JNIEXPORT void JNICALL Java_com_dongnaoedu_ffmplayer_VideoUtils_sound
(JNIEnv *env, jobject jobj, jstring input_jstr, jstring output_jstr){
const char* input_cstr = (*env)->GetStringUTFChars(env,input_jstr,NULL);
const char* output_cstr = (*env)->GetStringUTFChars(env,output_jstr,NULL);
LOGI("%s","sound");
//注册组件
av_register_all();
AVFormatContext *pFormatCtx = avformat_alloc_context();
//打开音频文件
if(avformat_open_input(&pFormatCtx,input_cstr,NULL,NULL) != 0){
LOGI("%s","无法打开音频文件");
return;
}
//获取输入文件信息
if(avformat_find_stream_info(pFormatCtx,NULL) < 0){
LOGI("%s","无法获取输入文件信息");
return;
}
//获取音频流索引位置
int i = 0, audio_stream_idx = -1;
for(; i < pFormatCtx->nb_streams;i++){
if(pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO){
audio_stream_idx = i;
break;
}
}
//获取解码器
AVCodecContext *codecCtx = pFormatCtx->streams[audio_stream_idx]->codec;
AVCodec *codec = avcodec_find_decoder(codecCtx->codec_id);
if(codec == NULL){
LOGI("%s","无法获取解码器");
return;
}
//打开解码器
if(avcodec_open2(codecCtx,codec,NULL) < 0){
LOGI("%s","无法打开解码器");
return;
}
//压缩数据
AVPacket *packet = (AVPacket *)av_malloc(sizeof(AVPacket));
//解压缩数据
AVFrame *frame = av_frame_alloc();
//frame->16bit 44100 PCM 统一音频采样格式与采样率
SwrContext *swrCtx = swr_alloc();
//重采样设置参数-------------start
//输入的采样格式
enum AVSampleFormat in_sample_fmt = codecCtx->sample_fmt;
//输出采样格式16bit PCM
enum AVSampleFormat out_sample_fmt = AV_SAMPLE_FMT_S16;
//输入采样率
int in_sample_rate = codecCtx->sample_rate;
//输出采样率
int out_sample_rate = 44100;
//获取输入的声道布局
//根据声道个数获取默认的声道布局(2个声道,默认立体声stereo)
//av_get_default_channel_layout(codecCtx->channels);
uint64_t in_ch_layout = codecCtx->channel_layout;
//输出的声道布局(立体声)
uint64_t out_ch_layout = AV_CH_LAYOUT_STEREO;
swr_alloc_set_opts(swrCtx,
out_ch_layout,out_sample_fmt,out_sample_rate,
in_ch_layout,in_sample_fmt,in_sample_rate,
0, NULL);
//输出的声道个数
int out_channel_nb = av_get_channel_layout_nb_channels(out_ch_layout);
//重采样设置参数-------------end
swr_init(swrCtx);
//16bit 44100 PCM 数据
uint8_t *out_buffer = (uint8_t *)av_malloc(MAX_AUDIO_FRME_SIZE);
FILE *fp_pcm = fopen(output_cstr,"wb");
int got_frame = 0,index = 0, ret;
//不断读取压缩数据
while(av_read_frame(pFormatCtx,packet) >= 0){
//解码
ret = avcodec_decode_audio4(codecCtx,frame,&got_frame,packet);
if(ret < 0){
LOGI("%s","解码完成");
}
//解码一帧成功
if(got_frame > 0){
LOGI("解码:%d",index++);
swr_convert(swrCtx, &out_buffer, MAX_AUDIO_FRME_SIZE,frame->data,frame->nb_samples);
//获取sample的size
int out_buffer_size = av_samples_get_buffer_size(NULL, out_channel_nb,
frame->nb_samples, out_sample_fmt, 1);
fwrite(out_buffer,1,out_buffer_size,fp_pcm);
}
av_free_packet(packet);
}
fclose(fp_pcm);
av_frame_free(&frame);
av_free(out_buffer);
swr_free(&swrCtx);
avcodec_close(codecCtx);
avformat_close_input(&pFormatCtx);
(*env)->ReleaseStringUTFChars(env,input_jstr,input_cstr);
(*env)->ReleaseStringUTFChars(env,output_jstr,output_cstr);
}