-
Notifications
You must be signed in to change notification settings - Fork 4
Expand file tree
/
Copy pathSwrResample.cpp
More file actions
165 lines (135 loc) · 5.17 KB
/
Copy pathSwrResample.cpp
File metadata and controls
165 lines (135 loc) · 5.17 KB
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
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
#include "SwrResample.h"
int SwrResample::Init(int64_t src_ch_layout, int64_t dst_ch_layout,
int src_rate, int dst_rate,
enum AVSampleFormat src_sample_fmt, enum AVSampleFormat dst_sample_fmt,
int src_nb_samples)
{
#ifdef WRITE_RESAMPLE_PCM_FILE
outdecodedswffile = fopen("decode_resample.pcm", "wb");
if (!outdecodedswffile) {
std::cout << "open out put swr file failed";
}
#endif // WRITE_RESAMPLE_PCM_FILE
src_sample_fmt_ = src_sample_fmt;
dst_sample_fmt_ = dst_sample_fmt;
int ret;
/* create resampler context */
swr_ctx = swr_alloc();
if (!swr_ctx) {
std::cout << "Could not allocate resampler context" << std::endl;
ret = AVERROR(ENOMEM);
return ret;
}
/* set options */
av_opt_set_int(swr_ctx, "in_channel_layout", src_ch_layout, 0);
av_opt_set_int(swr_ctx, "in_sample_rate", src_rate, 0);
av_opt_set_sample_fmt(swr_ctx, "in_sample_fmt", src_sample_fmt, 0);
av_opt_set_int(swr_ctx, "out_channel_layout", dst_ch_layout, 0);
av_opt_set_int(swr_ctx, "out_sample_rate", dst_rate, 0);
av_opt_set_sample_fmt(swr_ctx, "out_sample_fmt", dst_sample_fmt, 0);
/* initialize the resampling context */
if ((ret = swr_init(swr_ctx)) < 0) {
std::cout << "Failed to initialize the resampling context" << std::endl;
return -1;
}
//配置输入的参数
/*
* src_nb_samples: 描述一整的采样个数 比如这里就是 1024
* src_linesize: 描述一行采样字节长度
* 当是planr 结构 LLLLLRRRRRR 的时候 比如 一帧1024个采样，32位表示。那就是 1024*4 = 4096
* 当是非palner 结构的时候 LRLRLR 比如一帧1024采样 32位表示 双通道 1024*4*2 = 8196 要乘以通道
* src_nb_channels : 可以根据布局获得音频的通道
* ret 返回输入数据的长度 比如这里 1024 * 4 * 2 = 8196 (32bit，双声道，1024个采样)
*/
src_nb_channels = av_get_channel_layout_nb_channels(src_ch_layout);
ret = av_samples_alloc_array_and_samples(&src_data_, &src_linesize, src_nb_channels,
src_nb_samples, src_sample_fmt, 0);
if (ret < 0) {
std::cout << "Could not allocate source samples\n" << std::endl;
return -1;
}
src_nb_samples_ = src_nb_samples;
//配置输出的参数
int max_dst_nb_samples = dst_nb_samples_ =
av_rescale_rnd(src_nb_samples, dst_rate, src_rate, AV_ROUND_UP);
dst_nb_channels = av_get_channel_layout_nb_channels(dst_ch_layout);
ret = av_samples_alloc_array_and_samples(&dst_data_, &dst_linesize, dst_nb_channels,
dst_nb_samples_, dst_sample_fmt, 0);
if (ret < 0) {
std::cout << "Could not allocate destination samples" << std::endl;
return -1;
}
int data_size = av_get_bytes_per_sample(dst_sample_fmt_);
audioPlayer.SetFormat(dst_nb_samples_, dst_rate, data_size*8, dst_nb_channels);
}
int SwrResample::WriteInput(AVFrame* frame)
{
int planar = av_sample_fmt_is_planar(src_sample_fmt_);
int data_size = av_get_bytes_per_sample(src_sample_fmt_);
if (planar)
{
//src是planar类型的话，src_data里面数据是LLLLLLLRRRRR 结构，src_data_[0] 指向全部的L，src_data_[1] 指向全部R
// src_data_ 里面其实一个长 uint8_t *buf，src_data_[0] 指向L开始的位置，src_data_[1]指向R的位置
// linesize 是 b_samples * sample_size 就是比如 48000*4
for (int ch = 0; ch < src_nb_channels; ch++) {
memcpy(src_data_[ch], frame->data[ch], data_size * frame->nb_samples);
}
}
else
{
//src是非planar类型的话，src_data里面数据是LRLRLRLR 结构，src_data_[0] 指向全部数据 没有src_data[1]
// linesize 是nb_samples * sample_size * nb_channels 比如 48000*4*2
for (int i = 0; i < frame->nb_samples; i++){
for (int ch = 0; ch < src_nb_channels; ch++)
{
memcpy(src_data_[0], frame->data[ch]+data_size*i, data_size);
}
}
}
return 0;
}
int SwrResample::SwrConvert()
{
int ret = swr_convert(swr_ctx, dst_data_, dst_nb_samples_, (const uint8_t**)src_data_, src_nb_samples_);
if (ret < 0) {
fprintf(stderr, "Error while converting\n");
exit(1);
}
int dst_bufsize = av_samples_get_buffer_size(&dst_linesize, dst_nb_channels,
ret, dst_sample_fmt_, 1);
int planar = av_sample_fmt_is_planar(dst_sample_fmt_);
if (planar)
{
int data_size = av_get_bytes_per_sample(dst_sample_fmt_);
#ifdef WRITE_RESAMPLE_PCM_FILE
for (int i = 0; i < dst_nb_samples_; i++) {
for (int ch = 0; ch < dst_nb_channels; ch++)
{
fwrite(dst_data_[ch] + i * data_size, 1, data_size, outdecodedswffile);
}
}
#endif // WRITE_RESAMPLE_PCM_FILE
}
else {
//非planr结构，dst_data_[0] 里面存在着全部数据
#ifdef WRITE_RESAMPLE_PCM_FILE
fwrite(dst_data_[0], 1, dst_bufsize, outdecodedswffile);
#endif
audioPlayer.writeData((const char*)(dst_data_[0]), dst_bufsize);
}
return dst_bufsize;
}
void SwrResample::Close()
{
#ifdef WRITE_RESAMPLE_PCM_FILE
fclose(outdecodedswffile);
#endif
if (src_data_)
av_freep(&src_data_[0]);
av_freep(&src_data_);
if (dst_data_)
av_freep(&dst_data_[0]);
av_freep(&dst_data_);
swr_free(&swr_ctx);
audioPlayer.Close();
}