FreeRDP
tsmf_alsa.c
1 
20 #include <freerdp/config.h>
21 
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 
27 #include <winpr/crt.h>
28 
29 #include <alsa/asoundlib.h>
30 
31 #include <freerdp/types.h>
32 #include <freerdp/codec/dsp.h>
33 
34 #include "tsmf_audio.h"
35 
36 typedef struct
37 {
38  ITSMFAudioDevice iface;
39 
40  char device[32];
41  snd_pcm_t* out_handle;
42  UINT32 source_rate;
43  UINT32 actual_rate;
44  UINT32 source_channels;
45  UINT32 actual_channels;
46  UINT32 bytes_per_sample;
47 } TSMFAlsaAudioDevice;
48 
49 static BOOL tsmf_alsa_open_device(TSMFAlsaAudioDevice* alsa)
50 {
51  int error = 0;
52  error = snd_pcm_open(&alsa->out_handle, alsa->device, SND_PCM_STREAM_PLAYBACK, 0);
53 
54  if (error < 0)
55  {
56  WLog_ERR(TAG, "failed to open device %s", alsa->device);
57  return FALSE;
58  }
59 
60  DEBUG_TSMF("open device %s", alsa->device);
61  return TRUE;
62 }
63 
64 static BOOL tsmf_alsa_open(ITSMFAudioDevice* audio, const char* device)
65 {
66  TSMFAlsaAudioDevice* alsa = (TSMFAlsaAudioDevice*)audio;
67 
68  if (!device)
69  {
70  strncpy(alsa->device, "default", sizeof(alsa->device));
71  }
72  else
73  {
74  strncpy(alsa->device, device, sizeof(alsa->device) - 1);
75  }
76 
77  return tsmf_alsa_open_device(alsa);
78 }
79 
80 static BOOL tsmf_alsa_set_format(ITSMFAudioDevice* audio, UINT32 sample_rate, UINT32 channels,
81  UINT32 bits_per_sample)
82 {
83  int error = 0;
84  snd_pcm_uframes_t frames = 0;
85  snd_pcm_hw_params_t* hw_params = NULL;
86  snd_pcm_sw_params_t* sw_params = NULL;
87  TSMFAlsaAudioDevice* alsa = (TSMFAlsaAudioDevice*)audio;
88 
89  if (!alsa->out_handle)
90  return FALSE;
91 
92  snd_pcm_drop(alsa->out_handle);
93  alsa->actual_rate = alsa->source_rate = sample_rate;
94  alsa->actual_channels = alsa->source_channels = channels;
95  alsa->bytes_per_sample = bits_per_sample / 8;
96  error = snd_pcm_hw_params_malloc(&hw_params);
97 
98  if (error < 0)
99  {
100  WLog_ERR(TAG, "snd_pcm_hw_params_malloc failed");
101  return FALSE;
102  }
103 
104  snd_pcm_hw_params_any(alsa->out_handle, hw_params);
105  snd_pcm_hw_params_set_access(alsa->out_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
106  snd_pcm_hw_params_set_format(alsa->out_handle, hw_params, SND_PCM_FORMAT_S16_LE);
107  snd_pcm_hw_params_set_rate_near(alsa->out_handle, hw_params, &alsa->actual_rate, NULL);
108  snd_pcm_hw_params_set_channels_near(alsa->out_handle, hw_params, &alsa->actual_channels);
109  frames = sample_rate;
110  snd_pcm_hw_params_set_buffer_size_near(alsa->out_handle, hw_params, &frames);
111  snd_pcm_hw_params(alsa->out_handle, hw_params);
112  snd_pcm_hw_params_free(hw_params);
113  error = snd_pcm_sw_params_malloc(&sw_params);
114 
115  if (error < 0)
116  {
117  WLog_ERR(TAG, "snd_pcm_sw_params_malloc");
118  return FALSE;
119  }
120 
121  snd_pcm_sw_params_current(alsa->out_handle, sw_params);
122  snd_pcm_sw_params_set_start_threshold(alsa->out_handle, sw_params, frames / 2);
123  snd_pcm_sw_params(alsa->out_handle, sw_params);
124  snd_pcm_sw_params_free(sw_params);
125  snd_pcm_prepare(alsa->out_handle);
126  DEBUG_TSMF("sample_rate %" PRIu32 " channels %" PRIu32 " bits_per_sample %" PRIu32 "",
127  sample_rate, channels, bits_per_sample);
128  DEBUG_TSMF("hardware buffer %lu frames", frames);
129 
130  if ((alsa->actual_rate != alsa->source_rate) ||
131  (alsa->actual_channels != alsa->source_channels))
132  {
133  DEBUG_TSMF("actual rate %" PRIu32 " / channel %" PRIu32 " is different "
134  "from source rate %" PRIu32 " / channel %" PRIu32 ", resampling required.",
135  alsa->actual_rate, alsa->actual_channels, alsa->source_rate,
136  alsa->source_channels);
137  }
138 
139  return TRUE;
140 }
141 
142 static BOOL tsmf_alsa_play(ITSMFAudioDevice* audio, const BYTE* src, UINT32 data_size)
143 {
144  const BYTE* pindex = NULL;
145  TSMFAlsaAudioDevice* alsa = (TSMFAlsaAudioDevice*)audio;
146  DEBUG_TSMF("data_size %" PRIu32 "", data_size);
147 
148  if (alsa->out_handle)
149  {
150  const size_t rbytes_per_frame = 1ULL * alsa->actual_channels * alsa->bytes_per_sample;
151  pindex = src;
152  const BYTE* end = pindex + data_size;
153 
154  while (pindex < end)
155  {
156  const size_t len = (size_t)(end - pindex);
157  const size_t frames = len / rbytes_per_frame;
158  snd_pcm_sframes_t error = snd_pcm_writei(alsa->out_handle, pindex, frames);
159 
160  if (error == -EPIPE)
161  {
162  snd_pcm_recover(alsa->out_handle, -EPIPE, 0);
163  error = 0;
164  }
165  else if (error < 0)
166  {
167  DEBUG_TSMF("error len %ld", error);
168  snd_pcm_close(alsa->out_handle);
169  alsa->out_handle = 0;
170  tsmf_alsa_open_device(alsa);
171  break;
172  }
173 
174  DEBUG_TSMF("%d frames played.", error);
175 
176  if (error == 0)
177  break;
178 
179  pindex += (size_t)error * rbytes_per_frame;
180  }
181  }
182 
183  return TRUE;
184 }
185 
186 static UINT64 tsmf_alsa_get_latency(ITSMFAudioDevice* audio)
187 {
188  UINT64 latency = 0;
189  snd_pcm_sframes_t frames = 0;
190  TSMFAlsaAudioDevice* alsa = (TSMFAlsaAudioDevice*)audio;
191 
192  if (alsa->out_handle && alsa->actual_rate > 0 &&
193  snd_pcm_delay(alsa->out_handle, &frames) == 0 && frames > 0)
194  {
195  latency = ((UINT64)frames) * 10000000LL / (UINT64)alsa->actual_rate;
196  }
197 
198  return latency;
199 }
200 
201 static BOOL tsmf_alsa_flush(ITSMFAudioDevice* audio)
202 {
203  return TRUE;
204 }
205 
206 static void tsmf_alsa_free(ITSMFAudioDevice* audio)
207 {
208  TSMFAlsaAudioDevice* alsa = (TSMFAlsaAudioDevice*)audio;
209  DEBUG_TSMF("");
210 
211  if (alsa->out_handle)
212  {
213  snd_pcm_drain(alsa->out_handle);
214  snd_pcm_close(alsa->out_handle);
215  }
216 
217  free(alsa);
218 }
219 
220 FREERDP_ENTRY_POINT(UINT VCAPITYPE alsa_freerdp_tsmf_client_audio_subsystem_entry(void* ptr))
221 {
222  ITSMFAudioDevice** sptr = (ITSMFAudioDevice**)ptr;
223  WINPR_ASSERT(sptr);
224  *sptr = NULL;
225 
226  TSMFAlsaAudioDevice* alsa = calloc(1, sizeof(TSMFAlsaAudioDevice));
227  if (!alsa)
228  return ERROR_OUTOFMEMORY;
229 
230  alsa->iface.Open = tsmf_alsa_open;
231  alsa->iface.SetFormat = tsmf_alsa_set_format;
232  alsa->iface.Play = tsmf_alsa_play;
233  alsa->iface.GetLatency = tsmf_alsa_get_latency;
234  alsa->iface.Flush = tsmf_alsa_flush;
235  alsa->iface.Free = tsmf_alsa_free;
236  *sptr = &alsa->iface;
237  return CHANNEL_RC_OK;
238 }