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1 /**
2  * \file pcm/pcm_iec958.c
3  * \ingroup PCM_Plugins
4  * \brief PCM IEC958 Subframe Conversion Plugin Interface
5  * \author Takashi Iwai <tiwai@suse.de>
6  * \date 2004
7  */
8 /*
9  *  PCM - IEC958 Subframe Conversion Plugin
10  *  Copyright (c) 2004 by Takashi Iwai <tiwai@suse.de>
11  *
12  *
13  *   This library is free software; you can redistribute it and/or modify
14  *   it under the terms of the GNU Lesser General Public License as
15  *   published by the Free Software Foundation; either version 2.1 of
16  *   the License, or (at your option) any later version.
17  *
18  *   This program is distributed in the hope that it will be useful,
19  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
20  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  *   GNU Lesser General Public License for more details.
22  *
23  *   You should have received a copy of the GNU Lesser General Public
24  *   License along with this library; if not, write to the Free Software
25  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
26  *
27  */
28 
29 #include "pcm_local.h"
30 #include "pcm_plugin.h"
31 #include "plugin_ops.h"
32 #include "bswap.h"
33 
34 #ifndef PIC
35 /* entry for static linking */
36 const char *_snd_module_pcm_iec958 = "";
37 #endif
38 
39 /*
40  */
41 
42 #ifndef DOC_HIDDEN
43 
44 typedef struct snd_pcm_iec958 snd_pcm_iec958_t;
45 
46 typedef void (*iec958_f)(snd_pcm_iec958_t *iec,
47 			 const snd_pcm_channel_area_t *dst_areas,
48 			 snd_pcm_uframes_t dst_offset,
49 			 const snd_pcm_channel_area_t *src_areas,
50 			 snd_pcm_uframes_t src_offset,
51 			 unsigned int channels, snd_pcm_uframes_t frames);
52 
53 struct snd_pcm_iec958 {
54 	/* This field need to be the first */
55 	snd_pcm_plugin_t plug;
56 	unsigned int getput_idx;
57 	iec958_f func;
58 	snd_pcm_format_t sformat;
59 	snd_pcm_format_t format;
60 	unsigned int counter;
61 	unsigned char status[24];
62 	unsigned int byteswap;
63 	unsigned char preamble[3];	/* B/M/W or Z/X/Y */
64 	snd_pcm_fast_ops_t fops;
65 	int hdmi_mode;
66 };
67 
68 enum { PREAMBLE_Z, PREAMBLE_X, PREAMBLE_Y };
69 
70 #endif /* DOC_HIDDEN */
71 
72 /*
73  * Determine parity for time slots 4 upto 30
74  * to be sure that bit 4 upt 31 will carry
75  * an even number of ones and zeros.
76  */
iec958_parity(unsigned int data)77 static unsigned int iec958_parity(unsigned int data)
78 {
79 	unsigned int parity;
80 	int bit;
81 
82 	data >>= 4;     /* start from bit 4 */
83 	parity = 0;
84 	for (bit = 4; bit <= 30; bit++) {
85 		if (data & 1)
86 			parity++;
87 		data >>= 1;
88 	}
89 	return (parity & 1);
90 }
91 
92 /*
93  * Compose 32bit IEC958 subframe, two sub frames
94  * build one frame with two channels.
95  *
96  * bit 0-3  = preamble
97  *     4-7  = AUX (=0)
98  *     8-27 = data (12-27 for 16bit, 8-27 for 20bit, and 24bit without AUX)
99  *     28   = validity (0 for valid data, else 'in error')
100  *     29   = user data (0)
101  *     30   = channel status (24 bytes for 192 frames)
102  *     31   = parity
103  */
104 
iec958_subframe(snd_pcm_iec958_t * iec,uint32_t data,int channel)105 static inline uint32_t iec958_subframe(snd_pcm_iec958_t *iec, uint32_t data, int channel)
106 {
107 	unsigned int byte = iec->counter >> 3;
108 	unsigned int mask = 1 << (iec->counter - (byte << 3));
109 
110 	/* bit 4-27 */
111 	data >>= 4;
112 	data &= ~0xf;
113 
114 	/* set IEC status bits (up to 192 bits) */
115 	if (iec->status[byte] & mask)
116 		data |= 0x40000000;
117 
118 	if (iec958_parity(data))	/* parity bit 4-30 */
119 		data |= 0x80000000;
120 
121 	/* Preamble */
122 	if (channel)
123 		data |= iec->preamble[PREAMBLE_Y];	/* odd sub frame, 'Y' */
124 	else if (! iec->counter)
125 		data |= iec->preamble[PREAMBLE_Z];	/* Block start, 'Z' */
126 	else
127 		data |= iec->preamble[PREAMBLE_X];	/* even sub frame, 'X' */
128 
129 	if (iec->byteswap)
130 		data = bswap_32(data);
131 
132 	return data;
133 }
134 
iec958_to_s32(snd_pcm_iec958_t * iec,uint32_t data)135 static inline int32_t iec958_to_s32(snd_pcm_iec958_t *iec, uint32_t data)
136 {
137 	if (iec->byteswap)
138 		data = bswap_32(data);
139 	data &= ~0xf;
140 	data <<= 4;
141 	return (int32_t)data;
142 }
143 
144 #ifndef DOC_HIDDEN
snd_pcm_iec958_decode(snd_pcm_iec958_t * iec,const snd_pcm_channel_area_t * dst_areas,snd_pcm_uframes_t dst_offset,const snd_pcm_channel_area_t * src_areas,snd_pcm_uframes_t src_offset,unsigned int channels,snd_pcm_uframes_t frames)145 static void snd_pcm_iec958_decode(snd_pcm_iec958_t *iec,
146 				  const snd_pcm_channel_area_t *dst_areas,
147 				  snd_pcm_uframes_t dst_offset,
148 				  const snd_pcm_channel_area_t *src_areas,
149 				  snd_pcm_uframes_t src_offset,
150 				  unsigned int channels, snd_pcm_uframes_t frames)
151 {
152 #define PUT32_LABELS
153 #include "plugin_ops.h"
154 #undef PUT32_LABELS
155 	void *put = put32_labels[iec->getput_idx];
156 	unsigned int channel;
157 	for (channel = 0; channel < channels; ++channel) {
158 		const uint32_t *src;
159 		char *dst;
160 		int src_step, dst_step;
161 		snd_pcm_uframes_t frames1;
162 		const snd_pcm_channel_area_t *src_area = &src_areas[channel];
163 		const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
164 		src = snd_pcm_channel_area_addr(src_area, src_offset);
165 		dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
166 		src_step = snd_pcm_channel_area_step(src_area) / sizeof(uint32_t);
167 		dst_step = snd_pcm_channel_area_step(dst_area);
168 		frames1 = frames;
169 		while (frames1-- > 0) {
170 			int32_t sample = iec958_to_s32(iec, *src);
171 			goto *put;
172 #define PUT32_END after
173 #include "plugin_ops.h"
174 #undef PUT32_END
175 		after:
176 			src += src_step;
177 			dst += dst_step;
178 		}
179 	}
180 }
181 
snd_pcm_iec958_encode(snd_pcm_iec958_t * iec,const snd_pcm_channel_area_t * dst_areas,snd_pcm_uframes_t dst_offset,const snd_pcm_channel_area_t * src_areas,snd_pcm_uframes_t src_offset,unsigned int channels,snd_pcm_uframes_t frames)182 static void snd_pcm_iec958_encode(snd_pcm_iec958_t *iec,
183 				  const snd_pcm_channel_area_t *dst_areas,
184 				  snd_pcm_uframes_t dst_offset,
185 				  const snd_pcm_channel_area_t *src_areas,
186 				  snd_pcm_uframes_t src_offset,
187 				  unsigned int channels, snd_pcm_uframes_t frames)
188 {
189 #define GET32_LABELS
190 #include "plugin_ops.h"
191 #undef GET32_LABELS
192 	void *get = get32_labels[iec->getput_idx];
193 	unsigned int channel;
194 	int32_t sample = 0;
195 	int counter = iec->counter;
196 	int single_stream = iec->hdmi_mode &&
197 			    (iec->status[0] & IEC958_AES0_NONAUDIO) &&
198 			    (channels == 8);
199 	int counter_step = single_stream ? ((channels + 1) >> 1) : 1;
200 	for (channel = 0; channel < channels; ++channel) {
201 		const char *src;
202 		uint32_t *dst;
203 		int src_step, dst_step;
204 		snd_pcm_uframes_t frames1;
205 		const snd_pcm_channel_area_t *src_area = &src_areas[channel];
206 		const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
207 		src = snd_pcm_channel_area_addr(src_area, src_offset);
208 		dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
209 		src_step = snd_pcm_channel_area_step(src_area);
210 		dst_step = snd_pcm_channel_area_step(dst_area) / sizeof(uint32_t);
211 		frames1 = frames;
212 
213 		if (single_stream)
214 			iec->counter = (counter + (channel >> 1)) % 192;
215 		else
216 			iec->counter = counter;
217 
218 		while (frames1-- > 0) {
219 			goto *get;
220 #define GET32_END after
221 #include "plugin_ops.h"
222 #undef GET32_END
223 		after:
224 			sample = iec958_subframe(iec, sample, channel);
225 			// fprintf(stderr, "%d:%08x\n", frames1, sample);
226 			*dst = sample;
227 			src += src_step;
228 			dst += dst_step;
229 			iec->counter += counter_step;
230 			iec->counter %= 192;
231 		}
232 		if (single_stream) /* set counter to ch0 value for next iteration */
233 			iec->counter = (counter + frames * counter_step) % 192;
234 	}
235 }
236 #endif /* DOC_HIDDEN */
237 
snd_pcm_iec958_hw_refine_cprepare(snd_pcm_t * pcm,snd_pcm_hw_params_t * params)238 static int snd_pcm_iec958_hw_refine_cprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
239 {
240 	snd_pcm_iec958_t *iec = pcm->private_data;
241 	int err;
242 	snd_pcm_access_mask_t access_mask = { SND_PCM_ACCBIT_SHM };
243 	err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_ACCESS,
244 					 &access_mask);
245 	if (err < 0)
246 		return err;
247 	if (iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_LE ||
248 	    iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_BE) {
249 		snd_pcm_format_mask_t format_mask = { SND_PCM_FMTBIT_LINEAR };
250 		err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_FORMAT,
251 						 &format_mask);
252 	} else {
253 		snd_pcm_format_mask_t format_mask = {
254 			{ (1U << SND_PCM_FORMAT_IEC958_SUBFRAME_LE) |
255 			  (1U << SND_PCM_FORMAT_IEC958_SUBFRAME_BE) }
256 		};
257 		err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_FORMAT,
258 						 &format_mask);
259 	}
260 	if (err < 0)
261 		return err;
262 	err = _snd_pcm_hw_params_set_subformat(params, SND_PCM_SUBFORMAT_STD);
263 	if (err < 0)
264 		return err;
265 	params->info &= ~(SND_PCM_INFO_MMAP | SND_PCM_INFO_MMAP_VALID);
266 	return 0;
267 }
268 
snd_pcm_iec958_hw_refine_sprepare(snd_pcm_t * pcm,snd_pcm_hw_params_t * sparams)269 static int snd_pcm_iec958_hw_refine_sprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *sparams)
270 {
271 	snd_pcm_iec958_t *iec = pcm->private_data;
272 	snd_pcm_access_mask_t saccess_mask = { SND_PCM_ACCBIT_MMAP };
273 	_snd_pcm_hw_params_any(sparams);
274 	_snd_pcm_hw_param_set_mask(sparams, SND_PCM_HW_PARAM_ACCESS,
275 				   &saccess_mask);
276 	_snd_pcm_hw_params_set_format(sparams, iec->sformat);
277 	_snd_pcm_hw_params_set_subformat(sparams, SND_PCM_SUBFORMAT_STD);
278 	return 0;
279 }
280 
snd_pcm_iec958_hw_refine_schange(snd_pcm_t * pcm ATTRIBUTE_UNUSED,snd_pcm_hw_params_t * params,snd_pcm_hw_params_t * sparams)281 static int snd_pcm_iec958_hw_refine_schange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,
282 					    snd_pcm_hw_params_t *sparams)
283 {
284 	int err;
285 	unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |
286 			      SND_PCM_HW_PARBIT_RATE |
287 			      SND_PCM_HW_PARBIT_PERIOD_SIZE |
288 			      SND_PCM_HW_PARBIT_BUFFER_SIZE |
289 			      SND_PCM_HW_PARBIT_PERIODS |
290 			      SND_PCM_HW_PARBIT_PERIOD_TIME |
291 			      SND_PCM_HW_PARBIT_BUFFER_TIME |
292 			      SND_PCM_HW_PARBIT_TICK_TIME);
293 	err = _snd_pcm_hw_params_refine(sparams, links, params);
294 	if (err < 0)
295 		return err;
296 	return 0;
297 }
298 
snd_pcm_iec958_hw_refine_cchange(snd_pcm_t * pcm ATTRIBUTE_UNUSED,snd_pcm_hw_params_t * params,snd_pcm_hw_params_t * sparams)299 static int snd_pcm_iec958_hw_refine_cchange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,
300 					    snd_pcm_hw_params_t *sparams)
301 {
302 	int err;
303 	unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |
304 			      SND_PCM_HW_PARBIT_RATE |
305 			      SND_PCM_HW_PARBIT_PERIOD_SIZE |
306 			      SND_PCM_HW_PARBIT_BUFFER_SIZE |
307 			      SND_PCM_HW_PARBIT_PERIODS |
308 			      SND_PCM_HW_PARBIT_PERIOD_TIME |
309 			      SND_PCM_HW_PARBIT_BUFFER_TIME |
310 			      SND_PCM_HW_PARBIT_TICK_TIME);
311 	err = _snd_pcm_hw_params_refine(params, links, sparams);
312 	if (err < 0)
313 		return err;
314 	return 0;
315 }
316 
snd_pcm_iec958_hw_refine(snd_pcm_t * pcm,snd_pcm_hw_params_t * params)317 static int snd_pcm_iec958_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
318 {
319 	return snd_pcm_hw_refine_slave(pcm, params,
320 				       snd_pcm_iec958_hw_refine_cprepare,
321 				       snd_pcm_iec958_hw_refine_cchange,
322 				       snd_pcm_iec958_hw_refine_sprepare,
323 				       snd_pcm_iec958_hw_refine_schange,
324 				       snd_pcm_generic_hw_refine);
325 }
326 
snd_pcm_iec958_hw_params(snd_pcm_t * pcm,snd_pcm_hw_params_t * params)327 static int snd_pcm_iec958_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
328 {
329 	snd_pcm_iec958_t *iec = pcm->private_data;
330 	snd_pcm_format_t format;
331 	int err = snd_pcm_hw_params_slave(pcm, params,
332 					  snd_pcm_iec958_hw_refine_cchange,
333 					  snd_pcm_iec958_hw_refine_sprepare,
334 					  snd_pcm_iec958_hw_refine_schange,
335 					  snd_pcm_generic_hw_params);
336 	if (err < 0)
337 		return err;
338 
339 	err = INTERNAL(snd_pcm_hw_params_get_format)(params, &format);
340 	if (err < 0)
341 		return err;
342 
343 	iec->format = format;
344 	if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {
345 		if (iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_LE ||
346 		    iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_BE) {
347 			iec->getput_idx = snd_pcm_linear_get_index(format, SND_PCM_FORMAT_S32);
348 			iec->func = snd_pcm_iec958_encode;
349 			iec->byteswap = iec->sformat != SND_PCM_FORMAT_IEC958_SUBFRAME;
350 		} else {
351 			iec->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S32, iec->sformat);
352 			iec->func = snd_pcm_iec958_decode;
353 			iec->byteswap = format != SND_PCM_FORMAT_IEC958_SUBFRAME;
354 		}
355 	} else {
356 		if (iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_LE ||
357 		    iec->sformat == SND_PCM_FORMAT_IEC958_SUBFRAME_BE) {
358 			iec->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S32, format);
359 			iec->func = snd_pcm_iec958_decode;
360 			iec->byteswap = iec->sformat != SND_PCM_FORMAT_IEC958_SUBFRAME;
361 		} else {
362 			iec->getput_idx = snd_pcm_linear_get_index(iec->sformat, SND_PCM_FORMAT_S32);
363 			iec->func = snd_pcm_iec958_encode;
364 			iec->byteswap = format != SND_PCM_FORMAT_IEC958_SUBFRAME;
365 		}
366 	}
367 
368 	if ((iec->status[0] & IEC958_AES0_PROFESSIONAL) == 0) {
369 		if ((iec->status[3] & IEC958_AES3_CON_FS) == IEC958_AES3_CON_FS_NOTID) {
370 			unsigned int rate = 0;
371 			unsigned char fs;
372 
373 			err = INTERNAL(snd_pcm_hw_params_get_rate)(params, &rate, 0);
374 			if (err < 0)
375 				rate = 0;
376 
377 			switch (rate) {
378 			case 22050:
379 				fs = IEC958_AES3_CON_FS_22050;
380 				break;
381 			case 24000:
382 				fs = IEC958_AES3_CON_FS_24000;
383 				break;
384 			case 32000:
385 				fs = IEC958_AES3_CON_FS_32000;
386 				break;
387 			case 44100:
388 				fs = IEC958_AES3_CON_FS_44100;
389 				break;
390 			case 48000:
391 				fs = IEC958_AES3_CON_FS_48000;
392 				break;
393 			case 88200:
394 				fs = IEC958_AES3_CON_FS_88200;
395 				break;
396 			case 96000:
397 				fs = IEC958_AES3_CON_FS_96000;
398 				break;
399 			case 176400:
400 				fs = IEC958_AES3_CON_FS_176400;
401 				break;
402 			case 192000:
403 				fs = IEC958_AES3_CON_FS_192000;
404 				break;
405 			case 768000:
406 				fs = IEC958_AES3_CON_FS_768000;
407 				break;
408 			default:
409 				fs = IEC958_AES3_CON_FS_NOTID;
410 				break;
411 			}
412 
413 			iec->status[3] &= ~IEC958_AES3_CON_FS;
414 			iec->status[3] |= fs;
415 		}
416 
417 		if ((iec->status[4] & IEC958_AES4_CON_WORDLEN) == IEC958_AES4_CON_WORDLEN_NOTID) {
418 			unsigned char ws;
419 			switch (snd_pcm_format_width(format)) {
420 			case 16:
421 				ws = IEC958_AES4_CON_WORDLEN_20_16;
422 				break;
423 			case 18:
424 				ws = IEC958_AES4_CON_WORDLEN_22_18;
425 				break;
426 			case 20:
427 				ws = IEC958_AES4_CON_WORDLEN_20_16 | IEC958_AES4_CON_MAX_WORDLEN_24;
428 				break;
429 			case 24:
430 			case 32: /* Assume 24-bit width for 32-bit samples. */
431 				ws = IEC958_AES4_CON_WORDLEN_24_20 | IEC958_AES4_CON_MAX_WORDLEN_24;
432 				break;
433 			default:
434 				ws = IEC958_AES4_CON_WORDLEN_NOTID;
435 				break;
436 			}
437 			iec->status[4] &= ~(IEC958_AES4_CON_MAX_WORDLEN_24 | IEC958_AES4_CON_WORDLEN);
438 			iec->status[4] |= ws;
439 		}
440 	}
441 	return 0;
442 }
443 
444 static snd_pcm_uframes_t
snd_pcm_iec958_write_areas(snd_pcm_t * pcm,const snd_pcm_channel_area_t * areas,snd_pcm_uframes_t offset,snd_pcm_uframes_t size,const snd_pcm_channel_area_t * slave_areas,snd_pcm_uframes_t slave_offset,snd_pcm_uframes_t * slave_sizep)445 snd_pcm_iec958_write_areas(snd_pcm_t *pcm,
446 			   const snd_pcm_channel_area_t *areas,
447 			   snd_pcm_uframes_t offset,
448 			   snd_pcm_uframes_t size,
449 			   const snd_pcm_channel_area_t *slave_areas,
450 			   snd_pcm_uframes_t slave_offset,
451 			   snd_pcm_uframes_t *slave_sizep)
452 {
453 	snd_pcm_iec958_t *iec = pcm->private_data;
454 	if (size > *slave_sizep)
455 		size = *slave_sizep;
456 	iec->func(iec, slave_areas, slave_offset,
457 		  areas, offset,
458 		  pcm->channels, size);
459 	*slave_sizep = size;
460 	return size;
461 }
462 
463 static snd_pcm_uframes_t
snd_pcm_iec958_read_areas(snd_pcm_t * pcm,const snd_pcm_channel_area_t * areas,snd_pcm_uframes_t offset,snd_pcm_uframes_t size,const snd_pcm_channel_area_t * slave_areas,snd_pcm_uframes_t slave_offset,snd_pcm_uframes_t * slave_sizep)464 snd_pcm_iec958_read_areas(snd_pcm_t *pcm,
465 			  const snd_pcm_channel_area_t *areas,
466 			  snd_pcm_uframes_t offset,
467 			  snd_pcm_uframes_t size,
468 			  const snd_pcm_channel_area_t *slave_areas,
469 			  snd_pcm_uframes_t slave_offset,
470 			  snd_pcm_uframes_t *slave_sizep)
471 {
472 	snd_pcm_iec958_t *iec = pcm->private_data;
473 	if (size > *slave_sizep)
474 		size = *slave_sizep;
475 	iec->func(iec, areas, offset,
476 		  slave_areas, slave_offset,
477 		  pcm->channels, size);
478 	*slave_sizep = size;
479 	return size;
480 }
481 
snd_pcm_iec958_init(snd_pcm_t * pcm)482 static int snd_pcm_iec958_init(snd_pcm_t *pcm)
483 {
484 	snd_pcm_iec958_t *iec = pcm->private_data;
485 	iec->counter = 0;
486 	return 0;
487 }
488 
snd_pcm_iec958_dump(snd_pcm_t * pcm,snd_output_t * out)489 static void snd_pcm_iec958_dump(snd_pcm_t *pcm, snd_output_t *out)
490 {
491 	snd_pcm_iec958_t *iec = pcm->private_data;
492 	snd_output_printf(out, "IEC958 subframe conversion PCM (%s)\n",
493 			  snd_pcm_format_name(iec->sformat));
494 	if (pcm->setup) {
495 		snd_output_printf(out, "Its setup is:\n");
496 		snd_pcm_dump_setup(pcm, out);
497 	}
498 	snd_output_printf(out, "Slave: ");
499 	snd_pcm_dump(iec->plug.gen.slave, out);
500 }
501 
snd_pcm_iec958_rewind(snd_pcm_t * pcm,snd_pcm_uframes_t frames)502 static snd_pcm_sframes_t snd_pcm_iec958_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
503 {
504 	unsigned int counter_decrement;
505 	snd_pcm_iec958_t *iec = pcm->private_data;
506 	snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
507 	if (result <= 0)
508 		return result;
509 
510 	counter_decrement = result % 192;
511 	iec->counter += 192 - counter_decrement;
512 	iec->counter %= 192;
513 	return result;
514 }
515 
snd_pcm_iec958_forward(snd_pcm_t * pcm,snd_pcm_uframes_t frames)516 static snd_pcm_sframes_t snd_pcm_iec958_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
517 
518 {
519 	unsigned int counter_increment;
520 	snd_pcm_iec958_t *iec = pcm->private_data;
521 	snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
522 	if (result <= 0)
523 		return result;
524 
525 	counter_increment = result % 192;
526 	iec->counter += counter_increment;
527 	iec->counter %= 192;
528 	return result;
529 }
530 
531 static const snd_pcm_ops_t snd_pcm_iec958_ops = {
532 	.close = snd_pcm_generic_close,
533 	.info = snd_pcm_generic_info,
534 	.hw_refine = snd_pcm_iec958_hw_refine,
535 	.hw_params = snd_pcm_iec958_hw_params,
536 	.hw_free = snd_pcm_generic_hw_free,
537 	.sw_params = snd_pcm_generic_sw_params,
538 	.channel_info = snd_pcm_generic_channel_info,
539 	.dump = snd_pcm_iec958_dump,
540 	.nonblock = snd_pcm_generic_nonblock,
541 	.async = snd_pcm_generic_async,
542 	.mmap = snd_pcm_generic_mmap,
543 	.munmap = snd_pcm_generic_munmap,
544 	.query_chmaps = snd_pcm_generic_query_chmaps,
545 	.get_chmap = snd_pcm_generic_get_chmap,
546 	.set_chmap = snd_pcm_generic_set_chmap,
547 };
548 
549 /**
550  * \brief Creates a new IEC958 subframe conversion PCM
551  * \param pcmp Returns created PCM handle
552  * \param name Name of PCM
553  * \param sformat Slave (destination) format
554  * \param slave Slave PCM handle
555  * \param close_slave When set, the slave PCM handle is closed with copy PCM
556  * \param status_bits The IEC958 status bits
557  * \param preamble_vals The preamble byte values
558  * \param hdmi_mode When set, enable HDMI compliant formatting
559  * \retval zero on success otherwise a negative error code
560  * \warning Using of this function might be dangerous in the sense
561  *          of compatibility reasons. The prototype might be freely
562  *          changed in future.
563  */
snd_pcm_iec958_open(snd_pcm_t ** pcmp,const char * name,snd_pcm_format_t sformat,snd_pcm_t * slave,int close_slave,const unsigned char * status_bits,const unsigned char * preamble_vals,int hdmi_mode)564 int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sformat,
565 			snd_pcm_t *slave, int close_slave,
566 			const unsigned char *status_bits,
567 			const unsigned char *preamble_vals,
568 		        int hdmi_mode)
569 {
570 	snd_pcm_t *pcm;
571 	snd_pcm_iec958_t *iec;
572 	int err;
573 	static const unsigned char default_status_bits[] = {
574 		IEC958_AES0_CON_EMPHASIS_NONE,
575 		IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER,
576 		0,
577 		IEC958_AES3_CON_FS_NOTID, /* will be set in hwparams */
578 		IEC958_AES4_CON_WORDLEN_NOTID /* will be set in hwparams */
579 	};
580 
581 	assert(pcmp && slave);
582 	if (snd_pcm_format_linear(sformat) != 1 &&
583 	    sformat != SND_PCM_FORMAT_IEC958_SUBFRAME_LE &&
584 	    sformat != SND_PCM_FORMAT_IEC958_SUBFRAME_BE)
585 		return -EINVAL;
586 	iec = calloc(1, sizeof(snd_pcm_iec958_t));
587 	if (!iec) {
588 		return -ENOMEM;
589 	}
590 	snd_pcm_plugin_init(&iec->plug);
591 	iec->sformat = sformat;
592 	iec->plug.read = snd_pcm_iec958_read_areas;
593 	iec->plug.write = snd_pcm_iec958_write_areas;
594 	iec->plug.init = snd_pcm_iec958_init;
595 	iec->plug.undo_read = snd_pcm_plugin_undo_read_generic;
596 	iec->plug.undo_write = snd_pcm_plugin_undo_write_generic;
597 	iec->plug.gen.slave = slave;
598 	iec->plug.gen.close_slave = close_slave;
599 
600 	if (status_bits)
601 		memcpy(iec->status, status_bits, sizeof(iec->status));
602 	else
603 		memcpy(iec->status, default_status_bits, sizeof(default_status_bits));
604 
605 	memcpy(iec->preamble, preamble_vals, 3);
606 
607 	iec->hdmi_mode = hdmi_mode;
608 
609 	err = snd_pcm_new(&pcm, SND_PCM_TYPE_IEC958, name, slave->stream, slave->mode);
610 	if (err < 0) {
611 		free(iec);
612 		return err;
613 	}
614 	pcm->ops = &snd_pcm_iec958_ops;
615 
616 	iec->fops = snd_pcm_plugin_fast_ops;
617 	iec->fops.rewind = snd_pcm_iec958_rewind;
618 	iec->fops.forward = snd_pcm_iec958_forward;
619 	pcm->fast_ops = &iec->fops;
620 
621 	pcm->private_data = iec;
622 	pcm->poll_fd = slave->poll_fd;
623 	pcm->poll_events = slave->poll_events;
624 	pcm->tstamp_type = slave->tstamp_type;
625 	snd_pcm_set_hw_ptr(pcm, &iec->plug.hw_ptr, -1, 0);
626 	snd_pcm_set_appl_ptr(pcm, &iec->plug.appl_ptr, -1, 0);
627 	*pcmp = pcm;
628 
629 	return 0;
630 }
631 
632 /*! \page pcm_plugins
633 
634 \section pcm_plugins_iec958 Plugin: IEC958
635 
636 This plugin converts 32bit IEC958 subframe samples to linear, or linear to
637 32bit IEC958 subframe samples.
638 
639 \code
640 pcm.name {
641         type iec958             # IEC958 subframe conversion PCM
642         slave STR               # Slave name
643         # or
644         slave {                 # Slave definition
645                 pcm STR         # Slave PCM name
646                 # or
647                 pcm { }         # Slave PCM definition
648         }
649 	[status status-bytes]	# IEC958 status bits (given in byte array)
650 	# IEC958 preamble bits definitions
651 	# B/M/W or Z/X/Y, B = block start, M = even subframe, W = odd subframe
652 	# As default, Z = 0x08, Y = 0x04, X = 0x02
653 	[preamble.z or preamble.b val]
654 	[preamble.x or preamble.m val]
655 	[preamble.y or preamble.w val]
656 	[hdmi_mode true]
657 }
658 \endcode
659 
660 When <code>hdmi_mode</code> is true, 8-channel compressed data is
661 formatted as 4 contiguous frames of a single IEC958 stream as required
662 by the HDMI HBR specification.
663 
664 \subsection pcm_plugins_iec958_funcref Function reference
665 
666 <UL>
667   <LI>snd_pcm_iec958_open()
668   <LI>_snd_pcm_iec958_open()
669 </UL>
670 
671 */
672 
673 /**
674  * \brief Creates a new IEC958 subframe conversion PCM
675  * \param pcmp Returns created PCM handle
676  * \param name Name of PCM
677  * \param root Root configuration node
678  * \param conf Configuration node with copy PCM description
679  * \param stream Stream type
680  * \param mode Stream mode
681  * \retval zero on success otherwise a negative error code
682  * \warning Using of this function might be dangerous in the sense
683  *          of compatibility reasons. The prototype might be freely
684  *          changed in future.
685  */
_snd_pcm_iec958_open(snd_pcm_t ** pcmp,const char * name,snd_config_t * root,snd_config_t * conf,snd_pcm_stream_t stream,int mode)686 int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
687 			 snd_config_t *root, snd_config_t *conf,
688 			 snd_pcm_stream_t stream, int mode)
689 {
690 	snd_config_iterator_t i, next;
691 	int err;
692 	snd_pcm_t *spcm;
693 	snd_config_t *slave = NULL, *sconf;
694 	snd_config_t *status = NULL, *preamble = NULL;
695 	snd_pcm_format_t sformat;
696 	unsigned char status_bits[24];
697 	unsigned char preamble_vals[3] = {
698 		0x08, 0x02, 0x04 /* Z, X, Y */
699 	};
700 	int hdmi_mode = 0;
701 
702 	snd_config_for_each(i, next, conf) {
703 		snd_config_t *n = snd_config_iterator_entry(i);
704 		const char *id;
705 		if (snd_config_get_id(n, &id) < 0)
706 			continue;
707 		if (snd_pcm_conf_generic_id(id))
708 			continue;
709 		if (strcmp(id, "slave") == 0) {
710 			slave = n;
711 			continue;
712 		}
713 		if (strcmp(id, "status") == 0) {
714 			if (snd_config_get_type(n) != SND_CONFIG_TYPE_COMPOUND) {
715 				SNDERR("Invalid type for %s", id);
716 				return -EINVAL;
717 			}
718 			status = n;
719 			continue;
720 		}
721 		if (strcmp(id, "preamble") == 0) {
722 			if (snd_config_get_type(n) != SND_CONFIG_TYPE_COMPOUND) {
723 				SNDERR("Invalid type for %s", id);
724 				return -EINVAL;
725 			}
726 			preamble = n;
727 			continue;
728 		}
729 		if (strcmp(id, "hdmi_mode") == 0) {
730 			err = snd_config_get_bool(n);
731 			if (err < 0)
732 				continue;
733 			hdmi_mode = err;
734 			continue;
735 		}
736 		SNDERR("Unknown field %s", id);
737 		return -EINVAL;
738 	}
739 	memset(status_bits, 0, sizeof(status_bits));
740 	if (status) {
741 		snd_config_iterator_t i, inext;
742 		int bytes = 0;
743 		snd_config_for_each(i, inext, status) {
744 			long val;
745 			snd_config_t *n = snd_config_iterator_entry(i);
746 			if (snd_config_get_type(n) != SND_CONFIG_TYPE_INTEGER) {
747 				SNDERR("invalid IEC958 status bits");
748 				return -EINVAL;
749 			}
750 			err = snd_config_get_integer(n, &val);
751 			if (err < 0) {
752 				SNDERR("invalid IEC958 status bits");
753 				return err;
754 			}
755 			status_bits[bytes] = val;
756 			bytes++;
757 			if (bytes >= (int)sizeof(status_bits))
758 				break;
759 		}
760 		// fprintf(stderr, "STATUS bits: %02x %02x %02x %02x\n", status_bits[0], status_bits[1], status_bits[2], status_bits[3]);
761 	}
762 	if (preamble) {
763 		snd_config_iterator_t i, inext;
764 		snd_config_for_each(i, inext, preamble) {
765 			long val;
766 			snd_config_t *n = snd_config_iterator_entry(i);
767 			const char *id;
768 			int idx;
769 			if (snd_config_get_id(n, &id) < 0)
770 				continue;
771 			if (strcmp(id, "b") == 0 || strcmp(id, "z") == 0)
772 				idx = PREAMBLE_Z;
773 			else if (strcmp(id, "m") == 0 || strcmp(id, "x") == 0)
774 				idx = PREAMBLE_X;
775 			else if (strcmp(id, "w") == 0 || strcmp(id, "y") == 0)
776 				idx = PREAMBLE_Y;
777 			else {
778 				SNDERR("invalid IEC958 preamble type %s", id);
779 				return -EINVAL;
780 			}
781 			err = snd_config_get_integer(n, &val);
782 			if (err < 0) {
783 				SNDERR("invalid IEC958 preamble value");
784 				return err;
785 			}
786 			preamble_vals[idx] = val;
787 		}
788 	}
789 	if (!slave) {
790 		SNDERR("slave is not defined");
791 		return -EINVAL;
792 	}
793 	err = snd_pcm_slave_conf(root, slave, &sconf, 1,
794 				 SND_PCM_HW_PARAM_FORMAT, SCONF_MANDATORY, &sformat);
795 	if (err < 0)
796 		return err;
797 	if (snd_pcm_format_linear(sformat) != 1 &&
798 	    sformat != SND_PCM_FORMAT_IEC958_SUBFRAME_LE &&
799 	    sformat != SND_PCM_FORMAT_IEC958_SUBFRAME_BE) {
800 	    	snd_config_delete(sconf);
801 		SNDERR("invalid slave format");
802 		return -EINVAL;
803 	}
804 	err = snd_pcm_open_slave(&spcm, root, sconf, stream, mode, conf);
805 	snd_config_delete(sconf);
806 	if (err < 0)
807 		return err;
808 	err = snd_pcm_iec958_open(pcmp, name, sformat, spcm, 1,
809 				  status ? status_bits : NULL,
810 				  preamble_vals, hdmi_mode);
811 	if (err < 0)
812 		snd_pcm_close(spcm);
813 	return err;
814 }
815 #ifndef DOC_HIDDEN
816 SND_DLSYM_BUILD_VERSION(_snd_pcm_iec958_open, SND_PCM_DLSYM_VERSION);
817 #endif
818