git.oblomov.eu Git - linux-2.6/blob - sound/core/oss/pcm_plugin.c

   1 /*
   2  *  PCM Plug-In shared (kernel/library) code
   3  *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
   4  *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
   5  *
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Library General Public License as
   9  *   published by the Free Software Foundation; either version 2 of
  10  *   the License, or (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU Library General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Library General Public
  18  *   License along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #if 0
  24 #define PLUGIN_DEBUG
  25 #endif
  26
  27 #include <sound/driver.h>
  28 #include <linux/slab.h>
  29 #include <linux/time.h>
  30 #include <linux/vmalloc.h>
  31 #include <sound/core.h>
  32 #include <sound/pcm.h>
  33 #include <sound/pcm_params.h>
  34 #include "pcm_plugin.h"
  35
  36 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
  37 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
  38
  39 /*
  40  *  because some cards might have rates "very close", we ignore
  41  *  all "resampling" requests within +-5%
  42  */
  43 static int rate_match(unsigned int src_rate, unsigned int dst_rate)
  44 {
  45         unsigned int low = (src_rate * 95) / 100;
  46         unsigned int high = (src_rate * 105) / 100;
  47         return dst_rate >= low && dst_rate <= high;
  48 }
  49
  50 static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
  51 {
  52         struct snd_pcm_plugin_format *format;
  53         ssize_t width;
  54         size_t size;
  55         unsigned int channel;
  56         struct snd_pcm_plugin_channel *c;
  57
  58         if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  59                 format = &plugin->src_format;
  60         } else {
  61                 format = &plugin->dst_format;
  62         }
  63         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
  64                 return width;
  65         size = frames * format->channels * width;
  66         snd_assert((size % 8) == 0, return -ENXIO);
  67         size /= 8;
  68         if (plugin->buf_frames < frames) {
  69                 vfree(plugin->buf);
  70                 plugin->buf = vmalloc(size);
  71                 plugin->buf_frames = frames;
  72         }
  73         if (!plugin->buf) {
  74                 plugin->buf_frames = 0;
  75                 return -ENOMEM;
  76         }
  77         c = plugin->buf_channels;
  78         if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
  79                 for (channel = 0; channel < format->channels; channel++, c++) {
  80                         c->frames = frames;
  81                         c->enabled = 1;
  82                         c->wanted = 0;
  83                         c->area.addr = plugin->buf;
  84                         c->area.first = channel * width;
  85                         c->area.step = format->channels * width;
  86                 }
  87         } else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
  88                 snd_assert((size % format->channels) == 0,);
  89                 size /= format->channels;
  90                 for (channel = 0; channel < format->channels; channel++, c++) {
  91                         c->frames = frames;
  92                         c->enabled = 1;
  93                         c->wanted = 0;
  94                         c->area.addr = plugin->buf + (channel * size);
  95                         c->area.first = 0;
  96                         c->area.step = width;
  97                 }
  98         } else
  99                 return -EINVAL;
 100         return 0;
 101 }
 102
 103 int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
 104 {
 105         int err;
 106         snd_assert(snd_pcm_plug_first(plug) != NULL, return -ENXIO);
 107         if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
 108                 struct snd_pcm_plugin *plugin = snd_pcm_plug_first(plug);
 109                 while (plugin->next) {
 110                         if (plugin->dst_frames)
 111                                 frames = plugin->dst_frames(plugin, frames);
 112                         snd_assert(frames > 0, return -ENXIO);
 113                         plugin = plugin->next;
 114                         err = snd_pcm_plugin_alloc(plugin, frames);
 115                         if (err < 0)
 116                                 return err;
 117                 }
 118         } else {
 119                 struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
 120                 while (plugin->prev) {
 121                         if (plugin->src_frames)
 122                                 frames = plugin->src_frames(plugin, frames);
 123                         snd_assert(frames > 0, return -ENXIO);
 124                         plugin = plugin->prev;
 125                         err = snd_pcm_plugin_alloc(plugin, frames);
 126                         if (err < 0)
 127                                 return err;
 128                 }
 129         }
 130         return 0;
 131 }
 132
 133
 134 snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
 135                                        snd_pcm_uframes_t frames,
 136                                        struct snd_pcm_plugin_channel **channels)
 137 {
 138         *channels = plugin->buf_channels;
 139         return frames;
 140 }
 141
 142 int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
 143                          const char *name,
 144                          struct snd_pcm_plugin_format *src_format,
 145                          struct snd_pcm_plugin_format *dst_format,
 146                          size_t extra,
 147                          struct snd_pcm_plugin **ret)
 148 {
 149         struct snd_pcm_plugin *plugin;
 150         unsigned int channels;
 151
 152         snd_assert(plug != NULL, return -ENXIO);
 153         snd_assert(src_format != NULL && dst_format != NULL, return -ENXIO);
 154         plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
 155         if (plugin == NULL)
 156                 return -ENOMEM;
 157         plugin->name = name;
 158         plugin->plug = plug;
 159         plugin->stream = snd_pcm_plug_stream(plug);
 160         plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 161         plugin->src_format = *src_format;
 162         plugin->src_width = snd_pcm_format_physical_width(src_format->format);
 163         snd_assert(plugin->src_width > 0, );
 164         plugin->dst_format = *dst_format;
 165         plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
 166         snd_assert(plugin->dst_width > 0, );
 167         if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
 168                 channels = src_format->channels;
 169         else
 170                 channels = dst_format->channels;
 171         plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
 172         if (plugin->buf_channels == NULL) {
 173                 snd_pcm_plugin_free(plugin);
 174                 return -ENOMEM;
 175         }
 176         plugin->client_channels = snd_pcm_plugin_client_channels;
 177         *ret = plugin;
 178         return 0;
 179 }
 180
 181 int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
 182 {
 183         if (! plugin)
 184                 return 0;
 185         if (plugin->private_free)
 186                 plugin->private_free(plugin);
 187         kfree(plugin->buf_channels);
 188         vfree(plugin->buf);
 189         kfree(plugin);
 190         return 0;
 191 }
 192
 193 snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
 194 {
 195         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
 196         int stream = snd_pcm_plug_stream(plug);
 197
 198         snd_assert(plug != NULL, return -ENXIO);
 199         if (drv_frames == 0)
 200                 return 0;
 201         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 202                 plugin = snd_pcm_plug_last(plug);
 203                 while (plugin && drv_frames > 0) {
 204                         plugin_prev = plugin->prev;
 205                         if (plugin->src_frames)
 206                                 drv_frames = plugin->src_frames(plugin, drv_frames);
 207                         plugin = plugin_prev;
 208                 }
 209         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 210                 plugin = snd_pcm_plug_first(plug);
 211                 while (plugin && drv_frames > 0) {
 212                         plugin_next = plugin->next;
 213                         if (plugin->dst_frames)
 214                                 drv_frames = plugin->dst_frames(plugin, drv_frames);
 215                         plugin = plugin_next;
 216                 }
 217         } else
 218                 snd_BUG();
 219         return drv_frames;
 220 }
 221
 222 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
 223 {
 224         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
 225         snd_pcm_sframes_t frames;
 226         int stream = snd_pcm_plug_stream(plug);
 227
 228         snd_assert(plug != NULL, return -ENXIO);
 229         if (clt_frames == 0)
 230                 return 0;
 231         frames = clt_frames;
 232         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 233                 plugin = snd_pcm_plug_first(plug);
 234                 while (plugin && frames > 0) {
 235                         plugin_next = plugin->next;
 236                         if (plugin->dst_frames) {
 237                                 frames = plugin->dst_frames(plugin, frames);
 238                                 if (frames < 0)
 239                                         return frames;
 240                         }
 241                         plugin = plugin_next;
 242                 }
 243         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 244                 plugin = snd_pcm_plug_last(plug);
 245                 while (plugin) {
 246                         plugin_prev = plugin->prev;
 247                         if (plugin->src_frames) {
 248                                 frames = plugin->src_frames(plugin, frames);
 249                                 if (frames < 0)
 250                                         return frames;
 251                         }
 252                         plugin = plugin_prev;
 253                 }
 254         } else
 255                 snd_BUG();
 256         return frames;
 257 }
 258
 259 static int snd_pcm_plug_formats(struct snd_mask *mask, int format)
 260 {
 261         struct snd_mask formats = *mask;
 262         u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
 263                        SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
 264                        SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
 265                        SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
 266                        SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
 267                        SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
 268                        SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
 269                        SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
 270                        SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
 271         snd_mask_set(&formats, SNDRV_PCM_FORMAT_MU_LAW);
 272
 273         if (formats.bits[0] & (u32)linfmts)
 274                 formats.bits[0] |= (u32)linfmts;
 275         if (formats.bits[1] & (u32)(linfmts >> 32))
 276                 formats.bits[1] |= (u32)(linfmts >> 32);
 277         return snd_mask_test(&formats, format);
 278 }
 279
 280 static int preferred_formats[] = {
 281         SNDRV_PCM_FORMAT_S16_LE,
 282         SNDRV_PCM_FORMAT_S16_BE,
 283         SNDRV_PCM_FORMAT_U16_LE,
 284         SNDRV_PCM_FORMAT_U16_BE,
 285         SNDRV_PCM_FORMAT_S24_3LE,
 286         SNDRV_PCM_FORMAT_S24_3BE,
 287         SNDRV_PCM_FORMAT_U24_3LE,
 288         SNDRV_PCM_FORMAT_U24_3BE,
 289         SNDRV_PCM_FORMAT_S24_LE,
 290         SNDRV_PCM_FORMAT_S24_BE,
 291         SNDRV_PCM_FORMAT_U24_LE,
 292         SNDRV_PCM_FORMAT_U24_BE,
 293         SNDRV_PCM_FORMAT_S32_LE,
 294         SNDRV_PCM_FORMAT_S32_BE,
 295         SNDRV_PCM_FORMAT_U32_LE,
 296         SNDRV_PCM_FORMAT_U32_BE,
 297         SNDRV_PCM_FORMAT_S8,
 298         SNDRV_PCM_FORMAT_U8
 299 };
 300
 301 int snd_pcm_plug_slave_format(int format, struct snd_mask *format_mask)
 302 {
 303         int i;
 304
 305         if (snd_mask_test(format_mask, format))
 306                 return format;
 307         if (! snd_pcm_plug_formats(format_mask, format))
 308                 return -EINVAL;
 309         if (snd_pcm_format_linear(format)) {
 310                 unsigned int width = snd_pcm_format_width(format);
 311                 int unsignd = snd_pcm_format_unsigned(format) > 0;
 312                 int big = snd_pcm_format_big_endian(format) > 0;
 313                 unsigned int badness, best = -1;
 314                 int best_format = -1;
 315                 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
 316                         int f = preferred_formats[i];
 317                         unsigned int w;
 318                         if (!snd_mask_test(format_mask, f))
 319                                 continue;
 320                         w = snd_pcm_format_width(f);
 321                         if (w >= width)
 322                                 badness = w - width;
 323                         else
 324                                 badness = width - w + 32;
 325                         badness += snd_pcm_format_unsigned(f) != unsignd;
 326                         badness += snd_pcm_format_big_endian(f) != big;
 327                         if (badness < best) {
 328                                 best_format = f;
 329                                 best = badness;
 330                         }
 331                 }
 332                 return best_format >= 0 ? best_format : -EINVAL;
 333         } else {
 334                 switch (format) {
 335                 case SNDRV_PCM_FORMAT_MU_LAW:
 336                         for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
 337                                 int format1 = preferred_formats[i];
 338                                 if (snd_mask_test(format_mask, format1))
 339                                         return format1;
 340                         }
 341                 default:
 342                         return -EINVAL;
 343                 }
 344         }
 345 }
 346
 347 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
 348                                 struct snd_pcm_hw_params *params,
 349                                 struct snd_pcm_hw_params *slave_params)
 350 {
 351         struct snd_pcm_plugin_format tmpformat;
 352         struct snd_pcm_plugin_format dstformat;
 353         struct snd_pcm_plugin_format srcformat;
 354         int src_access, dst_access;
 355         struct snd_pcm_plugin *plugin = NULL;
 356         int err;
 357         int stream = snd_pcm_plug_stream(plug);
 358         int slave_interleaved = (params_channels(slave_params) == 1 ||
 359                                  params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
 360
 361         switch (stream) {
 362         case SNDRV_PCM_STREAM_PLAYBACK:
 363                 dstformat.format = params_format(slave_params);
 364                 dstformat.rate = params_rate(slave_params);
 365                 dstformat.channels = params_channels(slave_params);
 366                 srcformat.format = params_format(params);
 367                 srcformat.rate = params_rate(params);
 368                 srcformat.channels = params_channels(params);
 369                 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 370                 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 371                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 372                 break;
 373         case SNDRV_PCM_STREAM_CAPTURE:
 374                 dstformat.format = params_format(params);
 375                 dstformat.rate = params_rate(params);
 376                 dstformat.channels = params_channels(params);
 377                 srcformat.format = params_format(slave_params);
 378                 srcformat.rate = params_rate(slave_params);
 379                 srcformat.channels = params_channels(slave_params);
 380                 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 381                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 382                 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 383                 break;
 384         default:
 385                 snd_BUG();
 386                 return -EINVAL;
 387         }
 388         tmpformat = srcformat;
 389
 390         pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
 391                  srcformat.format,
 392                  srcformat.rate,
 393                  srcformat.channels);
 394         pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
 395                  dstformat.format,
 396                  dstformat.rate,
 397                  dstformat.channels);
 398
 399         /* Format change (linearization) */
 400         if (! rate_match(srcformat.rate, dstformat.rate) &&
 401             ! snd_pcm_format_linear(srcformat.format)) {
 402                 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
 403                         return -EINVAL;
 404                 tmpformat.format = SNDRV_PCM_FORMAT_S16;
 405                 err = snd_pcm_plugin_build_mulaw(plug,
 406                                                  &srcformat, &tmpformat,
 407                                                  &plugin);
 408                 if (err < 0)
 409                         return err;
 410                 err = snd_pcm_plugin_append(plugin);
 411                 if (err < 0) {
 412                         snd_pcm_plugin_free(plugin);
 413                         return err;
 414                 }
 415                 srcformat = tmpformat;
 416                 src_access = dst_access;
 417         }
 418
 419         /* channels reduction */
 420         if (srcformat.channels > dstformat.channels) {
 421                 tmpformat.channels = dstformat.channels;
 422                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 423                 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 424                 if (err < 0)
 425                         return err;
 426                 err = snd_pcm_plugin_append(plugin);
 427                 if (err < 0) {
 428                         snd_pcm_plugin_free(plugin);
 429                         return err;
 430                 }
 431                 srcformat = tmpformat;
 432                 src_access = dst_access;
 433         }
 434
 435         /* rate resampling */
 436         if (!rate_match(srcformat.rate, dstformat.rate)) {
 437                 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
 438                         /* convert to S16 for resampling */
 439                         tmpformat.format = SNDRV_PCM_FORMAT_S16;
 440                         err = snd_pcm_plugin_build_linear(plug,
 441                                                           &srcformat, &tmpformat,
 442                                                           &plugin);
 443                         if (err < 0)
 444                                 return err;
 445                         err = snd_pcm_plugin_append(plugin);
 446                         if (err < 0) {
 447                                 snd_pcm_plugin_free(plugin);
 448                                 return err;
 449                         }
 450                         srcformat = tmpformat;
 451                         src_access = dst_access;
 452                 }
 453                 tmpformat.rate = dstformat.rate;
 454                 err = snd_pcm_plugin_build_rate(plug,
 455                                                 &srcformat, &tmpformat,
 456                                                 &plugin);
 457                 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
 458                 if (err < 0)
 459                         return err;
 460                 err = snd_pcm_plugin_append(plugin);
 461                 if (err < 0) {
 462                         snd_pcm_plugin_free(plugin);
 463                         return err;
 464                 }
 465                 srcformat = tmpformat;
 466                 src_access = dst_access;
 467         }
 468
 469         /* format change */
 470         if (srcformat.format != dstformat.format) {
 471                 tmpformat.format = dstformat.format;
 472                 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
 473                     tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
 474                         err = snd_pcm_plugin_build_mulaw(plug,
 475                                                          &srcformat, &tmpformat,
 476                                                          &plugin);
 477                 }
 478                 else if (snd_pcm_format_linear(srcformat.format) &&
 479                          snd_pcm_format_linear(tmpformat.format)) {
 480                         err = snd_pcm_plugin_build_linear(plug,
 481                                                           &srcformat, &tmpformat,
 482                                                           &plugin);
 483                 }
 484                 else
 485                         return -EINVAL;
 486                 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
 487                 if (err < 0)
 488                         return err;
 489                 err = snd_pcm_plugin_append(plugin);
 490                 if (err < 0) {
 491                         snd_pcm_plugin_free(plugin);
 492                         return err;
 493                 }
 494                 srcformat = tmpformat;
 495                 src_access = dst_access;
 496         }
 497
 498         /* channels extension */
 499         if (srcformat.channels < dstformat.channels) {
 500                 tmpformat.channels = dstformat.channels;
 501                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 502                 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 503                 if (err < 0)
 504                         return err;
 505                 err = snd_pcm_plugin_append(plugin);
 506                 if (err < 0) {
 507                         snd_pcm_plugin_free(plugin);
 508                         return err;
 509                 }
 510                 srcformat = tmpformat;
 511                 src_access = dst_access;
 512         }
 513
 514         /* de-interleave */
 515         if (src_access != dst_access) {
 516                 err = snd_pcm_plugin_build_copy(plug,
 517                                                 &srcformat,
 518                                                 &tmpformat,
 519                                                 &plugin);
 520                 pdprintf("interleave change (copy: returns %i)\n", err);
 521                 if (err < 0)
 522                         return err;
 523                 err = snd_pcm_plugin_append(plugin);
 524                 if (err < 0) {
 525                         snd_pcm_plugin_free(plugin);
 526                         return err;
 527                 }
 528         }
 529
 530         return 0;
 531 }
 532
 533 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
 534                                          char *buf,
 535                                          snd_pcm_uframes_t count,
 536                                          struct snd_pcm_plugin_channel **channels)
 537 {
 538         struct snd_pcm_plugin *plugin;
 539         struct snd_pcm_plugin_channel *v;
 540         struct snd_pcm_plugin_format *format;
 541         int width, nchannels, channel;
 542         int stream = snd_pcm_plug_stream(plug);
 543
 544         snd_assert(buf != NULL, return -ENXIO);
 545         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 546                 plugin = snd_pcm_plug_first(plug);
 547                 format = &plugin->src_format;
 548         } else {
 549                 plugin = snd_pcm_plug_last(plug);
 550                 format = &plugin->dst_format;
 551         }
 552         v = plugin->buf_channels;
 553         *channels = v;
 554         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
 555                 return width;
 556         nchannels = format->channels;
 557         snd_assert(plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || format->channels <= 1, return -ENXIO);
 558         for (channel = 0; channel < nchannels; channel++, v++) {
 559                 v->frames = count;
 560                 v->enabled = 1;
 561                 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
 562                 v->area.addr = buf;
 563                 v->area.first = channel * width;
 564                 v->area.step = nchannels * width;
 565         }
 566         return count;
 567 }
 568
 569 snd_pcm_sframes_t snd_pcm_plug_write_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *src_channels, snd_pcm_uframes_t size)
 570 {
 571         struct snd_pcm_plugin *plugin, *next;
 572         struct snd_pcm_plugin_channel *dst_channels;
 573         int err;
 574         snd_pcm_sframes_t frames = size;
 575
 576         plugin = snd_pcm_plug_first(plug);
 577         while (plugin && frames > 0) {
 578                 if ((next = plugin->next) != NULL) {
 579                         snd_pcm_sframes_t frames1 = frames;
 580                         if (plugin->dst_frames)
 581                                 frames1 = plugin->dst_frames(plugin, frames);
 582                         if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
 583                                 return err;
 584                         }
 585                         if (err != frames1) {
 586                                 frames = err;
 587                                 if (plugin->src_frames)
 588                                         frames = plugin->src_frames(plugin, frames1);
 589                         }
 590                 } else
 591                         dst_channels = NULL;
 592                 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
 593                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 594                         return frames;
 595                 src_channels = dst_channels;
 596                 plugin = next;
 597         }
 598         return snd_pcm_plug_client_size(plug, frames);
 599 }
 600
 601 snd_pcm_sframes_t snd_pcm_plug_read_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *dst_channels_final, snd_pcm_uframes_t size)
 602 {
 603         struct snd_pcm_plugin *plugin, *next;
 604         struct snd_pcm_plugin_channel *src_channels, *dst_channels;
 605         snd_pcm_sframes_t frames = size;
 606         int err;
 607
 608         frames = snd_pcm_plug_slave_size(plug, frames);
 609         if (frames < 0)
 610                 return frames;
 611
 612         src_channels = NULL;
 613         plugin = snd_pcm_plug_first(plug);
 614         while (plugin && frames > 0) {
 615                 if ((next = plugin->next) != NULL) {
 616                         if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
 617                                 return err;
 618                         }
 619                         frames = err;
 620                 } else {
 621                         dst_channels = dst_channels_final;
 622                 }
 623                 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
 624                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 625                         return frames;
 626                 plugin = next;
 627                 src_channels = dst_channels;
 628         }
 629         return frames;
 630 }
 631
 632 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 633                          size_t samples, int format)
 634 {
 635         /* FIXME: sub byte resolution and odd dst_offset */
 636         unsigned char *dst;
 637         unsigned int dst_step;
 638         int width;
 639         const unsigned char *silence;
 640         if (!dst_area->addr)
 641                 return 0;
 642         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 643         width = snd_pcm_format_physical_width(format);
 644         if (width <= 0)
 645                 return -EINVAL;
 646         if (dst_area->step == (unsigned int) width && width >= 8)
 647                 return snd_pcm_format_set_silence(format, dst, samples);
 648         silence = snd_pcm_format_silence_64(format);
 649         if (! silence)
 650                 return -EINVAL;
 651         dst_step = dst_area->step / 8;
 652         if (width == 4) {
 653                 /* Ima ADPCM */
 654                 int dstbit = dst_area->first % 8;
 655                 int dstbit_step = dst_area->step % 8;
 656                 while (samples-- > 0) {
 657                         if (dstbit)
 658                                 *dst &= 0xf0;
 659                         else
 660                                 *dst &= 0x0f;
 661                         dst += dst_step;
 662                         dstbit += dstbit_step;
 663                         if (dstbit == 8) {
 664                                 dst++;
 665                                 dstbit = 0;
 666                         }
 667                 }
 668         } else {
 669                 width /= 8;
 670                 while (samples-- > 0) {
 671                         memcpy(dst, silence, width);
 672                         dst += dst_step;
 673                 }
 674         }
 675         return 0;
 676 }
 677
 678 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
 679                       const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 680                       size_t samples, int format)
 681 {
 682         /* FIXME: sub byte resolution and odd dst_offset */
 683         char *src, *dst;
 684         int width;
 685         int src_step, dst_step;
 686         src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
 687         if (!src_area->addr)
 688                 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
 689         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 690         if (!dst_area->addr)
 691                 return 0;
 692         width = snd_pcm_format_physical_width(format);
 693         if (width <= 0)
 694                 return -EINVAL;
 695         if (src_area->step == (unsigned int) width &&
 696             dst_area->step == (unsigned int) width && width >= 8) {
 697                 size_t bytes = samples * width / 8;
 698                 memcpy(dst, src, bytes);
 699                 return 0;
 700         }
 701         src_step = src_area->step / 8;
 702         dst_step = dst_area->step / 8;
 703         if (width == 4) {
 704                 /* Ima ADPCM */
 705                 int srcbit = src_area->first % 8;
 706                 int srcbit_step = src_area->step % 8;
 707                 int dstbit = dst_area->first % 8;
 708                 int dstbit_step = dst_area->step % 8;
 709                 while (samples-- > 0) {
 710                         unsigned char srcval;
 711                         if (srcbit)
 712                                 srcval = *src & 0x0f;
 713                         else
 714                                 srcval = (*src & 0xf0) >> 4;
 715                         if (dstbit)
 716                                 *dst = (*dst & 0xf0) | srcval;
 717                         else
 718                                 *dst = (*dst & 0x0f) | (srcval << 4);
 719                         src += src_step;
 720                         srcbit += srcbit_step;
 721                         if (srcbit == 8) {
 722                                 src++;
 723                                 srcbit = 0;
 724                         }
 725                         dst += dst_step;
 726                         dstbit += dstbit_step;
 727                         if (dstbit == 8) {
 728                                 dst++;
 729                                 dstbit = 0;
 730                         }
 731                 }
 732         } else {
 733                 width /= 8;
 734                 while (samples-- > 0) {
 735                         memcpy(dst, src, width);
 736                         src += src_step;
 737                         dst += dst_step;
 738                 }
 739         }
 740         return 0;
 741 }