x264中的x264_ratecontrol_t与rc两个速率控制相关的结构体的比较

两个RC结构的比较：

1 x264_t-->x264_ratecontrol_t:

structx264_ratecontrol_t

{

/*constants */

intb_abr;

intb_2pass;

intb_vbv;

intb_vbv_min_rate;

doublefps;

doublebitrate;

doublerate_tolerance;

doubleqcompress;

intnmb;/* number of macroblocksin a frame */

intqp_constant[3];

/*current frame */

ratecontrol_entry_t*rce;

intqp;/* qpfor current frame */

floatqpm;/* qpfor currentmacroblock:precise float for AQ */

floatqpa_rc;/* average of macroblocks'qpbeforeaq*/

floatqpa_rc_prev;

intqpa_aq; /* average of macroblocks'qpafteraq*/

intqpa_aq_prev;

floatqp_novbv;/* QP for the current frame if1-pass VBV was disabled. */

/*VBV stuff */

doublebuffer_size;

int64_tbuffer_fill_final;

doublebuffer_fill;/* planned buffer, if allin-progress frames hit their bit budget */

doublebuffer_rate;/* # of bits added tobuffer_fill after each frame */

doublevbv_max_rate;/* # of bits added to buffer_fillper second */

predictor_t*pred;/* predict frame size from satd*/

intsingle_frame_vbv;

doublerate_factor_max_increment;/* Don't allow RF above (CRF + thisvalue). */

/*ABR stuff */

intlast_satd;

doublelast_rceq;

doublecplxr_sum;/* sum of bits*qscale/rceq*/

doubleexpected_bits_sum;/* sum of qscale2bits after rceq,ratefactor,and overflow, only includes finished frames */

int64_tfiller_bits_sum;/* sum in bits of finished frames'filler data */

doublewanted_bits_window;/* target bitrate* window */

doublecbr_decay;

doubleshort_term_cplxsum;

doubleshort_term_cplxcount;

doublerate_factor_constant;

doubleip_offset;

doublepb_offset;

/*2pass stuff */

FILE*p_stat_file_out;

char*psz_stat_file_tmpname;

FILE*p_mbtree_stat_file_out;

char*psz_mbtree_stat_file_tmpname;

char*psz_mbtree_stat_file_name;

FILE*p_mbtree_stat_file_in;

intnum_entries;/* number ofratecontrol_entry_ts */

ratecontrol_entry_t*entry;/*FIXME:copy needed data and free this onceinitis done */

doublelast_qscale;

doublelast_qscale_for[3];/* last qscalefor a specificpicttype, used for max_diff &ipbfactor stuff */

intlast_non_b_pict_type;

doubleaccum_p_qp;/* for determining I-framequant*/

doubleaccum_p_norm;

doublelast_accum_p_norm;

doublelmin[3];/* minqscaleby frame type */

doublelmax[3];

doublelstep;/* max change (multiply) inqscaleper frame */

struct

{

uint16_t*qp_buffer[2];/* Global buffers for converting MB-treequantizer data. */

intqpbuf_pos;/* In order to handle pyramidreordering, QP buffer acts as a stack.

*This value is the current position (0 or 1). */

intsrc_mb_count;

/*Forrescaling*/

intrescale_enabled;

float*scale_buffer[2];/* Intermediate buffers */

intfiltersize[2];/* filter size (H/V) */

float*coeffs[2];

int*pos[2];

intsrcdim[2];/* Source dimensions (W/H) */

}mbtree;

/*MBRC stuff */

floatframe_size_estimated;/* Access to this variable must beatomic: double is

*not atomic on all arches we care about */

doubleframe_size_maximum;/* Maximum frame size due to MinCR */

doubleframe_size_planned;

doubleslice_size_planned;

predictor_t(*row_pred)[2];

predictor_trow_preds[3][2];

predictor_t*pred_b_from_p;/* predict B-frame size from P-framesatd*/

intbframes;/* # consecutive B-framesbefore this P-frame */

intbframe_bits;/* total cost of those frames*/

inti_zones;

x264_zone_t*zones;

x264_zone_t*prev_zone;

/*hrdstuff */

intinitial_cpb_removal_delay;

intinitial_cpb_removal_delay_offset;

doublenrt_first_access_unit;/* nominal removal time */

doubleprevious_cpb_final_arrival_time;

uint64_thrd_multiply_denom;

};

2 x264_t-->x264_param_t-->rc

/*Rate control parameters */

struct

{

inti_rc_method;/* X264_RC_* */

inti_qp_constant;/* 0 to (51 + 6*(x264_bit_depth-8)).0=lossless*/

inti_qp_min; /* minallowed QP value */

inti_qp_max; /* max allowed QP value */

inti_qp_step; /* max QP step between frames */

inti_bitrate;

floatf_rf_constant;/* 1pass VBR, nominal QP */

floatf_rf_constant_max;/* In CRF mode, maximum CRF as causedby VBV */

floatf_rate_tolerance;

inti_vbv_max_bitrate;

inti_vbv_buffer_size;

floatf_vbv_buffer_init;/* <=1: fraction of buffer_size. >1:kbit*/

floatf_ip_factor;

floatf_pb_factor;

inti_aq_mode; /* psyadaptive QP. (X264_AQ_*) */

floatf_aq_strength;

intb_mb_tree; /* Macroblock-treeratecontrol.*/

inti_lookahead;

/*2pass */

intb_stat_write;/* Enable statwriting in psz_stat_out */

char *psz_stat_out;

intb_stat_read;/* Read statfrom psz_stat_in and use it */

char *psz_stat_in;

/*2passparams(same asffmpegones) */

floatf_qcompress;/* 0.0 => cbr,1.0 => constantqp*/

floatf_qblur; /* temporally blur quants*/

floatf_complexity_blur;/* temporally blur complexity */

x264_zone_t*zones;/* ratecontroloverrides */

inti_zones; /* number of zone_t's */

char *psz_zones;/* alternate method of specifyingzones */

}rc;