TrueSpeech compatible audio decoder by Konstantin Shishkov

Originally committed as revision 4803 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 377 insertions, 0 deletions

diff --git a/libavcodec/truespeech.c b/libavcodec/truespeech.c
new file mode 100644
index 0000000000..e5ec00cce4
--- /dev/null
+++ b/libavcodec/truespeech.c
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+/*
+ * DSP Group TrueSpeech compatible decoder
+ * Copyright (c) 2005 Konstantin Shishkov
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include "avcodec.h"
+
+#include "truespeech_data.h"
+/**
+ * @file truespeech.c
+ * TrueSpeech decoder.
+ */
+
+/**
+ * TrueSpeech decoder context
+ */
+typedef struct {
+    /* input data */
+    int16_t vector[8];  //< input vector: 5/5/4/4/4/3/3/3
+    int offset1[2];     //< 8-bit value, used in one copying offset
+    int offset2[4];     //< 7-bit value, encodes offsets for copying and for two-point filter
+    int pulseoff[4];    //< 4-bit offset of pulse values block
+    int pulsepos[4];    //< 27-bit variable, encodes 7 pulse positions
+    int pulseval[4];    //< 7x2-bit pulse values
+    int flag;           //< 1-bit flag, shows how to choose filters
+    /* temporary data */
+    int filtbuf[146];   // some big vector used for storing filters
+    int prevfilt[8];    // filter from previous frame
+    int16_t tmp1[8];    // coefficients for adding to out
+    int16_t tmp2[8];    // coefficients for adding to out
+    int16_t tmp3[8];    // coefficients for adding to out
+    int16_t cvector[8]; // correlated input vector
+    int filtval;        // gain value for one function
+    int16_t newvec[60]; // tmp vector
+    int16_t filters[32]; // filters for every subframe
+} TSContext;
+
+static int truespeech_decode_init(AVCodecContext * avctx)
+{
+//    TSContext *c = avctx->priv_data;
+
+    return 0;
+}
+
+static void truespeech_read_frame(TSContext *dec, uint8_t *input)
+{
+    uint32_t t;
+
+    /* first dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->flag = t & 1;
+
+    dec->vector[0] = ts_codebook[0][(t >>  1) & 0x1F];
+    dec->vector[1] = ts_codebook[1][(t >>  6) & 0x1F];
+    dec->vector[2] = ts_codebook[2][(t >> 11) &  0xF];
+    dec->vector[3] = ts_codebook[3][(t >> 15) &  0xF];
+    dec->vector[4] = ts_codebook[4][(t >> 19) &  0xF];
+    dec->vector[5] = ts_codebook[5][(t >> 23) &  0x7];
+    dec->vector[6] = ts_codebook[6][(t >> 26) &  0x7];
+    dec->vector[7] = ts_codebook[7][(t >> 29) &  0x7];
+
+    /* second dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->offset2[0] = (t >>  0) & 0x7F;
+    dec->offset2[1] = (t >>  7) & 0x7F;
+    dec->offset2[2] = (t >> 14) & 0x7F;
+    dec->offset2[3] = (t >> 21) & 0x7F;
+
+    dec->offset1[0] = ((t >> 28) & 0xF) << 4;
+
+    /* third dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulseval[0] = (t >>  0) & 0x3FFF;
+    dec->pulseval[1] = (t >> 14) & 0x3FFF;
+
+    dec->offset1[1] = (t >> 28) & 0x0F;
+
+    /* fourth dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulseval[2] = (t >>  0) & 0x3FFF;
+    dec->pulseval[3] = (t >> 14) & 0x3FFF;
+
+    dec->offset1[1] |= ((t >> 28) & 0x0F) << 4;
+
+    /* fifth dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulsepos[0] = (t >> 4) & 0x7FFFFFF;
+
+    dec->pulseoff[0] = (t >> 0) & 0xF;
+
+    dec->offset1[0] |= (t >> 31) & 1;
+
+    /* sixth dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulsepos[1] = (t >> 4) & 0x7FFFFFF;
+
+    dec->pulseoff[1] = (t >> 0) & 0xF;
+
+    dec->offset1[0] |= ((t >> 31) & 1) << 1;
+
+    /* seventh dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulsepos[2] = (t >> 4) & 0x7FFFFFF;
+
+    dec->pulseoff[2] = (t >> 0) & 0xF;
+
+    dec->offset1[0] |= ((t >> 31) & 1) << 2;
+
+    /* eighth dword */
+    t = LE_32(input);
+    input += 4;
+
+    dec->pulsepos[3] = (t >> 4) & 0x7FFFFFF;
+
+    dec->pulseoff[3] = (t >> 0) & 0xF;
+
+    dec->offset1[0] |= ((t >> 31) & 1) << 3;
+
+}
+
+static void truespeech_correlate_filter(TSContext *dec)
+{
+    int16_t tmp[8];
+    int i, j;
+
+    for(i = 0; i < 8; i++){
+        if(i > 0){
+            memcpy(tmp, dec->cvector, i * 2);
+            for(j = 0; j < i; j++)
+                dec->cvector[j] = ((tmp[i - j - 1] * dec->vector[i]) +
+                                   (dec->cvector[j] << 15) + 0x4000) >> 15;
+        }
+        dec->cvector[i] = (8 - dec->vector[i]) >> 3;
+    }
+    for(i = 0; i < 8; i++)
+        dec->cvector[i] = (dec->cvector[i] * ts_230[i]) >> 15;
+
+    dec->filtval = dec->vector[0];
+}
+
+static void truespeech_filters_merge(TSContext *dec)
+{
+    int i;
+
+    if(!dec->flag){
+        for(i = 0; i < 8; i++){
+            dec->filters[i + 0] = dec->prevfilt[i];
+            dec->filters[i + 8] = dec->prevfilt[i];
+        }
+    }else{
+        for(i = 0; i < 8; i++){
+            dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;
+            dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;
+        }
+    }
+    for(i = 0; i < 8; i++){
+        dec->filters[i + 16] = dec->cvector[i];
+        dec->filters[i + 24] = dec->cvector[i];
+    }
+}
+
+static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
+{
+    int16_t tmp[146 + 60], *ptr0, *ptr1, *filter;
+    int i, t, off;
+
+    t = dec->offset2[quart];
+    if(t == 127){
+        memset(dec->newvec, 0, 60 * 2);
+        return;
+    }
+    for(i = 0; i < 146; i++)
+        tmp[i] = dec->filtbuf[i];
+    off = (t / 25) + dec->offset1[quart >> 1] + 18;
+    ptr0 = tmp + 145 - off;
+    ptr1 = tmp + 146;
+    filter = ts_240 + (t % 25) * 2;
+    for(i = 0; i < 60; i++){
+        t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;
+        ptr0++;
+        dec->newvec[i] = t;
+        ptr1[i] = t;
+    }
+}
+
+static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
+{
+    int16_t tmp[7];
+    int i, j, t;
+    int16_t *ptr1, *ptr2;
+    int coef;
+
+    memset(out, 0, 60 * 2);
+    for(i = 0; i < 7; i++) {
+        t = dec->pulseval[quart] & 3;
+        dec->pulseval[quart] >>= 2;
+        tmp[6 - i] = ts_562[dec->pulseoff[quart] * 4 + t];
+    }
+
+    coef = dec->pulsepos[quart] >> 15;
+    ptr1 = ts_140 + 30;
+    ptr2 = tmp;
+    for(i = 0, j = 3; (i < 30) && (j > 0); i++){
+        t = *ptr1++;
+        if(coef >= t)
+            coef -= t;
+        else{
+            out[i] = *ptr2++;
+            ptr1 += 30;
+            j--;
+        }
+    }
+    coef = dec->pulsepos[quart] & 0x7FFF;
+    ptr1 = ts_140;
+    for(i = 30, j = 4; (i < 60) && (j > 0); i++){
+        t = *ptr1++;
+        if(coef >= t)
+            coef -= t;
+        else{
+            out[i] = *ptr2++;
+            ptr1 += 30;
+            j--;
+        }
+    }
+
+}
+
+static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
+{
+    int i;
+
+    for(i = 0; i < 86; i++)
+        dec->filtbuf[i] = dec->filtbuf[i + 60];
+    for(i = 0; i < 60; i++){
+        dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
+        out[i] += dec->newvec[i];
+    }
+}
+
+static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
+{
+    int i,k;
+    int t[8];
+    int16_t *ptr0, *ptr1;
+
+    ptr0 = dec->tmp1;
+    ptr1 = dec->filters + quart * 8;
+    for(i = 0; i < 60; i++){
+        int sum = 0;
+        for(k = 0; k < 8; k++)
+            sum += ptr0[k] * ptr1[k];
+        sum = (sum + (out[i] << 12) + 0x800) >> 12;
+        out[i] = clip(sum, -0x7FFE, 0x7FFE);
+        for(k = 7; k > 0; k--)
+            ptr0[k] = ptr0[k - 1];
+        ptr0[0] = out[i];
+    }
+
+    for(i = 0; i < 8; i++)
+        t[i] = (ts_5E2[i] * ptr1[i]) >> 15;
+
+    ptr0 = dec->tmp2;
+    for(i = 0; i < 60; i++){
+        int sum = 0;
+        for(k = 0; k < 8; k++)
+            sum += ptr0[k] * t[k];
+        for(k = 7; k > 0; k--)
+            ptr0[k] = ptr0[k - 1];
+        ptr0[0] = out[i];
+        out[i] = ((out[i] << 12) - sum) >> 12;
+    }
+
+    for(i = 0; i < 8; i++)
+        t[i] = (ts_5F2[i] * ptr1[i]) >> 15;
+
+    ptr0 = dec->tmp3;
+    for(i = 0; i < 60; i++){
+        int sum = out[i] << 12;
+        for(k = 0; k < 8; k++)
+            sum += ptr0[k] * t[k];
+        for(k = 7; k > 0; k--)
+            ptr0[k] = ptr0[k - 1];
+        ptr0[0] = clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
+
+        sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;
+        sum = sum - (sum >> 3);
+        out[i] = clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
+    }
+}
+
+static void truespeech_save_prevvec(TSContext *c)
+{
+    int i;
+
+    for(i = 0; i < 8; i++)
+        c->prevfilt[i] = c->cvector[i];
+}
+
+static int truespeech_decode_frame(AVCodecContext *avctx,
+                void *data, int *data_size,
+                uint8_t *buf, int buf_size)
+{
+    TSContext *c = avctx->priv_data;
+
+    int i;
+    short *samples = data;
+    int consumed = 0;
+    int16_t out_buf[240];
+
+    if (!buf_size)
+        return 0;
+
+    while (consumed < buf_size) {
+        truespeech_read_frame(c, buf + consumed);
+        consumed += 32;
+
+        truespeech_correlate_filter(c);
+        truespeech_filters_merge(c);
+
+        memset(out_buf, 0, 240 * 2);
+        for(i = 0; i < 4; i++) {
+            truespeech_apply_twopoint_filter(c, i);
+            truespeech_place_pulses(c, out_buf + i * 60, i);
+            truespeech_update_filters(c, out_buf + i * 60, i);
+            truespeech_synth(c, out_buf + i * 60, i);
+        }
+
+        truespeech_save_prevvec(c);
+
+        /* finally output decoded frame */
+        for(i = 0; i < 240; i++)
+            *samples++ = out_buf[i];
+
+    }
+
+    *data_size = consumed * 15;
+
+    return buf_size;
+}
+
+AVCodec truespeech_decoder = {
+    "truespeech",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_TRUESPEECH,
+    sizeof(TSContext),
+    truespeech_decode_init,
+    NULL,
+    NULL,
+    truespeech_decode_frame,
+};