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
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 yfor (i = 0; i < height; i++)fwrite(y_buf + i * y_wrap, 1, width, f);//save ufor (i = 0; i < height_half; i++)fwrite(u_buf + i * u_wrap, 1, width_half, f);//save vfor (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）
ffplay -video_size 720x1280 -i /Users/shenjianbin/Downloads/camera2_tencent.yuv
ffmpeg的AVFrame存储 pcm
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
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
