ffmpeg的pcm、yuv小知识点

baoyu455852024-02-22 13:26

ffmpeg的pcm、yuv小知识点

pcm、yuv保存调用，写个通用工具方法，平时快速保存，和调用方便查看自己bug

ffmpeg的AVFrame存储 yuv

调用方法

保存方法

复制代码

void save_yuv420p_file(unsigned char *y_buf , unsigned char *u_buf,unsigned char *v_buf,int linesizey,int linesizevu, int width,int height,char *filename)
{
    int i = 0;
    static FILE *f= NULL;
    if(f == NULL){
        f = fopen(filename,"wb");
    }
    int height_half = height / 2, width_half = width / 2;
    int y_wrap = linesizey;
    int u_wrap = linesizevu;
    //int u_wrap = pFrame->linesize[0];
    //int v_wrap = pFrame->linesize[0];
    int v_wrap = linesizevu;

    if (f != NULL) {
        //save y
        for (i = 0; i < height; i++)
            fwrite(y_buf + i * y_wrap, 1, width, f);
        //save u
        for (i = 0; i < height_half; i++)
            fwrite(u_buf + i * u_wrap, 1, width_half, f);
        //save v
        for (i = 0; i < height_half; i++)
            fwrite(v_buf + i * v_wrap, 1, width_half, f);
        fflush(f);
    }

}

ffmpeg命令播放yuv：（修改对应宽高和yuv文件路径）

复制代码

ffplay -video_size 720x1280 -i /Users/shenjianbin/Downloads/camera2_tencent.yuv

ffmpeg的AVFrame存储 pcm

复制代码

void savess_file(uint8_t *buf, int size,char *filename)
{
    static FILE *f= NULL;
    if(f == NULL){
        f = fopen(filename,"wb");
    }
    if (f != NULL) {
       fwrite(buf, sizeof(uint8_t), size, f);
        fflush(f);
    }

}

命令行操控

复制代码

 ffplay -ar 44100 -ac 2 -f  f32le /Users/songlin/audio/qt_record/05_05_23_05_35.pcm

ar: 采样率

ac: 声道数

f: 采样格式

s16le:PCM signed 16-bit little-endian

更多PCM的采样格式可以使用命令查看

Windows：ffmpeg -formats | findstr PCM

Mac：ffmpeg -formats | grep PCM