Hi, Aruna, Alex, So, if I'll just setup vbv-init=0.5:vbv-end=0.5 for separated encoding sessions -- there will be correct settings and buffer overflow should not be expected, right?
About frame number - as far as we measured there is non-linear dependency of encoding speed against GOP length, so we're have to use something about 25-50 frames in VBV adjustment. 2018-03-07 23:05 GMT+03:00 Alex Giladi <alex.gil...@gmail.com>: > Hi Vassily, > I would also add that you need to set a reasonable amount of frames for > the VBV adjustment, otherwise your last frames may suffer quality-wise. > Best, > Alex. > > On Wed, Mar 7, 2018 at 9:28 AM, Aruna Matheswaran < > ar...@multicorewareinc.com> wrote: > >> Hi, >> >> vbv-init specifies the portion of the vbv buffer which must be >> available before the encoder begins encoding and * vbv-end* denotes the >> portion of the vbv buffer that must be available after all the specified >> frames have been inserted into the vbv buffer. >> Therefore, while encoding multiple chunks in parallel and merging them >> into a single stream, *vbv-init of any chunk should be the same as the >> vbv-end of its previous chunk*. If vbv-end of chunk X is less than >> vbv-init of chunk X+1, there are chances for the buffer to overflow. >> >> Thanks, >> Aruna >> >> On Wed, Mar 7, 2018 at 4:43 PM, Vasiliy Volkov <volk.vasi...@gmail.com> >> wrote: >> >>> Hi, >>> >>> Recently libx265 gets vbv-end encoding option with comment that it can >>> be used for chunked encoding. My question is how it can be used? >>> >>> Recently we've split our encoding session into multiple processes -- so >>> multiple instances of libx265 encoder encodes same stream, GOP by GOP, and >>> then such stream merges into single stream again. It works well, but rate >>> controllers are not share their states between encoders instances and I >>> think such encoding is not VBV-compliant. >>> And from comment to vbv-end option I think that it can fix it encoding. >>> >>> Can somebody explain how this option should be used and how it can helps >>> us (or maybe not and we need to find another solution)? >>> >>> For example, we use such encoding options: >>> bitrate=4500:bufsize=10000:maxrate=5000, >>> and in such setup vbv-init by default is 0.9 >>> >>> For this setup what we need to specify for vbv-end? >>> >>> >>> >>> _______________________________________________ >>> x265-devel mailing list >>> email@example.com >>> https://mailman.videolan.org/listinfo/x265-devel >>> >>> >> >> _______________________________________________ >> x265-devel mailing list >> firstname.lastname@example.org >> https://mailman.videolan.org/listinfo/x265-devel >> >> > > _______________________________________________ > x265-devel mailing list > email@example.com > https://mailman.videolan.org/listinfo/x265-devel > >
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