編碼器的參數設定 X264

void 
x264_param_default
( x264_param_t *param )

{

……

  
 
/* Video properties */

   
param->i_csp          
= X264_CSP_I420;

   
param->i_width        
= 352;

   
param->i_height       
= 288;

   
param->vui.i_sar_width = 0;

   
param->vui.i_sar_height= 0;

   
param->i_fps_num      
= 25;

   
param->i_fps_den      
= 1;

   
param->i_level_idc    
= 40; /* level 4.0 is sufficient for 720x576 with



16 reference frames */

  
 
/* Encoder parameters */

  
 


param->i_frame_reference = 1;
//

參考幀的個數

   
param->i_keyint_max = 250;
//


最大
IDR

幀間距，預設
250

  
 
param->i_keyint_min = 25;


/
/

最小
IDR

幀間距，預設
25

  
 
param->i_bframe = 0;
//


在
IP

幀之間可插入的
B

幀數量最大值，範圍
0~16

，預設
0

   
param->i_scenecut_threshold =40;
//


畫面動態變化限，當超出此值時插入
I

幀，預設
40

   
param->b_bframe_adaptive = 0;//


好像是自適應的
B

幀個數

   
param->i_bframe_bias = 0;
//


控制插入
B

幀判定，範圍
-100~+100

，越高越容易插入
B

幀，預設
0

   
param->b_bframe_pyramid = 0;
//


允許
B

幀做參考幀

 

    param->b_deblocking_filter = 0;

    param->i_deblocking_filter_alphac0 = 0;

   
param->i_deblocking_filter_beta = 0;

 

   
param->b_cabac = 0;

   
param->i_cabac_init_idc = -1;

 

   
param->rc.b_cbr = 0;//


是否使用碼率控制

   
param->rc.i_bitrate = 1000;

   
param->rc.f_rate_tolerance = 1.0;

   
param->rc.i_vbv_max_bitrate = 0;

   
param->rc.i_vbv_buffer_size = 0;

   
param->rc.f_vbv_buffer_init = 0.9;

    param->rc.i_qp_constant = 30;

    param->rc.i_qp_min = 20;

   
param->rc.i_qp_max = 51;

   
param->rc.i_qp_step = 4;

   
param->rc.f_ip_factor = 1.4;

   
param->rc.f_pb_factor = 1.3;

 

   
param->rc.b_stat_write = 0;

   
param->rc.psz_stat_out = "x264_2pass.log";

   
param->rc.b_stat_read = 0;

   
param->rc.psz_stat_in = "x264_2pass.log";

   
param->rc.psz_rc_eq = "blurCplx^(1-qComp)";

   
param->rc.f_qcompress = 1.0;

   
param->rc.f_qblur = 1.0;

   
param->rc.f_complexity_blur = 20;

 

   
/* Log */

   
param->pf_log = x264_log_default;

   
param->p_log_private = NULL;

   
param->i_log_level = X264_LOG_NONE;

 

  
 
/* */

   
param->analyse.intra = X264_ANALYSE_I4x4;//


幀內預測模式

   
param->analyse.inter = X264_ANALYSE_I4x4 | X264_ANALYSE_PSUB16x16 | X264_ANALYSE_BSUB16x16; //


幀間預測模式

   
param->analyse.i_direct_mv_pred = X264_DIRECT_PRED_TEMPORAL;

   
param->analyse.i_me_method = X264_ME_DIA;//


好像是運動補償的演算法選擇

   
param->analyse.i_me_range = 8;
// me


為
umh/esa

時的搜尋半徑（以像素位單位），最大
64

，預設
16

   
param->analyse.i_subpel_refine = 3;//


亞像素搜尋範圍

   
param->analyse.b_chroma_me = 1;

   
param->analyse.i_mv_range = 512;//


運動向量搜尋範圍

   
param->analyse.i_chroma_qp_offset = 0;
//


色度和亮度之間的量化差
,

範圍
-12~+12

，預設
0

   
param->analyse.b_psnr = 0;//


是否使用信噪比

 

   
param->b_aud = 0;

}