1 /*****************************************************************************
2 * integer.c: integer software volume
3 *****************************************************************************
4 * Copyright (C) 2011 Rémi Denis-Courmont
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
20
21 #ifdef HAVE_CONFIG_H
22 # include "config.h"
23 #endif
24
25 #include <math.h>
26 #include <limits.h>
27
28 #include <vlc_common.h>
29 #include <vlc_plugin.h>
30 #include <vlc_aout.h>
31 #include <vlc_aout_volume.h>
32
33 static int Activate (vlc_object_t *);
34
35 vlc_module_begin ()
set_category(CAT_AUDIO)36 set_category (CAT_AUDIO)
37 set_subcategory (SUBCAT_AUDIO_MISC)
38 set_description (N_("Integer audio volume"))
39 set_capability ("audio volume", 9)
40 set_callbacks (Activate, NULL)
41 vlc_module_end ()
42
43 static void FilterS32N (audio_volume_t *vol, block_t *block, float volume)
44 {
45 int32_t *p = (int32_t *)block->p_buffer;
46
47 int_fast32_t mult = lroundf (volume * 0x1.p24f);
48 if (mult == (1 << 24))
49 return;
50
51 for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
52 {
53 int_fast64_t s = (*p * (int_fast64_t)mult) >> INT64_C(24);
54 if (s > INT32_MAX)
55 s = INT32_MAX;
56 else
57 if (s < INT32_MIN)
58 s = INT32_MIN;
59 *(p++) = s;
60 }
61 (void) vol;
62 }
63
FilterS16N(audio_volume_t * vol,block_t * block,float volume)64 static void FilterS16N (audio_volume_t *vol, block_t *block, float volume)
65 {
66 int16_t *p = (int16_t *)block->p_buffer;
67
68 int_fast16_t mult = lroundf (volume * 0x1.p8f);
69 if (mult == (1 << 8))
70 return;
71
72 for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
73 {
74 int_fast32_t s = (*p * (int_fast32_t)mult) >> 8;
75 if (s > INT16_MAX)
76 s = INT16_MAX;
77 else
78 if (s < INT16_MIN)
79 s = INT16_MIN;
80 *(p++) = s;
81 }
82 (void) vol;
83 }
84
FilterU8(audio_volume_t * vol,block_t * block,float volume)85 static void FilterU8 (audio_volume_t *vol, block_t *block, float volume)
86 {
87 uint8_t *p = (uint8_t *)block->p_buffer;
88
89 int_fast16_t mult = lroundf (volume * 0x1.p8f);
90 if (mult == (1 << 8))
91 return;
92
93 for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
94 {
95 int_fast32_t s = (((int_fast8_t)(*p - 128)) * (int_fast32_t)mult) >> 8;
96 if (s > INT8_MAX)
97 s = INT8_MAX;
98 else
99 if (s < INT8_MIN)
100 s = INT8_MIN;
101 *(p++) = s + 128;
102 }
103 (void) vol;
104 }
105
Activate(vlc_object_t * obj)106 static int Activate (vlc_object_t *obj)
107 {
108 audio_volume_t *vol = (audio_volume_t *)obj;
109
110 switch (vol->format)
111 {
112 case VLC_CODEC_S32N:
113 vol->amplify = FilterS32N;
114 break;
115 case VLC_CODEC_S16N:
116 vol->amplify = FilterS16N;
117 break;
118 case VLC_CODEC_U8:
119 vol->amplify = FilterU8;
120 break;
121 default:
122 return -1;
123 }
124 return 0;
125 }
126