嵌入式linux------ffmpeg移植 解码H264（am335x解码H264到yuv420并通过SDL显示）

/*
编译命令：arm-linux-gcc -o show2642 264showyuv2.c -I/usr/local/ffmpeg_arm/include/   -L/usr/local/ffmpeg_arm/lib/ -lswresample -lavformat -lavutil -lavcodec -lswscale -lx264   libSDL.a
*/
#include "stdio.h"
#include "stdlib.h"

#include "libavformat/avformat.h"
#include "libavdevice/avdevice.h"
#include "libswresample/swresample.h"
#include "libavutil/opt.h"
#include "libavutil/channel_layout.h"
#include "libavutil/parseutils.h"
#include "libavutil/samplefmt.h"
#include "libavutil/fifo.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/dict.h"
#include "libavutil/mathematics.h"
#include "libavutil/pixdesc.h"
#include "libavutil/avstring.h"
#include "libavutil/imgutils.h"
#include "libavutil/timestamp.h"
#include "libavutil/bprint.h"
#include "libavutil/time.h"
#include "libavutil/threadmessage.h"
#include "/usr/local/ffmpeg_arm/include/SDL/SDL.h"

#include "libavfilter/avcodec.h"
#include "libavcodec/avcodec.h"

#if HAVE_SYS_RESOURCE_H
#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#elif HAVE_GETPROCESSTIMES
#include <windows.h>
#endif
#if HAVE_GETPROCESSMEMORYINFO
#include <windows.h>
#include <psapi.h>
#endif

#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#if HAVE_TERMIOS_H
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <termios.h>
#elif HAVE_KBHIT
#include <conio.h>
#endif

#if HAVE_PTHREADS
#include <pthread.h>
#endif

#include <time.h>

#include "libavutil/avassert.h"

#define MAX_LEN  1024 * 50

////此方法參考官网的样例
static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
FILE *f)
{
//  FILE *f;
int i;
// f = fopen(filename,"w");
// fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255);
for (i = 0; i < ysize; i++)
fwrite(buf + i * wrap, 1, xsize, f);
//  fclose(f);
}

int main()
{
//以下初始化h264解码库
//avcodec_init();
int w = 720;
int h = 576,retu;
SDL_Rect rect;
av_register_all();

AVFrame *pFrame_ = NULL;

/* find the video encoder */
AVCodec *videoCodec = avcodec_find_decoder(CODEC_ID_H264);//得到264的解码器类
if(!videoCodec)
{
printf("avcodec_find_decoder error\n");
return -1;
}

AVCodecParserContext *avParserContext = av_parser_init(CODEC_ID_H264);//得到解析帧类。主要用于后面的帧头查找
if(!avParserContext)
{
printf("av_parser_init  error\n");
return -1;
}
AVCodecContext *codec_ = avcodec_alloc_context3(videoCodec);//解码会话层
if(!codec_)
{
printf("avcodec_alloc_context3  error\n");
return -1;
}

//初始化參数，以下的參数应该由详细的业务决定
codec_->time_base.num = 1;
codec_->frame_number = 1; //每包一个视频帧
codec_->codec_type = AVMEDIA_TYPE_VIDEO;
codec_->bit_rate = 0;
codec_->time_base.den = 25;//帧率
codec_->width = 720;//视频宽
codec_->height = 576;//视频高

if(avcodec_open2(codec_, videoCodec, NULL) >= 0)//打开解码器
{
pFrame_ = avcodec_alloc_frame();// Allocate video frame    成功打开解码器后， 此时能够分配帧内存， 当然你也能够在后面每次都分配、释放， 在此我省功夫， 仅仅在開始分配一次
if (!pFrame_) {
fprintf(stderr, "Could not allocate video frame\n");
exit(1);
}
}
else
{
printf("avcodec_open2 error\n");
return -1;
}

AVPacket packet = {0};
int dwBufsize = 10;
int frameFinished = dwBufsize;//这个是随便填入数字，没什么作用

av_init_packet(&packet);
packet.data = NULL;//这里填入一个指向完整H264数据帧的指针
packet.size = 0;//这个填入H264数据帧的大小

FILE *myH264 = fopen("1.264", "rb");//解码的文件264
if(myH264 == NULL)
{
perror("cant open 264 file\n");
return -1;
}

FILE *yuvfile = fopen("my264.yuv", "wb");//成功解码后保存成的YUV文件， 能够用YUV工具打开浏览
if(yuvfile == NULL)
{
perror("cant open YUV file\n");
return -1;
}

int readFileLen = 1;
char readBuf[MAX_LEN];
unsigned char *parseBuf = malloc(20*MAX_LEN);//这个地方浪费了我一个下午时间， 当时我用的是栈内存。即unsigned char parseBuf[20*MAX_LEN]。 结果执行程序一直报错， 此处须要用堆内存才干正常解码
int  parseBufLen = 0;

int frameCount = 0;
printf("begin...\n");
printf("readBuf address  is %x\n", readBuf);
/////////////////////////SDL init////////////////////////////////////////
SDL_Surface* hello = NULL;
SDL_Surface* screen = NULL;

//Start SDL
// SDL_Init( SDL_INIT_EVERYTHING );
SDL_Init(SDL_INIT_VIDEO);

//Set up screen
screen = SDL_SetVideoMode( 1024, 768, 32, SDL_SWSURFACE );
SDL_Overlay* overlay = SDL_CreateYUVOverlay(w, h, SDL_YV12_OVERLAY, screen);

SDL_LockSurface(screen);
SDL_LockYUVOverlay(overlay);
//////////////////////////////////////////////////////////////////////
while(readFileLen > 0)//開始解码工作
{
//printf("begin...\n");
readFileLen = fread(readBuf, 1, sizeof(readBuf), myH264);//首先从文件中读出数据
if(readFileLen <= 0)
{
printf("read over\n");
break;
}
else
{
int handleLen = 0;
int handleFileLen = readFileLen;
while(handleFileLen > 0)
{
int nLength = av_parser_parse2(avParserContext, codec_, &parseBuf, &parseBufLen, readBuf + handleLen, handleFileLen, 0, 0, 0);//查找264帧头

handleFileLen -= nLength;
handleLen += nLength;

if(parseBufLen <= 0)//当parseBufLen大于0时，说明查找到了帧头
{
continue;
}
packet.size = parseBufLen;//将查找到的帧长度送入
packet.data = parseBuf;//将查找到的帧内存送入
if(frameCount>100)break;
//printf("parseBuf address is %x\n", parseBuf);
while(packet.size > 0)
{//以下開始真正的解码
int decodeLen = avcodec_decode_video2(codec_, pFrame_, &frameFinished, &packet);
if(decodeLen < 0)
break;
packet.size -= decodeLen;
packet.data += decodeLen;
if(frameFinished > 0)//成功解码
{
int picSize = codec_->height * codec_->width;
//int newSize = picSize * 1.5;

//申请内存
//unsigned char *buf = malloc(newSize);

int height = pFrame_->height;
int width = pFrame_->width;

//printf("OK, get data\n");
//printf("Frame height is %d\n", height);
//printf("Frame width is %d\n", width);
frameCount ++;
printf("Frame count is %d\n", frameCount);

pgm_save(pFrame_->data[0], pFrame_->linesize[0],//保存Y
codec_->width, codec_->height, yuvfile);
pgm_save(pFrame_->data[1], pFrame_->linesize[1],//保存U
codec_->width/2, codec_->height/2, yuvfile);
pgm_save(pFrame_->data[2], pFrame_->linesize[2],//保存V
codec_->width/2, codec_->height/2, yuvfile);

///有了YUV数据。 后面能够用FFMPEG提供的转换方法。将其转成RGB数据，进行兴许的显示或其他的图像处理工作
////sdl
int i;
for(i=0;i<576;i++)
{//fwrite(buf + i * wrap, 1, xsize, f);
memcpy(overlay->pixels[0]+i*720, pFrame_->data[0]+i*pFrame_->linesize[0], 720);
}
for(i=0;i<288;i++)
{
memcpy(overlay->pixels[2]+i*360, pFrame_->data[1]+i*pFrame_->linesize[1], 360);
memcpy(overlay->pixels[1]+i*360, pFrame_->data[2]+i*pFrame_->linesize[2], 360);                                                                      }

SDL_UnlockYUVOverlay(overlay);
SDL_UnlockSurface(screen);

rect.w = w;
rect.h = h;
rect.x = rect.y = 0;
SDL_DisplayYUVOverlay(overlay, &rect);
//sdl
//SDL_Delay(40);
}
else
printf("failed to decodec\n");
}
}
}
}
//////释放工作
avcodec_close(codec_);
av_free(codec_);
av_free_packet(&packet);
av_frame_free(&pFrame_);
//SDL
SDL_FreeYUVOverlay(overlay);
SDL_FreeSurface(screen);
//Quit SDL
SDL_Quit();
fclose(yuvfile);
fclose(myH264);

}