ffmpeg 实现音频aac编码

来源：互联网发布：jav番号新域名编辑：程序博客网时间：2024/05/22 12:40

1、编译ffmepg

./configure --disable-yasm --enable-nonfree --enable-libfaac --prefix=/home/ffmpeg/1_ffmpeg-2.1.1/install

2、编译audio_enc.c

makefile：

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#!/bin/sh
INCLUDE = ../include
LIB_DIR = ../lib
LDFLAGS =  -lfaac -lavcodec -lavformat -lavdevice -lavfilter -lavutil -lswresample -pthread  -ldl -lswscale -lasound -lz -lm -lbz2
 
SRC=audio_enc.c
all:$(SRC)
    gcc -g -Wall $(SRC) -o target -I $(INCLUDE) -L $(LIB_DIR) $(LDFLAGS)

注意：在这里编译的时候需要加上aac库，可能会找不到库函数undefined reference to `faacEncEncode'等

程序运行时，需要提供一个和程序参数一致的wav音频文件：

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/*
* Copyright(C), 2013, Ubuntu Inc.
* File name:        audio_enc.c
* Author:           xubinbin 徐彬彬 (Beijing China)
* Version:          1.0
* Date:             2013.12.23
* Description:      Use ffmpeg achieve aac audio coding.
* Function List:   
* Email:            xubbwd@gmail.com
*/
 
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
 
#include <libavutil/opt.h>
#include <libavutil/mathematics.h>
#include <libavformat/avformat.h>
 
FILE * fp_in = NULL;
FILE * fp_out = NULL;
 
static int frame_count;
 
int main(int argc, char **argv)
{
    int ret;
    AVCodec *audio_codec;
    AVCodecContext *c;
    AVFrame *frame;
    AVPacket pkt;
    int got_output;
 
    /* Initialize libavcodec, and register all codecs and formats. */
    av_register_all();
    avcodec_register_all();
    //avdevice_register_all();
 
    audio_codec = avcodec_find_encoder(AV_CODEC_ID_AAC);
    c = avcodec_alloc_context3(audio_codec);
 
    c->codec_id = AV_CODEC_ID_AAC;
    c->sample_fmt = AV_SAMPLE_FMT_S16;
    c->sample_rate = 44100;
    c->channels = 2;
    c->channel_layout = AV_CH_LAYOUT_STEREO;
    c->bit_rate = 64000;
 
    /* open the codec */
    ret = avcodec_open2(c, audio_codec, NULL);
    if (ret < 0) {
        fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
        exit(1);
    }
 
    /* allocate and init a re-usable frame */
    frame = avcodec_alloc_frame();
    if (!frame) {
        fprintf(stderr, "Could not allocate video frame\n");
        exit(1);
    }
 
 
    frame->nb_samples = c->frame_size;
    frame->format = c->sample_fmt;
    frame->channels = c->channels;
    frame->channel_layout = c->channel_layout;
    frame->linesize[0] = 4096;
    frame->extended_data = frame->data[0] = av_malloc((size_t)frame->linesize[0]);
 
    av_init_packet(&pkt);
 
    fp_in = fopen("in.wav","rb");
    fp_out= fopen("out.aac","wb");
 
    //printf("frame->nb_samples = %d\n",frame->nb_samples);
     
    while(1)
    {
        frame_count++;
        bzero(frame->data[0],frame->linesize[0]);
        ret = fread(frame->data[0],frame->linesize[0],1,fp_in);
        if(ret <= 0)
        {
            printf("read over !\n");
            break;
        }
        ret = avcodec_encode_audio2(c, &pkt, frame, &got_output);
        if (ret < 0) {
            fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
            exit(1);
        }
     
        if(got_output > 0)
        {
            //printf("pkt.size = %d\n",pkt.size);
            fwrite(pkt.data,pkt.size,1,fp_out);
            av_free_packet(&pkt);
        }
 
        #if 0
        if(frame_count > 10)
        {
            printf("break @@@@@@@@@@@@\n");
            break;
        }
        #endif
    }
 
    avcodec_close(c);
    av_free(c);
    avcodec_free_frame(&frame);
 
    fclose(fp_in);
    fclose(fp_out);
 
    return 0;
}

转载自：http://hi.baidu.com/285988185/item/6864b8b0c9640445ba0e12a6

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