1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
/* audio_resample.h
*
* Copyright (c) 2003-2012 HandBrake Team
* This file is part of the HandBrake source code
* Homepage: <http://handbrake.fr/>
* It may be used under the terms of the GNU General Public License v2.
* For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
*/
/* Implements a libavresample wrapper for convenience.
*
* Supports sample_fmt and channel_layout conversion.
*
* sample_rate conversion will come later (libavresample doesn't support
* sample_rate conversion with float samples yet). */
#ifndef AUDIO_RESAMPLE_H
#define AUDIO_RESAMPLE_H
#include <math.h>
#include <stdint.h>
#include "libavutil/audioconvert.h"
#include "libavresample/avresample.h"
/* Default mix level for center and surround channels */
#define HB_MIXLEV_DEFAULT ((double)M_SQRT1_2)
typedef struct
{
int do_remix;
int resample_needed;
AVAudioResampleContext *avresample;
struct
{
uint64_t channel_layout;
double center_mix_level;
double surround_mix_level;
enum AVSampleFormat sample_fmt;
} in;
struct
{
int channels;
uint64_t channel_layout;
double center_mix_level;
double surround_mix_level;
enum AVSampleFormat sample_fmt;
} resample;
struct
{
int channels;
int sample_size;
int normalize_mix_level;
uint64_t channel_layout;
enum AVSampleFormat sample_fmt;
enum AVMatrixEncoding matrix_encoding;
} out;
} hb_audio_resample_t;
/* Initialize an hb_audio_resample_t for converting audio to the requested
* sample_fmt and mixdown.
*
* Also sets the default audio input characteristics, so that they are the same
* as the output characteristics (no conversion needed).
*
* If do_remix is 0, it will be assumed that any remixing was *already* done.
*/
hb_audio_resample_t* hb_audio_resample_init(enum AVSampleFormat sample_fmt,
int hb_amixdown, int do_remix,
int normalize_mix_level);
/* The following functions set the audio input characteristics.
*
* They should be called whenever the relevant characteristic(s) differ from the
* requested output characteristics, or if they may have changed in the source.
*
* Note: channel_layout is automatically sanitized.
*/
void hb_audio_resample_set_channel_layout(hb_audio_resample_t *resample,
uint64_t channel_layout,
int channels);
void hb_audio_resample_set_mix_levels(hb_audio_resample_t *resample,
double surround_mix_level,
double center_mix_level);
void hb_audio_resample_set_sample_fmt(hb_audio_resample_t *resample,
enum AVSampleFormat sample_fmt);
/* Update an hb_audio_resample_t.
*
* Must be called after using any of the above functions.
*/
int hb_audio_resample_update(hb_audio_resample_t *resample);
/* Free an hb_audio_remsample_t. */
void hb_audio_resample_free(hb_audio_resample_t *resample);
/* Convert input samples to the requested output characteristics
* (sample_fmt and channel_layout + matrix_encoding).
*
* Returns an hb_buffer_t with the converted output.
*
* resampling is only done when necessary.
*/
hb_buffer_t* hb_audio_resample(hb_audio_resample_t *resample,
void *samples, int nsamples);
#endif /* AUDIO_RESAMPLE_H */
|
