FFMpeg版本:4.3.1
#include<iostream>
#include<windows.h>
using namespace std;
//用到的C的头文件
extern "C"
{
#include<libavcodec/avcodec.h>
#include<libavfilter/avfilter.h>
#include<libavfilter/buffersink.h>
#include<libavfilter/buffersrc.h>
#include<libavfilter/avfiltergraph.h>
#include<libavformat/avformat.h>
#include<libavutil/avutil.h>
#include<libavutil/fifo.h>
#include<libavutil/audio_fifo.h>
#include<libavdevice/avdevice.h>
#include <libavutil/frame.h>
#include <libavutil/mem.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
}
//对用到的预编译
#pragma comment(lib, "avcodec.lib")
#pragma comment(lib, "avfilter.lib")
#pragma comment(lib, "avutil.lib")
#pragma comment(lib, "avformat.lib")
#pragma comment(lib, "swscale.lib")
//第一个音频文件
#define AUDIO_INBUF_SIZE 20480
#define AUDIO_REFILL_THRESH 4096
static void decode(AVCodecContext* dec_ctx, AVPacket* pkt, AVFrame* frame,
FILE* outfile)
{
int i, ch;
int ret, data_size;
/* send the packet with the compressed data to the decoder */
ret = avcodec_send_packet(dec_ctx, pkt);
if (ret < 0) {
fprintf(stderr, "Error submitting the packet to the decoder
");
exit(1);
}
/* read all the output frames (in general there may be any number of them */
while (ret >= 0) {
ret = avcodec_receive_frame(dec_ctx, frame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return;
else if (ret < 0) {
fprintf(stderr, "Error during decoding
");
exit(1);
}
data_size = av_get_bytes_per_sample(dec_ctx->sample_fmt);
if (data_size < 0) {
/* This should not occur, checking just for paranoia */
fprintf(stderr, "Failed to calculate data size
");
exit(1);
}
for (i = 0; i < frame->nb_samples; i++)
for (ch = 0; ch < dec_ctx->channels; ch++)
fwrite(frame->data[ch] + data_size * i, 1, data_size, outfile);
}
}
int main()
{
const char* outfilename, * filename;
const AVCodec* codec;
AVCodecContext* c = NULL;
AVCodecParserContext* parser = NULL;
int len, ret;
FILE* f, * outfile;
uint8_t inbuf[AUDIO_INBUF_SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
uint8_t* data;
size_t data_size;
AVPacket* pkt;
AVFrame* decoded_frame = NULL;
filename = "D:\FFMpeg\project\pcm_aac\pcm_aac\outdio.mp3";
outfilename = "D:\FFMpeg\project\pcm_aac\pcm_aac\outdio.pcm";
/* register all the codecs */
avcodec_register_all();
pkt = av_packet_alloc();
/* find the MPEG audio decoder */
codec = avcodec_find_decoder(AV_CODEC_ID_MP3);
if (!codec) {
fprintf(stderr, "Codec not found
");
exit(1);
}
parser = av_parser_init(codec->id);
if (!parser) {
fprintf(stderr, "Parser not found
");
exit(1);
}
c = avcodec_alloc_context3(codec);
if (!c) {
fprintf(stderr, "Could not allocate audio codec context
");
exit(1);
}
/* open it */
if (avcodec_open2(c, codec, NULL) < 0) {
fprintf(stderr, "Could not open codec
");
exit(1);
}
f = fopen(filename, "rb");
if (!f) {
fprintf(stderr, "Could not open %s
", filename);
exit(1);
}
outfile = fopen(outfilename, "wb");
if (!outfile) {
av_free(c);
exit(1);
}
/* decode until eof */
data = inbuf;
data_size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
while (data_size > 0) {
if (!decoded_frame) {
if (!(decoded_frame = av_frame_alloc())) {
fprintf(stderr, "Could not allocate audio frame
");
exit(1);
}
}
ret = av_parser_parse2(parser, c, &pkt->data, &pkt->size,
data, data_size,
AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);
if (ret < 0) {
fprintf(stderr, "Error while parsing
");
exit(1);
}
data += ret;
data_size -= ret;
cout << c->sample_rate << endl;
cout << c->channels << endl;
if (pkt->size)
decode(c, pkt, decoded_frame, outfile);
if (data_size < AUDIO_REFILL_THRESH) {
memmove(inbuf, data, data_size);
data = inbuf;
len = fread(data + data_size, 1,
AUDIO_INBUF_SIZE - data_size, f);
if (len > 0)
data_size += len;
}
}
/* flush the decoder */
pkt->data = NULL;
pkt->size = 0;
decode(c, pkt, decoded_frame, outfile);
fclose(outfile);
fclose(f);
avcodec_free_context(&c);
av_parser_close(parser);
av_frame_free(&decoded_frame);
av_packet_free(&pkt);
return 0;
}