updated libfaad

CVS patchset: 3560
CVS date: 2002/12/16 18:59:50

1 files changed, 169 insertions, 0 deletions

diff --git a/src/libfaad/ssr.c b/src/libfaad/ssr.c
new file mode 100644
index 000000000..a4865a25d
--- /dev/null
+++ b/src/libfaad/ssr.c
@@ -0,0 +1,169 @@
+/*
+** FAAD - Freeware Advanced Audio Decoder
+** Copyright (C) 2002 M. Bakker
+**  
+** 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+**
+** $Id: ssr.c,v 1.1 2002/12/16 19:01:17 miguelfreitas Exp $
+**/
+
+#include "common.h"
+#include "structs.h"
+
+#ifdef SSR_DEC
+
+#include "syntax.h"
+#include "filtbank.h"
+#include "ssr.h"
+#include "ssr_fb.h"
+
+void ssr_decode(ssr_info *ssr, fb_info *fb, uint8_t window_sequence,
+                uint8_t window_shape, uint8_t window_shape_prev,
+                real_t *freq_in, real_t *time_out, real_t *overlap,
+                real_t ipqf_buffer[SSR_BANDS][96/4],
+                real_t *prev_fmd, uint16_t frame_len)
+{
+    uint8_t band;
+    uint16_t ssr_frame_len = frame_len/SSR_BANDS;
+    real_t time_tmp[2048];
+    real_t output[1024];
+
+    memset(output, 0, 1024*sizeof(real_t));
+    memset(time_tmp, 0, 2048*sizeof(real_t));
+
+    for (band = 0; band < SSR_BANDS; band++)
+    {
+        int16_t j;
+
+        /* uneven bands have inverted frequency scale */
+        if (band == 1 || band == 3)
+        {
+            for (j = 0; j < ssr_frame_len/2; j++)
+            {
+                real_t tmp;
+                tmp = freq_in[j + ssr_frame_len*band];
+                freq_in[j + ssr_frame_len*band] =
+                    freq_in[ssr_frame_len - j - 1 + ssr_frame_len*band];
+                freq_in[ssr_frame_len - j - 1 + ssr_frame_len*band] = tmp;
+            }
+        }
+
+        /* non-overlapping inverse filterbank for SSR */
+        ssr_ifilter_bank(fb, window_sequence, window_shape, window_shape_prev,
+            freq_in + band*ssr_frame_len, time_tmp + band*ssr_frame_len,
+            ssr_frame_len);
+
+        /* gain control */
+        ssr_gain_control(ssr, time_tmp, output, overlap, prev_fmd,
+            band, window_sequence, ssr_frame_len);
+    }
+
+    /* inverse pqf to bring subbands together again */
+    ssr_ipqf(ssr, output, time_out, ipqf_buffer, frame_len, SSR_BANDS);
+}
+
+static void ssr_gain_control(ssr_info *ssr, real_t *data, real_t *output,
+                             real_t *overlap, real_t *prev_fmd, uint8_t band,
+                             uint8_t window_sequence, uint16_t frame_len)
+{
+    uint16_t i;
+    real_t gc_function[2*1024/SSR_BANDS];
+
+    if (window_sequence != EIGHT_SHORT_SEQUENCE)
+    {
+        ssr_gc_function(ssr, &prev_fmd[band * frame_len*2],
+            gc_function, window_sequence, frame_len);
+
+        for (i = 0; i < frame_len*2; i++)
+            data[band * frame_len*2 + i] *= gc_function[i];
+        for (i = 0; i < frame_len; i++)
+        {
+            output[band*frame_len + i] = overlap[band*frame_len + i] +
+                data[band*frame_len*2 + i];
+        }
+        for (i = 0; i < frame_len; i++)
+        {
+            overlap[band*frame_len + i] =
+                data[band*frame_len*2 + frame_len + i];
+        }
+    } else {
+        uint8_t w;
+        for (w = 0; w < 8; w++)
+        {
+            uint16_t frame_len8 = frame_len/8;
+            uint16_t frame_len16 = frame_len/16;
+
+            ssr_gc_function(ssr, &prev_fmd[band*frame_len*2 + w*frame_len*2/8],
+                gc_function, window_sequence, frame_len);
+
+            for (i = 0; i < frame_len8*2; i++)
+                data[band*frame_len*2 + w*frame_len8*2+i] *= gc_function[i];
+            for (i = 0; i < frame_len8; i++)
+            {
+                overlap[band*frame_len + i + 7*frame_len16 + w*frame_len8] +=
+                    data[band*frame_len*2 + 2*w*frame_len8 + i];
+            }
+            for (i = 0; i < frame_len8; i++)
+            {
+                overlap[band*frame_len + i + 7*frame_len16 + (w+1)*frame_len8] =
+                    data[band*frame_len*2 + 2*w*frame_len8 + frame_len8 + i];
+            }
+        }
+        for (i = 0; i < frame_len; i++)
+            output[band*frame_len + i] = overlap[band*frame_len + i];
+        for (i = 0; i < frame_len; i++)
+            overlap[band*frame_len + i] = overlap[band*frame_len + i + frame_len];
+    }
+}
+
+static void ssr_gc_function(ssr_info *ssr, real_t *prev_fmd,
+                            real_t *gc_function, uint8_t window_sequence,
+                            uint16_t frame_len)
+{
+    uint16_t i;
+    uint16_t len_area1, len_area2;
+    int32_t aloc[10];
+    real_t alev[10];
+
+    switch (window_sequence)
+    {
+    case ONLY_LONG_SEQUENCE:
+        len_area1 = frame_len/SSR_BANDS;
+        len_area2 = 0;
+        break;
+    case LONG_START_SEQUENCE:
+        len_area1 = (frame_len/SSR_BANDS)*7/32;
+        len_area2 = (frame_len/SSR_BANDS)/16;
+        break;
+    case EIGHT_SHORT_SEQUENCE:
+        len_area1 = (frame_len/8)/SSR_BANDS;
+        len_area2 = 0;
+        break;
+    case LONG_STOP_SEQUENCE:
+        len_area1 = (frame_len/SSR_BANDS);
+        len_area2 = 0;
+        break;
+    }
+
+    /* decode bitstream information */
+
+    /* build array M */
+
+
+    for (i = 0; i < frame_len*2; i++)
+        gc_function[i] = 1;
+}
+
+#endif