<div dir="ltr"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Hi, Aruna, Alex,</span><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">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?</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br class="gmail-Apple-interchange-newline"></div><div>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.</div></div><div class="gmail_extra"><br><div class="gmail_quote">2018-03-07 23:05 GMT+03:00 Alex Giladi <span dir="ltr"><<a href="mailto:alex.giladi@gmail.com" target="_blank">alex.giladi@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Vassily,<div>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.<div>Best,</div><div>Alex.</div></div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Mar 7, 2018 at 9:28 AM, Aruna Matheswaran <span dir="ltr"><<a href="mailto:aruna@multicorewareinc.com" target="_blank">aruna@multicorewareinc.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">

<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Hi,</span><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"> vbv-init<span style="font-weight:bold"> </span>specifies the portion of the vbv buffer which must be available before the encoder begins encoding and <b style="font-weight:400"><span> </span>vbv-end</b><span style="font-weight:400"> </span>denotes the portion of the vbv buffer that must be available after all the specified frames have been inserted into the vbv buffer.</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">Therefore, while encoding multiple chunks in parallel and merging them into a single stream,<span> </span><b>vbv-init of any chunk should be the same as the vbv-end of its previous chunk</b>. If vbv-end of chunk X is less than vbv-init of chunk X+1, there are chances for the buffer to overflow.</div>

<br><div>Thanks,</div><div>Aruna</div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="m_729471185554556130h5">On Wed, Mar 7, 2018 at 4:43 PM, Vasiliy Volkov <span dir="ltr"><<a href="mailto:volk.vasiliy@gmail.com" target="_blank">volk.vasiliy@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="m_729471185554556130h5"><div dir="ltr">Hi,<div><br></div><div>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?</div><div><br></div><div>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.</div><div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">And from comment to vbv-end option I think that it can fix it encoding.</div><br></div><div>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)?</div><div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br class="m_729471185554556130m_8514864066750614274m_-6045188516419633996gmail-Apple-interchange-newline">For example, we use such encoding options: bitrate=4500:bufsize=10000:max<wbr>rate=5000, and in such setup vbv-init by default is 0.9</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial">For this setup what we need to specify for vbv-end?</div><br class="m_729471185554556130m_8514864066750614274m_-6045188516419633996gmail-Apple-interchange-newline"><br></div></div>
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