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
| #include <stdio.h>
#include "libavcodec/avcodec.h"
#include "libavfilter/avfilter.h"
#include "libavformat/avformat.h"
#include "libavutil/avutil.h"
#include "libavutil/ffversion.h"
#include "libswresample/swresample.h"
#include "libswscale/swscale.h"
#include "libpostproc/postprocess.h"
#define MAX_AUDIO_FRAME_SIZE 192000
int main()
{
const char inFileName[] = "/home/jackey/Music/test.mp3";
const char outFileName[] = "test.pcm";
FILE *file=fopen(outFileName,"w+b");
if(!file){
printf("Cannot open output file.\n");
return -1;
}
AVFormatContext *fmtCtx =avformat_alloc_context();
AVCodecContext *codecCtx = NULL;
AVPacket *pkt=av_packet_alloc();
AVFrame *frame = av_frame_alloc();
int aStreamIndex = -1;
do{
if(avformat_open_input(&fmtCtx,inFileName,NULL,NULL)<0){
printf("Cannot open input file.\n");
break;
}
if(avformat_find_stream_info(fmtCtx,NULL)<0){
printf("Cannot find any stream in file.\n");
break;
}
av_dump_format(fmtCtx,0,inFileName,0);
for(size_t i=0;i<fmtCtx->nb_streams;i++){
if(fmtCtx->streams[i]->codecpar->codec_type==AVMEDIA_TYPE_AUDIO){
aStreamIndex=(int)i;
break;
}
}
if(aStreamIndex==-1){
printf("Cannot find audio stream.\n");
break;
}
AVCodecParameters *aCodecPara = fmtCtx->streams[aStreamIndex]->codecpar;
AVCodec *codec = avcodec_find_decoder(aCodecPara->codec_id);
if(!codec){
printf("Cannot find any codec for audio.\n");
break;
}
codecCtx = avcodec_alloc_context3(codec);
if(avcodec_parameters_to_context(codecCtx,aCodecPara)<0){
printf("Cannot alloc codec context.\n");
break;
}
codecCtx->pkt_timebase=fmtCtx->streams[aStreamIndex]->time_base;
if(avcodec_open2(codecCtx,codec,NULL)<0){
printf("Cannot open audio codec.\n");
break;
}
uint64_t out_channel_layout = codecCtx->channel_layout;
enum AVSampleFormat out_sample_fmt = AV_SAMPLE_FMT_S16;
int out_sample_rate = codecCtx->sample_rate;
int out_channels = av_get_channel_layout_nb_channels(out_channel_layout);
uint8_t *audio_out_buffer = (uint8_t*)av_malloc(MAX_AUDIO_FRAME_SIZE*2);
SwrContext *swr_ctx = swr_alloc_set_opts(NULL,
out_channel_layout,
out_sample_fmt,
out_sample_rate,
codecCtx->channel_layout,
codecCtx->sample_fmt,
codecCtx->sample_rate,
0,NULL);
swr_init(swr_ctx);
while(av_read_frame(fmtCtx,pkt)>=0){
if(pkt->stream_index==aStreamIndex){
if(avcodec_send_packet(codecCtx,pkt)>=0){
while(avcodec_receive_frame(codecCtx,frame)>=0){
if(av_sample_fmt_is_planar(codecCtx->sample_fmt)){
int len = swr_convert(swr_ctx,
&audio_out_buffer,
MAX_AUDIO_FRAME_SIZE*2,
(const uint8_t**)frame->data,
frame->nb_samples);
if(len<=0){
continue;
}
int dst_bufsize = av_samples_get_buffer_size(0,
out_channels,
len,
out_sample_fmt,
1);
fwrite(audio_out_buffer,1,dst_bufsize,file);
}
}
}
}
av_packet_unref(pkt);
}
}while(0);
av_frame_free(&frame);
av_packet_free(&pkt);
avcodec_close(codecCtx);
avcodec_free_context(&codecCtx);
avformat_free_context(fmtCtx);
fclose(file);
return 0;
}
|
