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));
}

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

        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)
        {
                char val;

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

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

                while (posout < outbuffer + 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 shifts left: %d, right: %d (%d/%d)\n", factor_left, factor_right,
               format->wBitsPerSample, format->nChannels));
}

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

        outbuffer = xmalloc(size);

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

        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	inline void
39	rdpsnd_dsp_softvol(unsigned char inbuffer, unsigned char outbuffer, unsigned int size,
40	WAVEFORMATEX * format)
41	{
42	unsigned int factor_left, factor_right;
43	unsigned char *posin = inbuffer;
44	unsigned char *posout = outbuffer;
45
46	factor_left = (softvol_left * 256) / 65535;
47	factor_right = (softvol_right * 256) / 65535;
48
49	if (format->nChannels == 1)
50	{
51	factor_left = factor_right = (factor_left + factor_right) / 2;
52	}
53
54	if (format->wBitsPerSample == 8)
55	{
56	char val;
57
58	while (posout < outbuffer + size)
59	{
60	/* Left */
61	val = *posin++;
62	val = (val * factor_left) >> 8;
63	*posout++ = val;
64
65	/* Right */
66	val = *posin++;
67	val = (val * factor_right) >> 8;
68	*posout++ = val;
69	}
70	}
71	else
72	{
73	short val;
74
75	while (posout < outbuffer + size)
76	{
77	/* Left */
78	val = *posin++;
79	val \|= *posin++ << 8;
80	val = (val * factor_left) >> 8;
81	*posout++ = val & 0xff;
82	*posout++ = val >> 8;
83
84	/* Right */
85	val = *posin++;
86	val \|= *posin++ << 8;
87	val = (val * factor_right) >> 8;
88	*posout++ = val & 0xff;
89	*posout++ = val >> 8;
90	}
91	}
92
93	DEBUG(("using softvol with shifts left: %d, right: %d (%d/%d)\n", factor_left, factor_right,
94	format->wBitsPerSample, format->nChannels));
95	}
96
97	unsigned char *
98	rdpsnd_dsp_process(unsigned char inbuffer, unsigned int size, struct audio_driver current_driver,
99	WAVEFORMATEX * format)
100	{
101	unsigned char *outbuffer;
102
103	outbuffer = xmalloc(size);
104
105	/* Software volume control */
106	if (current_driver->wave_out_volume == rdpsnd_dsp_softvol_set)
107	{
108	rdpsnd_dsp_softvol(inbuffer, outbuffer, size, format);
109	}
110	else
111	{
112	memcpy(outbuffer, inbuffer, size);
113	}
114
115	return outbuffer;
116	}