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1da177e4 LT |
1 | /* |
2 | * Rate conversion Plug-In | |
c1017a4c | 3 | * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz> |
1da177e4 LT |
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 | ||
6ac77bc1 | 36 | struct rate_channel { |
1da177e4 LT |
37 | signed short last_S1; |
38 | signed short last_S2; | |
6ac77bc1 | 39 | }; |
1da177e4 | 40 | |
6ac77bc1 TI |
41 | typedef void (*rate_f)(struct snd_pcm_plugin *plugin, |
42 | const struct snd_pcm_plugin_channel *src_channels, | |
43 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
44 | int src_frames, int dst_frames); |
45 | ||
6ac77bc1 | 46 | struct rate_priv { |
1da177e4 LT |
47 | unsigned int pitch; |
48 | unsigned int pos; | |
49 | rate_f func; | |
1da177e4 | 50 | snd_pcm_sframes_t old_src_frames, old_dst_frames; |
6ac77bc1 TI |
51 | struct rate_channel channels[0]; |
52 | }; | |
1da177e4 | 53 | |
6ac77bc1 | 54 | static void rate_init(struct snd_pcm_plugin *plugin) |
1da177e4 LT |
55 | { |
56 | unsigned int channel; | |
6ac77bc1 | 57 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
1da177e4 LT |
58 | data->pos = 0; |
59 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
60 | data->channels[channel].last_S1 = 0; | |
61 | data->channels[channel].last_S2 = 0; | |
62 | } | |
63 | } | |
64 | ||
6ac77bc1 TI |
65 | static void resample_expand(struct snd_pcm_plugin *plugin, |
66 | const struct snd_pcm_plugin_channel *src_channels, | |
67 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
68 | int src_frames, int dst_frames) |
69 | { | |
70 | unsigned int pos = 0; | |
71 | signed int val; | |
72 | signed short S1, S2; | |
0534ab42 | 73 | signed short *src, *dst; |
1da177e4 LT |
74 | unsigned int channel; |
75 | int src_step, dst_step; | |
76 | int src_frames1, dst_frames1; | |
6ac77bc1 TI |
77 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
78 | struct rate_channel *rchannels = data->channels; | |
1da177e4 LT |
79 | |
80 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
81 | pos = data->pos; | |
82 | S1 = rchannels->last_S1; | |
83 | S2 = rchannels->last_S2; | |
84 | if (!src_channels[channel].enabled) { | |
85 | if (dst_channels[channel].wanted) | |
86 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | |
87 | dst_channels[channel].enabled = 0; | |
88 | continue; | |
89 | } | |
90 | dst_channels[channel].enabled = 1; | |
0534ab42 TI |
91 | src = (signed short *)src_channels[channel].area.addr + |
92 | src_channels[channel].area.first / 8 / 2; | |
93 | dst = (signed short *)dst_channels[channel].area.addr + | |
94 | dst_channels[channel].area.first / 8 / 2; | |
95 | src_step = src_channels[channel].area.step / 8 / 2; | |
96 | dst_step = dst_channels[channel].area.step / 8 / 2; | |
1da177e4 LT |
97 | src_frames1 = src_frames; |
98 | dst_frames1 = dst_frames; | |
99 | while (dst_frames1-- > 0) { | |
100 | if (pos & ~R_MASK) { | |
101 | pos &= R_MASK; | |
102 | S1 = S2; | |
103 | if (src_frames1-- > 0) { | |
0534ab42 | 104 | S2 = *src; |
1da177e4 LT |
105 | src += src_step; |
106 | } | |
107 | } | |
108 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | |
109 | if (val < -32768) | |
110 | val = -32768; | |
111 | else if (val > 32767) | |
112 | val = 32767; | |
0534ab42 | 113 | *dst = val; |
1da177e4 LT |
114 | dst += dst_step; |
115 | pos += data->pitch; | |
116 | } | |
117 | rchannels->last_S1 = S1; | |
118 | rchannels->last_S2 = S2; | |
119 | rchannels++; | |
120 | } | |
121 | data->pos = pos; | |
122 | } | |
123 | ||
6ac77bc1 TI |
124 | static void resample_shrink(struct snd_pcm_plugin *plugin, |
125 | const struct snd_pcm_plugin_channel *src_channels, | |
126 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
127 | int src_frames, int dst_frames) |
128 | { | |
129 | unsigned int pos = 0; | |
130 | signed int val; | |
131 | signed short S1, S2; | |
0534ab42 | 132 | signed short *src, *dst; |
1da177e4 LT |
133 | unsigned int channel; |
134 | int src_step, dst_step; | |
135 | int src_frames1, dst_frames1; | |
6ac77bc1 TI |
136 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
137 | struct rate_channel *rchannels = data->channels; | |
1da177e4 LT |
138 | |
139 | for (channel = 0; channel < plugin->src_format.channels; ++channel) { | |
140 | pos = data->pos; | |
141 | S1 = rchannels->last_S1; | |
142 | S2 = rchannels->last_S2; | |
143 | if (!src_channels[channel].enabled) { | |
144 | if (dst_channels[channel].wanted) | |
145 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | |
146 | dst_channels[channel].enabled = 0; | |
147 | continue; | |
148 | } | |
149 | dst_channels[channel].enabled = 1; | |
0534ab42 TI |
150 | src = (signed short *)src_channels[channel].area.addr + |
151 | src_channels[channel].area.first / 8 / 2; | |
152 | dst = (signed short *)dst_channels[channel].area.addr + | |
153 | dst_channels[channel].area.first / 8 / 2; | |
154 | src_step = src_channels[channel].area.step / 8 / 2; | |
155 | dst_step = dst_channels[channel].area.step / 8 / 2; | |
1da177e4 LT |
156 | src_frames1 = src_frames; |
157 | dst_frames1 = dst_frames; | |
158 | while (dst_frames1 > 0) { | |
159 | S1 = S2; | |
160 | if (src_frames1-- > 0) { | |
0534ab42 | 161 | S1 = *src; |
1da177e4 LT |
162 | src += src_step; |
163 | } | |
164 | if (pos & ~R_MASK) { | |
165 | pos &= R_MASK; | |
166 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | |
167 | if (val < -32768) | |
168 | val = -32768; | |
169 | else if (val > 32767) | |
170 | val = 32767; | |
0534ab42 | 171 | *dst = val; |
1da177e4 LT |
172 | dst += dst_step; |
173 | dst_frames1--; | |
174 | } | |
175 | pos += data->pitch; | |
176 | } | |
177 | rchannels->last_S1 = S1; | |
178 | rchannels->last_S2 = S2; | |
179 | rchannels++; | |
180 | } | |
181 | data->pos = pos; | |
182 | } | |
183 | ||
6ac77bc1 | 184 | static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames) |
1da177e4 | 185 | { |
6ac77bc1 | 186 | struct rate_priv *data; |
1da177e4 LT |
187 | snd_pcm_sframes_t res; |
188 | ||
189 | snd_assert(plugin != NULL, return -ENXIO); | |
190 | if (frames == 0) | |
191 | return 0; | |
6ac77bc1 | 192 | data = (struct rate_priv *)plugin->extra_data; |
1da177e4 LT |
193 | if (plugin->src_format.rate < plugin->dst_format.rate) { |
194 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | |
195 | } else { | |
196 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | |
197 | } | |
198 | if (data->old_src_frames > 0) { | |
199 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames; | |
200 | while (data->old_src_frames < frames1) { | |
201 | frames1 >>= 1; | |
202 | res1 <<= 1; | |
203 | } | |
204 | while (data->old_src_frames > frames1) { | |
205 | frames1 <<= 1; | |
206 | res1 >>= 1; | |
207 | } | |
208 | if (data->old_src_frames == frames1) | |
209 | return res1; | |
210 | } | |
211 | data->old_src_frames = frames; | |
212 | data->old_dst_frames = res; | |
213 | return res; | |
214 | } | |
215 | ||
6ac77bc1 | 216 | static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames) |
1da177e4 | 217 | { |
6ac77bc1 | 218 | struct rate_priv *data; |
1da177e4 LT |
219 | snd_pcm_sframes_t res; |
220 | ||
221 | snd_assert(plugin != NULL, return -ENXIO); | |
222 | if (frames == 0) | |
223 | return 0; | |
6ac77bc1 | 224 | data = (struct rate_priv *)plugin->extra_data; |
1da177e4 LT |
225 | if (plugin->src_format.rate < plugin->dst_format.rate) { |
226 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | |
227 | } else { | |
228 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | |
229 | } | |
230 | if (data->old_dst_frames > 0) { | |
231 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames; | |
232 | while (data->old_dst_frames < frames1) { | |
233 | frames1 >>= 1; | |
234 | res1 <<= 1; | |
235 | } | |
236 | while (data->old_dst_frames > frames1) { | |
237 | frames1 <<= 1; | |
238 | res1 >>= 1; | |
239 | } | |
240 | if (data->old_dst_frames == frames1) | |
241 | return res1; | |
242 | } | |
243 | data->old_dst_frames = frames; | |
244 | data->old_src_frames = res; | |
245 | return res; | |
246 | } | |
247 | ||
6ac77bc1 TI |
248 | static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin, |
249 | const struct snd_pcm_plugin_channel *src_channels, | |
250 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
251 | snd_pcm_uframes_t frames) |
252 | { | |
253 | snd_pcm_uframes_t dst_frames; | |
6ac77bc1 | 254 | struct rate_priv *data; |
1da177e4 LT |
255 | |
256 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | |
257 | if (frames == 0) | |
258 | return 0; | |
259 | #ifdef CONFIG_SND_DEBUG | |
260 | { | |
261 | unsigned int channel; | |
262 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
263 | snd_assert(src_channels[channel].area.first % 8 == 0 && | |
264 | src_channels[channel].area.step % 8 == 0, | |
265 | return -ENXIO); | |
266 | snd_assert(dst_channels[channel].area.first % 8 == 0 && | |
267 | dst_channels[channel].area.step % 8 == 0, | |
268 | return -ENXIO); | |
269 | } | |
270 | } | |
271 | #endif | |
272 | ||
273 | dst_frames = rate_dst_frames(plugin, frames); | |
274 | if (dst_frames > dst_channels[0].frames) | |
275 | dst_frames = dst_channels[0].frames; | |
6ac77bc1 | 276 | data = (struct rate_priv *)plugin->extra_data; |
1da177e4 LT |
277 | data->func(plugin, src_channels, dst_channels, frames, dst_frames); |
278 | return dst_frames; | |
279 | } | |
280 | ||
6ac77bc1 TI |
281 | static int rate_action(struct snd_pcm_plugin *plugin, |
282 | enum snd_pcm_plugin_action action, | |
47eaebfd | 283 | unsigned long udata) |
1da177e4 LT |
284 | { |
285 | snd_assert(plugin != NULL, return -ENXIO); | |
286 | switch (action) { | |
287 | case INIT: | |
288 | case PREPARE: | |
289 | rate_init(plugin); | |
290 | break; | |
291 | default: | |
292 | break; | |
293 | } | |
294 | return 0; /* silenty ignore other actions */ | |
295 | } | |
296 | ||
6ac77bc1 TI |
297 | int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug, |
298 | struct snd_pcm_plugin_format *src_format, | |
299 | struct snd_pcm_plugin_format *dst_format, | |
300 | struct snd_pcm_plugin **r_plugin) | |
1da177e4 LT |
301 | { |
302 | int err; | |
6ac77bc1 TI |
303 | struct rate_priv *data; |
304 | struct snd_pcm_plugin *plugin; | |
1da177e4 LT |
305 | |
306 | snd_assert(r_plugin != NULL, return -ENXIO); | |
307 | *r_plugin = NULL; | |
308 | ||
309 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); | |
310 | snd_assert(src_format->channels > 0, return -ENXIO); | |
0534ab42 TI |
311 | snd_assert(src_format->format == SNDRV_PCM_FORMAT_S16, return -ENXIO); |
312 | snd_assert(dst_format->format == SNDRV_PCM_FORMAT_S16, return -ENXIO); | |
1da177e4 LT |
313 | snd_assert(src_format->rate != dst_format->rate, return -ENXIO); |
314 | ||
315 | err = snd_pcm_plugin_build(plug, "rate conversion", | |
316 | src_format, dst_format, | |
6ac77bc1 TI |
317 | sizeof(struct rate_priv) + |
318 | src_format->channels * sizeof(struct rate_channel), | |
1da177e4 LT |
319 | &plugin); |
320 | if (err < 0) | |
321 | return err; | |
6ac77bc1 | 322 | data = (struct rate_priv *)plugin->extra_data; |
1da177e4 LT |
323 | if (src_format->rate < dst_format->rate) { |
324 | data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate; | |
325 | data->func = resample_expand; | |
326 | } else { | |
327 | data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate; | |
328 | data->func = resample_shrink; | |
329 | } | |
330 | data->pos = 0; | |
331 | rate_init(plugin); | |
332 | data->old_src_frames = data->old_dst_frames = 0; | |
333 | plugin->transfer = rate_transfer; | |
334 | plugin->src_frames = rate_src_frames; | |
335 | plugin->dst_frames = rate_dst_frames; | |
336 | plugin->action = rate_action; | |
337 | *r_plugin = plugin; | |
338 | return 0; | |
339 | } |