117 lines
2.8 KiB
C
117 lines
2.8 KiB
C
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/*
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rdesktop: A Remote Desktop Protocol client.
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Sound DSP routines
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Copyright (C) Michael Gernoth 2006
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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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 General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; 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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#include "rdesktop.h"
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#include "rdpsnd.h"
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#include "rdpsnd_dsp.h"
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#define MAX_VOLUME 65535
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static uint16 softvol_left = MAX_VOLUME;
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static uint16 softvol_right = MAX_VOLUME;
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void
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rdpsnd_dsp_softvol_set(uint16 left, uint16 right)
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{
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softvol_left = left;
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softvol_right = right;
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DEBUG(("rdpsnd_dsp_softvol_set: left: %u, right: %u\n", left, right));
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}
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inline void
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rdpsnd_dsp_softvol(unsigned char *inbuffer, unsigned char *outbuffer, unsigned int size,
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WAVEFORMATEX * format)
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{
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unsigned int factor_left, factor_right;
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unsigned char *posin = inbuffer;
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unsigned char *posout = outbuffer;
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factor_left = (softvol_left * 256) / 65535;
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factor_right = (softvol_right * 256) / 65535;
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if (format->nChannels == 1)
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{
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factor_left = factor_right = (factor_left + factor_right) / 2;
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}
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if (format->wBitsPerSample == 8)
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{
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char val;
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while (posout < outbuffer + size)
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{
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/* Left */
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val = *posin++;
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val = (val * factor_left) >> 8;
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*posout++ = val;
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/* Right */
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val = *posin++;
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val = (val * factor_right) >> 8;
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*posout++ = val;
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}
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}
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else
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{
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short val;
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while (posout < outbuffer + size)
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{
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/* Left */
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val = *posin++;
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val |= *posin++ << 8;
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val = (val * factor_left) >> 8;
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*posout++ = val & 0xff;
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*posout++ = val >> 8;
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/* Right */
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val = *posin++;
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val |= *posin++ << 8;
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val = (val * factor_right) >> 8;
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*posout++ = val & 0xff;
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*posout++ = val >> 8;
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}
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}
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DEBUG(("using softvol with shifts left: %d, right: %d (%d/%d)\n", factor_left, factor_right,
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format->wBitsPerSample, format->nChannels));
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}
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unsigned char *
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rdpsnd_dsp_process(unsigned char *inbuffer, unsigned int size, struct audio_driver *current_driver,
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WAVEFORMATEX * format)
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{
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unsigned char *outbuffer;
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outbuffer = xmalloc(size);
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/* Software volume control */
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if (current_driver->wave_out_volume == rdpsnd_dsp_softvol_set)
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{
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rdpsnd_dsp_softvol(inbuffer, outbuffer, size, format);
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}
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else
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{
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memcpy(outbuffer, inbuffer, size);
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}
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return outbuffer;
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}
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