swscale: fix gbrap to gbrap alpha scaling
[ffmpeg.git] / libavcodec / acelp_pitch_delay.c
index 9b35fcc..1965772 100644 (file)
@@ -3,26 +3,30 @@
  *
  * Copyright (c) 2008 Vladimir Voroshilov
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav 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 FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/common.h"
+#include "libavutil/float_dsp.h"
+#include "libavutil/mathematics.h"
 #include "avcodec.h"
 #include "acelp_pitch_delay.h"
-#include "acelp_math.h"
+#include "celp_math.h"
+#include "audiodsp.h"
 
 int ff_acelp_decode_8bit_to_1st_delay3(int ac_index)
 {
@@ -83,10 +87,11 @@ void ff_acelp_update_past_gain(
     if(erasure)
         quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10)
     else
-        quant_energy[0] = (6165 * ((ff_log2(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
+        quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
 }
 
 int16_t ff_acelp_decode_gain_code(
+    AudioDSPContext *adsp,
     int gain_corr_factor,
     const int16_t* fc_v,
     int mr_energy,
@@ -102,18 +107,72 @@ int16_t ff_acelp_decode_gain_code(
     for(i=0; i<ma_pred_order; i++)
         mr_energy += quant_energy[i] * ma_prediction_coeff[i];
 
-#ifdef G729_BITEXACT
-    mr_energy += (((-6165LL * ff_log2(sum_of_squares(fc_v, subframe_size, 0, 0))) >> 3) & ~0x3ff);
-
-    mr_energy = (5439 * (mr_energy >> 15)) >> 8;           // (0.15) = (0.15) * (7.23)
-
-    return bidir_sal(
-               ((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1),
-               (mr_energy >> 15) - 25
-           );
-#else
     mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) /
-                sqrt(sum_of_squares(fc_v, subframe_size, 0, 0));
+                sqrt(adsp->scalarproduct_int16(fc_v, fc_v, subframe_size));
     return mr_energy >> 12;
-#endif
+}
+
+float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
+                            float *prediction_error, float energy_mean,
+                            const float *pred_table)
+{
+    // Equations 66-69:
+    // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
+    // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
+    float val = fixed_gain_factor *
+        exp2f(M_LOG2_10 * 0.05 *
+              (avpriv_scalarproduct_float_c(pred_table, prediction_error, 4) +
+               energy_mean)) /
+        sqrtf(fixed_mean_energy);
+
+    // update quantified prediction error energy history
+    memmove(&prediction_error[0], &prediction_error[1],
+            3 * sizeof(prediction_error[0]));
+    prediction_error[3] = 20.0 * log10f(fixed_gain_factor);
+
+    return val;
+}
+
+void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index,
+                         const int prev_lag_int, const int subframe,
+                         int third_as_first, int resolution)
+{
+    /* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */
+    if (subframe == 0 || (subframe == 2 && third_as_first)) {
+
+        if (pitch_index < 197)
+            pitch_index += 59;
+        else
+            pitch_index = 3 * pitch_index - 335;
+
+    } else {
+        if (resolution == 4) {
+            int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
+                                           PITCH_DELAY_MAX - 9);
+
+            // decoding with 4-bit resolution
+            if (pitch_index < 4) {
+                // integer only precision for [search_range_min, search_range_min+3]
+                pitch_index = 3 * (pitch_index + search_range_min) + 1;
+            } else if (pitch_index < 12) {
+                // 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3]
+                pitch_index += 3 * search_range_min + 7;
+            } else {
+                // integer only precision for [search_range_min+6, search_range_min+9]
+                pitch_index = 3 * (pitch_index + search_range_min - 6) + 1;
+            }
+        } else {
+            // decoding with 5 or 6 bit resolution, 1/3 fractional precision
+            pitch_index--;
+
+            if (resolution == 5) {
+                pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
+                                           PITCH_DELAY_MAX - 19);
+            } else
+                pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
+                                           PITCH_DELAY_MAX - 9);
+        }
+    }
+    *lag_int  = pitch_index * 10923 >> 15;
+    *lag_frac = pitch_index - 3 * *lag_int - 1;
 }