/* * Ima-ADPCM conversion Plug-In Interface * Copyright (c) 1999 by Jaroslav Kysela * Uros Bizjak * * Based on reference implementation by Sun Microsystems, Inc. * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Library 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 Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #include #include #include #include "../pcm_local.h" static short qtab_721[7] = { -124, 80, 178, 246, 300, 349, 400 }; /* * Maps G.721 code word to reconstructed scale factor normalized log * magnitude values. */ static short _dqlntab[16] = { -2048, 4, 135, 213, 273, 323, 373, 425, 425, 373, 323, 273, 213, 135, 4, -2048 }; /* Maps G.721 code word to log of scale factor multiplier. */ static short _witab[16] = { -12, 18, 41, 64, 112, 198, 355, 1122, 1122, 355, 198, 112, 64, 41, 18, -12 }; /* * Maps G.721 code words to a set of values whose long and short * term averages are computed and then compared to give an indication * how stationary (steady state) the signal is. */ static short _fitab[16] = { 0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00, 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0 }; static short power2[15] = { 1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000 }; /* * The following is the definition of the state structure * used by the G.721/G.723 encoder and decoder to preserve their internal * state between successive calls. The meanings of the majority * of the state structure fields are explained in detail in the * CCITT Recommendation G.721. The field names are essentially indentical * to variable names in the bit level description of the coding algorithm * included in this Recommendation. */ typedef struct g72x_state { long yl; /* Locked or steady state step size multiplier. */ short yu; /* Unlocked or non-steady state step size multiplier. */ short dms; /* Short term energy estimate. */ short dml; /* Long term energy estimate. */ short ap; /* Linear weighting coefficient of 'yl' and 'yu'. */ short a[2]; /* Coefficients of pole portion of prediction filter. */ short b[6]; /* Coefficients of zero portion of prediction filter. */ short pk[2]; /* * Signs of previous two samples of a partially * reconstructed signal. */ short dq[6]; /* * Previous 6 samples of the quantized difference * signal represented in an internal floating point * format. */ short sr[2]; /* * Previous 2 samples of the quantized difference * signal represented in an internal floating point * format. */ char td; /* delayed tone detect, new in 1988 version */ } g72x_state_t; /* * quan() * * quantizes the input val against the table of size short integers. * It returns i if table[i - 1] <= val < table[i]. * * Using linear search for simple coding. */ static inline int quan( int val, short *table, int size) { int i; for (i = 0; i < size; i++) if (val < *table++) break; return (i); } /* * fmult() * * returns the integer product of the 14-bit integer "an" and * "floating point" representation (4-bit exponent, 6-bit mantissa) "srn". */ static inline int fmult( int an, int srn) { short anmag, anexp, anmant; short wanexp, wanmant; short retval; anmag = (an > 0) ? an : ((-an) & 0x1FFF); anexp = quan(anmag, power2, 15) - 6; anmant = (anmag == 0) ? 32 : (anexp >= 0) ? anmag >> anexp : anmag << -anexp; wanexp = anexp + ((srn >> 6) & 0xF) - 13; wanmant = (anmant * (srn & 077) + 0x30) >> 4; retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : (wanmant >> -wanexp); return (((an ^ srn) < 0) ? -retval : retval); } /* * predictor_zero() * * computes the estimated signal from 6-zero predictor. * */ static inline int predictor_zero(g72x_state_t *state_ptr) { int i; int sezi; sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]); for (i = 1; i < 6; i++) /* ACCUM */ sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]); return (sezi); } /* * predictor_pole() * * computes the estimated signal from 2-pole predictor. * */ static inline int predictor_pole(g72x_state_t *state_ptr) { return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); } /* * step_size() * * computes the quantization step size of the adaptive quantizer. * */ static inline int step_size(g72x_state_t *state_ptr) { int y; int dif; int al; if (state_ptr->ap >= 256) return (state_ptr->yu); else { y = state_ptr->yl >> 6; dif = state_ptr->yu - y; al = state_ptr->ap >> 2; if (dif > 0) y += (dif * al) >> 6; else if (dif < 0) y += (dif * al + 0x3F) >> 6; return (y); } } /* * quantize() * * Given a raw sample, 'd', of the difference signal and a * quantization step size scale factor, 'y', this routine returns the * ADPCM codeword to which that sample gets quantized. The step * size scale factor division operation is done in the log base 2 domain * as a subtraction. */ static inline int quantize( int d, /* Raw difference signal sample */ int y, /* Step size multiplier */ short *table, /* quantization table */ int size) { /* table size of short integers */ short dqm; /* Magnitude of 'd' */ short exp; /* Integer part of base 2 log of 'd' */ short mant; /* Fractional part of base 2 log */ short dl; /* Log of magnitude of 'd' */ short dln; /* Step size scale factor normalized log */ int i; /* * LOG * * Compute base 2 log of 'd', and store in 'dl'. */ dqm = abs(d); exp = quan(dqm >> 1, power2, 15); mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ dl = (exp << 7) + mant; /* * SUBTB * * "Divide" by step size multiplier. */ dln = dl - (y >> 2); /* * QUAN * * Obtain codword i for 'd'. */ i = quan(dln, table, size); if (d < 0) /* take 1's complement of i */ return ((size << 1) + 1 - i); else if (i == 0) /* take 1's complement of 0 */ return ((size << 1) + 1); /* new in 1988 */ else return (i); } /* * reconstruct() * * Returns reconstructed difference signal 'dq' obtained from * codeword 'dqln' and quantization step size scale factor 'y'. * Multiplication is performed in log base 2 domain as addition. */ static inline int reconstruct( int sign, /* 0 for non-negative value */ int dqln, /* G.72x codeword */ int y) { /* Step size multiplier */ short dql; /* Log of 'dq' magnitude */ short dex; /* Integer part of log */ short dqt; short dq; /* Reconstructed difference signal sample */ dql = dqln + (y >> 2); /* ADDA */ if (dql < 0) { return ((sign) ? -0x8000 : 0); } else { /* ANTILOG */ dex = (dql >> 7) & 15; dqt = 128 + (dql & 127); dq = (dqt << 7) >> (14 - dex); return ((sign) ? (dq - 0x8000) : dq); } } /* * update() * * updates the state variables for each output code */ static void update( int y, /* quantizer step size */ int wi, /* scale factor multiplier */ int fi, /* for long/short term energies */ int dq, /* quantized prediction difference */ int sr, /* reconstructed signal */ int dqsez, /* difference from 2-pole predictor */ g72x_state_t *state_ptr) { /* coder state pointer */ int cnt; short mag, exp; /* Adaptive predictor, FLOAT A */ short a2p = 0; /* LIMC */ short a1ul; /* UPA1 */ short pks1; /* UPA2 */ short fa1; char tr; /* tone/transition detector */ short ylint, thr2, dqthr; short ylfrac, thr1; short pk0; pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ mag = dq & 0x7FFF; /* prediction difference magnitude */ /* TRANS */ ylint = state_ptr->yl >> 15; /* exponent part of yl */ ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ thr1 = (32 + ylfrac) << ylint; /* threshold */ thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ if (state_ptr->td == 0) /* signal supposed voice */ tr = 0; else if (mag <= dqthr) /* supposed data, but small mag */ tr = 0; /* treated as voice */ else /* signal is data (modem) */ tr = 1; /* * Quantizer scale factor adaptation. */ /* FUNCTW & FILTD & DELAY */ /* update non-steady state step size multiplier */ state_ptr->yu = y + ((wi - y) >> 5); /* LIMB */ if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ state_ptr->yu = 544; else if (state_ptr->yu > 5120) state_ptr->yu = 5120; /* FILTE & DELAY */ /* update steady state step size multiplier */ state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); /* * Adaptive predictor coefficients. */ if (tr == 1) { /* reset a's and b's for modem signal */ state_ptr->a[0] = 0; state_ptr->a[1] = 0; state_ptr->b[0] = 0; state_ptr->b[1] = 0; state_ptr->b[2] = 0; state_ptr->b[3] = 0; state_ptr->b[4] = 0; state_ptr->b[5] = 0; } else { /* update a's and b's */ pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ /* update predictor pole a[1] */ a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); if (dqsez != 0) { fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; if (fa1 < -8191) /* a2p = function of fa1 */ a2p -= 0x100; else if (fa1 > 8191) a2p += 0xFF; else a2p += fa1 >> 5; if (pk0 ^ state_ptr->pk[1]) /* LIMC */ if (a2p <= -12160) a2p = -12288; else if (a2p >= 12416) a2p = 12288; else a2p -= 0x80; else if (a2p <= -12416) a2p = -12288; else if (a2p >= 12160) a2p = 12288; else a2p += 0x80; } /* TRIGB & DELAY */ state_ptr->a[1] = a2p; /* UPA1 */ /* update predictor pole a[0] */ state_ptr->a[0] -= state_ptr->a[0] >> 8; if (dqsez != 0) { if (pks1 == 0) state_ptr->a[0] += 192; else state_ptr->a[0] -= 192; } /* LIMD */ a1ul = 15360 - a2p; if (state_ptr->a[0] < -a1ul) state_ptr->a[0] = -a1ul; else if (state_ptr->a[0] > a1ul) state_ptr->a[0] = a1ul; /* UPB : update predictor zeros b[6] */ for (cnt = 0; cnt < 6; cnt++) { state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; if (dq & 0x7FFF) { /* XOR */ if ((dq ^ state_ptr->dq[cnt]) >= 0) state_ptr->b[cnt] += 128; else state_ptr->b[cnt] -= 128; } } } for (cnt = 5; cnt > 0; cnt--) state_ptr->dq[cnt] = state_ptr->dq[cnt - 1]; /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ if (mag == 0) { state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20; } else { exp = quan(mag, power2, 15); state_ptr->dq[0] = (dq >= 0) ? (exp << 6) + ((mag << 6) >> exp) : (exp << 6) + ((mag << 6) >> exp) - 0x400; } state_ptr->sr[1] = state_ptr->sr[0]; /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ if (sr == 0) { state_ptr->sr[0] = 0x20; } else if (sr > 0) { exp = quan(sr, power2, 15); state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); } else if (sr > -32768) { mag = -sr; exp = quan(mag, power2, 15); state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; } else state_ptr->sr[0] = 0xFC20; /* DELAY A */ state_ptr->pk[1] = state_ptr->pk[0]; state_ptr->pk[0] = pk0; /* TONE */ if (tr == 1) /* this sample has been treated as data */ state_ptr->td = 0; /* next one will be treated as voice */ else if (a2p < -11776) /* small sample-to-sample correlation */ state_ptr->td = 1; /* signal may be data */ else /* signal is voice */ state_ptr->td = 0; /* * Adaptation speed control. */ state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ if (tr == 1) state_ptr->ap = 256; else if (y < 1536) /* SUBTC */ state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (state_ptr->td == 1) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= (state_ptr->dml >> 3)) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else state_ptr->ap += (-state_ptr->ap) >> 4; } /* * g72x_init_state() * * This routine initializes and/or resets the g72x_state structure * pointed to by 'state_ptr'. * All the initial state values are specified in the CCITT G.721 document. */ static inline void g72x_init_state(g72x_state_t *state_ptr) { int cnta; state_ptr->yl = 34816; state_ptr->yu = 544; state_ptr->dms = 0; state_ptr->dml = 0; state_ptr->ap = 0; for (cnta = 0; cnta < 2; cnta++) { state_ptr->a[cnta] = 0; state_ptr->pk[cnta] = 0; state_ptr->sr[cnta] = 32; } for (cnta = 0; cnta < 6; cnta++) { state_ptr->b[cnta] = 0; state_ptr->dq[cnta] = 32; } state_ptr->td = 0; } /* * g721_encoder() * * Encodes the input vale of linear PCM and returns the resulting code. */ static inline int g721_encoder( int sl, g72x_state_t *state_ptr) { short sezi, se, sez; /* ACCUM */ short d; /* SUBTA */ short sr; /* ADDB */ short y; /* MIX */ short dqsez; /* ADDC */ short dq, i; sl >>= 2; /* 14-bit dynamic range */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ d = sl - se; /* estimation difference */ /* quantize the prediction difference */ y = step_size(state_ptr); /* quantizer step size */ i = quantize(d, y, qtab_721, 7); /* i = ADPCM code */ dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */ sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ dqsez = sr + sez - se; /* pole prediction diff. */ update(y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); return (i); } /* * g721_decoder() * * Description: * * Decodes a 4-bit code of G.721 encoded data of i and * returns the resulting linear PCM */ static inline int g721_decoder( int i, g72x_state_t *state_ptr) { short sezi, sei, sez, se; /* ACCUM */ short y; /* MIX */ short sr; /* ADDB */ short dq; short dqsez; i &= 0x0f; /* mask to get proper bits */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ y = step_size(state_ptr); /* dynamic quantizer step size */ dq = reconstruct(i & 0x08, _dqlntab[i], y); /* quantized diff. */ sr = (dq < 0) ? (se - (dq & 0x3FFF)) : se + dq; /* reconst. signal */ dqsez = sr - se + sez; /* pole prediction diff. */ update(y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); return (sr << 2); /* sr was 14-bit dynamic range */ } /* * Basic Ima-ADPCM plugin */ typedef enum { _S8_ADPCM, _U8_ADPCM, _S16LE_ADPCM, _U16LE_ADPCM, _S16BE_ADPCM, _U16BE_ADPCM, _ADPCM_S8, _ADPCM_U8, _ADPCM_S16LE, _ADPCM_U16LE, _ADPCM_S16BE, _ADPCM_U16BE } combination_t; struct adpcm_private_data { combination_t cmd; g72x_state_t state; }; static void adpcm_conv_u8bit_adpcm(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned char *dst_ptr, size_t size) { unsigned int pcm; while (size-- > 0) { pcm = ((*src_ptr++) ^ 0x80) << 8; *dst_ptr++ = g721_encoder((signed short)(pcm), state_ptr); } } static void adpcm_conv_s8bit_adpcm(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned char *dst_ptr, size_t size) { unsigned int pcm; while (size-- > 0) { pcm = *src_ptr++ << 8; *dst_ptr++ = g721_encoder((signed short)(pcm), state_ptr); } } static void adpcm_conv_s16bit_adpcm(g72x_state_t *state_ptr, unsigned short *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_encoder((signed short)(*src_ptr++), state_ptr); } static void adpcm_conv_s16bit_swap_adpcm(g72x_state_t *state_ptr, unsigned short *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_encoder((signed short)(bswap_16(*src_ptr++)), state_ptr); } static void adpcm_conv_u16bit_adpcm(g72x_state_t *state_ptr, unsigned short *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_encoder((signed short)((*src_ptr++) ^ 0x8000), state_ptr); } static void adpcm_conv_u16bit_swap_adpcm(g72x_state_t *state_ptr, unsigned short *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_encoder((signed short)(bswap_16((*src_ptr++) ^ 0x8000)), state_ptr); } static void adpcm_conv_adpcm_u8bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_decoder((*src_ptr++) >> 8, state_ptr) ^ 0x80; } static void adpcm_conv_adpcm_s8bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned char *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_decoder(*src_ptr++, state_ptr) >> 8; } static void adpcm_conv_adpcm_s16bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned short *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_decoder(*src_ptr++, state_ptr); } static void adpcm_conv_adpcm_swap_s16bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned short *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = bswap_16(g721_decoder(*src_ptr++, state_ptr)); } static void adpcm_conv_adpcm_u16bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned short *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = g721_decoder(*src_ptr++, state_ptr) ^ 0x8000; } static void adpcm_conv_adpcm_swap_u16bit(g72x_state_t *state_ptr, unsigned char *src_ptr, unsigned short *dst_ptr, size_t size) { while (size-- > 0) *dst_ptr++ = bswap_16(g721_decoder(*src_ptr++, state_ptr) ^ 0x8000); } static ssize_t adpcm_transfer(snd_pcm_plugin_t *plugin, char *src_ptr, size_t src_size, char *dst_ptr, size_t dst_size) { struct adpcm_private_data *data; if (plugin == NULL || src_ptr == NULL || src_size < 0 || dst_ptr == NULL || dst_size < 0) return -EINVAL; if (src_size == 0) return 0; data = (struct adpcm_private_data *)snd_pcm_plugin_extra_data(plugin); if (data == NULL) return -EINVAL; switch (data->cmd) { case _U8_ADPCM: if (dst_size < src_size) return -EINVAL; adpcm_conv_u8bit_adpcm(&data->state, src_ptr, dst_ptr, src_size); return src_size; case _S8_ADPCM: if (dst_size < src_size) return -EINVAL; adpcm_conv_s8bit_adpcm(&data->state, src_ptr, dst_ptr, src_size); return src_size; case _S16LE_ADPCM: if ((dst_size << 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_s16bit_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_s16bit_swap_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #else #error "Have to be coded..." #endif return src_size >> 1; case _U16LE_ADPCM: if ((dst_size << 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_u16bit_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_u16bit_swap_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #else #error "Have to be coded..." #endif return src_size >> 1; case _S16BE_ADPCM: if ((dst_size << 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_s16bit_swap_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_s16bit_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #else #error "Have to be coded..." #endif return src_size >> 1; case _U16BE_ADPCM: if ((dst_size << 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_u16bit_swap_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_u16bit_adpcm(&data->state, (short *)src_ptr, dst_ptr, src_size >> 1); #else #error "Have to be coded..." #endif return src_size >> 1; case _ADPCM_U8: if (dst_size < src_size) return -EINVAL; adpcm_conv_adpcm_u8bit(&data->state, src_ptr, dst_ptr, src_size); return src_size; case _ADPCM_S8: if (dst_size < src_size) return -EINVAL; adpcm_conv_adpcm_s8bit(&data->state, src_ptr, dst_ptr, src_size); return src_size; case _ADPCM_S16LE: if ((dst_size >> 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_adpcm_s16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_adpcm_swap_s16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #else #error "Have to be coded..." #endif return src_size << 1; case _ADPCM_U16LE: if ((dst_size >> 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_adpcm_u16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_adpcm_swap_u16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #else #error "Have to be coded..." #endif return src_size << 1; case _ADPCM_S16BE: if ((dst_size >> 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_adpcm_swap_s16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_adpcm_s16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #else #error "Have to be coded..." #endif return src_size << 1; case _ADPCM_U16BE: if ((dst_size >> 1) < src_size) return -EINVAL; #if __BYTE_ORDER == __LITTLE_ENDIAN adpcm_conv_adpcm_swap_u16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #elif __BYTE_ORDER == __BIG_ENDIAN adpcm_conv_adpcm_u16bit(&data->state, src_ptr, (short *)dst_ptr, src_size); #else #error "Have to be coded..." #endif return dst_size << 1; default: return -EIO; } } static int adpcm_action(snd_pcm_plugin_t *plugin, snd_pcm_plugin_action_t action) { struct adpcm_private_data *data; if (plugin == NULL) return -EINVAL; data = (struct adpcm_private_data *)snd_pcm_plugin_extra_data(plugin); if (action == PREPARE) g72x_init_state(&data->state); return 0; /* silenty ignore other actions */ } static ssize_t adpcm_src_size(snd_pcm_plugin_t *plugin, size_t size) { struct adpcm_private_data *data; if (!plugin || size <= 0) return -EINVAL; data = (struct adpcm_private_data *)snd_pcm_plugin_extra_data(plugin); switch (data->cmd) { case _U8_ADPCM: case _S8_ADPCM: case _ADPCM_U8: case _ADPCM_S8: return size; case _U16LE_ADPCM: case _S16LE_ADPCM: case _U16BE_ADPCM: case _S16BE_ADPCM: return size * 2; case _ADPCM_U16LE: case _ADPCM_S16LE: case _ADPCM_U16BE: case _ADPCM_S16BE: return size / 2; default: return -EIO; } } static ssize_t adpcm_dst_size(snd_pcm_plugin_t *plugin, size_t size) { struct adpcm_private_data *data; if (!plugin || size <= 0) return -EINVAL; data = (struct adpcm_private_data *)snd_pcm_plugin_extra_data(plugin); switch (data->cmd) { case _U8_ADPCM: case _S8_ADPCM: case _ADPCM_U8: case _ADPCM_S8: return size; case _U16LE_ADPCM: case _S16LE_ADPCM: case _U16BE_ADPCM: case _S16BE_ADPCM: return size / 2; case _ADPCM_U16LE: case _ADPCM_S16LE: case _ADPCM_U16BE: case _ADPCM_S16BE: return size * 2; default: return -EIO; } } int snd_pcm_plugin_build_adpcm(int src_format, int dst_format, snd_pcm_plugin_t **r_plugin) { struct adpcm_private_data *data; snd_pcm_plugin_t *plugin; combination_t cmd; if (!r_plugin) return -EINVAL; *r_plugin = NULL; if (dst_format == SND_PCM_SFMT_IMA_ADPCM) { switch (src_format) { case SND_PCM_SFMT_U8: cmd = _U8_ADPCM; break; case SND_PCM_SFMT_S8: cmd = _S8_ADPCM; break; case SND_PCM_SFMT_U16_LE: cmd = _U16LE_ADPCM; break; case SND_PCM_SFMT_S16_LE: cmd = _S16LE_ADPCM; break; case SND_PCM_SFMT_U16_BE: cmd = _U16BE_ADPCM; break; case SND_PCM_SFMT_S16_BE: cmd = _S16BE_ADPCM; break; default: return -EINVAL; } } else if (src_format == SND_PCM_SFMT_IMA_ADPCM) { switch (dst_format) { case SND_PCM_SFMT_U8: cmd = _ADPCM_U8; break; case SND_PCM_SFMT_S8: cmd = _ADPCM_S8; break; case SND_PCM_SFMT_U16_LE: cmd = _ADPCM_U16LE; break; case SND_PCM_SFMT_S16_LE: cmd = _ADPCM_S16LE; break; case SND_PCM_SFMT_U16_BE: cmd = _ADPCM_U16BE; break; case SND_PCM_SFMT_S16_BE: cmd = _ADPCM_S16BE; break; default: return -EINVAL; } } else { return -EINVAL; } plugin = snd_pcm_plugin_build("Ima-ADPCM<->linear conversion", sizeof(struct adpcm_private_data)); if (plugin == NULL) return -ENOMEM; data = (struct adpcm_private_data *)snd_pcm_plugin_extra_data(plugin); data->cmd = cmd; plugin->transfer = adpcm_transfer; plugin->src_size = adpcm_src_size; plugin->dst_size = adpcm_dst_size; plugin->action = adpcm_action; *r_plugin = plugin; return 0; }