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1da177e4 LT |
1 | /* |
2 | * Rate conversion Plug-In | |
3 | * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz> | |
4 | * | |
5 | * | |
6 | * This library is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU Library General Public License as | |
8 | * published by the Free Software Foundation; either version 2 of | |
9 | * the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU Library General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU Library General Public | |
17 | * License along with this library; if not, write to the Free Software | |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <sound/driver.h> | |
23 | #include <linux/time.h> | |
24 | #include <sound/core.h> | |
25 | #include <sound/pcm.h> | |
26 | #include "pcm_plugin.h" | |
27 | ||
28 | #define SHIFT 11 | |
29 | #define BITS (1<<SHIFT) | |
30 | #define R_MASK (BITS-1) | |
31 | ||
32 | /* | |
33 | * Basic rate conversion plugin | |
34 | */ | |
35 | ||
36 | typedef struct { | |
37 | signed short last_S1; | |
38 | signed short last_S2; | |
39 | } rate_channel_t; | |
40 | ||
41 | typedef void (*rate_f)(snd_pcm_plugin_t *plugin, | |
42 | const snd_pcm_plugin_channel_t *src_channels, | |
43 | snd_pcm_plugin_channel_t *dst_channels, | |
44 | int src_frames, int dst_frames); | |
45 | ||
46 | typedef struct rate_private_data { | |
47 | unsigned int pitch; | |
48 | unsigned int pos; | |
49 | rate_f func; | |
50 | int get, put; | |
51 | snd_pcm_sframes_t old_src_frames, old_dst_frames; | |
52 | rate_channel_t channels[0]; | |
53 | } rate_t; | |
54 | ||
55 | static void rate_init(snd_pcm_plugin_t *plugin) | |
56 | { | |
57 | unsigned int channel; | |
58 | rate_t *data = (rate_t *)plugin->extra_data; | |
59 | data->pos = 0; | |
60 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
61 | data->channels[channel].last_S1 = 0; | |
62 | data->channels[channel].last_S2 = 0; | |
63 | } | |
64 | } | |
65 | ||
66 | static void resample_expand(snd_pcm_plugin_t *plugin, | |
67 | const snd_pcm_plugin_channel_t *src_channels, | |
68 | snd_pcm_plugin_channel_t *dst_channels, | |
69 | int src_frames, int dst_frames) | |
70 | { | |
71 | unsigned int pos = 0; | |
72 | signed int val; | |
73 | signed short S1, S2; | |
74 | char *src, *dst; | |
75 | unsigned int channel; | |
76 | int src_step, dst_step; | |
77 | int src_frames1, dst_frames1; | |
78 | rate_t *data = (rate_t *)plugin->extra_data; | |
79 | rate_channel_t *rchannels = data->channels; | |
80 | ||
81 | #define GET_S16_LABELS | |
82 | #define PUT_S16_LABELS | |
83 | #include "plugin_ops.h" | |
84 | #undef GET_S16_LABELS | |
85 | #undef PUT_S16_LABELS | |
86 | void *get = get_s16_labels[data->get]; | |
87 | void *put = put_s16_labels[data->put]; | |
88 | signed short sample = 0; | |
89 | ||
90 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
91 | pos = data->pos; | |
92 | S1 = rchannels->last_S1; | |
93 | S2 = rchannels->last_S2; | |
94 | if (!src_channels[channel].enabled) { | |
95 | if (dst_channels[channel].wanted) | |
96 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | |
97 | dst_channels[channel].enabled = 0; | |
98 | continue; | |
99 | } | |
100 | dst_channels[channel].enabled = 1; | |
101 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; | |
102 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; | |
103 | src_step = src_channels[channel].area.step / 8; | |
104 | dst_step = dst_channels[channel].area.step / 8; | |
105 | src_frames1 = src_frames; | |
106 | dst_frames1 = dst_frames; | |
107 | while (dst_frames1-- > 0) { | |
108 | if (pos & ~R_MASK) { | |
109 | pos &= R_MASK; | |
110 | S1 = S2; | |
111 | if (src_frames1-- > 0) { | |
112 | goto *get; | |
113 | #define GET_S16_END after_get | |
114 | #include "plugin_ops.h" | |
115 | #undef GET_S16_END | |
116 | after_get: | |
117 | S2 = sample; | |
118 | src += src_step; | |
119 | } | |
120 | } | |
121 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | |
122 | if (val < -32768) | |
123 | val = -32768; | |
124 | else if (val > 32767) | |
125 | val = 32767; | |
126 | sample = val; | |
127 | goto *put; | |
128 | #define PUT_S16_END after_put | |
129 | #include "plugin_ops.h" | |
130 | #undef PUT_S16_END | |
131 | after_put: | |
132 | dst += dst_step; | |
133 | pos += data->pitch; | |
134 | } | |
135 | rchannels->last_S1 = S1; | |
136 | rchannels->last_S2 = S2; | |
137 | rchannels++; | |
138 | } | |
139 | data->pos = pos; | |
140 | } | |
141 | ||
142 | static void resample_shrink(snd_pcm_plugin_t *plugin, | |
143 | const snd_pcm_plugin_channel_t *src_channels, | |
144 | snd_pcm_plugin_channel_t *dst_channels, | |
145 | int src_frames, int dst_frames) | |
146 | { | |
147 | unsigned int pos = 0; | |
148 | signed int val; | |
149 | signed short S1, S2; | |
150 | char *src, *dst; | |
151 | unsigned int channel; | |
152 | int src_step, dst_step; | |
153 | int src_frames1, dst_frames1; | |
154 | rate_t *data = (rate_t *)plugin->extra_data; | |
155 | rate_channel_t *rchannels = data->channels; | |
156 | ||
157 | #define GET_S16_LABELS | |
158 | #define PUT_S16_LABELS | |
159 | #include "plugin_ops.h" | |
160 | #undef GET_S16_LABELS | |
161 | #undef PUT_S16_LABELS | |
162 | void *get = get_s16_labels[data->get]; | |
163 | void *put = put_s16_labels[data->put]; | |
164 | signed short sample = 0; | |
165 | ||
166 | for (channel = 0; channel < plugin->src_format.channels; ++channel) { | |
167 | pos = data->pos; | |
168 | S1 = rchannels->last_S1; | |
169 | S2 = rchannels->last_S2; | |
170 | if (!src_channels[channel].enabled) { | |
171 | if (dst_channels[channel].wanted) | |
172 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | |
173 | dst_channels[channel].enabled = 0; | |
174 | continue; | |
175 | } | |
176 | dst_channels[channel].enabled = 1; | |
177 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; | |
178 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; | |
179 | src_step = src_channels[channel].area.step / 8; | |
180 | dst_step = dst_channels[channel].area.step / 8; | |
181 | src_frames1 = src_frames; | |
182 | dst_frames1 = dst_frames; | |
183 | while (dst_frames1 > 0) { | |
184 | S1 = S2; | |
185 | if (src_frames1-- > 0) { | |
186 | goto *get; | |
187 | #define GET_S16_END after_get | |
188 | #include "plugin_ops.h" | |
189 | #undef GET_S16_END | |
190 | after_get: | |
191 | S2 = sample; | |
192 | src += src_step; | |
193 | } | |
194 | if (pos & ~R_MASK) { | |
195 | pos &= R_MASK; | |
196 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | |
197 | if (val < -32768) | |
198 | val = -32768; | |
199 | else if (val > 32767) | |
200 | val = 32767; | |
201 | sample = val; | |
202 | goto *put; | |
203 | #define PUT_S16_END after_put | |
204 | #include "plugin_ops.h" | |
205 | #undef PUT_S16_END | |
206 | after_put: | |
207 | dst += dst_step; | |
208 | dst_frames1--; | |
209 | } | |
210 | pos += data->pitch; | |
211 | } | |
212 | rchannels->last_S1 = S1; | |
213 | rchannels->last_S2 = S2; | |
214 | rchannels++; | |
215 | } | |
216 | data->pos = pos; | |
217 | } | |
218 | ||
219 | static snd_pcm_sframes_t rate_src_frames(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames) | |
220 | { | |
221 | rate_t *data; | |
222 | snd_pcm_sframes_t res; | |
223 | ||
224 | snd_assert(plugin != NULL, return -ENXIO); | |
225 | if (frames == 0) | |
226 | return 0; | |
227 | data = (rate_t *)plugin->extra_data; | |
228 | if (plugin->src_format.rate < plugin->dst_format.rate) { | |
229 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | |
230 | } else { | |
231 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | |
232 | } | |
233 | if (data->old_src_frames > 0) { | |
234 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames; | |
235 | while (data->old_src_frames < frames1) { | |
236 | frames1 >>= 1; | |
237 | res1 <<= 1; | |
238 | } | |
239 | while (data->old_src_frames > frames1) { | |
240 | frames1 <<= 1; | |
241 | res1 >>= 1; | |
242 | } | |
243 | if (data->old_src_frames == frames1) | |
244 | return res1; | |
245 | } | |
246 | data->old_src_frames = frames; | |
247 | data->old_dst_frames = res; | |
248 | return res; | |
249 | } | |
250 | ||
251 | static snd_pcm_sframes_t rate_dst_frames(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames) | |
252 | { | |
253 | rate_t *data; | |
254 | snd_pcm_sframes_t res; | |
255 | ||
256 | snd_assert(plugin != NULL, return -ENXIO); | |
257 | if (frames == 0) | |
258 | return 0; | |
259 | data = (rate_t *)plugin->extra_data; | |
260 | if (plugin->src_format.rate < plugin->dst_format.rate) { | |
261 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | |
262 | } else { | |
263 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | |
264 | } | |
265 | if (data->old_dst_frames > 0) { | |
266 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames; | |
267 | while (data->old_dst_frames < frames1) { | |
268 | frames1 >>= 1; | |
269 | res1 <<= 1; | |
270 | } | |
271 | while (data->old_dst_frames > frames1) { | |
272 | frames1 <<= 1; | |
273 | res1 >>= 1; | |
274 | } | |
275 | if (data->old_dst_frames == frames1) | |
276 | return res1; | |
277 | } | |
278 | data->old_dst_frames = frames; | |
279 | data->old_src_frames = res; | |
280 | return res; | |
281 | } | |
282 | ||
283 | static snd_pcm_sframes_t rate_transfer(snd_pcm_plugin_t *plugin, | |
284 | const snd_pcm_plugin_channel_t *src_channels, | |
285 | snd_pcm_plugin_channel_t *dst_channels, | |
286 | snd_pcm_uframes_t frames) | |
287 | { | |
288 | snd_pcm_uframes_t dst_frames; | |
289 | rate_t *data; | |
290 | ||
291 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | |
292 | if (frames == 0) | |
293 | return 0; | |
294 | #ifdef CONFIG_SND_DEBUG | |
295 | { | |
296 | unsigned int channel; | |
297 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
298 | snd_assert(src_channels[channel].area.first % 8 == 0 && | |
299 | src_channels[channel].area.step % 8 == 0, | |
300 | return -ENXIO); | |
301 | snd_assert(dst_channels[channel].area.first % 8 == 0 && | |
302 | dst_channels[channel].area.step % 8 == 0, | |
303 | return -ENXIO); | |
304 | } | |
305 | } | |
306 | #endif | |
307 | ||
308 | dst_frames = rate_dst_frames(plugin, frames); | |
309 | if (dst_frames > dst_channels[0].frames) | |
310 | dst_frames = dst_channels[0].frames; | |
311 | data = (rate_t *)plugin->extra_data; | |
312 | data->func(plugin, src_channels, dst_channels, frames, dst_frames); | |
313 | return dst_frames; | |
314 | } | |
315 | ||
316 | static int rate_action(snd_pcm_plugin_t *plugin, | |
317 | snd_pcm_plugin_action_t action, | |
318 | unsigned long udata ATTRIBUTE_UNUSED) | |
319 | { | |
320 | snd_assert(plugin != NULL, return -ENXIO); | |
321 | switch (action) { | |
322 | case INIT: | |
323 | case PREPARE: | |
324 | rate_init(plugin); | |
325 | break; | |
326 | default: | |
327 | break; | |
328 | } | |
329 | return 0; /* silenty ignore other actions */ | |
330 | } | |
331 | ||
332 | int snd_pcm_plugin_build_rate(snd_pcm_plug_t *plug, | |
333 | snd_pcm_plugin_format_t *src_format, | |
334 | snd_pcm_plugin_format_t *dst_format, | |
335 | snd_pcm_plugin_t **r_plugin) | |
336 | { | |
337 | int err; | |
338 | rate_t *data; | |
339 | snd_pcm_plugin_t *plugin; | |
340 | ||
341 | snd_assert(r_plugin != NULL, return -ENXIO); | |
342 | *r_plugin = NULL; | |
343 | ||
344 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); | |
345 | snd_assert(src_format->channels > 0, return -ENXIO); | |
346 | snd_assert(snd_pcm_format_linear(src_format->format) != 0, return -ENXIO); | |
347 | snd_assert(snd_pcm_format_linear(dst_format->format) != 0, return -ENXIO); | |
348 | snd_assert(src_format->rate != dst_format->rate, return -ENXIO); | |
349 | ||
350 | err = snd_pcm_plugin_build(plug, "rate conversion", | |
351 | src_format, dst_format, | |
352 | sizeof(rate_t) + src_format->channels * sizeof(rate_channel_t), | |
353 | &plugin); | |
354 | if (err < 0) | |
355 | return err; | |
356 | data = (rate_t *)plugin->extra_data; | |
357 | data->get = getput_index(src_format->format); | |
358 | snd_assert(data->get >= 0 && data->get < 4*2*2, return -EINVAL); | |
359 | data->put = getput_index(dst_format->format); | |
360 | snd_assert(data->put >= 0 && data->put < 4*2*2, return -EINVAL); | |
361 | ||
362 | if (src_format->rate < dst_format->rate) { | |
363 | data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate; | |
364 | data->func = resample_expand; | |
365 | } else { | |
366 | data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate; | |
367 | data->func = resample_shrink; | |
368 | } | |
369 | data->pos = 0; | |
370 | rate_init(plugin); | |
371 | data->old_src_frames = data->old_dst_frames = 0; | |
372 | plugin->transfer = rate_transfer; | |
373 | plugin->src_frames = rate_src_frames; | |
374 | plugin->dst_frames = rate_dst_frames; | |
375 | plugin->action = rate_action; | |
376 | *r_plugin = plugin; | |
377 | return 0; | |
378 | } |