ios ffmpeg h264 decode

来源：互联网发布：单片机实验报告总结编辑：程序博客网时间：2024/06/02 02:16
ios使用ffmpeg解码h264数据封装。
#import "FFMpegAVCDecoder.h"#ifdef __cplusplusextern "C" {#endif    #include <libavutil/opt.h>#include <libavcodec/avcodec.h>#include <libavformat/avformat.h>#include <libswscale/swscale.h>    #ifdef __cplusplus};#endif@interface FFMpegAVCDecoder(){    AVCodec *_videoCodec;    AVCodecContext *_pCodecCtx;    AVFrame *_pFrame;    char* _yuvBuf;}@end@implementation FFMpegAVCDecoder-(int)initDecoder{        av_register_all();        /* find the video encoder */    _videoCodec = avcodec_find_decoder(AV_CODEC_ID_H264);    _pCodecCtx = avcodec_alloc_context3(_videoCodec);        if (!_videoCodec)        return -1;    _pCodecCtx->time_base.num = 1;    _pCodecCtx->frame_number = 1; //每包一个视频帧        if(avcodec_open2(_pCodecCtx, _videoCodec,NULL) >= 0)        _pFrame = av_frame_alloc();// Allocate video frame    else          return -1;        return 0;}-(int)decode:(char *)buf len:(int)len{    int frameFinished = len;    AVPacket packet = {        .data = (uint8_t*)buf,        .size = len,    };        avcodec_decode_video2(_pCodecCtx, _pFrame, &frameFinished, &packet);    if(frameFinished)//成功解码    {        int picSize = _pCodecCtx->height * _pCodecCtx->width;        int newSize = picSize * 3/2;                if (!_yuvBuf) {            _yuvBuf = (char*)malloc(newSize);        }                int height = _pCodecCtx->height;        int width = _pCodecCtx->width;                        //写入数据        int pos=0,i;        for (i=0; i<height; i++)        {            memcpy(_yuvBuf+pos,_pFrame->data[0] + i * _pFrame->linesize[0], width);            pos+=width;        }        for (i=0; i<height/2; i++)        {            memcpy(_yuvBuf+pos,_pFrame->data[1] + i * _pFrame->linesize[1], width/2);            pos+=width/2;        }        for (i=0; i<height/2; i++)        {            memcpy(_yuvBuf+pos,_pFrame->data[2] + i * _pFrame->linesize[2], width/2);            pos+=width/2;        }                  //TODO:解码数据回调    }        return 0;}-(void)freeDecoder{    if(_pCodecCtx){        avcodec_close(_pCodecCtx);        _videoCodec = NULL;    }    if (_pFrame) {        av_frame_free(&_pFrame);        _pFrame = NULL;    }    if (_yuvBuf) {        free(_yuvBuf);        _yuvBuf = NULL;    }}@end
阅读全文
0 0