下面将aac解码成pcm的代码，主要是参考某位博主的博客，原文地址忘记在哪了！
#include<stdio.h> #include<stdlib.h> #include<string.h> #define __STDC_CONSTANT_MACROS extern "C" { #include <libavcodec/avcodec.h> #include <libavformat/avformat.h> #include <libavdevice/avdevice.h> #include<libswresample/swresample.h> } #define MAX_AUDIO_FRAME_SIZE 192000 #define SAMPLE_PRT(fmt...) \ do {\ printf("[%s]-%d: ", __FUNCTION__, __LINE__);\ printf(fmt);\ }while(0) const char *in_file = "./hefang.aac"; const char *out_file = "./hefang.pcm"; int main() { //注册所有的工具 av_register_all(); AVFormatContext *fmt_ctx = NULL; AVCodecContext *cod_ctx = NULL; AVCodec *cod = NULL; //分配一个avformat fmt_ctx = avformat_alloc_context(); if (fmt_ctx == NULL) printf("alloc fail"); //打开文件，解封装 if (avformat_open_input(&fmt_ctx, in_file, NULL, NULL) != 0) printf("open fail"); //查找文件的相关流信息 if (avformat_find_stream_info(fmt_ctx, NULL) < 0) printf("find stream fail"); //输出格式信息 av_dump_format(fmt_ctx, 0, in_file, 0); //查找解码信息 int stream_index = -1; for (int i = 0; i < fmt_ctx->nb_streams; i++) if (fmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) { stream_index = i; break; } if (stream_index == -1) printf("find stream fail"); //保存解码器 cod_ctx = fmt_ctx->streams[stream_index]->codec; cod = avcodec_find_decoder(cod_ctx->codec_id); if (cod == NULL) printf("find codec fail"); if (avcodec_open2(cod_ctx, cod, NULL) < 0) printf("can't open codec"); FILE *out_fb = NULL; out_fb = fopen(out_file, "wb"); //创建packet,用于存储解码前的数据 AVPacket *packet = (AVPacket *)malloc(sizeof(AVPacket)); av_init_packet(packet); //设置转码后输出相关参数 //采样的布局方式 uint64_t out_channel_layout = AV_CH_LAYOUT_MONO; //采样个数 int out_nb_samples = 1024; //采样格式 enum AVSampleFormat sample_fmt = AV_SAMPLE_FMT_S16; //采样率 int out_sample_rate = 44100; //通道数 int out_channels = av_get_channel_layout_nb_channels(out_channel_layout); printf("%d\n",out_channels); //创建buffer int buffer_size = av_samples_get_buffer_size(NULL, out_channels, out_nb_samples, sample_fmt, 1); //注意要用av_malloc uint8_t *buffer = (uint8_t *)av_malloc(MAX_AUDIO_FRAME_SIZE * 2); //创建Frame，用于存储解码后的数据 AVFrame *frame = av_frame_alloc(); int got_picture; int64_t in_channel_layout = av_get_default_channel_layout(cod_ctx->channels); //打开转码器 struct SwrContext *convert_ctx = swr_alloc(); //设置转码参数 convert_ctx = swr_alloc_set_opts(convert_ctx, out_channel_layout, sample_fmt, out_sample_rate, \ in_channel_layout, cod_ctx->sample_fmt, cod_ctx->sample_rate, 0, NULL); //初始化转码器 swr_init(convert_ctx); //while循环，每次读取一帧，并转码 while (av_read_frame(fmt_ctx, packet) >= 0) { if (packet->stream_index == stream_index) { //解码声音 if (avcodec_decode_audio4(cod_ctx, frame, &got_picture, packet) < 0) { printf("decode error"); return -1; } if (got_picture > 0) { //转码 swr_convert(convert_ctx, &buffer, MAX_AUDIO_FRAME_SIZE, (const uint8_t **)frame->data, frame->nb_samples); printf("pts:%10lld\t packet size:%d\n", packet->pts, packet->size); fwrite(buffer, 1, buffer_size, out_fb); } got_picture=0; } av_free_packet(packet); } swr_free(&convert_ctx); fclose(out_fb); return 0; }windows:不懂
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文章来源: ffmpeg aac解码pcm