git ssb

0+

cel / foostudio



Commit e03a630124fa47eb03d508fcfd576f8ebe4f28f1

Browse Files

Playback MVP

Charles Lehner committed on 10/15/2016, 12:25:57 AM
Parent: fdc9644582b3e2b875598b772c5bdda6c74ef9e5

Files changed

Makefilechanged
studio.cchanged
tune.cchanged
tune.hchanged
README.mdadded
MakefileView
@@ -1,14 +1,16 @@
1-CFLAGS = -std=c99 -fPIC
2-LDLIBS = -ldl -lm
1 …+CFLAGS = -std=c99
2 …+LIB_CFLAGS = -fPIC
3 …+LDLIBS = -ldl -lasound -lm
4 …+LIB_LDLIBS = -lm
35 …
46 … all: studio tune.so
57 …
68 … studio: studio.c tune.h
79 … $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $< $(LDLIBS)
810 …
911 … tune.so : tune.c tune.h
10- $(CC) $(CFLAGS) -shared $(LDFLAGS) -o $@ $< $(LDLIBS)
12 …+ $(CC) $(LIB_CFLAGS) -shared $(LDFLAGS) -o $@ $< $(LIB_LDLIBS)
1113 …
1214 … clean:
1315 … $(RM) *.o *.so studio
1416 …
studio.cView
@@ -1,7 +1,9 @@
11 … #define _DEFAULT_SOURCE
2 …+#include <alsa/asoundlib.h>
23 … #include <dlfcn.h>
34 … #include <err.h>
5 …+#include <math.h>
46 … #include <stdbool.h>
57 … #include <stdio.h>
68 … #include <sys/stat.h>
79 … #include <sys/types.h>
@@ -13,8 +15,14 @@
1315 … ino_t inode;
1416 … struct tune *tune;
1517 … };
1618 …
19 …+static unsigned int rate = 44100;
20 …+static unsigned int channels = 1;
21 …+static unsigned int latency = 500000; /* ring buffer length in us */
22 …+static snd_pcm_format_t format = SND_PCM_FORMAT_FLOAT;
23 …+static const char *dl_fname = "./tune.so";
24 …+
1725 … static int tune_dl_load(struct tune_dl *dl, const char *libfname)
1826 … {
1927 … struct stat st;
2028 … if (stat(libfname, &st) < 0) {
@@ -47,29 +55,231 @@
4755 … }
4856 … return 0;
4957 … }
5058 …
59 …+/*
60 …+ * Underrun and suspend recovery, from alsa-lib/test/pcm.c
61 …+ */
62 …+
63 …+static int xrun_recovery(snd_pcm_t *handle, int err)
64 …+{
65 …+ if (err == -EPIPE) { /* under-run */
66 …+ err = snd_pcm_prepare(handle);
67 …+ if (err < 0)
68 …+ warnx("Can't recovery from underrun, prepare failed: %s", snd_strerror(err));
69 …+ return 0;
70 …+ } else if (err == -ESTRPIPE) {
71 …+ while ((err = snd_pcm_resume(handle)) == -EAGAIN)
72 …+ sleep(1); /* wait until the suspend flag is released */
73 …+ if (err < 0) {
74 …+ err = snd_pcm_prepare(handle);
75 …+ if (err < 0)
76 …+ warnx("Can't recovery from suspend, prepare failed: %s", snd_strerror(err));
77 …+ }
78 …+ return 0;
79 …+ }
80 …+ return err;
81 …+}
82 …+
83 …+static void generate(struct tune_dl *dl,
84 …+ const snd_pcm_channel_area_t *areas,
85 …+ snd_pcm_uframes_t offset,
86 …+ int count, double *_phase)
87 …+{
88 …+ double phase = *_phase;
89 …+ double step = 2. * M_PI/(double)rate;
90 …+ unsigned char *samples[channels];
91 …+ int steps[channels];
92 …+ unsigned int chn;
93 …+ int format_bits = snd_pcm_format_width(format);
94 …+ unsigned int maxval = (1 << (format_bits - 1)) - 1;
95 …+ int bps = format_bits / 8; /* bytes per sample */
96 …+ int phys_bps = snd_pcm_format_physical_width(format) / 8;
97 …+ int big_endian = snd_pcm_format_big_endian(format) == 1;
98 …+ int to_unsigned = snd_pcm_format_unsigned(format) == 1;
99 …+ int is_float = (
100 …+ format == SND_PCM_FORMAT_FLOAT_LE ||
101 …+ format == SND_PCM_FORMAT_FLOAT_BE ||
102 …+ format == SND_PCM_FORMAT_FLOAT64_LE ||
103 …+ format == SND_PCM_FORMAT_FLOAT64_BE);
104 …+
105 …+ /* verify and prepare the contents of areas */
106 …+ for (chn = 0; chn < channels; chn++) {
107 …+ if ((areas[chn].first % 8) != 0) {
108 …+ errx(1, "areas[%i].first == %i, aborting...", chn, areas[chn].first);
109 …+ }
110 …+ samples[chn] = /*(signed short *)*/(((unsigned char *)areas[chn].addr) + (areas[chn].first / 8));
111 …+ if ((areas[chn].step % 16) != 0) {
112 …+ errx(1, "areas[%i].step == %i, aborting...", chn, areas[chn].step);
113 …+ }
114 …+ steps[chn] = areas[chn].step / 8;
115 …+ samples[chn] += offset * steps[chn];
116 …+ }
117 …+
118 …+ tune_dl_load(dl, dl_fname);
119 …+
120 …+ /* fill the channel areas */
121 …+ while (count-- > 0) {
122 …+ union {
123 …+ float f;
124 …+ int i;
125 …+ } fval;
126 …+ int res, i;
127 …+ if (is_float) {
128 …+ if (dl->handle && dl->tune->play) {
129 …+ fval.f = dl->tune->play(dl->tune, phase);
130 …+ } else {
131 …+ // val.f = sin(phase);
132 …+ fval.f = 0;
133 …+ }
134 …+ res = fval.i;
135 …+ } else
136 …+ res = sin(phase) * maxval;
137 …+ if (to_unsigned)
138 …+ res ^= 1U << (format_bits - 1);
139 …+ for (chn = 0; chn < channels; chn++) {
140 …+ /* Generate data in native endian format */
141 …+ if (big_endian) {
142 …+ for (i = 0; i < bps; i++)
143 …+ *(samples[chn] + phys_bps - 1 - i) = (res >> i * 8) & 0xff;
144 …+ } else {
145 …+ for (i = 0; i < bps; i++)
146 …+ *(samples[chn] + i) = (res >> i * 8) & 0xff;
147 …+ }
148 …+ samples[chn] += steps[chn];
149 …+ }
150 …+ phase += step;
151 …+ /*
152 …+ if (phase >= max_phase)
153 …+ phase -= max_phase;
154 …+ */
155 …+ }
156 …+ *_phase = phase;
157 …+}
158 …+
159 …+
51160 … int main(int argc, char *argv[])
52161 … {
53162 … struct tune_dl dl = {0};
54- const char *fname = "./tune.so";
55- if (tune_dl_load(&dl, fname) < 0) {
163 …+ int err;
164 …+ snd_pcm_t *pcm_out;
165 …+ const char *device_out = "default";
166 …+
167 …+ if (argc > 2) {
168 …+ device_out = argv[2];
169 …+ }
170 …+
171 …+ if (tune_dl_load(&dl, dl_fname) < 0) {
56172 … return 1;
57173 … }
174 …+
175 …+ if ((err = snd_pcm_open(&pcm_out, device_out, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
176 …+ warnx("Playback open error: %s", snd_strerror(err));
177 …+ return 1;
178 …+ }
179 …+
180 …+ if ((err = snd_pcm_set_params(pcm_out,
181 …+ format,
182 …+ SND_PCM_ACCESS_MMAP_INTERLEAVED,
183 …+ channels,
184 …+ rate,
185 …+ 1,
186 …+ latency)) < 0) {
187 …+ warnx("Playback open error: %s", snd_strerror(err));
188 …+ return 1;
189 …+ }
190 …+
58191 … if (dl.tune->init) {
59192 … dl.tune->init(dl.tune);
60193 … }
61- int t = 0;
194 …+
195 …+ snd_pcm_uframes_t buffer_size;
196 …+ snd_pcm_uframes_t period_size;
197 …+ if ((err = snd_pcm_get_params(pcm_out, &buffer_size, &period_size)) < 0) {
198 …+ warnx("Playback get params error: %s", snd_strerror(err));
199 …+ return 1;
200 …+ }
201 …+
202 …+ double phase = 0;
203 …+ const snd_pcm_channel_area_t *my_areas;
204 …+ snd_pcm_uframes_t offset, frames, size;
205 …+ snd_pcm_sframes_t avail, commitres;
206 …+ snd_pcm_state_t state;
207 …+ int first = 1;
208 …+
62209 … while (1) {
63- (void) tune_dl_load(&dl, fname);
64- if (dl.handle && dl.tune->play) {
65- double sample = dl.tune->play(dl.tune, t);
66- printf("%d %f\n", t, sample);
210 …+ state = snd_pcm_state(pcm_out);
211 …+ if (state == SND_PCM_STATE_XRUN) {
212 …+ err = xrun_recovery(pcm_out, -EPIPE);
213 …+ if (err < 0) {
214 …+ printf("XRUN recovery failed: %s\n", snd_strerror(err));
215 …+ return err;
216 …+ }
217 …+ first = 1;
218 …+ } else if (state == SND_PCM_STATE_SUSPENDED) {
219 …+ err = xrun_recovery(pcm_out, -ESTRPIPE);
220 …+ if (err < 0) {
221 …+ printf("SUSPEND recovery failed: %s\n", snd_strerror(err));
222 …+ return err;
223 …+ }
67224 … }
68- (void) tune_dl_load(&dl, fname);
69- usleep(100000);
70- t++;
225 …+ avail = snd_pcm_avail_update(pcm_out);
226 …+ if (avail < 0) {
227 …+ err = xrun_recovery(pcm_out, avail);
228 …+ if (err < 0) {
229 …+ printf("avail update failed: %s\n", snd_strerror(err));
230 …+ return err;
231 …+ }
232 …+ first = 1;
233 …+ continue;
234 …+ }
235 …+ if (avail < period_size) {
236 …+ if (first) {
237 …+ first = 0;
238 …+ err = snd_pcm_start(pcm_out);
239 …+ if (err < 0) {
240 …+ printf("Start error: %s\n", snd_strerror(err));
241 …+ exit(EXIT_FAILURE);
242 …+ }
243 …+ } else {
244 …+ err = snd_pcm_wait(pcm_out, -1);
245 …+ if (err < 0) {
246 …+ if ((err = xrun_recovery(pcm_out, err)) < 0) {
247 …+ printf("snd_pcm_wait error: %s\n", snd_strerror(err));
248 …+ exit(EXIT_FAILURE);
249 …+ }
250 …+ first = 1;
251 …+ }
252 …+ }
253 …+ continue;
254 …+ }
255 …+ size = period_size;
256 …+ while (size > 0) {
257 …+ frames = size;
258 …+ err = snd_pcm_mmap_begin(pcm_out, &my_areas, &offset, &frames);
259 …+ if (err < 0) {
260 …+ if ((err = xrun_recovery(pcm_out, err)) < 0) {
261 …+ printf("MMAP begin avail error: %s\n", snd_strerror(err));
262 …+ exit(EXIT_FAILURE);
263 …+ }
264 …+ first = 1;
265 …+ }
266 …+ generate(&dl, my_areas, offset, frames, &phase);
267 …+ // generate_sine(my_areas, offset, frames, &phase);
268 …+ commitres = snd_pcm_mmap_commit(pcm_out, offset, frames);
269 …+ if (commitres < 0 || (snd_pcm_uframes_t)commitres != frames) {
270 …+ if ((err = xrun_recovery(pcm_out, commitres >= 0 ? -EPIPE : commitres)) < 0) {
271 …+ printf("MMAP commit error: %s\n", snd_strerror(err));
272 …+ exit(EXIT_FAILURE);
273 …+ }
274 …+ first = 1;
275 …+ }
276 …+ size -= frames;
277 …+ }
278 …+
71279 … }
72280 … if (dl.tune->deinit) {
73281 … dl.tune->deinit(dl.tune);
74282 … }
283 …+
284 …+ snd_pcm_close(pcm_out);
75285 … }
tune.cView
@@ -8,11 +8,11 @@
88 … static void tune_reload(struct tune *tune)
99 … {
1010 … }
1111 …
12-static double tune_play(struct tune *tune, int time)
12 …+static float tune_play(struct tune *tune, double time)
1313 … {
14- return sin(time);
14 …+ return 0.99 * sin(time*440);
1515 … }
1616 …
1717 … static void tune_deinit(struct tune *tune)
1818 … {
tune.hView
@@ -3,8 +3,8 @@
33 … struct tune {
44 … void (*init)(struct tune *);
55 … void (*deinit)(struct tune *);
66 … void (*reload)(struct tune *);
7- double (*play)(struct tune *, int time);
7 …+ float (*play)(struct tune *, double time);
88 … };
99 …
1010 … extern const struct tune TUNE;
README.mdView
@@ -1,0 +1,3 @@
1 …+http://nullprogram.com/blog/2014/12/23/
2 …+http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
3 …+/home/cel/src/alsa-lib/test/pcm_min.c

Built with git-ssb-web