mirror of
https://github.com/alsa-project/alsa-lib.git
synced 2025-10-29 05:40:25 -04:00
c39882f602
- changed snd_config_get_id function to follow semantic of other get functions
- added snd_config_test_id
- added runtime pointer type (not persistent)
- added snd_config_make_pointer, snd_config_set_pointer, snd_config_get_pointer
- added type/contents checking for callback functions
- changed 'void *private_data' to 'snd_config_t *private_data'
- renamed card_strtype functions to card_driver
Control:
- fixed passing parameters to snd_ctl_async
Async handlers:
- added public snd_async_handler_get_signo function
Documentation:
- moved all documentation to source files
468 lines
13 KiB
C
468 lines
13 KiB
C
/*
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* PCM - A-Law conversion
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* Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
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*
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Library General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <byteswap.h>
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#include "pcm_local.h"
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#include "pcm_plugin.h"
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#ifndef PIC
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/* entry for static linking */
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const char *_snd_module_pcm_alaw = "";
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#endif
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typedef void (*alaw_f)(const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset,
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unsigned int channels, snd_pcm_uframes_t frames,
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unsigned int getputidx);
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typedef struct {
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/* This field need to be the first */
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snd_pcm_plugin_t plug;
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unsigned int getput_idx;
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alaw_f func;
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snd_pcm_format_t sformat;
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} snd_pcm_alaw_t;
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static inline int val_seg(int val)
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{
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int r = 1;
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val >>= 8;
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if (val & 0xf0) {
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val >>= 4;
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r += 4;
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}
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if (val & 0x0c) {
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val >>= 2;
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r += 2;
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}
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if (val & 0x02)
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r += 1;
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return r;
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}
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/*
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* s16_to_alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
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*
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* s16_to_alaw() accepts an 16-bit integer and encodes it as A-law data.
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*
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* Linear Input Code Compressed Code
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* ------------------------ ---------------
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* 0000000wxyza 000wxyz
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* 0000001wxyza 001wxyz
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* 000001wxyzab 010wxyz
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* 00001wxyzabc 011wxyz
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* 0001wxyzabcd 100wxyz
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* 001wxyzabcde 101wxyz
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* 01wxyzabcdef 110wxyz
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* 1wxyzabcdefg 111wxyz
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*
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* For further information see John C. Bellamy's Digital Telephony, 1982,
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* John Wiley & Sons, pps 98-111 and 472-476.
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*/
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static unsigned char s16_to_alaw(int pcm_val)
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{
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int mask;
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int seg;
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unsigned char aval;
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if (pcm_val >= 0) {
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mask = 0xD5;
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} else {
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mask = 0x55;
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pcm_val = -pcm_val;
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if (pcm_val > 0x7fff)
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pcm_val = 0x7fff;
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}
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if (pcm_val < 256)
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aval = pcm_val >> 4;
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else {
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/* Convert the scaled magnitude to segment number. */
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seg = val_seg(pcm_val);
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aval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);
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}
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return aval ^ mask;
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}
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/*
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* alaw_to_s16() - Convert an A-law value to 16-bit linear PCM
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*
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*/
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static int alaw_to_s16(unsigned char a_val)
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{
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int t;
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int seg;
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a_val ^= 0x55;
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t = a_val & 0x7f;
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if (t < 16)
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t = (t << 4) + 8;
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else {
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seg = (t >> 4) & 0x07;
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t = ((t & 0x0f) << 4) + 0x108;
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t <<= seg -1;
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}
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return ((a_val & 0x80) ? t : -t);
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}
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void snd_pcm_alaw_decode(const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset,
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unsigned int channels, snd_pcm_uframes_t frames,
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unsigned int putidx)
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{
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#define PUT16_LABELS
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#include "plugin_ops.h"
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#undef PUT16_LABELS
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void *put = put16_labels[putidx];
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unsigned int channel;
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for (channel = 0; channel < channels; ++channel) {
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const unsigned char *src;
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char *dst;
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int src_step, dst_step;
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snd_pcm_uframes_t frames1;
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area);
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dst_step = snd_pcm_channel_area_step(dst_area);
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frames1 = frames;
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while (frames1-- > 0) {
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int16_t sample = alaw_to_s16(*src);
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goto *put;
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#define PUT16_END after
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#include "plugin_ops.h"
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#undef PUT16_END
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after:
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src += src_step;
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dst += dst_step;
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}
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}
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}
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void snd_pcm_alaw_encode(const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset,
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unsigned int channels, snd_pcm_uframes_t frames,
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unsigned int getidx)
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{
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#define GET16_LABELS
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#include "plugin_ops.h"
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#undef GET16_LABELS
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void *get = get16_labels[getidx];
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unsigned int channel;
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int16_t sample = 0;
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for (channel = 0; channel < channels; ++channel) {
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const char *src;
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char *dst;
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int src_step, dst_step;
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snd_pcm_uframes_t frames1;
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area);
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dst_step = snd_pcm_channel_area_step(dst_area);
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frames1 = frames;
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while (frames1-- > 0) {
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goto *get;
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#define GET16_END after
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#include "plugin_ops.h"
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#undef GET16_END
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after:
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*dst = s16_to_alaw(sample);
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src += src_step;
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dst += dst_step;
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}
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}
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}
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static int snd_pcm_alaw_hw_refine_cprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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int err;
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snd_pcm_access_mask_t access_mask = { SND_PCM_ACCBIT_SHM };
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err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_ACCESS,
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&access_mask);
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if (err < 0)
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return err;
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if (alaw->sformat == SND_PCM_FORMAT_A_LAW) {
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snd_pcm_format_mask_t format_mask = { SND_PCM_FMTBIT_LINEAR };
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err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_FORMAT,
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&format_mask);
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} else {
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err = _snd_pcm_hw_params_set_format(params,
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SND_PCM_FORMAT_A_LAW);
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}
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if (err < 0)
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return err;
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err = _snd_pcm_hw_params_set_subformat(params, SND_PCM_SUBFORMAT_STD);
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if (err < 0)
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return err;
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params->info &= ~(SND_PCM_INFO_MMAP | SND_PCM_INFO_MMAP_VALID);
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return 0;
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}
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static int snd_pcm_alaw_hw_refine_sprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *sparams)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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snd_pcm_access_mask_t saccess_mask = { SND_PCM_ACCBIT_MMAP };
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_snd_pcm_hw_params_any(sparams);
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_snd_pcm_hw_param_set_mask(sparams, SND_PCM_HW_PARAM_ACCESS,
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&saccess_mask);
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_snd_pcm_hw_params_set_format(sparams, alaw->sformat);
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_snd_pcm_hw_params_set_subformat(sparams, SND_PCM_SUBFORMAT_STD);
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return 0;
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}
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static int snd_pcm_alaw_hw_refine_schange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,
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snd_pcm_hw_params_t *sparams)
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{
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int err;
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unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |
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SND_PCM_HW_PARBIT_RATE |
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SND_PCM_HW_PARBIT_PERIOD_SIZE |
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SND_PCM_HW_PARBIT_BUFFER_SIZE |
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SND_PCM_HW_PARBIT_PERIODS |
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SND_PCM_HW_PARBIT_PERIOD_TIME |
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SND_PCM_HW_PARBIT_BUFFER_TIME |
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SND_PCM_HW_PARBIT_TICK_TIME);
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err = _snd_pcm_hw_params_refine(sparams, links, params);
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if (err < 0)
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return err;
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return 0;
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}
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static int snd_pcm_alaw_hw_refine_cchange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,
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snd_pcm_hw_params_t *sparams)
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{
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int err;
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unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |
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SND_PCM_HW_PARBIT_RATE |
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SND_PCM_HW_PARBIT_PERIOD_SIZE |
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SND_PCM_HW_PARBIT_BUFFER_SIZE |
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SND_PCM_HW_PARBIT_PERIODS |
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SND_PCM_HW_PARBIT_PERIOD_TIME |
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SND_PCM_HW_PARBIT_BUFFER_TIME |
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SND_PCM_HW_PARBIT_TICK_TIME);
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err = _snd_pcm_hw_params_refine(params, links, sparams);
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if (err < 0)
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return err;
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return 0;
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}
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static int snd_pcm_alaw_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
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{
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return snd_pcm_hw_refine_slave(pcm, params,
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snd_pcm_alaw_hw_refine_cprepare,
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snd_pcm_alaw_hw_refine_cchange,
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snd_pcm_alaw_hw_refine_sprepare,
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snd_pcm_alaw_hw_refine_schange,
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snd_pcm_plugin_hw_refine_slave);
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}
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static int snd_pcm_alaw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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int err = snd_pcm_hw_params_slave(pcm, params,
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snd_pcm_alaw_hw_refine_cchange,
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snd_pcm_alaw_hw_refine_sprepare,
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snd_pcm_alaw_hw_refine_schange,
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snd_pcm_plugin_hw_params_slave);
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if (err < 0)
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return err;
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if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {
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if (alaw->sformat == SND_PCM_FORMAT_A_LAW) {
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alaw->getput_idx = snd_pcm_linear_get_index(snd_pcm_hw_params_get_format(params), SND_PCM_FORMAT_S16);
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alaw->func = snd_pcm_alaw_encode;
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} else {
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alaw->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S16, alaw->sformat);
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alaw->func = snd_pcm_alaw_decode;
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}
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} else {
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if (alaw->sformat == SND_PCM_FORMAT_A_LAW) {
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alaw->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S16, snd_pcm_hw_params_get_format(params));
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alaw->func = snd_pcm_alaw_decode;
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} else {
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alaw->getput_idx = snd_pcm_linear_get_index(alaw->sformat, SND_PCM_FORMAT_S16);
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alaw->func = snd_pcm_alaw_encode;
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}
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}
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return 0;
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}
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static snd_pcm_uframes_t
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snd_pcm_alaw_write_areas(snd_pcm_t *pcm,
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const snd_pcm_channel_area_t *areas,
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snd_pcm_uframes_t offset,
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snd_pcm_uframes_t size,
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const snd_pcm_channel_area_t *slave_areas,
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snd_pcm_uframes_t slave_offset,
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snd_pcm_uframes_t *slave_sizep)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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if (size > *slave_sizep)
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size = *slave_sizep;
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alaw->func(slave_areas, slave_offset,
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areas, offset,
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pcm->channels, size,
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alaw->getput_idx);
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*slave_sizep = size;
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return size;
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}
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static snd_pcm_uframes_t
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snd_pcm_alaw_read_areas(snd_pcm_t *pcm,
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const snd_pcm_channel_area_t *areas,
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snd_pcm_uframes_t offset,
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snd_pcm_uframes_t size,
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const snd_pcm_channel_area_t *slave_areas,
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snd_pcm_uframes_t slave_offset,
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snd_pcm_uframes_t *slave_sizep)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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if (size > *slave_sizep)
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size = *slave_sizep;
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alaw->func(areas, offset,
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slave_areas, slave_offset,
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pcm->channels, size,
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alaw->getput_idx);
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*slave_sizep = size;
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return size;
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}
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static void snd_pcm_alaw_dump(snd_pcm_t *pcm, snd_output_t *out)
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{
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snd_pcm_alaw_t *alaw = pcm->private_data;
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snd_output_printf(out, "A-Law conversion PCM (%s)\n",
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snd_pcm_format_name(alaw->sformat));
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if (pcm->setup) {
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snd_output_printf(out, "Its setup is:\n");
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snd_pcm_dump_setup(pcm, out);
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}
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snd_output_printf(out, "Slave: ");
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snd_pcm_dump(alaw->plug.slave, out);
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}
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snd_pcm_ops_t snd_pcm_alaw_ops = {
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close: snd_pcm_plugin_close,
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info: snd_pcm_plugin_info,
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hw_refine: snd_pcm_alaw_hw_refine,
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hw_params: snd_pcm_alaw_hw_params,
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hw_free: snd_pcm_plugin_hw_free,
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sw_params: snd_pcm_plugin_sw_params,
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channel_info: snd_pcm_plugin_channel_info,
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dump: snd_pcm_alaw_dump,
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nonblock: snd_pcm_plugin_nonblock,
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async: snd_pcm_plugin_async,
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mmap: snd_pcm_plugin_mmap,
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munmap: snd_pcm_plugin_munmap,
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};
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int snd_pcm_alaw_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sformat, snd_pcm_t *slave, int close_slave)
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{
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snd_pcm_t *pcm;
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snd_pcm_alaw_t *alaw;
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int err;
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assert(pcmp && slave);
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if (snd_pcm_format_linear(sformat) != 1 &&
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sformat != SND_PCM_FORMAT_A_LAW)
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return -EINVAL;
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alaw = calloc(1, sizeof(snd_pcm_alaw_t));
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if (!alaw) {
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return -ENOMEM;
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}
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alaw->sformat = sformat;
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alaw->plug.read = snd_pcm_alaw_read_areas;
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alaw->plug.write = snd_pcm_alaw_write_areas;
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alaw->plug.slave = slave;
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alaw->plug.close_slave = close_slave;
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err = snd_pcm_new(&pcm, SND_PCM_TYPE_ALAW, name, slave->stream, slave->mode);
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if (err < 0) {
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free(alaw);
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return err;
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}
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pcm->ops = &snd_pcm_alaw_ops;
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pcm->fast_ops = &snd_pcm_plugin_fast_ops;
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pcm->private_data = alaw;
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pcm->poll_fd = slave->poll_fd;
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pcm->hw_ptr = &alaw->plug.hw_ptr;
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pcm->appl_ptr = &alaw->plug.appl_ptr;
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*pcmp = pcm;
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return 0;
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}
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int _snd_pcm_alaw_open(snd_pcm_t **pcmp, const char *name,
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snd_config_t *root, snd_config_t *conf,
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snd_pcm_stream_t stream, int mode)
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{
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snd_config_iterator_t i, next;
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int err;
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snd_pcm_t *spcm;
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snd_config_t *slave = NULL, *sconf;
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snd_pcm_format_t sformat;
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snd_config_for_each(i, next, conf) {
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snd_config_t *n = snd_config_iterator_entry(i);
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const char *id;
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if (snd_config_get_id(n, &id) < 0)
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continue;
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if (snd_pcm_conf_generic_id(id))
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continue;
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if (strcmp(id, "slave") == 0) {
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slave = n;
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continue;
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}
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SNDERR("Unknown field %s", id);
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return -EINVAL;
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}
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if (!slave) {
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SNDERR("slave is not defined");
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return -EINVAL;
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}
|
|
err = snd_pcm_slave_conf(root, slave, &sconf, 1,
|
|
SND_PCM_HW_PARAM_FORMAT, SCONF_MANDATORY, &sformat);
|
|
if (err < 0)
|
|
return err;
|
|
if (snd_pcm_format_linear(sformat) != 1 &&
|
|
sformat != SND_PCM_FORMAT_A_LAW) {
|
|
snd_config_delete(sconf);
|
|
SNDERR("invalid slave format");
|
|
return -EINVAL;
|
|
}
|
|
err = snd_pcm_open_slave(&spcm, root, sconf, stream, mode);
|
|
snd_config_delete(sconf);
|
|
if (err < 0)
|
|
return err;
|
|
err = snd_pcm_alaw_open(pcmp, name, sformat, spcm, 1);
|
|
if (err < 0)
|
|
snd_pcm_close(spcm);
|
|
return err;
|
|
}
|
|
SND_DLSYM_BUILD_VERSION(_snd_pcm_alaw_open, SND_PCM_DLSYM_VERSION);
|