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 <linux/slab.h>
  28 #include <linux/time.h>
  29 #include <linux/vmalloc.h>
  30 #include <sound/core.h>
  31 #include <sound/pcm.h>
  32 #include <sound/pcm_params.h>
  33 #include "pcm_plugin.h"
  34
  35 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
  36 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
  37
  38 /*
  39  *  because some cards might have rates "very close", we ignore
  40  *  all "resampling" requests within +-5%
  41  */
  42 static int rate_match(unsigned int src_rate, unsigned int dst_rate)
  43 {
  44         unsigned int low = (src_rate * 95) / 100;
  45         unsigned int high = (src_rate * 105) / 100;
  46         return dst_rate >= low && dst_rate <= high;
  47 }
  48
  49 static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
  50 {
  51         struct snd_pcm_plugin_format *format;
  52         ssize_t width;
  53         size_t size;
  54         unsigned int channel;
  55         struct snd_pcm_plugin_channel *c;
  56
  57         if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  58                 format = &plugin->src_format;
  59         } else {
  60                 format = &plugin->dst_format;
  61         }
  62         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
  63                 return width;
  64         size = frames * format->channels * width;
  65         if (snd_BUG_ON(size % 8))
  66                 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                 if (snd_BUG_ON(size % format->channels))
  89                         return -EINVAL;
  90                 size /= format->channels;
  91                 for (channel = 0; channel < format->channels; channel++, c++) {
  92                         c->frames = frames;
  93                         c->enabled = 1;
  94                         c->wanted = 0;
  95                         c->area.addr = plugin->buf + (channel * size);
  96                         c->area.first = 0;
  97                         c->area.step = width;
  98                 }
  99         } else
 100                 return -EINVAL;
 101         return 0;
 102 }
 103
 104 int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
 105 {
 106         int err;
 107         if (snd_BUG_ON(!snd_pcm_plug_first(plug)))
 108                 return -ENXIO;
 109         if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
 110                 struct snd_pcm_plugin *plugin = snd_pcm_plug_first(plug);
 111                 while (plugin->next) {
 112                         if (plugin->dst_frames)
 113                                 frames = plugin->dst_frames(plugin, frames);
 114                         if (snd_BUG_ON(frames <= 0))
 115                                 return -ENXIO;
 116                         plugin = plugin->next;
 117                         err = snd_pcm_plugin_alloc(plugin, frames);
 118                         if (err < 0)
 119                                 return err;
 120                 }
 121         } else {
 122                 struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
 123                 while (plugin->prev) {
 124                         if (plugin->src_frames)
 125                                 frames = plugin->src_frames(plugin, frames);
 126                         if (snd_BUG_ON(frames <= 0))
 127                                 return -ENXIO;
 128                         plugin = plugin->prev;
 129                         err = snd_pcm_plugin_alloc(plugin, frames);
 130                         if (err < 0)
 131                                 return err;
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137
 138 snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
 139                                        snd_pcm_uframes_t frames,
 140                                        struct snd_pcm_plugin_channel **channels)
 141 {
 142         *channels = plugin->buf_channels;
 143         return frames;
 144 }
 145
 146 int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
 147                          const char *name,
 148                          struct snd_pcm_plugin_format *src_format,
 149                          struct snd_pcm_plugin_format *dst_format,
 150                          size_t extra,
 151                          struct snd_pcm_plugin **ret)
 152 {
 153         struct snd_pcm_plugin *plugin;
 154         unsigned int channels;
 155
 156         if (snd_BUG_ON(!plug))
 157                 return -ENXIO;
 158         if (snd_BUG_ON(!src_format || !dst_format))
 159                 return -ENXIO;
 160         plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
 161         if (plugin == NULL)
 162                 return -ENOMEM;
 163         plugin->name = name;
 164         plugin->plug = plug;
 165         plugin->stream = snd_pcm_plug_stream(plug);
 166         plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 167         plugin->src_format = *src_format;
 168         plugin->src_width = snd_pcm_format_physical_width(src_format->format);
 169         snd_BUG_ON(plugin->src_width <= 0);
 170         plugin->dst_format = *dst_format;
 171         plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
 172         snd_BUG_ON(plugin->dst_width <= 0);
 173         if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
 174                 channels = src_format->channels;
 175         else
 176                 channels = dst_format->channels;
 177         plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
 178         if (plugin->buf_channels == NULL) {
 179                 snd_pcm_plugin_free(plugin);
 180                 return -ENOMEM;
 181         }
 182         plugin->client_channels = snd_pcm_plugin_client_channels;
 183         *ret = plugin;
 184         return 0;
 185 }
 186
 187 int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
 188 {
 189         if (! plugin)
 190                 return 0;
 191         if (plugin->private_free)
 192                 plugin->private_free(plugin);
 193         kfree(plugin->buf_channels);
 194         vfree(plugin->buf);
 195         kfree(plugin);
 196         return 0;
 197 }
 198
 199 snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
 200 {
 201         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
 202         int stream = snd_pcm_plug_stream(plug);
 203
 204         if (snd_BUG_ON(!plug))
 205                 return -ENXIO;
 206         if (drv_frames == 0)
 207                 return 0;
 208         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 209                 plugin = snd_pcm_plug_last(plug);
 210                 while (plugin && drv_frames > 0) {
 211                         plugin_prev = plugin->prev;
 212                         if (plugin->src_frames)
 213                                 drv_frames = plugin->src_frames(plugin, drv_frames);
 214                         plugin = plugin_prev;
 215                 }
 216         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 217                 plugin = snd_pcm_plug_first(plug);
 218                 while (plugin && drv_frames > 0) {
 219                         plugin_next = plugin->next;
 220                         if (plugin->dst_frames)
 221                                 drv_frames = plugin->dst_frames(plugin, drv_frames);
 222                         plugin = plugin_next;
 223                 }
 224         } else
 225                 snd_BUG();
 226         return drv_frames;
 227 }
 228
 229 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
 230 {
 231         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
 232         snd_pcm_sframes_t frames;
 233         int stream = snd_pcm_plug_stream(plug);
 234
 235         if (snd_BUG_ON(!plug))
 236                 return -ENXIO;
 237         if (clt_frames == 0)
 238                 return 0;
 239         frames = clt_frames;
 240         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 241                 plugin = snd_pcm_plug_first(plug);
 242                 while (plugin && frames > 0) {
 243                         plugin_next = plugin->next;
 244                         if (plugin->dst_frames) {
 245                                 frames = plugin->dst_frames(plugin, frames);
 246                                 if (frames < 0)
 247                                         return frames;
 248                         }
 249                         plugin = plugin_next;
 250                 }
 251         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 252                 plugin = snd_pcm_plug_last(plug);
 253                 while (plugin) {
 254                         plugin_prev = plugin->prev;
 255                         if (plugin->src_frames) {
 256                                 frames = plugin->src_frames(plugin, frames);
 257                                 if (frames < 0)
 258                                         return frames;
 259                         }
 260                         plugin = plugin_prev;
 261                 }
 262         } else
 263                 snd_BUG();
 264         return frames;
 265 }
 266
 267 static int snd_pcm_plug_formats(struct snd_mask *mask, int format)
 268 {
 269         struct snd_mask formats = *mask;
 270         u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
 271                        SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
 272                        SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
 273                        SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
 274                        SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
 275                        SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
 276                        SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
 277                        SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
 278                        SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
 279         snd_mask_set(&formats, SNDRV_PCM_FORMAT_MU_LAW);
 280
 281         if (formats.bits[0] & (u32)linfmts)
 282                 formats.bits[0] |= (u32)linfmts;
 283         if (formats.bits[1] & (u32)(linfmts >> 32))
 284                 formats.bits[1] |= (u32)(linfmts >> 32);
 285         return snd_mask_test(&formats, format);
 286 }
 287
 288 static int preferred_formats[] = {
 289         SNDRV_PCM_FORMAT_S16_LE,
 290         SNDRV_PCM_FORMAT_S16_BE,
 291         SNDRV_PCM_FORMAT_U16_LE,
 292         SNDRV_PCM_FORMAT_U16_BE,
 293         SNDRV_PCM_FORMAT_S24_3LE,
 294         SNDRV_PCM_FORMAT_S24_3BE,
 295         SNDRV_PCM_FORMAT_U24_3LE,
 296         SNDRV_PCM_FORMAT_U24_3BE,
 297         SNDRV_PCM_FORMAT_S24_LE,
 298         SNDRV_PCM_FORMAT_S24_BE,
 299         SNDRV_PCM_FORMAT_U24_LE,
 300         SNDRV_PCM_FORMAT_U24_BE,
 301         SNDRV_PCM_FORMAT_S32_LE,
 302         SNDRV_PCM_FORMAT_S32_BE,
 303         SNDRV_PCM_FORMAT_U32_LE,
 304         SNDRV_PCM_FORMAT_U32_BE,
 305         SNDRV_PCM_FORMAT_S8,
 306         SNDRV_PCM_FORMAT_U8
 307 };
 308
 309 int snd_pcm_plug_slave_format(int format, struct snd_mask *format_mask)
 310 {
 311         int i;
 312
 313         if (snd_mask_test(format_mask, format))
 314                 return format;
 315         if (! snd_pcm_plug_formats(format_mask, format))
 316                 return -EINVAL;
 317         if (snd_pcm_format_linear(format)) {
 318                 unsigned int width = snd_pcm_format_width(format);
 319                 int unsignd = snd_pcm_format_unsigned(format) > 0;
 320                 int big = snd_pcm_format_big_endian(format) > 0;
 321                 unsigned int badness, best = -1;
 322                 int best_format = -1;
 323                 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
 324                         int f = preferred_formats[i];
 325                         unsigned int w;
 326                         if (!snd_mask_test(format_mask, f))
 327                                 continue;
 328                         w = snd_pcm_format_width(f);
 329                         if (w >= width)
 330                                 badness = w - width;
 331                         else
 332                                 badness = width - w + 32;
 333                         badness += snd_pcm_format_unsigned(f) != unsignd;
 334                         badness += snd_pcm_format_big_endian(f) != big;
 335                         if (badness < best) {
 336                                 best_format = f;
 337                                 best = badness;
 338                         }
 339                 }
 340                 return best_format >= 0 ? best_format : -EINVAL;
 341         } else {
 342                 switch (format) {
 343                 case SNDRV_PCM_FORMAT_MU_LAW:
 344                         for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
 345                                 int format1 = preferred_formats[i];
 346                                 if (snd_mask_test(format_mask, format1))
 347                                         return format1;
 348                         }
 349                 default:
 350                         return -EINVAL;
 351                 }
 352         }
 353 }
 354
 355 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
 356                                 struct snd_pcm_hw_params *params,
 357                                 struct snd_pcm_hw_params *slave_params)
 358 {
 359         struct snd_pcm_plugin_format tmpformat;
 360         struct snd_pcm_plugin_format dstformat;
 361         struct snd_pcm_plugin_format srcformat;
 362         int src_access, dst_access;
 363         struct snd_pcm_plugin *plugin = NULL;
 364         int err;
 365         int stream = snd_pcm_plug_stream(plug);
 366         int slave_interleaved = (params_channels(slave_params) == 1 ||
 367                                  params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
 368
 369         switch (stream) {
 370         case SNDRV_PCM_STREAM_PLAYBACK:
 371                 dstformat.format = params_format(slave_params);
 372                 dstformat.rate = params_rate(slave_params);
 373                 dstformat.channels = params_channels(slave_params);
 374                 srcformat.format = params_format(params);
 375                 srcformat.rate = params_rate(params);
 376                 srcformat.channels = params_channels(params);
 377                 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 378                 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 379                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 380                 break;
 381         case SNDRV_PCM_STREAM_CAPTURE:
 382                 dstformat.format = params_format(params);
 383                 dstformat.rate = params_rate(params);
 384                 dstformat.channels = params_channels(params);
 385                 srcformat.format = params_format(slave_params);
 386                 srcformat.rate = params_rate(slave_params);
 387                 srcformat.channels = params_channels(slave_params);
 388                 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 389                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 390                 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 391                 break;
 392         default:
 393                 snd_BUG();
 394                 return -EINVAL;
 395         }
 396         tmpformat = srcformat;
 397
 398         pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
 399                  srcformat.format,
 400                  srcformat.rate,
 401                  srcformat.channels);
 402         pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
 403                  dstformat.format,
 404                  dstformat.rate,
 405                  dstformat.channels);
 406
 407         /* Format change (linearization) */
 408         if (! rate_match(srcformat.rate, dstformat.rate) &&
 409             ! snd_pcm_format_linear(srcformat.format)) {
 410                 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
 411                         return -EINVAL;
 412                 tmpformat.format = SNDRV_PCM_FORMAT_S16;
 413                 err = snd_pcm_plugin_build_mulaw(plug,
 414                                                  &srcformat, &tmpformat,
 415                                                  &plugin);
 416                 if (err < 0)
 417                         return err;
 418                 err = snd_pcm_plugin_append(plugin);
 419                 if (err < 0) {
 420                         snd_pcm_plugin_free(plugin);
 421                         return err;
 422                 }
 423                 srcformat = tmpformat;
 424                 src_access = dst_access;
 425         }
 426
 427         /* channels reduction */
 428         if (srcformat.channels > dstformat.channels) {
 429                 tmpformat.channels = dstformat.channels;
 430                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 431                 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 432                 if (err < 0)
 433                         return err;
 434                 err = snd_pcm_plugin_append(plugin);
 435                 if (err < 0) {
 436                         snd_pcm_plugin_free(plugin);
 437                         return err;
 438                 }
 439                 srcformat = tmpformat;
 440                 src_access = dst_access;
 441         }
 442
 443         /* rate resampling */
 444         if (!rate_match(srcformat.rate, dstformat.rate)) {
 445                 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
 446                         /* convert to S16 for resampling */
 447                         tmpformat.format = SNDRV_PCM_FORMAT_S16;
 448                         err = snd_pcm_plugin_build_linear(plug,
 449                                                           &srcformat, &tmpformat,
 450                                                           &plugin);
 451                         if (err < 0)
 452                                 return err;
 453                         err = snd_pcm_plugin_append(plugin);
 454                         if (err < 0) {
 455                                 snd_pcm_plugin_free(plugin);
 456                                 return err;
 457                         }
 458                         srcformat = tmpformat;
 459                         src_access = dst_access;
 460                 }
 461                 tmpformat.rate = dstformat.rate;
 462                 err = snd_pcm_plugin_build_rate(plug,
 463                                                 &srcformat, &tmpformat,
 464                                                 &plugin);
 465                 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
 466                 if (err < 0)
 467                         return err;
 468                 err = snd_pcm_plugin_append(plugin);
 469                 if (err < 0) {
 470                         snd_pcm_plugin_free(plugin);
 471                         return err;
 472                 }
 473                 srcformat = tmpformat;
 474                 src_access = dst_access;
 475         }
 476
 477         /* format change */
 478         if (srcformat.format != dstformat.format) {
 479                 tmpformat.format = dstformat.format;
 480                 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
 481                     tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
 482                         err = snd_pcm_plugin_build_mulaw(plug,
 483                                                          &srcformat, &tmpformat,
 484                                                          &plugin);
 485                 }
 486                 else if (snd_pcm_format_linear(srcformat.format) &&
 487                          snd_pcm_format_linear(tmpformat.format)) {
 488                         err = snd_pcm_plugin_build_linear(plug,
 489                                                           &srcformat, &tmpformat,
 490                                                           &plugin);
 491                 }
 492                 else
 493                         return -EINVAL;
 494                 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
 495                 if (err < 0)
 496                         return err;
 497                 err = snd_pcm_plugin_append(plugin);
 498                 if (err < 0) {
 499                         snd_pcm_plugin_free(plugin);
 500                         return err;
 501                 }
 502                 srcformat = tmpformat;
 503                 src_access = dst_access;
 504         }
 505
 506         /* channels extension */
 507         if (srcformat.channels < dstformat.channels) {
 508                 tmpformat.channels = dstformat.channels;
 509                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 510                 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 511                 if (err < 0)
 512                         return err;
 513                 err = snd_pcm_plugin_append(plugin);
 514                 if (err < 0) {
 515                         snd_pcm_plugin_free(plugin);
 516                         return err;
 517                 }
 518                 srcformat = tmpformat;
 519                 src_access = dst_access;
 520         }
 521
 522         /* de-interleave */
 523         if (src_access != dst_access) {
 524                 err = snd_pcm_plugin_build_copy(plug,
 525                                                 &srcformat,
 526                                                 &tmpformat,
 527                                                 &plugin);
 528                 pdprintf("interleave change (copy: returns %i)\n", err);
 529                 if (err < 0)
 530                         return err;
 531                 err = snd_pcm_plugin_append(plugin);
 532                 if (err < 0) {
 533                         snd_pcm_plugin_free(plugin);
 534                         return err;
 535                 }
 536         }
 537
 538         return 0;
 539 }
 540
 541 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
 542                                          char *buf,
 543                                          snd_pcm_uframes_t count,
 544                                          struct snd_pcm_plugin_channel **channels)
 545 {
 546         struct snd_pcm_plugin *plugin;
 547         struct snd_pcm_plugin_channel *v;
 548         struct snd_pcm_plugin_format *format;
 549         int width, nchannels, channel;
 550         int stream = snd_pcm_plug_stream(plug);
 551
 552         if (snd_BUG_ON(!buf))
 553                 return -ENXIO;
 554         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 555                 plugin = snd_pcm_plug_first(plug);
 556                 format = &plugin->src_format;
 557         } else {
 558                 plugin = snd_pcm_plug_last(plug);
 559                 format = &plugin->dst_format;
 560         }
 561         v = plugin->buf_channels;
 562         *channels = v;
 563         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
 564                 return width;
 565         nchannels = format->channels;
 566         if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
 567                        format->channels > 1))
 568                 return -ENXIO;
 569         for (channel = 0; channel < nchannels; channel++, v++) {
 570                 v->frames = count;
 571                 v->enabled = 1;
 572                 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
 573                 v->area.addr = buf;
 574                 v->area.first = channel * width;
 575                 v->area.step = nchannels * width;
 576         }
 577         return count;
 578 }
 579
 580 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)
 581 {
 582         struct snd_pcm_plugin *plugin, *next;
 583         struct snd_pcm_plugin_channel *dst_channels;
 584         int err;
 585         snd_pcm_sframes_t frames = size;
 586
 587         plugin = snd_pcm_plug_first(plug);
 588         while (plugin && frames > 0) {
 589                 if ((next = plugin->next) != NULL) {
 590                         snd_pcm_sframes_t frames1 = frames;
 591                         if (plugin->dst_frames)
 592                                 frames1 = plugin->dst_frames(plugin, frames);
 593                         if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
 594                                 return err;
 595                         }
 596                         if (err != frames1) {
 597                                 frames = err;
 598                                 if (plugin->src_frames)
 599                                         frames = plugin->src_frames(plugin, frames1);
 600                         }
 601                 } else
 602                         dst_channels = NULL;
 603                 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
 604                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 605                         return frames;
 606                 src_channels = dst_channels;
 607                 plugin = next;
 608         }
 609         return snd_pcm_plug_client_size(plug, frames);
 610 }
 611
 612 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)
 613 {
 614         struct snd_pcm_plugin *plugin, *next;
 615         struct snd_pcm_plugin_channel *src_channels, *dst_channels;
 616         snd_pcm_sframes_t frames = size;
 617         int err;
 618
 619         frames = snd_pcm_plug_slave_size(plug, frames);
 620         if (frames < 0)
 621                 return frames;
 622
 623         src_channels = NULL;
 624         plugin = snd_pcm_plug_first(plug);
 625         while (plugin && frames > 0) {
 626                 if ((next = plugin->next) != NULL) {
 627                         if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
 628                                 return err;
 629                         }
 630                         frames = err;
 631                 } else {
 632                         dst_channels = dst_channels_final;
 633                 }
 634                 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
 635                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 636                         return frames;
 637                 plugin = next;
 638                 src_channels = dst_channels;
 639         }
 640         return frames;
 641 }
 642
 643 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 644                          size_t samples, int format)
 645 {
 646         /* FIXME: sub byte resolution and odd dst_offset */
 647         unsigned char *dst;
 648         unsigned int dst_step;
 649         int width;
 650         const unsigned char *silence;
 651         if (!dst_area->addr)
 652                 return 0;
 653         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 654         width = snd_pcm_format_physical_width(format);
 655         if (width <= 0)
 656                 return -EINVAL;
 657         if (dst_area->step == (unsigned int) width && width >= 8)
 658                 return snd_pcm_format_set_silence(format, dst, samples);
 659         silence = snd_pcm_format_silence_64(format);
 660         if (! silence)
 661                 return -EINVAL;
 662         dst_step = dst_area->step / 8;
 663         if (width == 4) {
 664                 /* Ima ADPCM */
 665                 int dstbit = dst_area->first % 8;
 666                 int dstbit_step = dst_area->step % 8;
 667                 while (samples-- > 0) {
 668                         if (dstbit)
 669                                 *dst &= 0xf0;
 670                         else
 671                                 *dst &= 0x0f;
 672                         dst += dst_step;
 673                         dstbit += dstbit_step;
 674                         if (dstbit == 8) {
 675                                 dst++;
 676                                 dstbit = 0;
 677                         }
 678                 }
 679         } else {
 680                 width /= 8;
 681                 while (samples-- > 0) {
 682                         memcpy(dst, silence, width);
 683                         dst += dst_step;
 684                 }
 685         }
 686         return 0;
 687 }
 688
 689 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
 690                       const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 691                       size_t samples, int format)
 692 {
 693         /* FIXME: sub byte resolution and odd dst_offset */
 694         char *src, *dst;
 695         int width;
 696         int src_step, dst_step;
 697         src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
 698         if (!src_area->addr)
 699                 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
 700         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 701         if (!dst_area->addr)
 702                 return 0;
 703         width = snd_pcm_format_physical_width(format);
 704         if (width <= 0)
 705                 return -EINVAL;
 706         if (src_area->step == (unsigned int) width &&
 707             dst_area->step == (unsigned int) width && width >= 8) {
 708                 size_t bytes = samples * width / 8;
 709                 memcpy(dst, src, bytes);
 710                 return 0;
 711         }
 712         src_step = src_area->step / 8;
 713         dst_step = dst_area->step / 8;
 714         if (width == 4) {
 715                 /* Ima ADPCM */
 716                 int srcbit = src_area->first % 8;
 717                 int srcbit_step = src_area->step % 8;
 718                 int dstbit = dst_area->first % 8;
 719                 int dstbit_step = dst_area->step % 8;
 720                 while (samples-- > 0) {
 721                         unsigned char srcval;
 722                         if (srcbit)
 723                                 srcval = *src & 0x0f;
 724                         else
 725                                 srcval = (*src & 0xf0) >> 4;
 726                         if (dstbit)
 727                                 *dst = (*dst & 0xf0) | srcval;
 728                         else
 729                                 *dst = (*dst & 0x0f) | (srcval << 4);
 730                         src += src_step;
 731                         srcbit += srcbit_step;
 732                         if (srcbit == 8) {
 733                                 src++;
 734                                 srcbit = 0;
 735                         }
 736                         dst += dst_step;
 737                         dstbit += dstbit_step;
 738                         if (dstbit == 8) {
 739                                 dst++;
 740                                 dstbit = 0;
 741                         }
 742                 }
 743         } else {
 744                 width /= 8;
 745                 while (samples-- > 0) {
 746                         memcpy(dst, src, width);
 747                         src += src_step;
 748                         dst += dst_step;
 749                 }
 750         }
 751         return 0;
 752 }