<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Wow, it got merged (the EDTS version). Nice and thanks!<div class="">( <a href="https://github.com/nginx/nginx/commit/7927071ee26ff6313301b744a90240dccbc836db" class="">https://github.com/nginx/nginx/commit/7927071ee26ff6313301b744a90240dccbc836db</a> )</div><div class=""><br class=""></div><div class="">Thanks for filing the Firefox bug and following up with it, Roman.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">I can move our live services over to the updated nginx once FF fixes the bug (and some time goes by).</div><div class="">(No worries, that’s probably about when ubuntu nginx version will get updated, hehe).</div><div class=""><br class=""></div><div class="">I haven’t seen timescales like 24 before here in the US (esp. w/ TV - but I believe very rare otherwise out here).</div><div class="">Glad you found a good solution.</div><div class=""><div class=""><br class=""></div><div class="">I’m really looking forward to the new:</div><div class=""> start_key_frame</div><div class="">directive!</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">You might find this hopefully amusing, but I gave a talk at Demuxed 2021 October 7th, titled:</div><div class=""> "30,000 fps nginx - To Russia with Love”</div><div class="">while things were before the EDTS solution you all found and worked out.</div><div class="">(Video should hit YouTube by end of 2021).</div><div class=""><br class=""></div><div class="">Kind regards & gratefully!</div><div class="">- Tracey</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Oct 20, 2021, at 8:32 PM, Maxim Dounin <<a href="mailto:mdounin@mdounin.ru" class="">mdounin@mdounin.ru</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Hello!<br class=""><br class="">On Mon, Oct 04, 2021 at 03:41:47PM -0700, Tracey Jaquith wrote:<br class=""><br class=""><blockquote type="cite" class="">Hi Roman,<br class=""><br class="">OK, thanks!<br class=""><br class="">I’ve tested this on macosx & linux, so far with: chrome, safari, Firefox and iOS.<br class=""><br class="">However, I’m seeing Firefox is having alternate behavior where it plays video from the prior keyframe, <br class="">without audio, until it hits the desired start time in at least one video, though it’s not consistently doing this.<br class="">I suspect it’s the edit list — a nice solve for this. <br class="">I’ve had minor issues with edit lists in the past, for what that’s worth.<br class=""></blockquote><br class="">Thanks for testing. Just for the record:<br class=""><br class=""><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1735300" class="">https://bugzilla.mozilla.org/show_bug.cgi?id=1735300</a><br class=""><br class="">Hopefully this will be eventually fixed.<br class=""><br class="">[...]<br class=""><br class=""><blockquote type="cite" class="">And deep apologies…<br class=""><blockquote type="cite" class="">Another problem is track delay<br class=""></blockquote><br class="">I *should have* mentioned when I initially wrote in, that I was aware of the a/v sync slight slip <br class="">— and that in practice and running for over 3 months now, it hasn’t seemed to be any kind of issue.<br class=""><br class="">Assuming:<br class="">* the average (US TV) video might be 29.97 fps<br class="">* and thus timescale / duration of 30000 / 1001<br class="">* and that a typical max distance between keyframe GOPs w/ ffmpeg encoders and similar is 300 frames or about 10s<br class=""><br class="">Then:<br class="">* with a max of 10s between keyframes<br class="">* and 300 frames max would get “sped up” from 1001 => 1<br class=""><br class="">Then we’re looking at a maximum additional video frames duration of 1/100th of a second.<br class=""><br class="">(300 * 1001 / 30000) == 10.01<br class=""><br class="">(300 * 1 / 30000) == 0.01<br class=""><br class="">So the most the A/V sync could “drift” from those early added frames is 1/100th of a second, <br class="">where average might be 2-3x smaller than that.<br class="">In practice, it didn’t seem noticeable — <br class="">but I am quite impressed by your desire to minimize/eliminate that.<br class="">(In practice, from the broadcasters at least in the US, 1/100th of a second A/V slip is not uncommon).<br class=""></blockquote><br class="">While it looks quite well with timescale 30000, it is not uncommon <br class="">for video tracks to have timescale 25 or so. For example, the <br class="">test video in the ticket linked above uses timescale 24. With <br class="">such a timescale, resulting desync will be much more noticeable.<br class=""><br class="">-- <br class="">Maxim Dounin<br class="">http://mdounin.ru/<br class="">_______________________________________________<br class="">nginx-devel mailing list<br class="">nginx-devel@nginx.org<br class="">http://mailman.nginx.org/mailman/listinfo/nginx-devel</div></div></blockquote></div><br class=""><div class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">-Tracey</div><div class="">@tracey_pooh</div><div class="">TV Architect <a href="https://archive.org/tv" class="">https://archive.org/tv</a></div></div></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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