1 /***********************************************************************
2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3 Redistribution and use in source and binary forms, with or without
4 modification, are permitted provided that the following conditions
5 are met:
6 - Redistributions of source code must retain the above copyright notice,
7 this list of conditions and the following disclaimer.
8 - Redistributions in binary form must reproduce the above copyright
9 notice, this list of conditions and the following disclaimer in the
10 documentation and/or other materials provided with the distribution.
11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
12 names of specific contributors, may be used to endorse or promote
13 products derived from this software without specific prior written
14 permission.
15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 POSSIBILITY OF SUCH DAMAGE.
26 ***********************************************************************/
27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include "main.h"
33 #include "tuning_parameters.h"
34
35 /* Control internal sampling rate */
silk_control_audio_bandwidth(silk_encoder_state * psEncC,silk_EncControlStruct * encControl)36 opus_int silk_control_audio_bandwidth(
37 silk_encoder_state *psEncC, /* I/O Pointer to Silk encoder state */
38 silk_EncControlStruct *encControl /* I Control structure */
39 )
40 {
41 opus_int fs_kHz;
42 opus_int32 fs_Hz;
43
44 fs_kHz = psEncC->fs_kHz;
45 fs_Hz = silk_SMULBB( fs_kHz, 1000 );
46 if( fs_Hz == 0 ) {
47 /* Encoder has just been initialized */
48 fs_Hz = silk_min( psEncC->desiredInternal_fs_Hz, psEncC->API_fs_Hz );
49 fs_kHz = silk_DIV32_16( fs_Hz, 1000 );
50 } else if( fs_Hz > psEncC->API_fs_Hz || fs_Hz > psEncC->maxInternal_fs_Hz || fs_Hz < psEncC->minInternal_fs_Hz ) {
51 /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
52 fs_Hz = psEncC->API_fs_Hz;
53 fs_Hz = silk_min( fs_Hz, psEncC->maxInternal_fs_Hz );
54 fs_Hz = silk_max( fs_Hz, psEncC->minInternal_fs_Hz );
55 fs_kHz = silk_DIV32_16( fs_Hz, 1000 );
56 } else {
57 /* State machine for the internal sampling rate switching */
58 if( psEncC->sLP.transition_frame_no >= TRANSITION_FRAMES ) {
59 /* Stop transition phase */
60 psEncC->sLP.mode = 0;
61 }
62 if( psEncC->allow_bandwidth_switch || encControl->opusCanSwitch ) {
63 /* Check if we should switch down */
64 if( silk_SMULBB( psEncC->fs_kHz, 1000 ) > psEncC->desiredInternal_fs_Hz )
65 {
66 /* Switch down */
67 if( psEncC->sLP.mode == 0 ) {
68 /* New transition */
69 psEncC->sLP.transition_frame_no = TRANSITION_FRAMES;
70
71 /* Reset transition filter state */
72 silk_memset( psEncC->sLP.In_LP_State, 0, sizeof( psEncC->sLP.In_LP_State ) );
73 }
74 if( encControl->opusCanSwitch ) {
75 /* Stop transition phase */
76 psEncC->sLP.mode = 0;
77
78 /* Switch to a lower sample frequency */
79 fs_kHz = psEncC->fs_kHz == 16 ? 12 : 8;
80 } else {
81 if( psEncC->sLP.transition_frame_no <= 0 ) {
82 encControl->switchReady = 1;
83 /* Make room for redundancy */
84 encControl->maxBits -= encControl->maxBits * 5 / ( encControl->payloadSize_ms + 5 );
85 } else {
86 /* Direction: down (at double speed) */
87 psEncC->sLP.mode = -2;
88 }
89 }
90 }
91 else
92 /* Check if we should switch up */
93 if( silk_SMULBB( psEncC->fs_kHz, 1000 ) < psEncC->desiredInternal_fs_Hz )
94 {
95 /* Switch up */
96 if( encControl->opusCanSwitch ) {
97 /* Switch to a higher sample frequency */
98 fs_kHz = psEncC->fs_kHz == 8 ? 12 : 16;
99
100 /* New transition */
101 psEncC->sLP.transition_frame_no = 0;
102
103 /* Reset transition filter state */
104 silk_memset( psEncC->sLP.In_LP_State, 0, sizeof( psEncC->sLP.In_LP_State ) );
105
106 /* Direction: up */
107 psEncC->sLP.mode = 1;
108 } else {
109 if( psEncC->sLP.mode == 0 ) {
110 encControl->switchReady = 1;
111 /* Make room for redundancy */
112 encControl->maxBits -= encControl->maxBits * 5 / ( encControl->payloadSize_ms + 5 );
113 } else {
114 /* Direction: up */
115 psEncC->sLP.mode = 1;
116 }
117 }
118 } else {
119 if (psEncC->sLP.mode<0)
120 psEncC->sLP.mode = 1;
121 }
122 }
123 }
124
125 return fs_kHz;
126 }
127