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>
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.
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.
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
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"
35 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
36 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
39 * because some cards might have rates "very close", we ignore
40 * all "resampling" requests within +-5%
42 static int rate_match(unsigned int src_rate
, unsigned int dst_rate
)
44 unsigned int low
= (src_rate
* 95) / 100;
45 unsigned int high
= (src_rate
* 105) / 100;
46 return dst_rate
>= low
&& dst_rate
<= high
;
49 static int snd_pcm_plugin_alloc(struct snd_pcm_plugin
*plugin
, snd_pcm_uframes_t frames
)
51 struct snd_pcm_plugin_format
*format
;
55 struct snd_pcm_plugin_channel
*c
;
57 if (plugin
->stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
58 format
= &plugin
->src_format
;
60 format
= &plugin
->dst_format
;
62 if ((width
= snd_pcm_format_physical_width(format
->format
)) < 0)
64 size
= frames
* format
->channels
* width
;
65 if (snd_BUG_ON(size
% 8))
68 if (plugin
->buf_frames
< frames
) {
70 plugin
->buf
= vmalloc(size
);
71 plugin
->buf_frames
= frames
;
74 plugin
->buf_frames
= 0;
77 c
= plugin
->buf_channels
;
78 if (plugin
->access
== SNDRV_PCM_ACCESS_RW_INTERLEAVED
) {
79 for (channel
= 0; channel
< format
->channels
; channel
++, c
++) {
83 c
->area
.addr
= plugin
->buf
;
84 c
->area
.first
= channel
* width
;
85 c
->area
.step
= format
->channels
* width
;
87 } else if (plugin
->access
== SNDRV_PCM_ACCESS_RW_NONINTERLEAVED
) {
88 if (snd_BUG_ON(size
% format
->channels
))
90 size
/= format
->channels
;
91 for (channel
= 0; channel
< format
->channels
; channel
++, c
++) {
95 c
->area
.addr
= plugin
->buf
+ (channel
* size
);
104 int snd_pcm_plug_alloc(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t frames
)
107 if (snd_BUG_ON(!snd_pcm_plug_first(plug
)))
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))
116 plugin
= plugin
->next
;
117 err
= snd_pcm_plugin_alloc(plugin
, frames
);
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))
128 plugin
= plugin
->prev
;
129 err
= snd_pcm_plugin_alloc(plugin
, frames
);
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
)
142 *channels
= plugin
->buf_channels
;
146 int snd_pcm_plugin_build(struct snd_pcm_substream
*plug
,
148 struct snd_pcm_plugin_format
*src_format
,
149 struct snd_pcm_plugin_format
*dst_format
,
151 struct snd_pcm_plugin
**ret
)
153 struct snd_pcm_plugin
*plugin
;
154 unsigned int channels
;
156 if (snd_BUG_ON(!plug
))
158 if (snd_BUG_ON(!src_format
|| !dst_format
))
160 plugin
= kzalloc(sizeof(*plugin
) + extra
, GFP_KERNEL
);
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
;
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
);
182 plugin
->client_channels
= snd_pcm_plugin_client_channels
;
187 int snd_pcm_plugin_free(struct snd_pcm_plugin
*plugin
)
191 if (plugin
->private_free
)
192 plugin
->private_free(plugin
);
193 kfree(plugin
->buf_channels
);
199 snd_pcm_sframes_t
snd_pcm_plug_client_size(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t drv_frames
)
201 struct snd_pcm_plugin
*plugin
, *plugin_prev
, *plugin_next
;
202 int stream
= snd_pcm_plug_stream(plug
);
204 if (snd_BUG_ON(!plug
))
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
;
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
;
229 snd_pcm_sframes_t
snd_pcm_plug_slave_size(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t clt_frames
)
231 struct snd_pcm_plugin
*plugin
, *plugin_prev
, *plugin_next
;
232 snd_pcm_sframes_t frames
;
233 int stream
= snd_pcm_plug_stream(plug
);
235 if (snd_BUG_ON(!plug
))
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
);
249 plugin
= plugin_next
;
251 } else if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
252 plugin
= snd_pcm_plug_last(plug
);
254 plugin_prev
= plugin
->prev
;
255 if (plugin
->src_frames
) {
256 frames
= plugin
->src_frames(plugin
, frames
);
260 plugin
= plugin_prev
;
267 static int snd_pcm_plug_formats(struct snd_mask
*mask
, int format
)
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
);
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
);
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
,
309 int snd_pcm_plug_slave_format(int format
, struct snd_mask
*format_mask
)
313 if (snd_mask_test(format_mask
, format
))
315 if (! snd_pcm_plug_formats(format_mask
, format
))
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
];
326 if (!snd_mask_test(format_mask
, f
))
328 w
= snd_pcm_format_width(f
);
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
) {
340 return best_format
>= 0 ? best_format
: -EINVAL
;
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
))
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
)
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
;
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
);
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
);
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
;
396 tmpformat
= srcformat
;
398 pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
402 pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
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
)
412 tmpformat
.format
= SNDRV_PCM_FORMAT_S16
;
413 err
= snd_pcm_plugin_build_mulaw(plug
,
414 &srcformat
, &tmpformat
,
418 err
= snd_pcm_plugin_append(plugin
);
420 snd_pcm_plugin_free(plugin
);
423 srcformat
= tmpformat
;
424 src_access
= dst_access
;
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
);
434 err
= snd_pcm_plugin_append(plugin
);
436 snd_pcm_plugin_free(plugin
);
439 srcformat
= tmpformat
;
440 src_access
= dst_access
;
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
,
453 err
= snd_pcm_plugin_append(plugin
);
455 snd_pcm_plugin_free(plugin
);
458 srcformat
= tmpformat
;
459 src_access
= dst_access
;
461 tmpformat
.rate
= dstformat
.rate
;
462 err
= snd_pcm_plugin_build_rate(plug
,
463 &srcformat
, &tmpformat
,
465 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat
.rate
, tmpformat
.rate
, err
);
468 err
= snd_pcm_plugin_append(plugin
);
470 snd_pcm_plugin_free(plugin
);
473 srcformat
= tmpformat
;
474 src_access
= dst_access
;
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
,
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
,
494 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat
.format
, tmpformat
.format
, err
);
497 err
= snd_pcm_plugin_append(plugin
);
499 snd_pcm_plugin_free(plugin
);
502 srcformat
= tmpformat
;
503 src_access
= dst_access
;
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
);
513 err
= snd_pcm_plugin_append(plugin
);
515 snd_pcm_plugin_free(plugin
);
518 srcformat
= tmpformat
;
519 src_access
= dst_access
;
523 if (src_access
!= dst_access
) {
524 err
= snd_pcm_plugin_build_copy(plug
,
528 pdprintf("interleave change (copy: returns %i)\n", err
);
531 err
= snd_pcm_plugin_append(plugin
);
533 snd_pcm_plugin_free(plugin
);
541 snd_pcm_sframes_t
snd_pcm_plug_client_channels_buf(struct snd_pcm_substream
*plug
,
543 snd_pcm_uframes_t count
,
544 struct snd_pcm_plugin_channel
**channels
)
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
);
552 if (snd_BUG_ON(!buf
))
554 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
555 plugin
= snd_pcm_plug_first(plug
);
556 format
= &plugin
->src_format
;
558 plugin
= snd_pcm_plug_last(plug
);
559 format
= &plugin
->dst_format
;
561 v
= plugin
->buf_channels
;
563 if ((width
= snd_pcm_format_physical_width(format
->format
)) < 0)
565 nchannels
= format
->channels
;
566 if (snd_BUG_ON(plugin
->access
!= SNDRV_PCM_ACCESS_RW_INTERLEAVED
&&
567 format
->channels
> 1))
569 for (channel
= 0; channel
< nchannels
; channel
++, v
++) {
572 v
->wanted
= (stream
== SNDRV_PCM_STREAM_CAPTURE
);
574 v
->area
.first
= channel
* width
;
575 v
->area
.step
= nchannels
* width
;
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
)
582 struct snd_pcm_plugin
*plugin
, *next
;
583 struct snd_pcm_plugin_channel
*dst_channels
;
585 snd_pcm_sframes_t frames
= size
;
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) {
596 if (err
!= frames1
) {
598 if (plugin
->src_frames
)
599 frames
= plugin
->src_frames(plugin
, frames1
);
603 pdprintf("write plugin: %s, %li\n", plugin
->name
, frames
);
604 if ((frames
= plugin
->transfer(plugin
, src_channels
, dst_channels
, frames
)) < 0)
606 src_channels
= dst_channels
;
609 return snd_pcm_plug_client_size(plug
, frames
);
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
)
614 struct snd_pcm_plugin
*plugin
, *next
;
615 struct snd_pcm_plugin_channel
*src_channels
, *dst_channels
;
616 snd_pcm_sframes_t frames
= size
;
619 frames
= snd_pcm_plug_slave_size(plug
, frames
);
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) {
632 dst_channels
= dst_channels_final
;
634 pdprintf("read plugin: %s, %li\n", plugin
->name
, frames
);
635 if ((frames
= plugin
->transfer(plugin
, src_channels
, dst_channels
, frames
)) < 0)
638 src_channels
= dst_channels
;
643 int snd_pcm_area_silence(const struct snd_pcm_channel_area
*dst_area
, size_t dst_offset
,
644 size_t samples
, int format
)
646 /* FIXME: sub byte resolution and odd dst_offset */
648 unsigned int dst_step
;
650 const unsigned char *silence
;
653 dst
= dst_area
->addr
+ (dst_area
->first
+ dst_area
->step
* dst_offset
) / 8;
654 width
= snd_pcm_format_physical_width(format
);
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
);
662 dst_step
= dst_area
->step
/ 8;
665 int dstbit
= dst_area
->first
% 8;
666 int dstbit_step
= dst_area
->step
% 8;
667 while (samples
-- > 0) {
673 dstbit
+= dstbit_step
;
681 while (samples
-- > 0) {
682 memcpy(dst
, silence
, width
);
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
)
693 /* FIXME: sub byte resolution and odd dst_offset */
696 int src_step
, dst_step
;
697 src
= src_area
->addr
+ (src_area
->first
+ src_area
->step
* src_offset
) / 8;
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;
703 width
= snd_pcm_format_physical_width(format
);
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
);
712 src_step
= src_area
->step
/ 8;
713 dst_step
= dst_area
->step
/ 8;
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
;
723 srcval
= *src
& 0x0f;
725 srcval
= (*src
& 0xf0) >> 4;
727 *dst
= (*dst
& 0xf0) | srcval
;
729 *dst
= (*dst
& 0x0f) | (srcval
<< 4);
731 srcbit
+= srcbit_step
;
737 dstbit
+= dstbit_step
;
745 while (samples
-- > 0) {
746 memcpy(dst
, src
, width
);