(pulse->context);
    pulse->context = NULL;
  }
 
  if (pulse->mainloop)
  {
    pa_threaded_mainloop_free(pulse->mainloop);
    pulse->mainloop = NULL;
  }
 
  free(pulse->device_name);
  free(pulse);
}
 
static BOOL rdpsnd_pulse_default_format(rdpsndDevicePlugin* device, const AUDIO_FORMAT* desired,
                                        AUDIO_FORMAT* defaultFormat)
{
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!pulse || !defaultFormat)
    return FALSE;
 
  *defaultFormat = *desired;
  defaultFormat->data = NULL;
  defaultFormat->cbSize = 0;
  defaultFormat->wFormatTag = WAVE_FORMAT_PCM;
  if ((defaultFormat->nChannels < 1) || (defaultFormat->nChannels > PA_CHANNELS_MAX))
    defaultFormat->nChannels = 2;
  if ((defaultFormat->nSamplesPerSec < 1) || (defaultFormat->nSamplesPerSec > PA_RATE_MAX))
    defaultFormat->nSamplesPerSec = 44100;
  if ((defaultFormat->wBitsPerSample != 8) && (defaultFormat->wBitsPerSample != 16))
    defaultFormat->wBitsPerSample = 16;
 
  defaultFormat->nBlockAlign = defaultFormat->nChannels * defaultFormat->wBitsPerSample / 8;
  defaultFormat->nAvgBytesPerSec = defaultFormat->nBlockAlign * defaultFormat->nSamplesPerSec;
  return TRUE;
}
 
BOOL rdpsnd_pulse_format_supported(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format)
{
  WINPR_ASSERT(device);
  WINPR_ASSERT(format);
 
  switch (format->wFormatTag)
  {
    case WAVE_FORMAT_PCM:
      if (format->cbSize == 0 && (format->nSamplesPerSec <= PA_RATE_MAX) &&
          (format->wBitsPerSample == 8 || format->wBitsPerSample == 16) &&
          (format->nChannels >= 1 && format->nChannels <= PA_CHANNELS_MAX))
      {
        return TRUE;
      }
 
      break;
 
    default:
      break;
  }
 
  return FALSE;
}
 
static UINT32 rdpsnd_pulse_get_volume(rdpsndDevicePlugin* device)
{
  pa_operation* o = NULL;
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!rdpsnd_check_pulse(pulse, FALSE))
    return 0;
 
  pa_threaded_mainloop_lock(pulse->mainloop);
  o = pa_context_get_sink_info_by_index(pulse->context, 0, rdpsnd_pulse_get_sink_info, pulse);
  if (o)
    pa_operation_unref(o);
  pa_threaded_mainloop_unlock(pulse->mainloop);
  return pulse->volume;
}
 
static void rdpsnd_set_volume_success_cb(pa_context* c, int success, void* userdata)
{
  rdpsndPulsePlugin* pulse = userdata;
 
  if (!rdpsnd_check_pulse(pulse, TRUE))
    return;
  WINPR_ASSERT(c);
 
  WLog_INFO(TAG, "%d", success);
}
 
static BOOL rdpsnd_pulse_set_volume(rdpsndDevicePlugin* device, UINT32 value)
{
  pa_cvolume cv = { 0 };
  pa_volume_t left = 0;
  pa_volume_t right = 0;
  pa_operation* operation = NULL;
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!rdpsnd_check_pulse(pulse, TRUE))
  {
    WLog_WARN(TAG, "%s called before pulse backend was initialized");
    return FALSE;
  }
 
  left = (pa_volume_t)(value & 0xFFFF);
  right = (pa_volume_t)((value >> 16) & 0xFFFF);
  pa_cvolume_init(&cv);
  cv.channels = 2;
  cv.values[0] = PA_VOLUME_MUTED + (left * (PA_VOLUME_NORM - PA_VOLUME_MUTED)) / PA_VOLUME_NORM;
  cv.values[1] = PA_VOLUME_MUTED + (right * (PA_VOLUME_NORM - PA_VOLUME_MUTED)) / PA_VOLUME_NORM;
  pa_threaded_mainloop_lock(pulse->mainloop);
  operation = pa_context_set_sink_input_volume(pulse->context, pa_stream_get_index(pulse->stream),
                                               &cv, rdpsnd_set_volume_success_cb, pulse);
 
  if (operation)
    pa_operation_unref(operation);
 
  pa_threaded_mainloop_unlock(pulse->mainloop);
  return TRUE;
}
 
static UINT rdpsnd_pulse_play(rdpsndDevicePlugin* device, const BYTE* data, size_t size)
{
  size_t length = 0;
  void* pa_data = NULL;
  int status = 0;
  pa_usec_t latency = 0;
  int negative = 0;
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
 
  if (!data)
    return 0;
 
  pa_threaded_mainloop_lock(pulse->mainloop);
 
  if (!rdpsnd_check_pulse(pulse, TRUE))
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    // Discard this playback request and just attempt to reconnect the stream
    WLog_DBG(TAG, "reconnecting playback stream");
    rdpsnd_pulse_open_stream(device);
    return 0;
  }
 
  while (size > 0)
  {
    length = size;
 
    status = pa_stream_begin_write(pulse->stream, &pa_data, &length);
 
    if (status < 0)
      break;
 
    memcpy(pa_data, data, length);
 
    status = pa_stream_write(pulse->stream, pa_data, length, NULL, 0LL, PA_SEEK_RELATIVE);
 
    if (status < 0)
    {
      break;
    }
 
    data += length;
    size -= length;
  }
 
  if (pa_stream_get_latency(pulse->stream, &latency, &negative) != 0)
    latency = 0;
 
  pa_threaded_mainloop_unlock(pulse->mainloop);
 
  const pa_usec_t val = latency / 1000;
  if (val > UINT32_MAX)
    return UINT32_MAX;
  return (UINT32)val;
}
 
static UINT rdpsnd_pulse_parse_addin_args(rdpsndDevicePlugin* device, const ADDIN_ARGV* args)
{
  int status = 0;
  DWORD flags = 0;
  const COMMAND_LINE_ARGUMENT_A* arg = NULL;
  rdpsndPulsePlugin* pulse = (rdpsndPulsePlugin*)device;
  COMMAND_LINE_ARGUMENT_A rdpsnd_pulse_args[] = {
    { "dev", COMMAND_LINE_VALUE_REQUIRED, "<device>", NULL, NULL, -1, NULL, "device" },
    { "reconnect_delay_seconds", COMMAND_LINE_VALUE_REQUIRED, "<reconnect_delay_seconds>", NULL,
      NULL, -1, NULL, "reconnect_delay_seconds" },
    { NULL, 0, NULL, NULL, NULL, -1, NULL, NULL }
  };
  flags =
      COMMAND_LINE_SIGIL_NONE | COMMAND_LINE_SEPARATOR_COLON | COMMAND_LINE_IGN_UNKNOWN_KEYWORD;
 
  WINPR_ASSERT(pulse);
  WINPR_ASSERT(args);
 
  status = CommandLineParseArgumentsA(args->argc, args->argv, rdpsnd_pulse_args, flags, pulse,
                                      NULL, NULL);
 
  if (status < 0)
    return ERROR_INVALID_DATA;
 
  arg = rdpsnd_pulse_args;
 
  do
  {
    if (!(arg->Flags & COMMAND_LINE_VALUE_PRESENT))
      continue;
 
    CommandLineSwitchStart(arg) CommandLineSwitchCase(arg, "dev")
    {
      pulse->device_name = _strdup(arg->Value);
 
      if (!pulse->device_name)
        return ERROR_OUTOFMEMORY;
    }
    CommandLineSwitchCase(arg, "reconnect_delay_seconds")
    {
      unsigned long val = strtoul(arg->Value, NULL, 0);
 
      if ((errno != 0) || (val > INT32_MAX))
        return ERROR_INVALID_DATA;
 
      pulse->reconnect_delay_seconds = (time_t)val;
    }
    CommandLineSwitchEnd(arg)
  } while ((arg = CommandLineFindNextArgumentA(arg)) != NULL);
 
  return CHANNEL_RC_OK;
}
 
FREERDP_ENTRY_POINT(UINT VCAPITYPE pulse_freerdp_rdpsnd_client_subsystem_entry(
    PFREERDP_RDPSND_DEVICE_ENTRY_POINTS pEntryPoints))
{
  const ADDIN_ARGV* args = NULL;
  rdpsndPulsePlugin* pulse = NULL;
  UINT ret = 0;
 
  WINPR_ASSERT(pEntryPoints);
 
  pulse = (rdpsndPulsePlugin*)calloc(1, sizeof(rdpsndPulsePlugin));
 
  if (!pulse)
    return CHANNEL_RC_NO_MEMORY;
 
  pulse->device.Open = rdpsnd_pulse_open;
  pulse->device.FormatSupported = rdpsnd_pulse_format_supported;
  pulse->device.GetVolume = rdpsnd_pulse_get_volume;
  pulse->device.SetVolume = rdpsnd_pulse_set_volume;
  pulse->device.Play = rdpsnd_pulse_play;
  pulse->device.Close = rdpsnd_pulse_close;
  pulse->device.Free = rdpsnd_pulse_free;
  pulse->device.DefaultFormat = rdpsnd_pulse_default_format;
  args = pEntryPoints->args;
 
  if (args->argc > 1)
  {
    ret = rdpsnd_pulse_parse_addin_args(&pulse->device, args);
 
    if (ret != CHANNEL_RC_OK)
    {
      WLog_ERR(TAG, "error parsing arguments");
      goto error;
    }
  }
  pulse->reconnect_delay_seconds = 5;
  pulse->reconnect_time = time(NULL);
 
  ret = CHANNEL_RC_NO_MEMORY;
  pulse->mainloop = pa_threaded_mainloop_new();
 
  if (!pulse->mainloop)
    goto error;
 
  pa_threaded_mainloop_lock(pulse->mainloop);
 
  if (pa_threaded_mainloop_start(pulse->mainloop) < 0)
  {
    pa_threaded_mainloop_unlock(pulse->mainloop);
    goto error;
  }
 
  pa_threaded_mainloop_unlock(pulse->mainloop);
 
  if (!rdpsnd_pulse_context_connect((rdpsndDevicePlugin*)pulse))
    goto error;
 
  pEntryPoints->pRegisterRdpsndDevice(pEntryPoints->rdpsnd, (rdpsndDevicePlugin*)pulse);
  return CHANNEL_RC_OK;
error:
  rdpsnd_pulse_free((rdpsndDevicePlugin*)pulse);
  return ret;
}