526ddb13e2
Added wxMMedia2: it should work on linux (wave read/write, aiff read only)
I begin to write windows driver now
Added some file to filelist.txt
Make configure build wxMMedia2 makefiles
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3381 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
179 lines
5.4 KiB
C++
179 lines
5.4 KiB
C++
/*
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* This source code is a product of Sun Microsystems, Inc. and is provided
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* for unrestricted use. Users may copy or modify this source code without
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* charge.
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*
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* SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
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* THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
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*
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* Sun source code is provided with no support and without any obligation on
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* the part of Sun Microsystems, Inc. to assist in its use, correction,
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* modification or enhancement.
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*
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* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
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* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
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* OR ANY PART THEREOF.
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*
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* In no event will Sun Microsystems, Inc. be liable for any lost revenue
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* or profits or other special, indirect and consequential damages, even if
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* Sun has been advised of the possibility of such damages.
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*
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* Sun Microsystems, Inc.
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* 2550 Garcia Avenue
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* Mountain View, California 94043
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*/
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/*
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* g723_40.c
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*
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* Description:
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*
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* g723_40_encoder(), g723_40_decoder()
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*
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* These routines comprise an implementation of the CCITT G.723 40Kbps
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* ADPCM coding algorithm. Essentially, this implementation is identical to
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* the bit level description except for a few deviations which
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* take advantage of workstation attributes, such as hardware 2's
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* complement arithmetic.
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*
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* The deviation from the bit level specification (lookup tables),
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* preserves the bit level performance specifications.
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*
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* As outlined in the G.723 Recommendation, the algorithm is broken
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* down into modules. Each section of code below is preceded by
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* the name of the module which it is implementing.
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*
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*/
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#include "g72x.h"
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/*
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* Maps G.723_40 code word to ructeconstructed scale factor normalized log
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* magnitude values.
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*/
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static short _dqlntab[32] = {-2048, -66, 28, 104, 169, 224, 274, 318,
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358, 395, 429, 459, 488, 514, 539, 566,
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566, 539, 514, 488, 459, 429, 395, 358,
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318, 274, 224, 169, 104, 28, -66, -2048};
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/* Maps G.723_40 code word to log of scale factor multiplier. */
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static short _witab[32] = {448, 448, 768, 1248, 1280, 1312, 1856, 3200,
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4512, 5728, 7008, 8960, 11456, 14080, 16928, 22272,
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22272, 16928, 14080, 11456, 8960, 7008, 5728, 4512,
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3200, 1856, 1312, 1280, 1248, 768, 448, 448};
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/*
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* Maps G.723_40 code words to a set of values whose long and short
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* term averages are computed and then compared to give an indication
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* how stationary (steady state) the signal is.
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*/
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static short _fitab[32] = {0, 0, 0, 0, 0, 0x200, 0x200, 0x200,
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0x200, 0x200, 0x400, 0x600, 0x800, 0xA00, 0xC00, 0xC00,
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0xC00, 0xC00, 0xA00, 0x800, 0x600, 0x400, 0x200, 0x200,
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0x200, 0x200, 0x200, 0, 0, 0, 0, 0};
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static short qtab_723_40[15] = {-122, -16, 68, 139, 198, 250, 298, 339,
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378, 413, 445, 475, 502, 528, 553};
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/*
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* g723_40_encoder()
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*
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* Encodes a 16-bit linear PCM, A-law or u-law input sample and retuens
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* the resulting 5-bit CCITT G.723 40Kbps code.
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* Returns -1 if the input coding value is invalid.
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*/
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int
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g723_40_encoder(
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int sl,
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int in_coding,
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struct g72x_state *state_ptr)
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{
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short sei, sezi, se, sez; /* ACCUM */
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short d; /* SUBTA */
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short y; /* MIX */
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short sr; /* ADDB */
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short dqsez; /* ADDC */
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short dq, i;
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switch (in_coding) { /* linearize input sample to 14-bit PCM */
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case AUDIO_ENCODING_ALAW:
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sl = alaw2linear(sl) >> 2;
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break;
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case AUDIO_ENCODING_ULAW:
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sl = ulaw2linear(sl) >> 2;
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break;
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case AUDIO_ENCODING_LINEAR:
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sl = ((short) sl) >> 2; /* sl of 14-bit dynamic range */
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break;
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default:
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return (-1);
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}
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sezi = predictor_zero(state_ptr);
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sez = sezi >> 1;
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sei = sezi + predictor_pole(state_ptr);
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se = sei >> 1; /* se = estimated signal */
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d = sl - se; /* d = estimation difference */
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/* quantize prediction difference */
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y = step_size(state_ptr); /* adaptive quantizer step size */
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i = quantize(d, y, qtab_723_40, 15); /* i = ADPCM code */
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dq = reconstruct(i & 0x10, _dqlntab[i], y); /* quantized diff */
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sr = (dq < 0) ? se - (dq & 0x7FFF) : se + dq; /* reconstructed signal */
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dqsez = sr + sez - se; /* dqsez = pole prediction diff. */
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update(5, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
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return (i);
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}
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/*
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* g723_40_decoder()
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*
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* Decodes a 5-bit CCITT G.723 40Kbps code and returns
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* the resulting 16-bit linear PCM, A-law or u-law sample value.
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* -1 is returned if the output coding is unknown.
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*/
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int
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g723_40_decoder(
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int i,
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int out_coding,
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struct g72x_state *state_ptr)
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{
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short sezi, sei, sez, se; /* ACCUM */
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short y; /* MIX */
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short sr; /* ADDB */
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short dq;
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short dqsez;
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i &= 0x1f; /* mask to get proper bits */
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sezi = predictor_zero(state_ptr);
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sez = sezi >> 1;
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sei = sezi + predictor_pole(state_ptr);
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se = sei >> 1; /* se = estimated signal */
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y = step_size(state_ptr); /* adaptive quantizer step size */
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dq = reconstruct(i & 0x10, _dqlntab[i], y); /* estimation diff. */
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sr = (dq < 0) ? (se - (dq & 0x7FFF)) : (se + dq); /* reconst. signal */
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dqsez = sr - se + sez; /* pole prediction diff. */
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update(5, y, _witab[i], _fitab[i], dq, sr, dqsez, state_ptr);
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switch (out_coding) {
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case AUDIO_ENCODING_ALAW:
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return (tandem_adjust_alaw(sr, se, y, i, 0x10, qtab_723_40));
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case AUDIO_ENCODING_ULAW:
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return (tandem_adjust_ulaw(sr, se, y, i, 0x10, qtab_723_40));
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case AUDIO_ENCODING_LINEAR:
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return (sr << 2); /* sr was of 14-bit dynamic range */
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default:
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return (-1);
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}
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}
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