/*
- * Atrac common data
- * Copyright (c) 2009 Maxim Poliakovski
+ * common functions for the ATRAC family of decoders
+ *
+ * Copyright (c) 2009-2013 Maxim Poliakovski
* Copyright (c) 2009 Benjamin Larsson
*
- * 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
*/
/**
* @file
- * Atrac common header
+ * ATRAC common header
*/
#ifndef AVCODEC_ATRAC_H
#define AVCODEC_ATRAC_H
+/**
+ * Gain control parameters for one subband.
+ */
+typedef struct AtracGainInfo {
+ int num_points; ///< number of gain control points
+ int lev_code[7]; ///< level at corresponding control point
+ int loc_code[7]; ///< location of gain control points
+} AtracGainInfo;
+
+/**
+ * Gain compensation context structure.
+ */
+typedef struct AtracGCContext {
+ float gain_tab1[16]; ///< gain compensation level table
+ float gain_tab2[31]; ///< gain compensation interpolation table
+ int id2exp_offset; ///< offset for converting level index into level exponent
+ int loc_scale; ///< scale of location code = 2^loc_scale samples
+ int loc_size; ///< size of location code in samples
+} AtracGCContext;
+
extern float ff_atrac_sf_table[64];
-void atrac_generate_tables(void);
-void atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp);
+/**
+ * Generate common tables.
+ */
+void ff_atrac_generate_tables(void);
+
+/**
+ * Initialize gain compensation context.
+ *
+ * @param gctx pointer to gain compensation context to initialize
+ * @param id2exp_offset offset for converting level index into level exponent
+ * @param loc_scale location size factor
+ */
+void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
+ int loc_scale);
+
+/**
+ * Apply gain compensation and perform the MDCT overlapping part.
+ *
+ * @param gctx pointer to gain compensation context
+ * @param in input buffer
+ * @param prev previous buffer to perform overlap against
+ * @param gc_now gain control information for current frame
+ * @param gc_next gain control information for next frame
+ * @param num_samples number of samples to process
+ * @param out output data goes here
+ */
+void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
+ AtracGainInfo *gc_now, AtracGainInfo *gc_next,
+ int num_samples, float *out);
+
+/**
+ * Quadrature mirror synthesis filter.
+ *
+ * @param inlo lower part of spectrum
+ * @param inhi higher part of spectrum
+ * @param nIn size of spectrum buffer
+ * @param pOut out buffer
+ * @param delayBuf delayBuf buffer
+ * @param temp temp buffer
+ */
+void ff_atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp);
#endif /* AVCODEC_ATRAC_H */