ffmpeg+H.265+CBR软编码如何实现？

whitelxl

请教群里的大牛，ffmpeg如何实现libx265的CBR模式软编码？
我试了libx264使用-x264-params nal-hrd=cbr:force-cfr=1就可以实现CBR模式，但nal-hrd=cbr:force-cfr=1在libx265中不生效，请群里面的老师多指教，万分感谢！

孙悟空

[AppleScript] 纯文本查看 复制代码

Bitstream options:
   --[no-]repeat-headers         Emit SPS and PPS headers at each keyframe. Default disabled
   --[no-]info                   Emit SEI identifying encoder and parameters. Default enabled
   --[no-]hrd                    Enable HRD parameters signaling. Default disabled
   --[no-]idr-recovery-sei      Emit recovery point infor SEI at each IDR frame
   --[no-]temporal-layers        Enable a temporal sublayer for unreferenced B frames. Default disabled
   --[no-]aud                    Emit access unit delimiters at the start of each access unit. Default disabled
   --hash <integer>              Decoded Picture Hash SEI 0: disabled, 1: MD5, 2: CRC, 3: Checksum. Default 0
   --atc-sei <integer>           Emit the alternative transfer characteristics SEI message where the integer is the preferred transfer characteristics. Default disabled
   --pic-struct <integer>        Set the picture structure and emits it in the picture timing SEI message. Values in the range 0..12. See D.3.3 of the HEVC spec. for a detailed explanation.
   --log2-max-poc-lsb <integer>  Maximum of the picture order count
   --[no-]vui-timing-info        Emit VUI timing information in the bistream. Default enabled
   --[no-]vui-hrd-info           Emit VUI HRD information in the bistream. Default enabled
   --[no-]opt-qp-pps             Dynamically optimize QP in PPS (instead of default 26) based on QPs in previous GOP. Default disabled
   --[no-]opt-ref-list-length-pps  Dynamically set L0 and L1 ref list length in PPS (instead of default 0) based on values in last GOP. Default disabled
   --[no-]multi-pass-opt-rps     Enable storing commonly used RPS in SPS in multi pass mode. Default disabled
   --[no-]opt-cu-delta-qp        Optimize to signal consistent CU level delta QPs in frame. Default disabled

看x265的帮助信息里面是这样的，会不会使用姿势变了？

whitelxl

x265里面是这样的参数形式-x265-params strict-cbr=1，我现在输出整片是CBR形式了，可是切片输出就成VBR了，请大师兄指教，谢谢。
ffmpeg -i 1.ts -b:v 4000k -muxrate 4000k -c:v libx265 -x265-params strict-cbr=1:vbv-maxrate=4000:vbv-bufsize=4000  -c:a copy -t 20 -hls_time 10 out.m3u8

whitelxl

孙悟空 发表于 2022-7-4 16:00
[mw_shl_code=applescript,true]Bitstream options:
   --[no-]repeat-headers         Emit SPS and PPS h ...

谢谢大师兄！
是的，x265里面是这样的参数形式-x265-params strict-cbr=1，我现在输出整片是CBR形式了，可是切片输出就成VBR了，请大师兄指教，谢谢。
我的命令如下：
ffmpeg -i 1.ts -b:v 4000k -muxrate 4000k -c:v libx265 -x265-params strict-cbr=1:vbv-maxrate=4000:vbv-bufsize=4000  -c:a copy -t 20 -hls_time 10 out.m3u8

孙悟空

whitelxl 发表于 2022-7-5 14:14
谢谢大师兄！
是的，x265里面是这样的参数形式-x265-params strict-cbr=1，我现在输出整片是CBR形式了， ...

vbr的话，可能还是和压缩方式有关系，可以考虑控制vbv buffer. max rate 和min rate做到实际控制