blob: 72f09cbdde2f59be5b1265ec131d0280ed40723e
1 | /* |
2 | * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com> |
3 | * |
4 | * This file is part of FFmpeg. |
5 | * |
6 | * FFmpeg is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * FFmpeg 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 GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with FFmpeg; if not, write to the Free Software |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
19 | */ |
20 | |
21 | #ifndef AVRESAMPLE_DITHER_H |
22 | #define AVRESAMPLE_DITHER_H |
23 | |
24 | #include "avresample.h" |
25 | #include "audio_data.h" |
26 | |
27 | typedef struct DitherContext DitherContext; |
28 | |
29 | typedef struct DitherDSPContext { |
30 | /** |
31 | * Convert samples from flt to s16 with added dither noise. |
32 | * |
33 | * @param dst destination float array, range -0.5 to 0.5 |
34 | * @param src source int array, range INT_MIN to INT_MAX. |
35 | * @param dither float dither noise array |
36 | * @param len number of samples |
37 | */ |
38 | void (*quantize)(int16_t *dst, const float *src, float *dither, int len); |
39 | |
40 | int ptr_align; ///< src and dst constraints for quantize() |
41 | int samples_align; ///< len constraints for quantize() |
42 | |
43 | /** |
44 | * Convert dither noise from int to float with triangular distribution. |
45 | * |
46 | * @param dst destination float array, range -0.5 to 0.5 |
47 | * constraints: 32-byte aligned |
48 | * @param src0 source int array, range INT_MIN to INT_MAX. |
49 | * the array size is len * 2 |
50 | * constraints: 32-byte aligned |
51 | * @param len number of output noise samples |
52 | * constraints: multiple of 16 |
53 | */ |
54 | void (*dither_int_to_float)(float *dst, int *src0, int len); |
55 | } DitherDSPContext; |
56 | |
57 | /** |
58 | * Allocate and initialize a DitherContext. |
59 | * |
60 | * The parameters in the AVAudioResampleContext are used to initialize the |
61 | * DitherContext. |
62 | * |
63 | * @param avr AVAudioResampleContext |
64 | * @return newly-allocated DitherContext |
65 | */ |
66 | DitherContext *ff_dither_alloc(AVAudioResampleContext *avr, |
67 | enum AVSampleFormat out_fmt, |
68 | enum AVSampleFormat in_fmt, |
69 | int channels, int sample_rate, int apply_map); |
70 | |
71 | /** |
72 | * Free a DitherContext. |
73 | * |
74 | * @param c DitherContext |
75 | */ |
76 | void ff_dither_free(DitherContext **c); |
77 | |
78 | /** |
79 | * Convert audio sample format with dithering. |
80 | * |
81 | * @param c DitherContext |
82 | * @param dst destination audio data |
83 | * @param src source audio data |
84 | * @return 0 if ok, negative AVERROR code on failure |
85 | */ |
86 | int ff_convert_dither(DitherContext *c, AudioData *dst, AudioData *src); |
87 | |
88 | /* arch-specific initialization functions */ |
89 | |
90 | void ff_dither_init_x86(DitherDSPContext *ddsp, |
91 | enum AVResampleDitherMethod method); |
92 | |
93 | #endif /* AVRESAMPLE_DITHER_H */ |
94 |