xref: /aosp_15_r20/external/libxaac/encoder/ixheaace_block_switch.h (revision 15dc779a375ca8b5125643b829a8aa4b70d7f451)
1 /******************************************************************************
2  *                                                                            *
3  * Copyright (C) 2023 The Android Open Source Project
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at:
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  *****************************************************************************
18  * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
19  */
20 
21 #pragma once
22 
23 #define BLOCK_SWITCH_WINDOWS TRANS_FAC /* number of windows for energy calculation */
24 #define BLOCK_SWITCH_WINDOW_LEN \
25   FRAME_LEN_SHORT_128 /* minimal granularity of energy calculation */
26 
27 #define BLK_SWITCH_WIN 8
28 #define BLK_SWITCH_FILT_LEN 2
29 
30 /* Block types */
31 #define LONG_WINDOW 0
32 #define START_WINDOW 1
33 #define SHORT_WINDOW 2
34 #define STOP_WINDOW 3
35 
36 /* Window shapes */
37 #define SINE_WINDOW 0
38 #define KBD_WINDOW 1
39 
40 #define MAXIMUM_NO_OF_GROUPS 4
41 
42 #define ACC_WINDOW_NRG_FAC 0.3f
43 #define ONE_MINUS_ACC_WINDOW_NRG_FAC 0.7f
44 #define INV_ATTACK_RATIO_HIGH_BR 0.1f
45 #define INV_ATTACK_RATIO_LOW_BR 0.056f
46 #define MIN_ATTACK_NRG (1000000)
47 #define BLK_SWITCH_HIGH_BR_MONO (24000)
48 #define BLK_SWITCH_HIGH_BR_STEREO (16000)
49 
50 typedef struct {
51   FLOAT32 inv_attack_ratio;
52   WORD32 win_seq;
53   WORD32 nxt_win_seq;
54   WORD32 attack;
55   WORD32 lastattack;
56   WORD32 attack_idx;
57   WORD32 last_attack_idx;
58   WORD32 total_groups_cnt;
59   WORD32 group_len[TRANS_FAC];
60   FLOAT32 win_energy[BLK_SWITCH_FILT_LEN][BLK_SWITCH_WIN];
61   FLOAT32 win_energy_filt[BLK_SWITCH_FILT_LEN][BLK_SWITCH_WIN];
62   FLOAT32 iir_states[BLK_SWITCH_FILT_LEN];
63   FLOAT32 max_win_energy;
64   FLOAT32 acc_win_energy;
65   WORD32 win_seq_ld;      /* these are used to save window decision for LD. */
66   WORD32 next_win_seq_ld; /* nxt_win_seq and win_seq are always set to
67                                  LONG_WINDOW */
68 } ixheaace_block_switch_control;
69 
70 VOID iaace_init_block_switching(ixheaace_block_switch_control *pstr_blk_switch_ctrl,
71                                 const WORD32 bit_rate, const WORD32 num_chans);
72 
73 VOID iaace_block_switching(ixheaace_block_switch_control *pstr_blk_switch_ctrl,
74                            const FLOAT32 *ptr_time_signal, WORD32 frame_length, WORD32 num_chans);
75 
76 VOID iaace_sync_block_switching(ixheaace_block_switch_control *pstr_blk_switch_left_ctrl,
77                                 ixheaace_block_switch_control *pstr_blk_switch_right_ctrl,
78                                 const WORD32 num_channels);
79