20 /* ulaw[unsigned char] -> signed 16-bit */
22 /* alaw[unsigned char] -> signed 16-bit */
28 /* signed 16-bit -> law */
32 /* alaw -> ulaw */
34 /* ulaw -> alaw */
43 #define AMI_MASK 0x55
51 		0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF  in linear2alaw()
55 	if (pcm_val >= 0) {  in linear2alaw()
56 		/* Sign (7th) bit = 1 */  in linear2alaw()
57 		mask = AMI_MASK | 0x80;  in linear2alaw()
59 		/* Sign bit = 0 */  in linear2alaw()
61 		pcm_val = -pcm_val;  in linear2alaw()
65 	for (seg = 0; seg < 8; seg++) {  in linear2alaw()
71 		 ((pcm_val >> ((seg)  ?  (seg + 3)  :  4)) & 0x0F)) ^ mask;  in linear2alaw()
81 	i = ((alaw & 0x0F) << 4) + 8 /* rounding error */;  in alaw2linear()
82 	seg = (((int) alaw & 0x70) >> 4);  in alaw2linear()
84 		i = (i + 0x100) << (seg - 1);  in alaw2linear()
85 	return (short int) ((alaw & 0x80)  ?  i  :  -i);  in alaw2linear()
91 	static short etab[] = {0, 132, 396, 924, 1980, 4092, 8316, 16764};  in ulaw2linear()
93 	mu = 255 - ulaw;  in ulaw2linear()
94 	e = (mu & 0x70) / 16;  in ulaw2linear()
95 	f = mu & 0x0f;  in ulaw2linear()
98 	if (mu & 0x80)  in ulaw2linear()
99 		y = -y;  in ulaw2linear()
103 #define BIAS 0x84   /*!< define the add-in bias for 16 bit samples */
108 		0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,  in linear2ulaw()
116 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
117 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
118 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
119 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
120 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
121 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
122 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,  in linear2ulaw()
123 		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7};  in linear2ulaw()
127 	/* Get the sample into sign-magnitude. */  in linear2ulaw()
128 	sign = (sample >> 8) & 0x80;	  /* set aside the sign */  in linear2ulaw()
129 	if (sign != 0)  in linear2ulaw()
130 		sample = -sample;	      /* get magnitude */  in linear2ulaw()
134 	exponent = exp_lut[(sample >> 7) & 0xFF];  in linear2ulaw()
135 	mantissa = (sample >> (exponent + 3)) & 0x0F;  in linear2ulaw()
144 	for (i = 0; i < 256; i++)  in dsp_audio_generate_law_tables()
147 	for (i = 0; i < 256; i++)  in dsp_audio_generate_law_tables()
150 	for (i = 0; i < 256; i++) {  in dsp_audio_generate_law_tables()
164 		/* generating ulaw-table */  in dsp_audio_generate_s2law_table()
165 		for (i = -32768; i < 32768; i++) {  in dsp_audio_generate_s2law_table()
166 			dsp_audio_s16_to_law[i & 0xffff] =  in dsp_audio_generate_s2law_table()
170 		/* generating alaw-table */  in dsp_audio_generate_s2law_table()
171 		for (i = -32768; i < 32768; i++) {  in dsp_audio_generate_s2law_table()
172 			dsp_audio_s16_to_law[i & 0xffff] =  in dsp_audio_generate_s2law_table()
180  * the seven bit sample is the number of every second alaw-sample ordered by
181  * aplitude. 0x00 is negative, 0x7f is positive amplitude.
187  * generate table for conversion law from/to 7-bit alaw-like sample *
198 	for (i = 0; i < 256; i++) {  in dsp_audio_generate_seven()
199 		j = 0;  in dsp_audio_generate_seven()
200 		for (k = 0; k < 256; k++) {  in dsp_audio_generate_seven()
209 	for (i = 0; i < 256; i++) {  in dsp_audio_generate_seven()
210 		/* spl is the source: the law-sample (converted to alaw) */  in dsp_audio_generate_seven()
214 		/* find the 7-bit-sample */  in dsp_audio_generate_seven()
215 		for (j = 0; j < 256; j++) {  in dsp_audio_generate_seven()
219 		/* write 7-bit audio value */  in dsp_audio_generate_seven()
222 	for (i = 0; i < 128; i++) {  in dsp_audio_generate_seven()
231 /* mix 2*law -> law */
244 	i = 0;  in dsp_audio_generate_mix_table()
246 		j = 0;  in dsp_audio_generate_mix_table()
252 			if (sample < -32768)  in dsp_audio_generate_mix_table()
253 				sample = -32768;  in dsp_audio_generate_mix_table()
255 				dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_mix_table()
311 	i = 0;  in dsp_audio_generate_volume_changes()
314 			(dsp_audio_law_to_s32[i] * denum[7] / num[7]) & 0xffff];  in dsp_audio_generate_volume_changes()
316 			(dsp_audio_law_to_s32[i] * denum[6] / num[6]) & 0xffff];  in dsp_audio_generate_volume_changes()
318 			(dsp_audio_law_to_s32[i] * denum[5] / num[5]) & 0xffff];  in dsp_audio_generate_volume_changes()
320 			(dsp_audio_law_to_s32[i] * denum[4] / num[4]) & 0xffff];  in dsp_audio_generate_volume_changes()
322 			(dsp_audio_law_to_s32[i] * denum[3] / num[3]) & 0xffff];  in dsp_audio_generate_volume_changes()
324 			(dsp_audio_law_to_s32[i] * denum[2] / num[2]) & 0xffff];  in dsp_audio_generate_volume_changes()
326 			(dsp_audio_law_to_s32[i] * denum[1] / num[1]) & 0xffff];  in dsp_audio_generate_volume_changes()
328 			(dsp_audio_law_to_s32[i] * denum[0] / num[0]) & 0xffff];  in dsp_audio_generate_volume_changes()
329 		sample = dsp_audio_law_to_s32[i] * num[0] / denum[0];  in dsp_audio_generate_volume_changes()
330 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
331 			sample = -32768;  in dsp_audio_generate_volume_changes()
334 		dsp_audio_increase1[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
336 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
337 			sample = -32768;  in dsp_audio_generate_volume_changes()
340 		dsp_audio_increase2[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
342 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
343 			sample = -32768;  in dsp_audio_generate_volume_changes()
346 		dsp_audio_increase3[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
348 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
349 			sample = -32768;  in dsp_audio_generate_volume_changes()
352 		dsp_audio_increase4[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
354 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
355 			sample = -32768;  in dsp_audio_generate_volume_changes()
358 		dsp_audio_increase5[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
360 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
361 			sample = -32768;  in dsp_audio_generate_volume_changes()
364 		dsp_audio_increase6[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
366 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
367 			sample = -32768;  in dsp_audio_generate_volume_changes()
370 		dsp_audio_increase7[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
371 		sample = dsp_audio_law_to_s32[i] * num[7] / denum[7];  in dsp_audio_generate_volume_changes()
372 		if (sample < -32768)  in dsp_audio_generate_volume_changes()
373 			sample = -32768;  in dsp_audio_generate_volume_changes()
376 		dsp_audio_increase8[i] = dsp_audio_s16_to_law[sample & 0xffff];  in dsp_audio_generate_volume_changes()
388  * -8 to 8, which is a shift to the power of 2. 0 == no volume, 3 == volume*8
398 	if (volume == 0)  in dsp_change_volume()
402 	if (volume < 0) {  in dsp_change_volume()
404 		if (shift < 0)  in dsp_change_volume()
405 			shift = 0;  in dsp_change_volume()
407 		shift = volume + 7;  in dsp_change_volume()
412 	i = 0;  in dsp_change_volume()
413 	ii = skb->len;  in dsp_change_volume()
414 	p = skb->data;  in dsp_change_volume()