#if 1
/*** 最简单的基于FFmpeg的视频解码器（纯净版）* Simplest FFmpeg Decoder Pure** 雷霄骅 Lei Xiaohua* leixiaohua1020@126.com* 中国传媒大学/数字电视技术* Communication University of China / Digital TV Technology* http://blog.csdn.net/leixiaohua1020*** 本程序实现了视频码流(支持HEVC，H.264，MPEG2等)解码为YUV数据。* 它仅仅使用了libavcodec（而没有使用libavformat）。* 是最简单的FFmpeg视频解码方面的教程。* 通过学习本例子可以了解FFmpeg的解码流程。* This software is a simplest decoder based on FFmpeg.* It decode bitstreams to YUV pixel data.* It just use libavcodec (do not contains libavformat).* Suitable for beginner of FFmpeg.*/#include <stdio.h>#define __STDC_CONSTANT_MACROS#ifdef _WIN32
//Windows
extern "C"
{
#include "libavcodec/avcodec.h"
};
#else
//Linux...
#ifdef __cplusplus
extern "C"
{
#endif
#include "avcodec.h"
#ifdef __cplusplus
};
#endif
#endif//test different codec
#define TEST_H264  1
#define TEST_HEVC  0int simplest_ffmpeg_decoder_pure(int argc, char* argv[])
{AVCodec *pCodec;AVCodecContext *pCodecCtx= NULL;AVCodecParserContext *pCodecParserCtx=NULL;FILE *fp_in;FILE *fp_out;AVFrame	*pFrame;const int in_buffer_size=4096;unsigned char in_buffer[in_buffer_size + FF_INPUT_BUFFER_PADDING_SIZE];unsigned char *cur_ptr;int cur_size;AVPacket packet;int ret, got_picture;#if TEST_HEVCenum AVCodecID codec_id=AV_CODEC_ID_HEVC;char filepath_in[]="bigbuckbunny_480x272.hevc";
#elif TEST_H264enum AVCodecID codec_id=AV_CODEC_ID_H264;char filepath_in[]="bigbuckbunny_480x272.h264";
#elseenum AVCodecID codec_id=AV_CODEC_ID_MPEG2VIDEO;char filepath_in[]="bigbuckbunny_480x272.m2v";
#endifchar filepath_out[]="bigbuckbunny_480x272.yuv";int first_time=1;//av_log_set_level(AV_LOG_DEBUG);avcodec_register_all();pCodec = avcodec_find_decoder(codec_id);if (!pCodec) {printf("Codec not found\n");return -1;}pCodecCtx = avcodec_alloc_context3(pCodec);if (!pCodecCtx){printf("Could not allocate video codec context\n");return -1;}pCodecParserCtx=av_parser_init(codec_id);if (!pCodecParserCtx){printf("Could not allocate video parser context\n");return -1;}//if(pCodec->capabilities&CODEC_CAP_TRUNCATED)//    pCodecCtx->flags|= CODEC_FLAG_TRUNCATED; if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {printf("Could not open codec\n");return -1;}//Input Filefp_in = fopen(filepath_in, "rb");if (!fp_in) {printf("Could not open input stream\n");return -1;}//Output Filefp_out = fopen(filepath_out, "wb");if (!fp_out) {printf("Could not open output YUV file\n");return -1;}pFrame = av_frame_alloc();av_init_packet(&packet);while (1) {cur_size = fread(in_buffer, 1, in_buffer_size, fp_in);if (cur_size == 0)break;cur_ptr=in_buffer;while (cur_size>0){int len = av_parser_parse2(pCodecParserCtx, pCodecCtx,&packet.data, &packet.size,cur_ptr , cur_size ,AV_NOPTS_VALUE, AV_NOPTS_VALUE, AV_NOPTS_VALUE);cur_ptr += len;cur_size -= len;if(packet.size==0)continue;//Some Info from AVCodecParserContextprintf("[Packet]Size:%6d\t",packet.size);switch(pCodecParserCtx->pict_type){case AV_PICTURE_TYPE_I: printf("Type:I\t");break;case AV_PICTURE_TYPE_P: printf("Type:P\t");break;case AV_PICTURE_TYPE_B: printf("Type:B\t");break;default: printf("Type:Other\t");break;}printf("Number:%4d\n",pCodecParserCtx->output_picture_number);ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, &packet);if (ret < 0) {printf("Decode Error.\n");return ret;}if (got_picture) {if(first_time){printf("\nCodec Full Name:%s\n",pCodecCtx->codec->long_name);printf("width:%d\nheight:%d\n\n",pCodecCtx->width,pCodecCtx->height);first_time=0;}//Y, U, Vfor(int i=0;i<pFrame->height;i++){fwrite(pFrame->data[0]+pFrame->linesize[0]*i,1,pFrame->width,fp_out);}for(int i=0;i<pFrame->height/2;i++){fwrite(pFrame->data[1]+pFrame->linesize[1]*i,1,pFrame->width/2,fp_out);}for(int i=0;i<pFrame->height/2;i++){fwrite(pFrame->data[2]+pFrame->linesize[2]*i,1,pFrame->width/2,fp_out);}printf("Succeed to decode 1 frame!\n");}}}//Flush Decoderpacket.data = NULL;packet.size = 0;while(1){ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, &packet);if (ret < 0) {printf("Decode Error.\n");return ret;}if (!got_picture){break;}else {//Y, U, Vfor(int i=0;i<pFrame->height;i++){fwrite(pFrame->data[0]+pFrame->linesize[0]*i,1,pFrame->width,fp_out);}for(int i=0;i<pFrame->height/2;i++){fwrite(pFrame->data[1]+pFrame->linesize[1]*i,1,pFrame->width/2,fp_out);}for(int i=0;i<pFrame->height/2;i++){fwrite(pFrame->data[2]+pFrame->linesize[2]*i,1,pFrame->width/2,fp_out);}printf("Flush Decoder: Succeed to decode 1 frame!\n");}}fclose(fp_in);fclose(fp_out);av_parser_close(pCodecParserCtx);av_frame_free(&pFrame);avcodec_close(pCodecCtx);av_free(pCodecCtx);return 0;
}#endif