summaryrefslogtreecommitdiffstats
path: root/plugins/alsa/alsa-core-pcm.c
blob: ad8e842bc76d5f706ae1b581e05bb1974e1710f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
/*
 * Copyright(C) 2018 "IoT.bzh"
 * Author Fulup Ar Foll <fulup@iot.bzh>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http : //www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License

for the specific language governing permissions and
 * limitations under the License.
 *
 * reference :
 * https://github.com/zonque/simple-alsa-loop/blob/master/loop.c
 * https://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html#a31
 *
 */

#define _GNU_SOURCE  // needed for vasprintf

#include "alsa-softmixer.h"
#include <pthread.h>
#include <sys/syscall.h>
#include <sched.h>

STATIC int AlsaPeriodSize(snd_pcm_format_t pcmFormat) {
    int pcmSampleSize;

    switch (pcmFormat) {

        case SND_PCM_FORMAT_S8:
        case SND_PCM_FORMAT_U8:
            pcmSampleSize = 1;
            break;

        case SND_PCM_FORMAT_U16_LE:
        case SND_PCM_FORMAT_U16_BE:
        case SND_PCM_FORMAT_S16_LE:
        case SND_PCM_FORMAT_S16_BE:
            pcmSampleSize = 2;
            break;

        case SND_PCM_FORMAT_U32_LE:
        case SND_PCM_FORMAT_U32_BE:
        case SND_PCM_FORMAT_S32_LE:
        case SND_PCM_FORMAT_S32_BE:
            pcmSampleSize = 4;
            break;

        default:
            pcmSampleSize = 0;
    }

    return pcmSampleSize;
}

PUBLIC int AlsaPcmConf(CtlSourceT *source, AlsaPcmInfoT *pcm, AlsaPcmHwInfoT *opts) {
    char string[32];
    int error;
    snd_pcm_hw_params_t *pxmHwParams;
    snd_pcm_sw_params_t *pxmSwParams;

    // retrieve hadware config from PCM
    snd_pcm_hw_params_alloca(&pxmHwParams);
    snd_pcm_hw_params_any(pcm->handle, pxmHwParams);

    if (!opts->access) opts->access = SND_PCM_ACCESS_RW_INTERLEAVED;
    error = snd_pcm_hw_params_set_access(pcm->handle, pxmHwParams, opts->access);
    if (error) {
        AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s Set_Interleave=%d mode error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), opts->access, snd_strerror(error));
        goto OnErrorExit;
    };

    if (opts->format != SND_PCM_FORMAT_UNKNOWN) {
        if ((error = snd_pcm_hw_params_set_format(pcm->handle, pxmHwParams, opts->format)) < 0) {
            AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s Set_Format=%d error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), opts->format, snd_strerror(error));
            AlsaDumpFormats(source, pcm->handle);
            goto OnErrorExit;
        }
    }

    if (opts->rate > 0) {
        unsigned int pcmRate = opts->rate;
        if ((error = snd_pcm_hw_params_set_rate_near(pcm->handle, pxmHwParams, &opts->rate, 0)) < 0) {
            AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s Set_Rate=%d error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), opts->rate, snd_strerror(error));
            goto OnErrorExit;
        }

        // check we got requested rate
        if (opts->rate != pcmRate) {
            AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s Set_Rate ask=%dHz get=%dHz", pcm->uid, ALSA_PCM_UID(pcm->handle, string), pcmRate, opts->rate);
            goto OnErrorExit;
        }
    }

    if (opts->channels) {
        if ((error = snd_pcm_hw_params_set_channels(pcm->handle, pxmHwParams, opts->channels)) < 0) {
            AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s Set_Channels=%d error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), opts->channels, snd_strerror(error));
            goto OnErrorExit;
        };
    }

    // store selected values
    if ((error = snd_pcm_hw_params(pcm->handle, pxmHwParams)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s apply hwparams error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), snd_strerror(error));
        goto OnErrorExit;
    }

    // check we effective hw params after optional format change
    snd_pcm_hw_params_get_channels(pxmHwParams, &opts->channels);
    snd_pcm_hw_params_get_format(pxmHwParams, &opts->format);
    snd_pcm_hw_params_get_rate(pxmHwParams, &opts->rate, 0);
    opts->sampleSize = AlsaPeriodSize(opts->format);
    if (opts->sampleSize == 0) {
        AFB_ApiError(source->api, "AlsaPcmConf:%s Fail PCM=%s unsupported format format=%d", pcm->uid, ALSA_PCM_UID(pcm->handle, string), opts->format);
        goto OnErrorExit;
    }

    // retrieve software config from PCM
    snd_pcm_sw_params_alloca(&pxmSwParams);
    snd_pcm_sw_params_current(pcm->handle, pxmSwParams);

    if ((error = snd_pcm_sw_params_set_avail_min(pcm->handle, pxmSwParams, 16)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmConf:%s Fail to PCM=%s set_buffersize error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };

    // push software params into PCM
    if ((error = snd_pcm_sw_params(pcm->handle, pxmSwParams)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmConf:%s Fail to push software=%s params error=%s", pcm->uid, ALSA_PCM_UID(pcm->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };

    AFB_ApiNotice(source->api, "AlsaPcmConf:%s PCM=%s channels=%d rate=%d format=%d access=%d done", pcm->uid, ALSA_PCM_UID(pcm->handle,string), opts->channels, opts->rate, opts->format, opts->access);
    return 0;

OnErrorExit:
    return -1;
}

STATIC int AlsaPcmReadCB(sd_event_source* src, int fd, uint32_t revents, void* userData) {
    char string[32];
    int error;
    snd_pcm_sframes_t framesIn, framesOut, availIn, availOut;
    AlsaPcmCopyHandleT *pcmCopyHandle = (AlsaPcmCopyHandleT*) userData;

    // PCM has was closed
    if ((revents & EPOLLHUP) != 0) {
        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s hanghup/disconnected", ALSA_PCM_UID(pcmCopyHandle->pcmIn, string));
        goto ExitOnSuccess;
    }

    // ignore any non input events
    if ((revents & EPOLLIN) == 0) {
        goto ExitOnSuccess;
    }

    // retrieve PCM state
    snd_pcm_state_t pcmState = snd_pcm_state(pcmCopyHandle->pcmIn);
    
    // When pause flush remaining frame and wait
    if (pcmState == SND_PCM_STATE_PAUSED) {
        framesIn = snd_pcm_readi(pcmCopyHandle->pcmIn, pcmCopyHandle->buffer, pcmCopyHandle->frameCount);
        AFB_ApiInfo(pcmCopyHandle->api, "AlsaPcmReadCB: paused frame:%ld ignored", framesIn);
        goto ExitOnSuccess;
    }

    // When XRNS append try to restore PCM
    if (pcmState == SND_PCM_STATE_XRUN) {
        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s XRUN", ALSA_PCM_UID(pcmCopyHandle->pcmIn, string));
        snd_pcm_prepare(pcmCopyHandle->pcmIn);
    }

    // when PCM suspending loop until ready to go
    if (pcmState == SND_PCM_STATE_SUSPENDED) {
        while (1) {
            if ((error = snd_pcm_resume(pcmCopyHandle->pcmIn)) < 0) {
                AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s SUSPENDED fail to resume", ALSA_PCM_UID(pcmCopyHandle->pcmIn, string));
                sleep(1); // Fulup should be replace with corresponding AFB_timer
            } else {
                AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s SUSPENDED success to resume", ALSA_PCM_UID(pcmCopyHandle->pcmIn, string));
            }
        }
    }

    // do we have waiting frame
    availIn = snd_pcm_avail_update(pcmCopyHandle->pcmIn);
    if (availIn <= 0) {
        goto ExitOnSuccess;
    }

    // do we have space to push frame
    availOut = snd_pcm_avail_update(pcmCopyHandle->pcmOut);
    if (availOut <= 0) {
        snd_pcm_prepare(pcmCopyHandle->pcmOut);
        goto ExitOnSuccess;
    }

    // make sure we can push all input frame into output pcm without locking
    if (availOut < availIn) availIn = availOut;

    // we get too many data ignore some
    if (availIn > pcmCopyHandle->frameCount) {
        availIn = pcmCopyHandle->frameCount;
    }

    // effectively read pcmIn and push frame to pcmOut
    framesIn = snd_pcm_readi(pcmCopyHandle->pcmIn, pcmCopyHandle->buffer, availIn);
    if (framesIn < 0 || framesIn != availIn) {
        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PcmIn=%s UNDERUN frame=%ld", ALSA_PCM_UID(pcmCopyHandle->pcmIn, string), framesIn);
        goto ExitOnSuccess;
    }

    // In/Out frames transfer through buffer copy
    framesOut = snd_pcm_writei(pcmCopyHandle->pcmOut, pcmCopyHandle->buffer, framesIn);
    if (framesOut < 0 || framesOut != framesIn) {
        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PcmOut=%s UNDERUN frame=%ld", ALSA_PCM_UID(pcmCopyHandle->pcmOut, string), (framesIn - framesOut));
        goto ExitOnSuccess;
    }

    if (framesIn != framesOut) {
        AFB_ApiNotice(pcmCopyHandle->api, "AlsaPcmReadCB PCM=%s Loosing frames=%ld", ALSA_PCM_UID(pcmCopyHandle->pcmOut, string), (framesIn - framesOut));
        goto ExitOnSuccess;
    }
    
    return 0;

    // Cannot handle error in callback
ExitOnSuccess:
    return 0;
}

static void *LoopInThread(void *handle) {
    AlsaPcmCopyHandleT *pcmCopyHandle = (AlsaPcmCopyHandleT*) handle;
    int count = 0;
    int watchdog = MAINLOOP_WATCHDOG * 1000;
    pcmCopyHandle->tid = (int) syscall(SYS_gettid);

    AFB_ApiNotice(pcmCopyHandle->api, "LoopInThread:%s/%d Started", pcmCopyHandle->info, pcmCopyHandle->tid);


    /* loop until end */
    for (;;) {
        int res = sd_event_run(pcmCopyHandle->sdLoop, watchdog);
        if (res == 0) {
            AFB_ApiInfo(pcmCopyHandle->api, "LoopInThread:%s/%d Idle count=%d", pcmCopyHandle->info, pcmCopyHandle->tid, count++);
            continue;
        }
        if (res < 0) {
            AFB_ApiError(pcmCopyHandle->api, "LoopInThread:%s/%d ERROR=%i Exit errno=%s.\n", pcmCopyHandle->info, pcmCopyHandle->tid, res, strerror(res));
            break;
        }
    }
    pthread_exit(0);
}

PUBLIC int AlsaPcmCopy(CtlSourceT *source, AlsaLoopStreamT *loopStream, AlsaPcmInfoT *pcmIn, AlsaPcmInfoT *pcmOut, AlsaPcmHwInfoT * opts) {
    char string[32];
    struct pollfd *pcmInFds; 
    int error;

    // input and output should match
    error = AlsaPcmConf(source, pcmOut, opts);
    if (error) goto OnErrorExit;

    // Prepare PCM for usage
    if ((error = snd_pcm_prepare(pcmOut->handle)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmCopy: Fail to prepare PCM=%s error=%s", ALSA_PCM_UID(pcmOut->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };

    // prepare PCM for capture and replay
    error = AlsaPcmConf(source, pcmIn, opts);
    if (error) goto OnErrorExit;

    // Prepare PCM for usage
    if ((error = snd_pcm_start(pcmIn->handle)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmCopy: Fail to prepare PCM=%s error=%s", ALSA_PCM_UID(pcmIn->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };
    
    AlsaPcmCopyHandleT *pcmCopyHandle = &loopStream->copy;
    pcmCopyHandle->info = "pcmCpy";
    pcmCopyHandle->pcmIn = pcmIn->handle;
    pcmCopyHandle->pcmOut = pcmOut->handle;
    pcmCopyHandle->api = source->api;
    pcmCopyHandle->channels = opts->channels;
    pcmCopyHandle->frameSize = opts->channels * opts->sampleSize;
    pcmCopyHandle->frameCount = ALSA_BUFFER_FRAMES_COUNT;
    pcmCopyHandle->buffer = malloc(pcmCopyHandle->frameCount * pcmCopyHandle->frameSize);
    

    // get FD poll descriptor for capture PCM
    int pcmInCount = snd_pcm_poll_descriptors_count(pcmCopyHandle->pcmIn);
    if (pcmInCount <= 0) {
        AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s get fds count error=%s", ALSA_PCM_UID(pcmIn->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };

    pcmInFds = alloca(sizeof (*pcmInFds) * pcmInCount);
    if ((error = snd_pcm_poll_descriptors(pcmIn->handle, pcmInFds, pcmInCount)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s get pollfds error=%s", ALSA_PCM_UID(pcmOut->handle, string), snd_strerror(error));
        goto OnErrorExit;
    };

    // add poll descriptor to AGL systemd mainloop
    if ((error = sd_event_new(&pcmCopyHandle->sdLoop)) < 0) {
        fprintf(stderr, "LaunchCallRequest: fail pcmin=%s creating a new loop: %s\n", ALSA_PCM_UID(pcmOut->handle, string), strerror(error));
        goto OnErrorExit;
    }

    for (int idx = 0; idx < pcmInCount; idx++) {
        if ((error = sd_event_add_io(pcmCopyHandle->sdLoop, &pcmCopyHandle->evtsrc, pcmInFds[idx].fd, EPOLLIN, AlsaPcmReadCB, pcmCopyHandle)) < 0) {
            AFB_ApiError(source->api, "AlsaPcmCopy: Fail pcmIn=%s sd_event_add_io err=%d", ALSA_PCM_UID(pcmIn->handle, string), error);
            goto OnErrorExit;
        }
    }

    // start a thread with a mainloop to monitor Audio-Agent
    if ((error = pthread_create(&pcmCopyHandle->thread, NULL, &LoopInThread, pcmCopyHandle)) < 0) {
        AFB_ApiError(source->api, "AlsaPcmCopy: Fail create waiting thread pcmIn=%s err=%d", ALSA_PCM_UID(pcmIn->handle, string), error);
        goto OnErrorExit;
    }
    
    // request a higher priority for each audio stream thread
    struct sched_param params;
    params.sched_priority = sched_get_priority_max(SCHED_FIFO);
    error= pthread_setschedparam(pcmCopyHandle->thread, SCHED_FIFO, &params);
    if (error) {
        AFB_ApiWarning(source->api, "AlsaPcmCopy: Fail create increase stream thread priority pcmIn=%s err=%s", ALSA_PCM_UID(pcmIn->handle, string), strerror(error));        
    }

    return 0;

OnErrorExit:
    AFB_ApiError(source->api, "AlsaPcmCopy: - pcmIn=%s" , ALSA_PCM_UID(pcmIn->handle, string));
    AFB_ApiError(source->api, "AlsaPcmCopy: - pcmOut=%s", ALSA_PCM_UID(pcmOut->handle, string));
    return -1;
}