转载调用xvid 实现解码

2011-06-01 00:26:14)

转载

view plaincopy to clipboardprint?
///
intinit_decoder()
{
    intret;
   xvid_gbl_init_t  xvid_gbl_init;
   xvid_dec_create_txvid_dec_create;

   memset(&xvid_gbl_init, 0,sizeof(xvid_gbl_init_t));
   memset(&xvid_dec_create, 0,sizeof(xvid_dec_create_t));

    XDIM = 0;
    YDIM = 0;
    FORMAT = 0;
    CSP =XVID_CSP_BGR;
    BPP =3;

    dec_handle =NULL ;

    mp4_buffer =NULL ;
    out_buffer =NULL ;
    mp4_ptr =NULL ;

   xvid_gbl_init.version =XVID_VERSION;

   xvid_gbl_init.cpu_flags = 0; // use assemblyoptimized
   xvid_gbl_init.debug = 0;    // set debug level 0, no debugoutput
   xvid_global(NULL, 0, &xvid_gbl_init, NULL);//XVID初始化


   xvid_dec_create.version =XVID_VERSION;

   xvid_dec_create.width = 0;//解码后图像的宽度如果事先已经知道那么这里就填写否则设置0
   xvid_dec_create.height = 0;//解码后图像的高度如果事先已经知道那么这里就填写否则设置0
    ret =xvid_decore(NULL, XVID_DEC_CREATE,&xvid_dec_create, NULL);//创建xvid解码实例
    dec_handle =xvid_dec_create.handle;将创建的句柄赋值给dec_handle
   return(ret);
}
//
int decode_one_frame(unsigned char *istream, unsigned char*ostream,
                                     int istream_size, xvid_dec_stats_t*xvid_dec_stats)
{
    intret;
   xvid_dec_frame_txvid_dec_frame;

   memset(&xvid_dec_frame, 0,sizeof(xvid_dec_frame_t));
   memset(xvid_dec_stats, 0,sizeof(xvid_dec_stats_t));

   xvid_dec_frame.version =XVID_VERSION;
   xvid_dec_stats->version =XVID_VERSION;

   xvid_dec_frame.general         = 0;

   xvid_dec_frame.bitstream       = istream;//待解码的数据
   xvid_dec_frame.length          = istream_size;//待解码数据的长度

   xvid_dec_frame.output.plane[0] =ostream;//解码完成后存放原始视频流的缓冲区
   xvid_dec_frame.output.stride[0] =XDIM*BPP;//步长即一行像素所占的空间大小
   xvid_dec_frame.output.csp = CSP;//输出时采用的色场空间这里 XVID_CSP_BGR即采用RGB
    ret =xvid_decore(dec_handle, XVID_DEC_DECODE,&xvid_dec_frame, xvid_dec_stats);//ret 值解码前帧的长度
   return(ret);
}
///调用方式
do {

           used_bytes = decode_one_frame(mp4_ptr, out_buffer, useful_bytes,&xvid_dec_stats);

           if(xvid_dec_stats.type == XVID_TYPE_VOL)//如果输入一帧包含 VOL重新获得输出图像的宽度和高度
           {

               if(XDIM*YDIM <xvid_dec_stats.data.vol.width*xvid_dec_stats.data.vol.height)
               {

                   XDIM =xvid_dec_stats.data.vol.width;
                   YDIM =xvid_dec_stats.data.vol.height;


                   if(out_buffer)free(out_buffer);

                   out_buffer = (unsigned char*)malloc(XDIM*YDIM*4);//动态调整输出流存储空间的大小
                   if(out_buffer == NULL)
                       goto free_all_memory;
               }
           }

           if(used_bytes > 0){
               mp4_ptr += used_bytes;
               useful_bytes -=used_bytes;
           }
       } while (xvid_dec_stats.type <= 0&& useful_bytes >MIN_USEFUL_BYTES);


       draw_image(out_buffer) ;
///
int init_decoder()
{
int ret;
xvid_gbl_init_t  xvid_gbl_init;
xvid_dec_create_t xvid_dec_create;

memset(&xvid_gbl_init, 0,sizeof(xvid_gbl_init_t));
memset(&xvid_dec_create, 0,sizeof(xvid_dec_create_t));

XDIM = 0 ;
YDIM = 0 ;
FORMAT = 0 ;
CSP = XVID_CSP_BGR;
BPP = 3;

dec_handle = NULL ;

mp4_buffer = NULL ;
out_buffer = NULL ;
mp4_ptr = NULL ;

xvid_gbl_init.version = XVID_VERSION;

xvid_gbl_init.cpu_flags = 0; //use assembly optimized
xvid_gbl_init.debug = 0;    // set debug level 0, no debug output
xvid_global(NULL, 0,&xvid_gbl_init, NULL);//XVID 初始化

xvid_dec_create.version = XVID_VERSION;

xvid_dec_create.width =0;//解码后图像的宽度如果事先已经知道那么这里就填写否则设置0
xvid_dec_create.height = 0;//解码后图像的高度如果事先已经知道那么这里就填写否则设置0
ret = xvid_decore(NULL, XVID_DEC_CREATE,&xvid_dec_create, NULL);//创建xvid 解码实例
dec_handle = xvid_dec_create.handle;将创建的句柄赋值给 dec_handle
return(ret);
}
//
int decode_one_frame(unsigned char *istream, unsigned char*ostream,
          int istream_size, xvid_dec_stats_t *xvid_dec_stats)
{
int ret;
xvid_dec_frame_t xvid_dec_frame;

memset(&xvid_dec_frame, 0,sizeof(xvid_dec_frame_t));
memset(xvid_dec_stats, 0,sizeof(xvid_dec_stats_t));

xvid_dec_frame.version = XVID_VERSION;
xvid_dec_stats->version =XVID_VERSION;

xvid_dec_frame.general         = 0;

xvid_dec_frame.bitstream       = istream;//待解码的数据
xvid_dec_frame.length          = istream_size;//待解码数据的长度

xvid_dec_frame.output.plane[0] = ostream;//解码完成后存放原始视频流的缓冲区
xvid_dec_frame.output.stride[0] =XDIM*BPP;//步长即一行像素所占的空间大小
xvid_dec_frame.output.csp = CSP;//输出时采用的色场空间这里XVID_CSP_BGR 即采用RGB
ret = xvid_decore(dec_handle, XVID_DEC_DECODE,&xvid_dec_frame, xvid_dec_stats);//ret 值解码前帧的长度
return(ret);
}
///调用方式
do {

   used_bytes =decode_one_frame(mp4_ptr, out_buffer, useful_bytes,&xvid_dec_stats);

   if(xvid_dec_stats.type== XVID_TYPE_VOL)//如果输入一帧包含 VOL 重新获得输出图像的宽度和高度
   {

    if(XDIM*YDIM<xvid_dec_stats.data.vol.width*xvid_dec_stats.data.vol.height)
    {

     XDIM= xvid_dec_stats.data.vol.width;
     YDIM= xvid_dec_stats.data.vol.height;


     if(out_buffer)free(out_buffer);

     out_buffer= (unsigned char*)malloc(XDIM*YDIM*4);//动态调整输出流存储空间的大小
     if(out_buffer== NULL)
      gotofree_all_memory;
    }
   }

   if(used_bytes> 0) {
    mp4_ptr+= used_bytes;
    useful_bytes-= used_bytes;
   }
  } while (xvid_dec_stats.type<= 0 && useful_bytes> MIN_USEFUL_BYTES);


  draw_image(out_buffer);

2 Xvid编解码实践

关于编码器输入格式设置：

其中 en->width图像采集时的宽度（以像素为单位）

switch( input->format )
{
case FORMAT_RAW_BGR24:
   xvid_enc_frame.input.csp =XVID_CSP_BGR;
   xvid_enc_frame.input.stride[0]= en->width * 3;
   break;
case FORMAT_RAW_UYVY:
   xvid_enc_frame.input.csp =XVID_CSP_UYVY;
   xvid_enc_frame.input.stride[0]= en->width * 2;
   break;
case FORMAT_RAW_YUY2:
   xvid_enc_frame.input.csp =XVID_CSP_YUY2;
   xvid_enc_frame.input.stride[0]= en->width * 2;
   break;
}