Add an HE-AAC v1 decoder.

A large portion of this code was orignally authored by Robert Swain. The rest
was written by me. Full history is available at:
svn://svn.ffmpeg.org/soc/aac-sbr
http://github.com/aconverse/ffmpeg-heaac/tree/sbr_pub

Originally committed as revision 22316 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 187 insertions, 0 deletions

diff --git a/libavcodec/sbr.h b/libavcodec/sbr.h
new file mode 100644
index 0000000000..5095bdc0cb
--- /dev/null
+++ b/libavcodec/sbr.h
@@ -0,0 +1,187 @@
+/*
+ * Spectral Band Replication definitions and structures
+ * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
+ * Copyright (c) 2010      Alex Converse <alex.converse@gmail.com>
+ *
+ * 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 libavcodec/sbr.h
+ * Spectral Band Replication definitions and structures
+ * @author Robert Swain ( rob opendot cl )
+ */
+
+#ifndef AVCODEC_SBR_H
+#define AVCODEC_SBR_H
+
+#include <stdint.h>
+#include "fft.h"
+
+/**
+ * Spectral Band Replication header - spectrum parameters that invoke a reset if they differ from the previous header.
+ */
+typedef struct {
+    uint8_t bs_start_freq;
+    uint8_t bs_stop_freq;
+    uint8_t bs_xover_band;
+
+    /**
+     * @defgroup bs_header_extra_1     Variables associated with bs_header_extra_1
+     * @{
+     */
+    uint8_t bs_freq_scale;
+    uint8_t bs_alter_scale;
+    uint8_t bs_noise_bands;
+    /** @} */
+} SpectrumParameters;
+
+#define SBR_SYNTHESIS_BUF_SIZE ((1280-128)*2)
+
+/**
+ * Spectral Band Replication per channel data
+ */
+typedef struct {
+    /**
+     * @defgroup bitstream     Main bitstream data variables
+     * @{
+     */
+    unsigned           bs_frame_class;
+    unsigned           bs_add_harmonic_flag;
+    unsigned           bs_num_env[2];
+    uint8_t            bs_freq_res[7];
+    uint8_t            bs_var_bord[2];
+    uint8_t            bs_num_rel[2];
+    uint8_t            bs_rel_bord[2][3];
+    unsigned           bs_pointer;
+    unsigned           bs_num_noise;
+    uint8_t            bs_df_env[5];
+    uint8_t            bs_df_noise[2];
+    uint8_t            bs_invf_mode[2][5];
+    uint8_t            bs_add_harmonic[48];
+    unsigned           bs_amp_res;
+    /** @} */
+
+    /**
+     * @defgroup state         State variables
+     * @{
+     */
+    DECLARE_ALIGNED(16, float, synthesis_filterbank_samples)[SBR_SYNTHESIS_BUF_SIZE];
+    DECLARE_ALIGNED(16, float, analysis_filterbank_samples) [1312];
+    int                synthesis_filterbank_samples_offset;
+    ///l_APrev and l_A
+    int                e_a[2];
+    ///Chirp factors
+    float              bw_array[5];
+    ///QMF values of the original signal
+    float              W[2][32][32][2];
+    ///QMF output of the HF adjustor
+    float              Y[2][38][64][2];
+    float              g_temp[42][48];
+    float              q_temp[42][48];
+    uint8_t            s_indexmapped[8][48];
+    ///Envelope scalefactors
+    float              env_facs[6][48];
+    ///Noise scalefactors
+    float              noise_facs[3][5];
+    ///Envelope time borders
+    uint8_t            t_env[8];
+    ///Envelope time border of the last envelope of the previous frame
+    uint8_t            t_env_num_env_old;
+    ///Noise time borders
+    uint8_t            t_q[3];
+    unsigned           f_indexnoise;
+    unsigned           f_indexsine;
+    /** @} */
+} SBRData;
+
+/**
+ * Spectral Band Replication
+ */
+typedef struct {
+    int                sample_rate;
+    int                start;
+    int                reset;
+    SpectrumParameters spectrum_params;
+    int                bs_amp_res_header;
+    /**
+     * @defgroup bs_header_extra_2     variables associated with bs_header_extra_2
+     * @{
+     */
+    unsigned           bs_limiter_bands;
+    unsigned           bs_limiter_gains;
+    unsigned           bs_interpol_freq;
+    unsigned           bs_smoothing_mode;
+    /** @} */
+    unsigned           bs_coupling;
+    unsigned           k[5]; ///< k0, k1, k2
+    ///kx', and kx respectively, kx is the first QMF subband where SBR is used.
+    ///kx' is its value from the previous frame
+    unsigned           kx[2];
+    ///M' and M respectively, M is the number of QMF subbands that use SBR.
+    unsigned           m[2];
+    ///The number of frequency bands in f_master
+    unsigned           n_master;
+    SBRData            data[2];
+    ///N_Low and N_High respectively, the number of frequency bands for low and high resolution
+    unsigned           n[2];
+    ///Number of noise floor bands
+    unsigned           n_q;
+    ///Number of limiter bands
+    unsigned           n_lim;
+    ///The master QMF frequency grouping
+    uint16_t           f_master[49];
+    ///Frequency borders for low resolution SBR
+    uint16_t           f_tablelow[25];
+    ///Frequency borders for high resolution SBR
+    uint16_t           f_tablehigh[49];
+    ///Frequency borders for noise floors
+    uint16_t           f_tablenoise[6];
+    ///Frequency borders for the limiter
+    uint16_t           f_tablelim[29];
+    unsigned           num_patches;
+    uint8_t            patch_num_subbands[6];
+    uint8_t            patch_start_subband[6];
+    ///QMF low frequency input to the HF generator
+    float              X_low[32][40][2];
+    ///QMF output of the HF generator
+    float              X_high[64][40][2];
+    ///QMF values of the reconstructed signal
+    DECLARE_ALIGNED(16, float, X)[2][32][64];
+    ///Zeroth coefficient used to filter the subband signals
+    float              alpha0[64][2];
+    ///First coefficient used to filter the subband signals
+    float              alpha1[64][2];
+    ///Dequantized envelope scalefactors, remapped
+    float              e_origmapped[7][48];
+    ///Dequantized noise scalefactors, remapped
+    float              q_mapped[7][48];
+    ///Sinusoidal presence, remapped
+    uint8_t            s_mapped[7][48];
+    ///Estimated envelope
+    float              e_curr[7][48];
+    ///Amplitude adjusted noise scalefactors
+    float              q_m[7][48];
+    ///Sinusoidal levels
+    float              s_m[7][48];
+    float              gain[7][48];
+    DECLARE_ALIGNED(16, float, qmf_filter_scratch)[5][64];
+    RDFTContext        rdft;
+    FFTContext         mdct;
+} SpectralBandReplication;
+
+#endif /* AVCODEC_SBR_H */