trunk/rdesktop/rdpsnd_dsp.c

/*
   rdesktop: A Remote Desktop Protocol client.
   Sound DSP routines
   Copyright (C) Michael Gernoth 2006

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "rdesktop.h"
#include "rdpsnd.h"
#include "rdpsnd_dsp.h"

#define MAX_VOLUME 65535

static uint16 softvol_left = MAX_VOLUME;
static uint16 softvol_right = MAX_VOLUME;

void
rdpsnd_dsp_softvol_set(uint16 left, uint16 right)
{
        softvol_left = left;
        softvol_right = right;
        DEBUG(("rdpsnd_dsp_softvol_set: left: %u, right: %u\n", left, right));
}

void
rdpsnd_dsp_softvol(unsigned char *buffer, unsigned int size, WAVEFORMATEX * format)
{
        unsigned int factor_left, factor_right;
        unsigned char *posin = buffer;
        unsigned char *posout = buffer;

        if ((softvol_left == MAX_VOLUME) && (softvol_right == MAX_VOLUME))
                return;

        factor_left = (softvol_left * 256) / 65535;
        factor_right = (softvol_right * 256) / 65535;

        if (format->nChannels == 1)
        {
                factor_left = factor_right = (factor_left + factor_right) / 2;
        }

        if (format->wBitsPerSample == 8)
        {
                sint8 val;

                while (posout < buffer + size)
                {
                        /* Left */
                        val = *posin++;
                        val = (val * factor_left) >> 8;
                        *posout++ = val;

                        /* Right */
                        val = *posin++;
                        val = (val * factor_right) >> 8;
                        *posout++ = val;
                }
        }
        else
        {
                sint16 val;

                while (posout < buffer + size)
                {
                        /* Left */
                        val = *posin++;
                        val |= *posin++ << 8;
                        val = (val * factor_left) >> 8;
                        *posout++ = val & 0xff;
                        *posout++ = val >> 8;

                        /* Right */
                        val = *posin++;
                        val |= *posin++ << 8;
                        val = (val * factor_right) >> 8;
                        *posout++ = val & 0xff;
                        *posout++ = val >> 8;
                }
        }

        DEBUG(("using softvol with factors left: %d, right: %d (%d/%d)\n", factor_left, factor_right,
               format->wBitsPerSample, format->nChannels));
}

void
rdpsnd_dsp_swapbytes(unsigned char *buffer, unsigned int size, WAVEFORMATEX * format)
{
        int i;
        uint8 swap;

        if (format->wBitsPerSample == 8)
                return;

        for (i = 0; i < size; i += 2)
        {
                swap = *(buffer + i);
                *(buffer + i) = *(buffer + i + 1);
                *(buffer + i + 1) = swap;
        }
}

unsigned char *
rdpsnd_dsp_process(unsigned char *inbuffer, unsigned int size, struct audio_driver *current_driver,
                   WAVEFORMATEX * format)
{
        unsigned char *outbuffer;

        outbuffer = xmalloc(size);

        memcpy(outbuffer, inbuffer, size);

        /* Software volume control */
        if (current_driver->wave_out_volume == rdpsnd_dsp_softvol_set)
                rdpsnd_dsp_softvol(outbuffer, size, format);

#ifdef B_ENDIAN
        if (current_driver->need_byteswap_on_be)
                rdpsnd_dsp_swapbytes(outbuffer, size, format);
#endif

        return outbuffer;
}
1	/*
2	rdesktop: A Remote Desktop Protocol client.
3	Sound DSP routines
4	Copyright (C) Michael Gernoth 2006
5
6	This program is free software; you can redistribute it and/or modify
7	it under the terms of the GNU General Public License as published by
8	the Free Software Foundation; either version 2 of the License, or
9	(at your option) any later version.
10
11	This program is distributed in the hope that it will be useful,
12	but WITHOUT ANY WARRANTY; without even the implied warranty of
13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	GNU General Public License for more details.
15
16	You should have received a copy of the GNU General Public License
17	along with this program; if not, write to the Free Software
18	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19	*/
20
21	#include "rdesktop.h"
22	#include "rdpsnd.h"
23	#include "rdpsnd_dsp.h"
24
25	#define MAX_VOLUME 65535
26
27	static uint16 softvol_left = MAX_VOLUME;
28	static uint16 softvol_right = MAX_VOLUME;
29
30	void
31	rdpsnd_dsp_softvol_set(uint16 left, uint16 right)
32	{
33	softvol_left = left;
34	softvol_right = right;
35	DEBUG(("rdpsnd_dsp_softvol_set: left: %u, right: %u\n", left, right));
36	}
37
38	void
39	rdpsnd_dsp_softvol(unsigned char buffer, unsigned int size, WAVEFORMATEX format)
40	{
41	unsigned int factor_left, factor_right;
42	unsigned char *posin = buffer;
43	unsigned char *posout = buffer;
44
45	if ((softvol_left == MAX_VOLUME) && (softvol_right == MAX_VOLUME))
46	return;
47
48	factor_left = (softvol_left * 256) / 65535;
49	factor_right = (softvol_right * 256) / 65535;
50
51	if (format->nChannels == 1)
52	{
53	factor_left = factor_right = (factor_left + factor_right) / 2;
54	}
55
56	if (format->wBitsPerSample == 8)
57	{
58	sint8 val;
59
60	while (posout < buffer + size)
61	{
62	/* Left */
63	val = *posin++;
64	val = (val * factor_left) >> 8;
65	*posout++ = val;
66
67	/* Right */
68	val = *posin++;
69	val = (val * factor_right) >> 8;
70	*posout++ = val;
71	}
72	}
73	else
74	{
75	sint16 val;
76
77	while (posout < buffer + size)
78	{
79	/* Left */
80	val = *posin++;
81	val \|= *posin++ << 8;
82	val = (val * factor_left) >> 8;
83	*posout++ = val & 0xff;
84	*posout++ = val >> 8;
85
86	/* Right */
87	val = *posin++;
88	val \|= *posin++ << 8;
89	val = (val * factor_right) >> 8;
90	*posout++ = val & 0xff;
91	*posout++ = val >> 8;
92	}
93	}
94
95	DEBUG(("using softvol with factors left: %d, right: %d (%d/%d)\n", factor_left, factor_right,
96	format->wBitsPerSample, format->nChannels));
97	}
98
99	void
100	rdpsnd_dsp_swapbytes(unsigned char buffer, unsigned int size, WAVEFORMATEX format)
101	{
102	int i;
103	uint8 swap;
104
105	if (format->wBitsPerSample == 8)
106	return;
107
108	for (i = 0; i < size; i += 2)
109	{
110	swap = *(buffer + i);
111	(buffer + i) = (buffer + i + 1);
112	*(buffer + i + 1) = swap;
113	}
114	}
115
116	unsigned char *
117	rdpsnd_dsp_process(unsigned char inbuffer, unsigned int size, struct audio_driver current_driver,
118	WAVEFORMATEX * format)
119	{
120	unsigned char *outbuffer;
121
122	outbuffer = xmalloc(size);
123
124	memcpy(outbuffer, inbuffer, size);
125
126	/* Software volume control */
127	if (current_driver->wave_out_volume == rdpsnd_dsp_softvol_set)
128	rdpsnd_dsp_softvol(outbuffer, size, format);
129
130	#ifdef B_ENDIAN
131	if (current_driver->need_byteswap_on_be)
132	rdpsnd_dsp_swapbytes(outbuffer, size, format);
133	#endif
134
135	return outbuffer;
136	}