ffmpeg vp8 编码参数对照

ffmpeg VP8 encoding options

Latest version hereoptiondescriptionvalues-vbtarget bitrate -qualityEncoder speed/quality and cpu usebest, good, realtime-speedCPU Used(-16..16)-rc_init_occupancynumber of bits which should be loaded into the rc buffer before decoding starts -rc_buf_aggressivity"currently useless", buffer use aggressiveness -bufsizeratecontrol buffer size (in bits) -passPass to execute (1/2) -passlogfileFirst pass statistics file name -vframesStop encoding after n input frames -minrateMinimal bitrate allowed in vbr/2pass mode -maxrateMaxium bitrate allowed in vbr/2pass mode -btbitrate tolerance in VBR/2pass mode -qmin (valid values 0-63, recommended value 0-4)-qmax (valid values --min-q to 63, recommended value 50-63)-qcomp float 0 - 1, 0 = CBR, 1 = VBR, (default 0.5)-gMinimum keyframe interval (frames) -keyint_minMaximum keyframe interval (frames) -vp8flags=+altrefAllow alternate reference frames -rc_lookaheadnumber of frames to look ahead for when encoding, 0 no limit0-25-arnr_max_framesax frames used in creating alt. ref. -arnr_strengthStrength of the temporal filter used in altref0-6-arnr_typealtref noise reduction filter type(1-3) 1 Backward Blur, 2 Forward Blur, 3 Center Blur (default)-slicesdirects the encoder to split the coefficient encoding across multiple data partitions that can be encoded independently. At the moment this parameter is interpreted as follows (1 = 1 coefficient partition, 2 = 2 partitions, 4 = 4 partitions, 8 = 8 partitions)1,2,4,8: recommended 1 for small images, 4 or 8 for HD-threadsnumber of threads to use for encoding, can't be 0 [auto] with VP8(recommended value : number of real cores - 1)-skip_thresholdTemporal resampling threshold (buf %)(0=disabled to 100)-rc_resize_allowedSpatial resampling enabled (bool)(0 disabled, 1 enabled)-rc_resize_downSpatial resampling down watermark, percentage of target data buffer.(0-100)-rc_resize_upSpatial resampling up watermark, percentage of target data buffer.(--resize-down-100)-vp8flags=+error_resilientEnable error resiliency features(0 disabled, 1 enabled <default 0>)-mb_thresholdThe static threshold imposes a change threshold on blocks below which they will be skipped by the encoder. This can be used to suppress signal noise and enhance the encode speed in situations where there are low levels of real movement. Values of above 1000 are not recommended and any non zero value runs the risk of introducing artifacts caused by regions of the image not being updated. In most scenarios this value should be set to 0.-profileBitstream profile number to use; reduce complexity if > 0(0-3: default and recommended value = 0)-sharpnessAnything above 0 weakens the deblocking effect of the loop filter.(0-7 : default and recommended value = 0)-nrcrude temporal noise filter.(0-6: default and recommended value = 0)-rc_buf_aggressivityundershoot target bitrate for each frame by x percent(valid float 0.1-1)-crfenables constant quality mode and sets quality(0-63) lower values are better quality

if anything is missing please send me a note j at xiph dot org

转自http://people.xiph.org/~j/ffmpeg.html