merge FAAD2 - the GPL AAC decoder library.

xine_decoder.c is working, but demux_qt must send some needed
initialization data. currently it's hardcoded to play my test stream, so
it's not usable yet.

CVS patchset: 2267
CVS date: 2002/07/14 23:43:01

1 files changed, 134 insertions, 0 deletions

diff --git a/src/libfaad/lt_predict.c b/src/libfaad/lt_predict.c
new file mode 100644
index 000000000..ff5c33f10
--- /dev/null
+++ b/src/libfaad/lt_predict.c
@@ -0,0 +1,134 @@
+/*
+** 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: lt_predict.c,v 1.1 2002/07/14 23:43:01 miguelfreitas Exp $
+**/
+
+
+#include "common.h"
+
+#ifdef LTP_DEC
+
+#include <stdlib.h>
+#include "syntax.h"
+#include "lt_predict.h"
+#include "filtbank.h"
+#include "tns.h"
+
+static real_t codebook[8] =
+{
+    0.570829f, 0.696616f, 0.813004f, 0.911304f, 0.984900f, 1.067894f,
+    1.194601f, 1.369533f
+};
+
+void lt_prediction(ic_stream *ics, ltp_info *ltp, real_t *spec,
+                   real_t *lt_pred_stat, fb_info *fb, uint8_t win_shape,
+                   uint8_t win_shape_prev, uint8_t sr_index,
+                   uint8_t object_type, uint16_t frame_len)
+{
+    uint8_t sfb;
+    uint16_t bin, i, num_samples;
+    real_t *x_est;
+    real_t *X_est;
+
+    if (ics->window_sequence != EIGHT_SHORT_SEQUENCE)
+    {
+        if (ltp->data_present)
+        {
+            num_samples = frame_len << 1;
+
+            x_est = malloc(num_samples*sizeof(real_t));
+            X_est = malloc(num_samples*sizeof(real_t));
+
+            for(i = 0; i < num_samples; i++)
+            {
+                /* The extra lookback M (N/2 for LD, 0 for LTP) is handled
+                   in the buffer updating */
+                x_est[i] = MUL(codebook[ltp->coef],
+                    lt_pred_stat[num_samples + i - ltp->lag]);
+            }
+
+            filter_bank_ltp(fb, ics->window_sequence, win_shape, win_shape_prev,
+                x_est, X_est, object_type, frame_len);
+
+            tns_encode_frame(ics, &(ics->tns), sr_index, object_type, X_est,
+                frame_len);
+
+            for (sfb = 0; sfb < ltp->last_band; sfb++)
+            {
+                if (ltp->long_used[sfb])
+                {
+                    uint16_t low  = ics->swb_offset[sfb];
+                    uint16_t high = ics->swb_offset[sfb+1];
+
+                    for (bin = low; bin < high; bin++)
+                    {
+                        spec[bin] += X_est[bin];
+                    }
+                }
+            }
+
+            free(x_est);
+            free(X_est);
+        }
+    }
+}
+
+void lt_update_state(real_t *lt_pred_stat, real_t *time, real_t *overlap,
+                     uint16_t frame_len, uint8_t object_type)
+{
+    uint16_t i;
+
+    /*
+     * The reference point for index i and the content of the buffer
+     * lt_pred_stat are arranged so that lt_pred_stat(0 ... N/2 - 1) contains the
+     * last aliased half window from the IMDCT, and lt_pred_stat(N/2 ... N-1)
+     * is always all zeros. The rest of lt_pred_stat (i<0) contains the previous
+     * fully reconstructed time domain samples, i.e., output of the decoder.
+     *
+     * These values are shifted up by N*2 to avoid (i<0)
+     *
+     * For the LD object type an extra 512 samples lookback is accomodated here.
+     */
+#ifdef LD_DEC
+    if (object_type == LD)
+    {
+        for (i = 0; i < frame_len; i++)
+        {
+            lt_pred_stat[i]  /* extra 512 */  = lt_pred_stat[i + frame_len];
+            lt_pred_stat[frame_len + i]       = lt_pred_stat[i + (frame_len * 2)];
+            lt_pred_stat[(frame_len * 2) + i] = time[i];
+            lt_pred_stat[(frame_len * 3) + i] = overlap[i];
+        }
+    } else {
+#endif
+        for (i = 0; i < frame_len; i++)
+        {
+            lt_pred_stat[i]                   = lt_pred_stat[i + frame_len];
+            lt_pred_stat[frame_len + i]       = time[i];
+            lt_pred_stat[(frame_len * 2) + i] = overlap[i];
+#if 0 /* set to zero once upon initialisation */
+            lt_pred_stat[(frame_len * 3) + i] = 0;
+#endif
+        }
+#ifdef LD_DEC
+    }
+#endif
+}
+
+#endif