ios使用ffmpeg解码h264数据封装。
#import "FFMpegAVCDecoder.h" #ifdef __cplusplus extern "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