FFmpeg decoding audio saved as PCM

[TOC] Introduction

A simple Save the PCM demo, note to save there for the two-channel processing, because the PCM pair of two channels is alternately stored code

/* * A simple Save the PCM demo, note to save there for the two-channel processing, because the PCM pair of channels are alternately stored * Miu *MK (821486004@qq.com) */#ifdef __cplusplus extern "C" {#endif #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libavdevice/avdevice.h" #include " Libavfilter/avfilter.h "#include" libavfilter/avfiltergraph.h "#include" libavfilter/buffersink.h "#include"

Libavfilter/buffersrc.h "#include" libavutil/audio_fifo.h "#include" libavutil/avutil.h "#include" libavutil/fifo.h " #ifdef __cplusplus} #endif #pragma comment (lib, "Avcodec.lib") #pragma comment (lib, "Avformat.lib") #pragma comment (lib , "Avutil.lib") #pragma comment (lib, "Avdevice.lib") #pragma comment (lib, "Avfilter.lib")//#pragma comment (lib, "avfilt Er.lib ")//#pragma comment (lib," Postproc.lib ")//#pragma comment (lib," Swresample.lib ") #pragma comment (lib," Swscale.lib ") #include <windows.h> #include <conio.h> #include <time.h> #include <tchar.h> avfo  
Rmatcontext *ifmt_ctx = NULL;

int g_audiostreamindex =-1; #incLude <stdio.h> int openinputfile (const char* filename) {int ret = 0; Open the input if (ret = avformat_open_input (&ifmt_ctx, filename, null, NULL)) < 0) {Prin  
        TF ("Can not open input");  
    return ret;   
        } if (ret = Avformat_find_stream_info (Ifmt_ctx, NULL)) {printf ("Can not find input stream info");  
    return ret; }//open the decoder for (int i = 0; i < ifmt_ctx->nb_streams; i++) {if (ifmt_ctx->
            Streams[i]->codec->codec_type = = Avmedia_type_audio) {g_audiostreamindex = i; ret = Avcodec_open2 (Ifmt_ctx->streams[i]->codec, Avcodec_find_decoder (ifmt_ctx->streams[i]-&gt  

            ; codec->codec_id), NULL);  
                if (Ret < 0) {printf ("Can not open decoder");  
            return ret;  
}}} return 0;  }

int _tmain (int argc, _tchar* argv[]) {if (ARGC < 2) {return-1;  
    } avpacket pkt_in, pkt_out;  
    Avframe *frame = NULL;  
    unsigned int stream_index;  

    Av_register_all ();  
        if (Openinputfile (argv[1) < 0) {printf ("Failed to open input file");  
    Goto end;  
    } FILE *p = NULL;
    Char tmpname[100]; sprintf_s (Tmpname, "%S_%D_%DCHANNEL.PCM", argv[1], Ifmt_ctx->streams[g_audiostreamindex]->codec->sample_
    Rate, ifmt_ctx->streams[g_audiostreamindex]->codec->channels);

    p = fopen (Tmpname, "w+b");
    int size = Av_get_bytes_per_sample (IFMT_CTX-&GT;STREAMS[G_AUDIOSTREAMINDEX]-&GT;CODEC-&GT;SAMPLE_FMT);  
        while (1) {if (Av_read_frame (Ifmt_ctx, &pkt_in) < 0) {break;  
        } pkt_out.data = NULL;  
        pkt_out.size = 0;  

        Av_init_packet (&pkt_out); if (G_audiostreamindex = = pkt_in.Stream_index) {stream_index = Pkt_in.stream_index;  
            frame = Av_frame_alloc ();  
            int got_frame =-1;  

            int ret =-1;  

            ret = Avcodec_decode_audio4 (Ifmt_ctx->streams[stream_index]->codec, Frame, &got_frame, &pkt_in);  
                if (Ret < 0) {Av_frame_free (&frame);  
                printf ("Decoding audio stream failed\n");  
            Break
                } if (Got_frame) {if (frame->data[0] && frame->data[1])
                    {for (int i = 0; i < ifmt_ctx->streams[stream_index]->codec->frame_size; i++)
                        {fwrite (frame->data[0] + i * size, 1, size, p);
                    Fwrite (frame->data[1] + i * size, 1, size, p);
             }} else if (Frame->data[0])   {fwrite (frame->data[0], 1, frame->linesize[0], p);  
}}}} fclose (P);  

    End:avformat_close_input (&AMP;IFMT_CTX);
    printf ("Enter any key to stop\n");  
    GetChar ();  
return 0;   }

Download Address

http://download.csdn.net/detail/dancing_night/9676984