深圳建设 骏域网站建设专家,做公众号首图网站,查企业公司用什么软件,广州网站制作网页X264学习笔记#xff08;1#xff09; X264编码流程 参数的初始化 1.opt#xff0c;param根据输入的参数和标准的规定#xff0c;进行初始化设置。 Opt的说明如下#xff1a; Opt-hin用于给出读入的yuv文件的指针地址 Opt-hout给出了输出的文件的指针地址 Opt-1 X264编码流程 参数的初始化 1.optparam根据输入的参数和标准的规定进行初始化设置。 Opt的说明如下 Opt-hin用于给出读入的yuv文件的指针地址 Opt-hout给出了输出的文件的指针地址 Opt-i_seek给出了起始编码帧的帧数是由编码时的seek命令参数决定的 如 X264 -seek 10 -o foreman.cif test.264 352x288 i_seek 设为10表示起始编码的帧为元序列的第十帧 Opt-qpfile按照说明为qp值文件输入进行定义这种方式的接口可以通过读入标准的文件格式对编码时的qp值进行定义。 Param的说明 typedef struct { /* CPU flags */ unsigned int cpu; int i_threads; /* divide each frame into multiple slices, encode in parallel */线程数用于多线程并行编码 /* Video Properties */ int i_width; 图像的宽度 int i_height; 图像的高度 int i_csp; /* CSP of encoded bitstream, only i420 supported */ 色彩空间的设置 int i_level_idc; level 值的设置 int i_frame_total; /* number of frames to encode if known, else 0 */ 总共需要编码的帧数由--frames设置 Vui参数集 struct { /* they will be reduced to be 0 x 65535 and prime */ int i_sar_height; int i_sar_width; int i_overscan; /* 0undef, 1no overscan, 2overscan */ /* see h264 annex E for the values of the following */ int i_vidformat; int b_fullrange; int i_colorprim; int i_transfer; int i_colmatrix; int i_chroma_loc; /* both top bottom */ } vui; int i_fps_num; int i_fps_den; 这两个参数是由fps帧率确定的赋值的过程见下 { float fps; if( sscanf( value, %d/%d, p-i_fps_num, p-i_fps_den ) 2 ) ; else if( sscanf( value, %f, fps ) ) { p-i_fps_num (int)(fps * 1000 .5); p-i_fps_den 1000; } else b_error 1; } Value的值就是fps。 /* Bitstream parameters */ int i_frame_reference; /* Maximum number of reference frames */ int i_keyint_max; /* Force an IDR keyframe at this interval */ int i_keyint_min; /* Scenecuts closer together than this are coded as I, not IDR. */ int i_scenecut_threshold; /* how aggressively to insert extra I frames */ int i_bframe; /* how many b-frame between 2 references pictures */ int b_bframe_adaptive; int i_bframe_bias; int b_bframe_pyramid; /* Keep some B-frames as references */ 去块滤波器需要的参数 int b_deblocking_filter; int i_deblocking_filter_alphac0; /* [-6, 6] -6 light filter, 6 strong */ int i_deblocking_filter_beta; /* [-6, 6] idem */ 熵编码 int b_cabac; int i_cabac_init_idc; 量化 int i_cqm_preset; char *psz_cqm_file; /* JM format */ uint8_t cqm_4iy[16]; /* used only if i_cqm_preset X264_CQM_CUSTOM */ uint8_t cqm_4ic[16]; uint8_t cqm_4py[16]; uint8_t cqm_4pc[16]; uint8_t cqm_8iy[64]; uint8_t cqm_8py[64]; /* Log */ void (*pf_log)( void *, int i_level, const char *psz, va_list ); void *p_log_private; int i_log_level; int b_visualize; /* Encoder analyser parameters */ struct { unsigned int intra; /* intra partitions */ unsigned int inter; /* inter partitions */ int b_transform_8x8; int b_weighted_bipred; /* implicit weighting for B-frames */ int i_direct_mv_pred; /* spatial vs temporal mv prediction */ int i_chroma_qp_offset; int i_me_method; /* motion estimation algorithm to use (X264_ME_*) */ int i_me_range; /* integer pixel motion estimation search range (from predicted mv) */ int i_mv_range; /* maximum length of a mv (in pixels) */ int i_subpel_refine; /* subpixel motion estimation quality */ int b_bidir_me; /* jointly optimize both MVs in B-frames */ int b_chroma_me; /* chroma ME for subpel and mode decision in P-frames */ int b_bframe_rdo; /* RD based mode decision for B-frames */ int b_mixed_references; /* allow each mb partition in P-frames to have its own reference number */ int i_trellis; /* trellis RD quantization */ int b_fast_pskip; /* early SKIP detection on P-frames */ int b_dct_decimate; /* transform coefficient thresholding on P-frames */ int i_noise_reduction; /* adaptive pseudo-deadzone */ int b_psnr; /* Do we compute PSNR stats (save a few % of cpu) */ } analyse; /* Rate control parameters */ struct { int i_rc_method; /* X264_RC_* */ int i_qp_constant; /* 0-51 */ int i_qp_min; /* min allowed QP value */ int i_qp_max; /* max allowed QP value */ int i_qp_step; /* max QP step between frames */ int i_bitrate; 比特率 --bitrate控制 int i_rf_constant; /* 1pass VBR, nominal QP */ float f_rate_tolerance; int i_vbv_max_bitrate; int i_vbv_buffer_size; float f_vbv_buffer_init; float f_ip_factor; float f_pb_factor; /* 2pass */ int b_stat_write; /* Enable stat writing in psz_stat_out */ char *psz_stat_out; int b_stat_read; /* Read stat from psz_stat_in and use it */ char *psz_stat_in; /* 2pass params (same as ffmpeg ones) */ char *psz_rc_eq; /* 2 pass rate control equation */ float f_qcompress; /* 0.0 cbr, 1.0 constant qp */ float f_qblur; /* temporally blur quants */ float f_complexity_blur; /* temporally blur complexity */ x264_zone_t *zones; /* ratecontrol overrides */ int i_zones; /* sumber of zone_ts */ char *psz_zones; /* alternate method of specifying zones */ } rc; /* Muxing parameters */ int b_aud; /* generate access unit delimiters */ int b_repeat_headers; /* put SPS/PPS before each keyframe */ int i_sps_id; /* SPS and PPS id number */ } x264_param_t;
