SDL ios音频简单测试例子-借鉴雷大神的代码

分手后的思念是犯贱 2022-05-31 00:20 75阅读 0赞

本实例主要代码如下：

AudioPlayerSDL2.mm

//
    //  AudioSDLTest.m
    //  AudioTest
    //
    //  Created by zhufu on 2018/1/20.
    //  Copyright © 2018年 zhufu. All rights reserved.
    //
    #import "AudioPlayerSDL2.h"
    //Buffer:
    //|-----------|-------------|
    //chunk-------pos---len-----|
    static  Uint32  audio_len;
    static  Uint8  *audio_pos;
    
    /* Audio Callback
     * The audio function callback takes the following parameters:
     * stream: A pointer to the audio buffer to be filled
     * len: The length (in bytes) of the audio buffer
     *
     */
    void  fill_audio(void *udata,Uint8 *stream,int len){
        //SDL 2.0
        SDL_memset(stream, 0, len);
        if(audio_len==0)        /*  Only  play  if  we  have  data  left  */
            return;
        
        len=(len>audio_len?audio_len:len);    /*  Mix  as  much  data  as  possible  */
        printf("audio   %d %d\n", audio_len, len);
        SDL_MixAudio(stream,audio_pos,len,SDL_MIX_MAXVOLUME);
        audio_pos += len;
        
        audio_len -= len;
    }
    
    int cppTest()
    {
        SDL_SetMainReady();
        //Init
        if(SDL_Init(SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
            printf( "Could not initialize SDL - %s\n", SDL_GetError());
            return -1;
        }
        //SDL_AudioSpec
        SDL_AudioSpec wanted_spec;
        wanted_spec.freq = 44100;
        wanted_spec.format = AUDIO_S16SYS;
        wanted_spec.channels = 2;
        wanted_spec.silence = 0;
        wanted_spec.samples = 1024;
        wanted_spec.callback = fill_audio;
        
        if (SDL_OpenAudio(&wanted_spec, NULL)<0){
            printf("can't open audio.\n");
            return -1;
        }
        
        NSString *ppth = [[NSBundle mainBundle] pathForResource:@"testv" ofType:@"pcm"];
        FILE *fp=fopen([ppth UTF8String],"r");
        if(fp==NULL){
            printf("cannot open this file\n");
            return -1;
        }
        //For YUV420P
        int pcm_buffer_size=4096;
        char *pcm_buffer=(char *)malloc(pcm_buffer_size);
        int data_count=0;
        
        while(1){
            if (fread(pcm_buffer, 1, pcm_buffer_size, fp) != pcm_buffer_size){
                // Loop
                fseek(fp, 0, SEEK_SET);
                fread(pcm_buffer, 1, pcm_buffer_size, fp);
                data_count=0;
            }
            printf("Now Playing %10d Bytes data.\n",data_count);
            data_count+=pcm_buffer_size;
            //Set audio buffer (PCM data)
            //Audio buffer length
            audio_len =pcm_buffer_size;
            audio_pos = (Uint8 *) pcm_buffer;
            //Play
            
            SDL_PauseAudio(0);
            while(audio_len>0){ //Wait until finish
                SDL_Delay(1);
            }
        }
        
        return 0;
    }

AudioPlayerSDL2.h

//
    //  AudioPlayerSDL2.h
    //  AudioTest
    //
    //  Created by zhufu on 2018/1/20.
    //  Copyright © 2018年 zhufu. All rights reserved.
    //
    
    #ifndef AudioPlayerSDL2_h
    #define AudioPlayerSDL2_h
    
    #include <stdio.h>
    #include "include/SDL.h"
    #include "AudioSDLTest.h"
    void  fill_audio(void *udata,Uint8 *stream,int len);
    int cppTest(void);
    
    #endif /* AudioPlayerSDL2_h */

源代码[https://github.com/zhu12345618/iOSAudioTest][https_github.com_zhu12345618_iOSAudioTest]

[https_github.com_zhu12345618_iOSAudioTest]: https://github.com/zhu12345618/iOSAudioTest