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                 kvfree(plugin->buf);
  70                 plugin->buf = kvzalloc(size, GFP_KERNEL);
  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((snd_pcm_sframes_t)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((snd_pcm_sframes_t)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         kvfree(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(const struct snd_mask *mask,
 270                                 snd_pcm_format_t format)
 271 {
 272         struct snd_mask formats = *mask;
 273         u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
 274                        SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
 275                        SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
 276                        SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
 277                        SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
 278                        SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
 279                        SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
 280                        SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
 281                        SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
 282         snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
 283
 284         if (formats.bits[0] & lower_32_bits(linfmts))
 285                 formats.bits[0] |= lower_32_bits(linfmts);
 286         if (formats.bits[1] & upper_32_bits(linfmts))
 287                 formats.bits[1] |= upper_32_bits(linfmts);
 288         return snd_mask_test(&formats, (__force int)format);
 289 }
 290
 291 static snd_pcm_format_t preferred_formats[] = {
 292         SNDRV_PCM_FORMAT_S16_LE,
 293         SNDRV_PCM_FORMAT_S16_BE,
 294         SNDRV_PCM_FORMAT_U16_LE,
 295         SNDRV_PCM_FORMAT_U16_BE,
 296         SNDRV_PCM_FORMAT_S24_3LE,
 297         SNDRV_PCM_FORMAT_S24_3BE,
 298         SNDRV_PCM_FORMAT_U24_3LE,
 299         SNDRV_PCM_FORMAT_U24_3BE,
 300         SNDRV_PCM_FORMAT_S24_LE,
 301         SNDRV_PCM_FORMAT_S24_BE,
 302         SNDRV_PCM_FORMAT_U24_LE,
 303         SNDRV_PCM_FORMAT_U24_BE,
 304         SNDRV_PCM_FORMAT_S32_LE,
 305         SNDRV_PCM_FORMAT_S32_BE,
 306         SNDRV_PCM_FORMAT_U32_LE,
 307         SNDRV_PCM_FORMAT_U32_BE,
 308         SNDRV_PCM_FORMAT_S8,
 309         SNDRV_PCM_FORMAT_U8
 310 };
 311
 312 snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
 313                                            const struct snd_mask *format_mask)
 314 {
 315         int i;
 316
 317         if (snd_mask_test(format_mask, (__force int)format))
 318                 return format;
 319         if (!snd_pcm_plug_formats(format_mask, format))
 320                 return (__force snd_pcm_format_t)-EINVAL;
 321         if (snd_pcm_format_linear(format)) {
 322                 unsigned int width = snd_pcm_format_width(format);
 323                 int unsignd = snd_pcm_format_unsigned(format) > 0;
 324                 int big = snd_pcm_format_big_endian(format) > 0;
 325                 unsigned int badness, best = -1;
 326                 snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
 327                 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
 328                         snd_pcm_format_t f = preferred_formats[i];
 329                         unsigned int w;
 330                         if (!snd_mask_test(format_mask, (__force int)f))
 331                                 continue;
 332                         w = snd_pcm_format_width(f);
 333                         if (w >= width)
 334                                 badness = w - width;
 335                         else
 336                                 badness = width - w + 32;
 337                         badness += snd_pcm_format_unsigned(f) != unsignd;
 338                         badness += snd_pcm_format_big_endian(f) != big;
 339                         if (badness < best) {
 340                                 best_format = f;
 341                                 best = badness;
 342                         }
 343                 }
 344                 if ((__force int)best_format >= 0)
 345                         return best_format;
 346                 else
 347                         return (__force snd_pcm_format_t)-EINVAL;
 348         } else {
 349                 switch (format) {
 350                 case SNDRV_PCM_FORMAT_MU_LAW:
 351                         for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
 352                                 snd_pcm_format_t format1 = preferred_formats[i];
 353                                 if (snd_mask_test(format_mask, (__force int)format1))
 354                                         return format1;
 355                         }
 356                         /* fall through */
 357                 default:
 358                         return (__force snd_pcm_format_t)-EINVAL;
 359                 }
 360         }
 361 }
 362
 363 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
 364                                 struct snd_pcm_hw_params *params,
 365                                 struct snd_pcm_hw_params *slave_params)
 366 {
 367         struct snd_pcm_plugin_format tmpformat;
 368         struct snd_pcm_plugin_format dstformat;
 369         struct snd_pcm_plugin_format srcformat;
 370         snd_pcm_access_t src_access, dst_access;
 371         struct snd_pcm_plugin *plugin = NULL;
 372         int err;
 373         int stream = snd_pcm_plug_stream(plug);
 374         int slave_interleaved = (params_channels(slave_params) == 1 ||
 375                                  params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
 376
 377         switch (stream) {
 378         case SNDRV_PCM_STREAM_PLAYBACK:
 379                 dstformat.format = params_format(slave_params);
 380                 dstformat.rate = params_rate(slave_params);
 381                 dstformat.channels = params_channels(slave_params);
 382                 srcformat.format = params_format(params);
 383                 srcformat.rate = params_rate(params);
 384                 srcformat.channels = params_channels(params);
 385                 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 386                 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 387                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 388                 break;
 389         case SNDRV_PCM_STREAM_CAPTURE:
 390                 dstformat.format = params_format(params);
 391                 dstformat.rate = params_rate(params);
 392                 dstformat.channels = params_channels(params);
 393                 srcformat.format = params_format(slave_params);
 394                 srcformat.rate = params_rate(slave_params);
 395                 srcformat.channels = params_channels(slave_params);
 396                 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
 397                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
 398                 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
 399                 break;
 400         default:
 401                 snd_BUG();
 402                 return -EINVAL;
 403         }
 404         tmpformat = srcformat;
 405
 406         pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
 407                  srcformat.format,
 408                  srcformat.rate,
 409                  srcformat.channels);
 410         pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
 411                  dstformat.format,
 412                  dstformat.rate,
 413                  dstformat.channels);
 414
 415         /* Format change (linearization) */
 416         if (! rate_match(srcformat.rate, dstformat.rate) &&
 417             ! snd_pcm_format_linear(srcformat.format)) {
 418                 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
 419                         return -EINVAL;
 420                 tmpformat.format = SNDRV_PCM_FORMAT_S16;
 421                 err = snd_pcm_plugin_build_mulaw(plug,
 422                                                  &srcformat, &tmpformat,
 423                                                  &plugin);
 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         /* channels reduction */
 436         if (srcformat.channels > dstformat.channels) {
 437                 tmpformat.channels = dstformat.channels;
 438                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 439                 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 440                 if (err < 0)
 441                         return err;
 442                 err = snd_pcm_plugin_append(plugin);
 443                 if (err < 0) {
 444                         snd_pcm_plugin_free(plugin);
 445                         return err;
 446                 }
 447                 srcformat = tmpformat;
 448                 src_access = dst_access;
 449         }
 450
 451         /* rate resampling */
 452         if (!rate_match(srcformat.rate, dstformat.rate)) {
 453                 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
 454                         /* convert to S16 for resampling */
 455                         tmpformat.format = SNDRV_PCM_FORMAT_S16;
 456                         err = snd_pcm_plugin_build_linear(plug,
 457                                                           &srcformat, &tmpformat,
 458                                                           &plugin);
 459                         if (err < 0)
 460                                 return err;
 461                         err = snd_pcm_plugin_append(plugin);
 462                         if (err < 0) {
 463                                 snd_pcm_plugin_free(plugin);
 464                                 return err;
 465                         }
 466                         srcformat = tmpformat;
 467                         src_access = dst_access;
 468                 }
 469                 tmpformat.rate = dstformat.rate;
 470                 err = snd_pcm_plugin_build_rate(plug,
 471                                                 &srcformat, &tmpformat,
 472                                                 &plugin);
 473                 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
 474                 if (err < 0)
 475                         return err;
 476                 err = snd_pcm_plugin_append(plugin);
 477                 if (err < 0) {
 478                         snd_pcm_plugin_free(plugin);
 479                         return err;
 480                 }
 481                 srcformat = tmpformat;
 482                 src_access = dst_access;
 483         }
 484
 485         /* format change */
 486         if (srcformat.format != dstformat.format) {
 487                 tmpformat.format = dstformat.format;
 488                 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
 489                     tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
 490                         err = snd_pcm_plugin_build_mulaw(plug,
 491                                                          &srcformat, &tmpformat,
 492                                                          &plugin);
 493                 }
 494                 else if (snd_pcm_format_linear(srcformat.format) &&
 495                          snd_pcm_format_linear(tmpformat.format)) {
 496                         err = snd_pcm_plugin_build_linear(plug,
 497                                                           &srcformat, &tmpformat,
 498                                                           &plugin);
 499                 }
 500                 else
 501                         return -EINVAL;
 502                 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, 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         /* channels extension */
 515         if (srcformat.channels < dstformat.channels) {
 516                 tmpformat.channels = dstformat.channels;
 517                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
 518                 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
 519                 if (err < 0)
 520                         return err;
 521                 err = snd_pcm_plugin_append(plugin);
 522                 if (err < 0) {
 523                         snd_pcm_plugin_free(plugin);
 524                         return err;
 525                 }
 526                 srcformat = tmpformat;
 527                 src_access = dst_access;
 528         }
 529
 530         /* de-interleave */
 531         if (src_access != dst_access) {
 532                 err = snd_pcm_plugin_build_copy(plug,
 533                                                 &srcformat,
 534                                                 &tmpformat,
 535                                                 &plugin);
 536                 pdprintf("interleave change (copy: returns %i)\n", err);
 537                 if (err < 0)
 538                         return err;
 539                 err = snd_pcm_plugin_append(plugin);
 540                 if (err < 0) {
 541                         snd_pcm_plugin_free(plugin);
 542                         return err;
 543                 }
 544         }
 545
 546         return 0;
 547 }
 548
 549 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
 550                                          char *buf,
 551                                          snd_pcm_uframes_t count,
 552                                          struct snd_pcm_plugin_channel **channels)
 553 {
 554         struct snd_pcm_plugin *plugin;
 555         struct snd_pcm_plugin_channel *v;
 556         struct snd_pcm_plugin_format *format;
 557         int width, nchannels, channel;
 558         int stream = snd_pcm_plug_stream(plug);
 559
 560         if (snd_BUG_ON(!buf))
 561                 return -ENXIO;
 562         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 563                 plugin = snd_pcm_plug_first(plug);
 564                 format = &plugin->src_format;
 565         } else {
 566                 plugin = snd_pcm_plug_last(plug);
 567                 format = &plugin->dst_format;
 568         }
 569         v = plugin->buf_channels;
 570         *channels = v;
 571         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
 572                 return width;
 573         nchannels = format->channels;
 574         if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
 575                        format->channels > 1))
 576                 return -ENXIO;
 577         for (channel = 0; channel < nchannels; channel++, v++) {
 578                 v->frames = count;
 579                 v->enabled = 1;
 580                 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
 581                 v->area.addr = buf;
 582                 v->area.first = channel * width;
 583                 v->area.step = nchannels * width;
 584         }
 585         return count;
 586 }
 587
 588 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)
 589 {
 590         struct snd_pcm_plugin *plugin, *next;
 591         struct snd_pcm_plugin_channel *dst_channels;
 592         int err;
 593         snd_pcm_sframes_t frames = size;
 594
 595         plugin = snd_pcm_plug_first(plug);
 596         while (plugin) {
 597                 if (frames <= 0)
 598                         return frames;
 599                 if ((next = plugin->next) != NULL) {
 600                         snd_pcm_sframes_t frames1 = frames;
 601                         if (plugin->dst_frames) {
 602                                 frames1 = plugin->dst_frames(plugin, frames);
 603                                 if (frames1 <= 0)
 604                                         return frames1;
 605                         }
 606                         if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
 607                                 return err;
 608                         }
 609                         if (err != frames1) {
 610                                 frames = err;
 611                                 if (plugin->src_frames) {
 612                                         frames = plugin->src_frames(plugin, frames1);
 613                                         if (frames <= 0)
 614                                                 return frames;
 615                                 }
 616                         }
 617                 } else
 618                         dst_channels = NULL;
 619                 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
 620                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 621                         return frames;
 622                 src_channels = dst_channels;
 623                 plugin = next;
 624         }
 625         return snd_pcm_plug_client_size(plug, frames);
 626 }
 627
 628 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)
 629 {
 630         struct snd_pcm_plugin *plugin, *next;
 631         struct snd_pcm_plugin_channel *src_channels, *dst_channels;
 632         snd_pcm_sframes_t frames = size;
 633         int err;
 634
 635         frames = snd_pcm_plug_slave_size(plug, frames);
 636         if (frames < 0)
 637                 return frames;
 638
 639         src_channels = NULL;
 640         plugin = snd_pcm_plug_first(plug);
 641         while (plugin && frames > 0) {
 642                 if ((next = plugin->next) != NULL) {
 643                         if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
 644                                 return err;
 645                         }
 646                         frames = err;
 647                 } else {
 648                         dst_channels = dst_channels_final;
 649                 }
 650                 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
 651                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
 652                         return frames;
 653                 plugin = next;
 654                 src_channels = dst_channels;
 655         }
 656         return frames;
 657 }
 658
 659 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 660                          size_t samples, snd_pcm_format_t format)
 661 {
 662         /* FIXME: sub byte resolution and odd dst_offset */
 663         unsigned char *dst;
 664         unsigned int dst_step;
 665         int width;
 666         const unsigned char *silence;
 667         if (!dst_area->addr)
 668                 return 0;
 669         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 670         width = snd_pcm_format_physical_width(format);
 671         if (width <= 0)
 672                 return -EINVAL;
 673         if (dst_area->step == (unsigned int) width && width >= 8)
 674                 return snd_pcm_format_set_silence(format, dst, samples);
 675         silence = snd_pcm_format_silence_64(format);
 676         if (! silence)
 677                 return -EINVAL;
 678         dst_step = dst_area->step / 8;
 679         if (width == 4) {
 680                 /* Ima ADPCM */
 681                 int dstbit = dst_area->first % 8;
 682                 int dstbit_step = dst_area->step % 8;
 683                 while (samples-- > 0) {
 684                         if (dstbit)
 685                                 *dst &= 0xf0;
 686                         else
 687                                 *dst &= 0x0f;
 688                         dst += dst_step;
 689                         dstbit += dstbit_step;
 690                         if (dstbit == 8) {
 691                                 dst++;
 692                                 dstbit = 0;
 693                         }
 694                 }
 695         } else {
 696                 width /= 8;
 697                 while (samples-- > 0) {
 698                         memcpy(dst, silence, width);
 699                         dst += dst_step;
 700                 }
 701         }
 702         return 0;
 703 }
 704
 705 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
 706                       const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
 707                       size_t samples, snd_pcm_format_t format)
 708 {
 709         /* FIXME: sub byte resolution and odd dst_offset */
 710         char *src, *dst;
 711         int width;
 712         int src_step, dst_step;
 713         src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
 714         if (!src_area->addr)
 715                 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
 716         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
 717         if (!dst_area->addr)
 718                 return 0;
 719         width = snd_pcm_format_physical_width(format);
 720         if (width <= 0)
 721                 return -EINVAL;
 722         if (src_area->step == (unsigned int) width &&
 723             dst_area->step == (unsigned int) width && width >= 8) {
 724                 size_t bytes = samples * width / 8;
 725                 memcpy(dst, src, bytes);
 726                 return 0;
 727         }
 728         src_step = src_area->step / 8;
 729         dst_step = dst_area->step / 8;
 730         if (width == 4) {
 731                 /* Ima ADPCM */
 732                 int srcbit = src_area->first % 8;
 733                 int srcbit_step = src_area->step % 8;
 734                 int dstbit = dst_area->first % 8;
 735                 int dstbit_step = dst_area->step % 8;
 736                 while (samples-- > 0) {
 737                         unsigned char srcval;
 738                         if (srcbit)
 739                                 srcval = *src & 0x0f;
 740                         else
 741                                 srcval = (*src & 0xf0) >> 4;
 742                         if (dstbit)
 743                                 *dst = (*dst & 0xf0) | srcval;
 744                         else
 745                                 *dst = (*dst & 0x0f) | (srcval << 4);
 746                         src += src_step;
 747                         srcbit += srcbit_step;
 748                         if (srcbit == 8) {
 749                                 src++;
 750                                 srcbit = 0;
 751                         }
 752                         dst += dst_step;
 753                         dstbit += dstbit_step;
 754                         if (dstbit == 8) {
 755                                 dst++;
 756                                 dstbit = 0;
 757                         }
 758                 }
 759         } else {
 760                 width /= 8;
 761                 while (samples-- > 0) {
 762                         memcpy(dst, src, width);
 763                         src += src_step;
 764                         dst += dst_step;
 765                 }
 766         }
 767         return 0;
 768 }