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1 /*
2  * WMA compatible codec
3  * Copyright (c) 2002-2007 The FFmpeg Project
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_WMA_H
23 #define AVCODEC_WMA_H
24 
25 #include "libavutil/float_dsp.h"
26 #include "libavutil/mem_internal.h"
27 
28 #include "avcodec.h"
29 #include "fft.h"
30 #include "get_bits.h"
31 #include "put_bits.h"
32 
33 /* size of blocks */
34 #define BLOCK_MIN_BITS 7
35 #define BLOCK_MAX_BITS 11
36 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
37 
38 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
39 
40 /* XXX: find exact max size */
41 #define HIGH_BAND_MAX_SIZE 16
42 
43 #define NB_LSP_COEFS 10
44 
45 /* XXX: is it a suitable value ? */
46 #define MAX_CODED_SUPERFRAME_SIZE 32768
47 
48 #define MAX_CHANNELS 2
49 
50 #define NOISE_TAB_SIZE 8192
51 
52 #define LSP_POW_BITS 7
53 
54 // FIXME should be in wmadec
55 #define VLCBITS 9
56 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
57 
58 typedef float WMACoef;          ///< type for decoded coefficients, int16_t would be enough for wma 1/2
59 
60 typedef struct CoefVLCTable {
61     int n;                      ///< total number of codes
62     int max_level;
63     const uint32_t *huffcodes;  ///< VLC bit values
64     const uint8_t *huffbits;    ///< VLC bit size
65     const uint16_t *levels;     ///< table to build run/level tables
66 } CoefVLCTable;
67 
68 typedef struct WMACodecContext {
69     AVCodecContext *avctx;
70     GetBitContext gb;
71     PutBitContext pb;
72     int version;                            ///< 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2)
73     int use_bit_reservoir;
74     int use_variable_block_len;
75     int use_exp_vlc;                        ///< exponent coding: 0 = lsp, 1 = vlc + delta
76     int use_noise_coding;                   ///< true if perceptual noise is added
77     int byte_offset_bits;
78     VLC exp_vlc;
79     int exponent_sizes[BLOCK_NB_SIZES];
80     uint16_t exponent_bands[BLOCK_NB_SIZES][25];
81     int high_band_start[BLOCK_NB_SIZES];    ///< index of first coef in high band
82     int coefs_start;                        ///< first coded coef
83     int coefs_end[BLOCK_NB_SIZES];          ///< max number of coded coefficients
84     int exponent_high_sizes[BLOCK_NB_SIZES];
85     int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
86     VLC hgain_vlc;
87 
88     /* coded values in high bands */
89     int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
90     int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
91 
92     /* there are two possible tables for spectral coefficients */
93 // FIXME the following 3 tables should be shared between decoders
94     VLC coef_vlc[2];
95     uint16_t *run_table[2];
96     float *level_table[2];
97     uint16_t *int_table[2];
98     const CoefVLCTable *coef_vlcs[2];
99     /* frame info */
100     int frame_len;                          ///< frame length in samples
101     int frame_len_bits;                     ///< frame_len = 1 << frame_len_bits
102     int nb_block_sizes;                     ///< number of block sizes
103     /* block info */
104     int reset_block_lengths;
105     int block_len_bits;                     ///< log2 of current block length
106     int next_block_len_bits;                ///< log2 of next block length
107     int prev_block_len_bits;                ///< log2 of prev block length
108     int block_len;                          ///< block length in samples
109     int block_num;                          ///< block number in current frame
110     int block_pos;                          ///< current position in frame
111     uint8_t ms_stereo;                      ///< true if mid/side stereo mode
112     uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
113     int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
114     DECLARE_ALIGNED(32, float, exponents)[MAX_CHANNELS][BLOCK_MAX_SIZE];
115     float max_exponent[MAX_CHANNELS];
116     WMACoef coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
117     DECLARE_ALIGNED(32, float, coefs)[MAX_CHANNELS][BLOCK_MAX_SIZE];
118     DECLARE_ALIGNED(32, FFTSample, output)[BLOCK_MAX_SIZE * 2];
119     FFTContext mdct_ctx[BLOCK_NB_SIZES];
120     const float *windows[BLOCK_NB_SIZES];
121     /* output buffer for one frame and the last for IMDCT windowing */
122     DECLARE_ALIGNED(32, float, frame_out)[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
123     /* last frame info */
124     uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + AV_INPUT_BUFFER_PADDING_SIZE]; /* padding added */
125     int last_bitoffset;
126     int last_superframe_len;
127     int exponents_initialized[MAX_CHANNELS];
128     float noise_table[NOISE_TAB_SIZE];
129     int noise_index;
130     float noise_mult; /* XXX: suppress that and integrate it in the noise array */
131     /* lsp_to_curve tables */
132     float lsp_cos_table[BLOCK_MAX_SIZE];
133     float lsp_pow_e_table[256];
134     float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
135     float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
136     AVFloatDSPContext *fdsp;
137 
138 #ifdef TRACE
139     int frame_count;
140 #endif /* TRACE */
141 } WMACodecContext;
142 
143 extern const uint8_t ff_wma_hgain_hufftab[37][2];
144 extern const float ff_wma_lsp_codebook[NB_LSP_COEFS][16];
145 extern const uint32_t ff_aac_scalefactor_code[121];
146 extern const uint8_t  ff_aac_scalefactor_bits[121];
147 
148 av_warn_unused_result
149 int ff_wma_init(AVCodecContext *avctx, int flags2);
150 
151 int ff_wma_total_gain_to_bits(int total_gain);
152 int ff_wma_end(AVCodecContext *avctx);
153 unsigned int ff_wma_get_large_val(GetBitContext *gb);
154 int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
155                             VLC *vlc, const float *level_table,
156                             const uint16_t *run_table, int version,
157                             WMACoef *ptr, int offset, int num_coefs,
158                             int block_len, int frame_len_bits,
159                             int coef_nb_bits);
160 
161 #endif /* AVCODEC_WMA_H */
162