kernel/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;
 203
 204         if (snd_BUG_ON(!plug))
 205                 return -ENXIO;
 206         if (drv_frames == 0)
 207                 return 0;
 208         stream = snd_pcm_plug_stream(plug);
 209         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 210                 plugin = snd_pcm_plug_last(plug);
 211                 while (plugin && drv_frames > 0) {
 212                         plugin_prev = plugin->prev;
 213                         if (plugin->src_frames)
 214                                 drv_frames = plugin->src_frames(plugin, drv_frames);
 215                         plugin = plugin_prev;
 216                 }
 217         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 218                 plugin = snd_pcm_plug_first(plug);
 219                 while (plugin && drv_frames > 0) {
 220                         plugin_next = plugin->next;
 221                         if (plugin->dst_frames)
 222                                 drv_frames = plugin->dst_frames(plugin, drv_frames);
 223                         plugin = plugin_next;
 224                 }
 225         } else
 226                 snd_BUG();
 227         return drv_frames;
 228 }
 229
 230 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
 231 {
 232         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
 233         snd_pcm_sframes_t frames;
 234         int stream;
 235
 236         if (snd_BUG_ON(!plug))
 237                 return -ENXIO;
 238         if (clt_frames == 0)
 239                 return 0;
 240         frames = clt_frames;
 241         stream = snd_pcm_plug_stream(plug);
 242         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 243                 plugin = snd_pcm_plug_first(plug);
 244                 while (plugin && frames > 0) {
 245                         plugin_next = plugin->next;
 246                         if (plugin->dst_frames) {
 247                                 frames = plugin->dst_frames(plugin, frames);
 248                                 if (frames < 0)
 249                                         return frames;
 250                         }
 251                         plugin = plugin_next;
 252                 }
 253         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 254                 plugin = snd_pcm_plug_last(plug);
 255                 while (plugin) {
 256                         plugin_prev = plugin->prev;
 257                         if (plugin->src_frames) {
 258                                 frames = plugin->src_frames(plugin, frames);
 259                                 if (frames < 0)
 260                                         return frames;
 261                         }
 262                         plugin = plugin_prev;
 263                 }
 264         } else
 265                 snd_BUG();
 266         return frames;
 267 }
 268
 269 static int snd_pcm_plug_formats(struct snd_mask *mask, snd_pcm_format_t format)
 270 {
 271         struct snd_mask formats = *mask;
 272         u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
 273                        SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
 274                        SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
 275                        SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
 276                        SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
 277                        SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
 278                        SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
 279                        SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
 280                        SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
 281         snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
 282
 283         if (formats.bits[0] & (u32)linfmts)
 284                 formats.bits[0] |= (u32)linfmts;
 285         if (formats.bits[1] & (u32)(linfmts >> 32))
 286                 formats.bits[1] |= (u32)(linfmts >> 32);
 287         return snd_mask_test(&formats, (__force int)format);
 288 }
 289
 290 static snd_pcm_format_t preferred_formats[] = {
 291         SNDRV_PCM_FORMAT_S16_LE,
 292         SNDRV_PCM_FORMAT_S16_BE,
 293         SNDRV_PCM_FORMAT_U16_LE,
 294         SNDRV_PCM_FORMAT_U16_BE,
 295         SNDRV_PCM_FORMAT_S24_3LE,
 296         SNDRV_PCM_FORMAT_S24_3BE,
 297         SNDRV_PCM_FORMAT_U24_3LE,
 298         SNDRV_PCM_FORMAT_U24_3BE,
 299         SNDRV_PCM_FORMAT_S24_LE,
 300         SNDRV_PCM_FORMAT_S24_BE,
 301         SNDRV_PCM_FORMAT_U24_LE,
 302         SNDRV_PCM_FORMAT_U24_BE,
 303         SNDRV_PCM_FORMAT_S32_LE,
 304         SNDRV_PCM_FORMAT_S32_BE,
 305         SNDRV_PCM_FORMAT_U32_LE,
 306         SNDRV_PCM_FORMAT_U32_BE,
 307         SNDRV_PCM_FORMAT_S8,
 308         SNDRV_PCM_FORMAT_U8
 309 };
 310
 311 snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
 312                                            struct snd_mask *format_mask)
 313 {
 314         int i;
 315
 316         if (snd_mask_test(format_mask, (__force int)format))
 317                 return format;
 318         if (!snd_pcm_plug_formats(format_mask, format))
 319                 return (__force snd_pcm_format_t)-EINVAL;
 320         if (snd_pcm_format_linear(format)) {
 321                 unsigned int width = snd_pcm_format_width(format);
 322                 int unsignd = snd_pcm_format_unsigned(format) > 0;
 323                 int big = snd_pcm_format_big_endian(format) > 0;
 324                 unsigned int badness, best = -1;
 325                 snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
 326                 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
 327                         snd_pcm_format_t f = preferred_formats[i];
 328                         unsigned int w;
 329                         if (!snd_mask_test(format_mask, (__force int)f))
 330                                 continue;
 331                         w = snd_pcm_format_width(f);
 332                         if (w >= width)
 333                                 badness = w - width;
 334                         else
 335                                 badness = width - w + 32;
 336                         badness += snd_pcm_format_unsigned(f) != unsignd;
 337                         badness += snd_pcm_format_big_endian(f) != big;
 338                         if (badness < best) {
 339                                 best_format = f;
 340                                 best = badness;
 341                         }
 342                 }
 343                 if ((__force int)best_format >= 0)
 344                         return best_format;
 345                 else
 346                         return (__force snd_pcm_format_t)-EINVAL;
 347         } else {
 348                 switch (format) {
 349                 case SNDRV_PCM_FORMAT_MU_LAW:
 350                         for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
 351                                 snd_pcm_format_t format1 = preferred_formats[i];
 352                                 if (snd_mask_test(format_mask, (__force int)format1))
 353                                         return format1;
 354                         }
 355                 default:
 356                         return (__force snd_pcm_format_t)-EINVAL;
 357                 }
 358         }
 359 }
 360
 361 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
 362                                 struct snd_pcm_hw_params *params,
 363                                 struct snd_pcm_hw_params *slave_params)
 364 {
 365         struct snd_pcm_plugin_format tmpformat;
 366         struct snd_pcm_plugin_format dstformat;
 367         struct snd_pcm_plugin_format srcformat;
 368         snd_pcm_access_t src_access, dst_access;
 369         struct snd_pcm_plugin *plugin = NULL;
 370         int err;
 371         int stream = snd_pcm_plug_stream(plug);
 372         int slave_interleaved = (params_channels(slave_params) == 1 ||
 373                                  params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
 374
 375         switch (stream) {
 376         case SNDRV_PCM_STREAM_PLAYBACK:
 377                 dstformat.format = params_format(slave_params);
 378                 dstformat.rate = params_rate(slave_params);
 379                 dstformat.channels = params_channels(slave_params);
 380                 srcformat.format = params_format(params);
 381                 srcformat.rate = params_rate(params);
 382                 srcformat.channels = params_channels(params);
 383                 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 384                 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 385                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 386                 break;
 387         case SNDRV_PCM_STREAM_CAPTURE:
 388                 dstformat.format = params_format(params);
 389                 dstformat.rate = params_rate(params);
 390                 dstformat.channels = params_channels(params);
 391                 srcformat.format = params_format(slave_params);
 392                 srcformat.rate = params_rate(slave_params);
 393                 srcformat.channels = params_channels(slave_params);
 394                 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 395                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 396                 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 397                 break;
 398         default:
 399                 snd_BUG();
 400                 return -EINVAL;
 401         }
 402         tmpformat = srcformat;
 403
 404         pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
 405                  srcformat.format,
 406                  srcformat.rate,
 407                  srcformat.channels);
 408         pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
 409                  dstformat.format,
 410                  dstformat.rate,
 411                  dstformat.channels);
 412
 413         /* Format change (linearization) */
 414         if (! rate_match(srcformat.rate, dstformat.rate) &&
 415             ! snd_pcm_format_linear(srcformat.format)) {
 416                 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
 417                         return -EINVAL;
 418                 tmpformat.format = SNDRV_PCM_FORMAT_S16;
 419                 err = snd_pcm_plugin_build_mulaw(plug,
 420                                                  &srcformat, &tmpformat,
 421                                                  &plugin);
 422                 if (err < 0)
 423                         return err;
 424                 err = snd_pcm_plugin_append(plugin);
 425                 if (err < 0) {
 426                         snd_pcm_plugin_free(plugin);
 427                         return err;
 428                 }
 429                 srcformat = tmpformat;
 430                 src_access = dst_access;
 431         }
 432
 433         /* channels reduction */
 434         if (srcformat.channels > dstformat.channels) {
 435                 tmpformat.channels = dstformat.channels;
 436                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 437                 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 438                 if (err < 0)
 439                         return err;
 440                 err = snd_pcm_plugin_append(plugin);
 441                 if (err < 0) {
 442                         snd_pcm_plugin_free(plugin);
 443                         return err;
 444                 }
 445                 srcformat = tmpformat;
 446                 src_access = dst_access;
 447         }
 448
 449         /* rate resampling */
 450         if (!rate_match(srcformat.rate, dstformat.rate)) {
 451                 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
 452                         /* convert to S16 for resampling */
 453                         tmpformat.format = SNDRV_PCM_FORMAT_S16;
 454                         err = snd_pcm_plugin_build_linear(plug,
 455                                                           &srcformat, &tmpformat,
 456                                                           &plugin);
 457                         if (err < 0)
 458                                 return err;
 459                         err = snd_pcm_plugin_append(plugin);
 460                         if (err < 0) {
 461                                 snd_pcm_plugin_free(plugin);
 462                                 return err;
 463                         }
 464                         srcformat = tmpformat;
 465                         src_access = dst_access;
 466                 }
 467                 tmpformat.rate = dstformat.rate;
 468                 err = snd_pcm_plugin_build_rate(plug,
 469                                                 &srcformat, &tmpformat,
 470                                                 &plugin);
 471                 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
 472                 if (err < 0)
 473                         return err;
 474                 err = snd_pcm_plugin_append(plugin);
 475                 if (err < 0) {
 476                         snd_pcm_plugin_free(plugin);
 477                         return err;
 478                 }
 479                 srcformat = tmpformat;
 480                 src_access = dst_access;
 481         }
 482
 483         /* format change */
 484         if (srcformat.format != dstformat.format) {
 485                 tmpformat.format = dstformat.format;
 486                 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
 487                     tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
 488                         err = snd_pcm_plugin_build_mulaw(plug,
 489                                                          &srcformat, &tmpformat,
 490                                                          &plugin);
 491                 }
 492                 else if (snd_pcm_format_linear(srcformat.format) &&
 493                          snd_pcm_format_linear(tmpformat.format)) {
 494                         err = snd_pcm_plugin_build_linear(plug,
 495                                                           &srcformat, &tmpformat,
 496                                                           &plugin);
 497                 }
 498                 else
 499                         return -EINVAL;
 500                 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
 501                 if (err < 0)
 502                         return err;
 503                 err = snd_pcm_plugin_append(plugin);
 504                 if (err < 0) {
 505                         snd_pcm_plugin_free(plugin);
 506                         return err;
 507                 }
 508                 srcformat = tmpformat;
 509                 src_access = dst_access;
 510         }
 511
 512         /* channels extension */
 513         if (srcformat.channels < dstformat.channels) {
 514                 tmpformat.channels = dstformat.channels;
 515                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 516                 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 517                 if (err < 0)
 518                         return err;
 519                 err = snd_pcm_plugin_append(plugin);
 520                 if (err < 0) {
 521                         snd_pcm_plugin_free(plugin);
 522                         return err;
 523                 }
 524                 srcformat = tmpformat;
 525                 src_access = dst_access;
 526         }
 527
 528         /* de-interleave */
 529         if (src_access != dst_access) {
 530                 err = snd_pcm_plugin_build_copy(plug,
 531                                                 &srcformat,
 532                                                 &tmpformat,
 533                                                 &plugin);
 534                 pdprintf("interleave change (copy: returns %i)\n", err);
 535                 if (err < 0)
 536                         return err;
 537                 err = snd_pcm_plugin_append(plugin);
 538                 if (err < 0) {
 539                         snd_pcm_plugin_free(plugin);
 540                         return err;
 541                 }
 542         }
 543
 544         return 0;
 545 }
 546
 547 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
 548                                          char *buf,
 549                                          snd_pcm_uframes_t count,
 550                                          struct snd_pcm_plugin_channel **channels)
 551 {
 552         struct snd_pcm_plugin *plugin;
 553         struct snd_pcm_plugin_channel *v;
 554         struct snd_pcm_plugin_format *format;
 555         int width, nchannels, channel;
 556         int stream = snd_pcm_plug_stream(plug);
 557
 558         if (snd_BUG_ON(!buf))
 559                 return -ENXIO;
 560         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 561                 plugin = snd_pcm_plug_first(plug);
 562                 format = &plugin->src_format;
 563         } else {
 564                 plugin = snd_pcm_plug_last(plug);
 565                 format = &plugin->dst_format;
 566         }
 567         v = plugin->buf_channels;
 568         *channels = v;
 569         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
 570                 return width;
 571         nchannels = format->channels;
 572         if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
 573                        format->channels > 1))
 574                 return -ENXIO;
 575         for (channel = 0; channel < nchannels; channel++, v++) {
 576                 v->frames = count;
 577                 v->enabled = 1;
 578                 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
 579                 v->area.addr = buf;
 580                 v->area.first = channel * width;
 581                 v->area.step = nchannels * width;
 582         }
 583         return count;
 584 }
 585
 586 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)
 587 {
 588         struct snd_pcm_plugin *plugin, *next;
 589         struct snd_pcm_plugin_channel *dst_channels;
 590         int err;
 591         snd_pcm_sframes_t frames = size;
 592
 593         plugin = snd_pcm_plug_first(plug);
 594         while (plugin && frames > 0) {
 595                 if ((next = plugin->next) != NULL) {
 596                         snd_pcm_sframes_t frames1 = frames;
 597                         if (plugin->dst_frames)
 598                                 frames1 = plugin->dst_frames(plugin, frames);
 599                         if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
 600                                 return err;
 601                         }
 602                         if (err != frames1) {
 603                                 frames = err;
 604                                 if (plugin->src_frames)
 605                                         frames = plugin->src_frames(plugin, frames1);
 606                         }
 607                 } else
 608                         dst_channels = NULL;
 609                 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
 610                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 611                         return frames;
 612                 src_channels = dst_channels;
 613                 plugin = next;
 614         }
 615         return snd_pcm_plug_client_size(plug, frames);
 616 }
 617
 618 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)
 619 {
 620         struct snd_pcm_plugin *plugin, *next;
 621         struct snd_pcm_plugin_channel *src_channels, *dst_channels;
 622         snd_pcm_sframes_t frames = size;
 623         int err;
 624
 625         frames = snd_pcm_plug_slave_size(plug, frames);
 626         if (frames < 0)
 627                 return frames;
 628
 629         src_channels = NULL;
 630         plugin = snd_pcm_plug_first(plug);
 631         while (plugin && frames > 0) {
 632                 if ((next = plugin->next) != NULL) {
 633                         if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
 634                                 return err;
 635                         }
 636                         frames = err;
 637                 } else {
 638                         dst_channels = dst_channels_final;
 639                 }
 640                 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
 641                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 642                         return frames;
 643                 plugin = next;
 644                 src_channels = dst_channels;
 645         }
 646         return frames;
 647 }
 648
 649 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 650                          size_t samples, snd_pcm_format_t format)
 651 {
 652         /* FIXME: sub byte resolution and odd dst_offset */
 653         unsigned char *dst;
 654         unsigned int dst_step;
 655         int width;
 656         const unsigned char *silence;
 657         if (!dst_area->addr)
 658                 return 0;
 659         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 660         width = snd_pcm_format_physical_width(format);
 661         if (width <= 0)
 662                 return -EINVAL;
 663         if (dst_area->step == (unsigned int) width && width >= 8)
 664                 return snd_pcm_format_set_silence(format, dst, samples);
 665         silence = snd_pcm_format_silence_64(format);
 666         if (! silence)
 667                 return -EINVAL;
 668         dst_step = dst_area->step / 8;
 669         if (width == 4) {
 670                 /* Ima ADPCM */
 671                 int dstbit = dst_area->first % 8;
 672                 int dstbit_step = dst_area->step % 8;
 673                 while (samples-- > 0) {
 674                         if (dstbit)
 675                                 *dst &= 0xf0;
 676                         else
 677                                 *dst &= 0x0f;
 678                         dst += dst_step;
 679                         dstbit += dstbit_step;
 680                         if (dstbit == 8) {
 681                                 dst++;
 682                                 dstbit = 0;
 683                         }
 684                 }
 685         } else {
 686                 width /= 8;
 687                 while (samples-- > 0) {
 688                         memcpy(dst, silence, width);
 689                         dst += dst_step;
 690                 }
 691         }
 692         return 0;
 693 }
 694
 695 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
 696                       const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 697                       size_t samples, snd_pcm_format_t format)
 698 {
 699         /* FIXME: sub byte resolution and odd dst_offset */
 700         char *src, *dst;
 701         int width;
 702         int src_step, dst_step;
 703         src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
 704         if (!src_area->addr)
 705                 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
 706         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 707         if (!dst_area->addr)
 708                 return 0;
 709         width = snd_pcm_format_physical_width(format);
 710         if (width <= 0)
 711                 return -EINVAL;
 712         if (src_area->step == (unsigned int) width &&
 713             dst_area->step == (unsigned int) width && width >= 8) {
 714                 size_t bytes = samples * width / 8;
 715                 memcpy(dst, src, bytes);
 716                 return 0;
 717         }
 718         src_step = src_area->step / 8;
 719         dst_step = dst_area->step / 8;
 720         if (width == 4) {
 721                 /* Ima ADPCM */
 722                 int srcbit = src_area->first % 8;
 723                 int srcbit_step = src_area->step % 8;
 724                 int dstbit = dst_area->first % 8;
 725                 int dstbit_step = dst_area->step % 8;
 726                 while (samples-- > 0) {
 727                         unsigned char srcval;
 728                         if (srcbit)
 729                                 srcval = *src & 0x0f;
 730                         else
 731                                 srcval = (*src & 0xf0) >> 4;
 732                         if (dstbit)
 733                                 *dst = (*dst & 0xf0) | srcval;
 734                         else
 735                                 *dst = (*dst & 0x0f) | (srcval << 4);
 736                         src += src_step;
 737                         srcbit += srcbit_step;
 738                         if (srcbit == 8) {
 739                                 src++;
 740                                 srcbit = 0;
 741                         }
 742                         dst += dst_step;
 743                         dstbit += dstbit_step;
 744                         if (dstbit == 8) {
 745                                 dst++;
 746                                 dstbit = 0;
 747                         }
 748                 }
 749         } else {
 750                 width /= 8;
 751                 while (samples-- > 0) {
 752                         memcpy(dst, src, width);
 753                         src += src_step;
 754                         dst += dst_step;
 755                 }
 756         }
 757         return 0;
 758 }