libavcodec का उपयोग करके ऑडियो डीकोड करें और libAO का उपयोग करके खेलते हैं?

Question

मैं ऑडियो फ़ाइलों को डीकोड करने के लिए निम्नलिखित कोड स्निपेट का उपयोग करता हूं (एमपी 3, डब्ल्यूएवी, डब्लूएमवी के साथ परीक्षण)।

लेकिन जब यह ऑडियो चलाता है, तो यह समय-समय पर स्थिर ध्वनियां और क्रैश देता है। क्या मैं यहां गलत कर रहा हूं पर कोई संकेत?

#include <stdlib.h> 
#include <stdio.h> 
#include <string.h> 
#include <math.h> 


extern "C" { 
#include "libavutil/mathematics.h" 
#include "libavformat/avformat.h" 
#include "libswscale/swscale.h" 
#include <ao/ao.h> 

} 

void die(const char *msg) 
{ 
    fprintf(stderr,"%s\n",msg); 
    exit(1); 
} 

int main(int argc, char **argv) 
{ 

    const char* input_filename=argv[1]; 

    //avcodec_register_all(); 
    av_register_all(); 
    //av_ini 

    AVFormatContext* container=avformat_alloc_context(); 
    if(avformat_open_input(&container,input_filename,NULL,NULL)<0){ 
     die("Could not open file"); 
    } 

    if(av_find_stream_info(container)<0){ 
     die("Could not find file info"); 
    } 
    av_dump_format(container,0,input_filename,false); 

    int stream_id=-1; 
    int i; 
    for(i=0;i<container->nb_streams;i++){ 
     if(container->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO){ 
      stream_id=i; 
      break; 
     } 
    } 
    if(stream_id==-1){ 
     die("Could not find Audio Stream"); 
    } 

    AVDictionary *metadata=container->metadata; 

    AVCodecContext *ctx=container->streams[stream_id]->codec; 
    AVCodec *codec=avcodec_find_decoder(ctx->codec_id); 

    if(codec==NULL){ 
     die("cannot find codec!"); 
    } 

    if(avcodec_open(ctx,codec)<0){ 
     die("Codec cannot be found"); 
    } 

    //ctx=avcodec_alloc_context3(codec); 

    //initialize AO lib 
    ao_initialize(); 

    int driver=ao_default_driver_id(); 

    ao_sample_format sformat; 
    sformat.bits=16; 
    sformat.channels=2; 
    sformat.rate=44100; 
    sformat.byte_format=AO_FMT_NATIVE; 
    sformat.matrix=0; 

    ao_device *adevice=ao_open_live(driver,&sformat,NULL); 
    //end of init AO LIB 

    AVPacket packet; 
    av_init_packet(&packet); 

    AVFrame *frame=avcodec_alloc_frame(); 

    int buffer_size=AVCODEC_MAX_AUDIO_FRAME_SIZE; 
    uint8_t buffer[buffer_size]; 
    packet.data=buffer; 
    packet.size =buffer_size; 



    int len; 
    int frameFinished=0; 
    while(av_read_frame(container,&packet)>=0) 
    { 

     if(packet.stream_index==stream_id){ 
      //printf("Audio Frame read \n"); 
      int len=avcodec_decode_audio4(ctx,frame,&frameFinished,&packet); 
      //frame-> 
      if(frameFinished){ 
       //printf("Finished reading Frame %d %d\n",packet.size,len); 
       ao_play(adevice, (char*)frame->data, len); 
      } 

     } 


    } 

    av_close_input_file(container); 
    ao_shutdown(); 
    return 0; 
} 

Answer 1

ठीक है, यहाँ एक काम कोड नमूना है:

int main(int argc, char **argv) 
{ 

    const char* input_filename=argv[1]; 

    //avcodec_register_all(); 
    av_register_all(); 
    //av_ini 

    AVFormatContext* container=avformat_alloc_context(); 
    if(avformat_open_input(&container,input_filename,NULL,NULL)<0){ 
     die("Could not open file"); 
    } 

    if(av_find_stream_info(container)<0){ 
     die("Could not find file info"); 
    } 
    av_dump_format(container,0,input_filename,false); 

    int stream_id=-1; 
    int i; 
    for(i=0;i<container->nb_streams;i++){ 
     if(container->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO){ 
      stream_id=i; 
      break; 
     } 
    } 
    if(stream_id==-1){ 
     die("Could not find Audio Stream"); 
    } 

    AVDictionary *metadata=container->metadata; 

    AVCodecContext *ctx=container->streams[stream_id]->codec; 
    AVCodec *codec=avcodec_find_decoder(ctx->codec_id); 

    if(codec==NULL){ 
     die("cannot find codec!"); 
    } 

    if(avcodec_open(ctx,codec)<0){ 
     die("Codec cannot be found"); 
    } 

    //ctx=avcodec_alloc_context3(codec); 

    //initialize AO lib 
    ao_initialize(); 

    int driver=ao_default_driver_id(); 

    ao_sample_format sformat; 
    AVSampleFormat sfmt=ctx->sample_fmt; 
    if(sfmt==AV_SAMPLE_FMT_U8){ 
     printf("U8\n"); 

     sformat.bits=8; 
    }else if(sfmt==AV_SAMPLE_FMT_S16){ 
     printf("S16\n"); 
     sformat.bits=16; 
    }else if(sfmt==AV_SAMPLE_FMT_S32){ 
     printf("S32\n"); 
     sformat.bits=32; 
    } 

    sformat.channels=ctx->channels; 
    sformat.rate=ctx->sample_rate; 
    sformat.byte_format=AO_FMT_NATIVE; 
    sformat.matrix=0; 

    ao_device *adevice=ao_open_live(driver,&sformat,NULL); 
    //end of init AO LIB 

    AVPacket packet; 
    av_init_packet(&packet); 

    AVFrame *frame=avcodec_alloc_frame(); 



    int buffer_size=AVCODEC_MAX_AUDIO_FRAME_SIZE+ FF_INPUT_BUFFER_PADDING_SIZE;; 
    uint8_t buffer[buffer_size]; 
    packet.data=buffer; 
    packet.size =buffer_size; 



    int len; 
    int frameFinished=0; 
    while(av_read_frame(container,&packet)>=0) 
    { 

     if(packet.stream_index==stream_id){ 
      //printf("Audio Frame read \n"); 
      int len=avcodec_decode_audio4(ctx,frame,&frameFinished,&packet); 
      //frame-> 
      if(frameFinished){ 
       //printf("Finished reading Frame len : %d , nb_samples:%d buffer_size:%d line size: %d \n",len,frame->nb_samples,buffer_size,frame->linesize[0]); 
       ao_play(adevice, (char*)frame->extended_data[0],frame->linesize[0]); 
      }else{ 
       //printf("Not Finished\n"); 
      } 

     }else { 
      printf("Someother packet possibly Video\n"); 
     } 


    } 

    av_close_input_file(container); 
    ao_shutdown(); 
    return 0; 
}