| 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 | |
| 24 | #ifdef CONFIG_SND_PCM_OSS_PLUGINS |
| 25 | |
| 26 | #include <linux/time.h> |
| 27 | #include <sound/core.h> |
| 28 | #include <sound/pcm.h> |
| 29 | #include "pcm_plugin.h" |
| 30 | |
| 31 | #define SHIFT 11 |
| 32 | #define BITS (1<<SHIFT) |
| 33 | #define R_MASK (BITS-1) |
| 34 | |
| 35 | /* |
| 36 | * Basic rate conversion plugin |
| 37 | */ |
| 38 | |
| 39 | struct rate_channel { |
| 40 | signed short last_S1; |
| 41 | signed short last_S2; |
| 42 | }; |
| 43 | |
| 44 | typedef void (*rate_f)(struct snd_pcm_plugin *plugin, |
| 45 | const struct snd_pcm_plugin_channel *src_channels, |
| 46 | struct snd_pcm_plugin_channel *dst_channels, |
| 47 | int src_frames, int dst_frames); |
| 48 | |
| 49 | struct rate_priv { |
| 50 | unsigned int pitch; |
| 51 | unsigned int pos; |
| 52 | rate_f func; |
| 53 | int get, put; |
| 54 | snd_pcm_sframes_t old_src_frames, old_dst_frames; |
| 55 | struct rate_channel channels[0]; |
| 56 | }; |
| 57 | |
| 58 | static void rate_init(struct snd_pcm_plugin *plugin) |
| 59 | { |
| 60 | unsigned int channel; |
| 61 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
| 62 | data->pos = 0; |
| 63 | for (channel = 0; channel < plugin->src_format.channels; channel++) { |
| 64 | data->channels[channel].last_S1 = 0; |
| 65 | data->channels[channel].last_S2 = 0; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | static void resample_expand(struct snd_pcm_plugin *plugin, |
| 70 | const struct snd_pcm_plugin_channel *src_channels, |
| 71 | struct snd_pcm_plugin_channel *dst_channels, |
| 72 | int src_frames, int dst_frames) |
| 73 | { |
| 74 | unsigned int pos = 0; |
| 75 | signed int val; |
| 76 | signed short S1, S2; |
| 77 | char *src, *dst; |
| 78 | unsigned int channel; |
| 79 | int src_step, dst_step; |
| 80 | int src_frames1, dst_frames1; |
| 81 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
| 82 | struct rate_channel *rchannels = data->channels; |
| 83 | |
| 84 | #define GET_S16_LABELS |
| 85 | #define PUT_S16_LABELS |
| 86 | #include "plugin_ops.h" |
| 87 | #undef GET_S16_LABELS |
| 88 | #undef PUT_S16_LABELS |
| 89 | void *get = get_s16_labels[data->get]; |
| 90 | void *put = put_s16_labels[data->put]; |
| 91 | signed short sample = 0; |
| 92 | |
| 93 | for (channel = 0; channel < plugin->src_format.channels; channel++) { |
| 94 | pos = data->pos; |
| 95 | S1 = rchannels->last_S1; |
| 96 | S2 = rchannels->last_S2; |
| 97 | if (!src_channels[channel].enabled) { |
| 98 | if (dst_channels[channel].wanted) |
| 99 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); |
| 100 | dst_channels[channel].enabled = 0; |
| 101 | continue; |
| 102 | } |
| 103 | dst_channels[channel].enabled = 1; |
| 104 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; |
| 105 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; |
| 106 | src_step = src_channels[channel].area.step / 8; |
| 107 | dst_step = dst_channels[channel].area.step / 8; |
| 108 | src_frames1 = src_frames; |
| 109 | dst_frames1 = dst_frames; |
| 110 | while (dst_frames1-- > 0) { |
| 111 | if (pos & ~R_MASK) { |
| 112 | pos &= R_MASK; |
| 113 | S1 = S2; |
| 114 | if (src_frames1-- > 0) { |
| 115 | goto *get; |
| 116 | #define GET_S16_END after_get |
| 117 | #include "plugin_ops.h" |
| 118 | #undef GET_S16_END |
| 119 | after_get: |
| 120 | S2 = sample; |
| 121 | src += src_step; |
| 122 | } |
| 123 | } |
| 124 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; |
| 125 | if (val < -32768) |
| 126 | val = -32768; |
| 127 | else if (val > 32767) |
| 128 | val = 32767; |
| 129 | sample = val; |
| 130 | goto *put; |
| 131 | #define PUT_S16_END after_put |
| 132 | #include "plugin_ops.h" |
| 133 | #undef PUT_S16_END |
| 134 | after_put: |
| 135 | dst += dst_step; |
| 136 | pos += data->pitch; |
| 137 | } |
| 138 | rchannels->last_S1 = S1; |
| 139 | rchannels->last_S2 = S2; |
| 140 | rchannels++; |
| 141 | } |
| 142 | data->pos = pos; |
| 143 | } |
| 144 | |
| 145 | static void resample_shrink(struct snd_pcm_plugin *plugin, |
| 146 | const struct snd_pcm_plugin_channel *src_channels, |
| 147 | struct snd_pcm_plugin_channel *dst_channels, |
| 148 | int src_frames, int dst_frames) |
| 149 | { |
| 150 | unsigned int pos = 0; |
| 151 | signed int val; |
| 152 | signed short S1, S2; |
| 153 | char *src, *dst; |
| 154 | unsigned int channel; |
| 155 | int src_step, dst_step; |
| 156 | int src_frames1, dst_frames1; |
| 157 | struct rate_priv *data = (struct rate_priv *)plugin->extra_data; |
| 158 | struct rate_channel *rchannels = data->channels; |
| 159 | |
| 160 | #define GET_S16_LABELS |
| 161 | #define PUT_S16_LABELS |
| 162 | #include "plugin_ops.h" |
| 163 | #undef GET_S16_LABELS |
| 164 | #undef PUT_S16_LABELS |
| 165 | void *get = get_s16_labels[data->get]; |
| 166 | void *put = put_s16_labels[data->put]; |
| 167 | signed short sample = 0; |
| 168 | |
| 169 | for (channel = 0; channel < plugin->src_format.channels; ++channel) { |
| 170 | pos = data->pos; |
| 171 | S1 = rchannels->last_S1; |
| 172 | S2 = rchannels->last_S2; |
| 173 | if (!src_channels[channel].enabled) { |
| 174 | if (dst_channels[channel].wanted) |
| 175 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); |
| 176 | dst_channels[channel].enabled = 0; |
| 177 | continue; |
| 178 | } |
| 179 | dst_channels[channel].enabled = 1; |
| 180 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; |
| 181 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; |
| 182 | src_step = src_channels[channel].area.step / 8; |
| 183 | dst_step = dst_channels[channel].area.step / 8; |
| 184 | src_frames1 = src_frames; |
| 185 | dst_frames1 = dst_frames; |
| 186 | while (dst_frames1 > 0) { |
| 187 | S1 = S2; |
| 188 | if (src_frames1-- > 0) { |
| 189 | goto *get; |
| 190 | #define GET_S16_END after_get |
| 191 | #include "plugin_ops.h" |
| 192 | #undef GET_S16_END |
| 193 | after_get: |
| 194 | S2 = sample; |
| 195 | src += src_step; |
| 196 | } |
| 197 | if (pos & ~R_MASK) { |
| 198 | pos &= R_MASK; |
| 199 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; |
| 200 | if (val < -32768) |
| 201 | val = -32768; |
| 202 | else if (val > 32767) |
| 203 | val = 32767; |
| 204 | sample = val; |
| 205 | goto *put; |
| 206 | #define PUT_S16_END after_put |
| 207 | #include "plugin_ops.h" |
| 208 | #undef PUT_S16_END |
| 209 | after_put: |
| 210 | dst += dst_step; |
| 211 | dst_frames1--; |
| 212 | } |
| 213 | pos += data->pitch; |
| 214 | } |
| 215 | rchannels->last_S1 = S1; |
| 216 | rchannels->last_S2 = S2; |
| 217 | rchannels++; |
| 218 | } |
| 219 | data->pos = pos; |
| 220 | } |
| 221 | |
| 222 | static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames) |
| 223 | { |
| 224 | struct rate_priv *data; |
| 225 | snd_pcm_sframes_t res; |
| 226 | |
| 227 | snd_assert(plugin != NULL, return -ENXIO); |
| 228 | if (frames == 0) |
| 229 | return 0; |
| 230 | data = (struct rate_priv *)plugin->extra_data; |
| 231 | if (plugin->src_format.rate < plugin->dst_format.rate) { |
| 232 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); |
| 233 | } else { |
| 234 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); |
| 235 | } |
| 236 | if (data->old_src_frames > 0) { |
| 237 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames; |
| 238 | while (data->old_src_frames < frames1) { |
| 239 | frames1 >>= 1; |
| 240 | res1 <<= 1; |
| 241 | } |
| 242 | while (data->old_src_frames > frames1) { |
| 243 | frames1 <<= 1; |
| 244 | res1 >>= 1; |
| 245 | } |
| 246 | if (data->old_src_frames == frames1) |
| 247 | return res1; |
| 248 | } |
| 249 | data->old_src_frames = frames; |
| 250 | data->old_dst_frames = res; |
| 251 | return res; |
| 252 | } |
| 253 | |
| 254 | static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames) |
| 255 | { |
| 256 | struct rate_priv *data; |
| 257 | snd_pcm_sframes_t res; |
| 258 | |
| 259 | snd_assert(plugin != NULL, return -ENXIO); |
| 260 | if (frames == 0) |
| 261 | return 0; |
| 262 | data = (struct rate_priv *)plugin->extra_data; |
| 263 | if (plugin->src_format.rate < plugin->dst_format.rate) { |
| 264 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); |
| 265 | } else { |
| 266 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); |
| 267 | } |
| 268 | if (data->old_dst_frames > 0) { |
| 269 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames; |
| 270 | while (data->old_dst_frames < frames1) { |
| 271 | frames1 >>= 1; |
| 272 | res1 <<= 1; |
| 273 | } |
| 274 | while (data->old_dst_frames > frames1) { |
| 275 | frames1 <<= 1; |
| 276 | res1 >>= 1; |
| 277 | } |
| 278 | if (data->old_dst_frames == frames1) |
| 279 | return res1; |
| 280 | } |
| 281 | data->old_dst_frames = frames; |
| 282 | data->old_src_frames = res; |
| 283 | return res; |
| 284 | } |
| 285 | |
| 286 | static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin, |
| 287 | const struct snd_pcm_plugin_channel *src_channels, |
| 288 | struct snd_pcm_plugin_channel *dst_channels, |
| 289 | snd_pcm_uframes_t frames) |
| 290 | { |
| 291 | snd_pcm_uframes_t dst_frames; |
| 292 | struct rate_priv *data; |
| 293 | |
| 294 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); |
| 295 | if (frames == 0) |
| 296 | return 0; |
| 297 | #ifdef CONFIG_SND_DEBUG |
| 298 | { |
| 299 | unsigned int channel; |
| 300 | for (channel = 0; channel < plugin->src_format.channels; channel++) { |
| 301 | snd_assert(src_channels[channel].area.first % 8 == 0 && |
| 302 | src_channels[channel].area.step % 8 == 0, |
| 303 | return -ENXIO); |
| 304 | snd_assert(dst_channels[channel].area.first % 8 == 0 && |
| 305 | dst_channels[channel].area.step % 8 == 0, |
| 306 | return -ENXIO); |
| 307 | } |
| 308 | } |
| 309 | #endif |
| 310 | |
| 311 | dst_frames = rate_dst_frames(plugin, frames); |
| 312 | if (dst_frames > dst_channels[0].frames) |
| 313 | dst_frames = dst_channels[0].frames; |
| 314 | data = (struct rate_priv *)plugin->extra_data; |
| 315 | data->func(plugin, src_channels, dst_channels, frames, dst_frames); |
| 316 | return dst_frames; |
| 317 | } |
| 318 | |
| 319 | static int rate_action(struct snd_pcm_plugin *plugin, |
| 320 | enum snd_pcm_plugin_action action, |
| 321 | unsigned long udata) |
| 322 | { |
| 323 | snd_assert(plugin != NULL, return -ENXIO); |
| 324 | switch (action) { |
| 325 | case INIT: |
| 326 | case PREPARE: |
| 327 | rate_init(plugin); |
| 328 | break; |
| 329 | default: |
| 330 | break; |
| 331 | } |
| 332 | return 0; /* silenty ignore other actions */ |
| 333 | } |
| 334 | |
| 335 | int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug, |
| 336 | struct snd_pcm_plugin_format *src_format, |
| 337 | struct snd_pcm_plugin_format *dst_format, |
| 338 | struct snd_pcm_plugin **r_plugin) |
| 339 | { |
| 340 | int err; |
| 341 | struct rate_priv *data; |
| 342 | struct snd_pcm_plugin *plugin; |
| 343 | |
| 344 | snd_assert(r_plugin != NULL, return -ENXIO); |
| 345 | *r_plugin = NULL; |
| 346 | |
| 347 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); |
| 348 | snd_assert(src_format->channels > 0, return -ENXIO); |
| 349 | snd_assert(snd_pcm_format_linear(src_format->format) != 0, return -ENXIO); |
| 350 | snd_assert(snd_pcm_format_linear(dst_format->format) != 0, return -ENXIO); |
| 351 | snd_assert(src_format->rate != dst_format->rate, return -ENXIO); |
| 352 | |
| 353 | err = snd_pcm_plugin_build(plug, "rate conversion", |
| 354 | src_format, dst_format, |
| 355 | sizeof(struct rate_priv) + |
| 356 | src_format->channels * sizeof(struct rate_channel), |
| 357 | &plugin); |
| 358 | if (err < 0) |
| 359 | return err; |
| 360 | data = (struct rate_priv *)plugin->extra_data; |
| 361 | data->get = getput_index(src_format->format); |
| 362 | snd_assert(data->get >= 0 && data->get < 4*2*2, return -EINVAL); |
| 363 | data->put = getput_index(dst_format->format); |
| 364 | snd_assert(data->put >= 0 && data->put < 4*2*2, return -EINVAL); |
| 365 | |
| 366 | if (src_format->rate < dst_format->rate) { |
| 367 | data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate; |
| 368 | data->func = resample_expand; |
| 369 | } else { |
| 370 | data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate; |
| 371 | data->func = resample_shrink; |
| 372 | } |
| 373 | data->pos = 0; |
| 374 | rate_init(plugin); |
| 375 | data->old_src_frames = data->old_dst_frames = 0; |
| 376 | plugin->transfer = rate_transfer; |
| 377 | plugin->src_frames = rate_src_frames; |
| 378 | plugin->dst_frames = rate_dst_frames; |
| 379 | plugin->action = rate_action; |
| 380 | *r_plugin = plugin; |
| 381 | return 0; |
| 382 | } |
| 383 | |
| 384 | #endif |