1 files changed, 55 insertions, 0 deletions
diff --git a/libavcodec/aacenc_tns.h b/libavcodec/aacenc_tns.h
new file mode 100644
index 0000000000..a7c119f368
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+++ b/libavcodec/aacenc_tns.h
@@ -0,0 +1,55 @@
+/*
+ * AAC encoder TNS
+ * Copyright (C) 2015 Rostislav Pehlivanov
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * AAC encoder temporal noise shaping
+ * @author Rostislav Pehlivanov ( atomnuker gmail com )
+ */
+
+#ifndef AVCODEC_AACENC_TNS_H
+#define AVCODEC_AACENC_TNS_H
+
+#include "aacenc.h"
+
+/* Could be set to 3 to save an additional bit at the cost of little quality */
+#define TNS_Q_BITS 4
+
+/* Coefficient resolution in short windows */
+#define TNS_Q_BITS_SHORT 3
+
+/* TNS will only be used if the LPC gain is within these margins */
+#define TNS_GAIN_THRESHOLD_LOW  1.437f
+#define TNS_GAIN_THRESHOLD_HIGH 21.19f
+
+/* If the energy ratio between the low SFBs vs the high SFBs is not between
+ * those two values, use 2 filters instead */
+#define TNS_E_RATIO_LOW  0.77
+#define TNS_E_RATIO_HIGH 1.23
+
+/* Do not use TNS if the psy band spread is below this value */
+#define TNS_SPREAD_THRESHOLD 0.5f
+
+void ff_aac_encode_tns_info(AACEncContext *s, SingleChannelElement *sce);
+void ff_aac_apply_tns(AACEncContext *s, SingleChannelElement *sce);
+void ff_aac_search_for_tns(AACEncContext *s, SingleChannelElement *sce);
+
+#endif /* AVCODEC_AACENC_TNS_H */