X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/e0376efaebf5b5cb562fb1f718098ab5646c2744..a884e7517ce4372838bb8a30d89f818ba3b5768a:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index 3b1fcbb4ef..399c27e443 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -6,6 +6,60 @@ http://people.skolelinux.org/pere/blog/ + + Measuring and adjusting the loudness of a TV channel using bs1770gain + http://people.skolelinux.org/pere/blog/Measuring_and_adjusting_the_loudness_of_a_TV_channel_using_bs1770gain.html + http://people.skolelinux.org/pere/blog/Measuring_and_adjusting_the_loudness_of_a_TV_channel_using_bs1770gain.html + Thu, 11 Jun 2015 13:40:00 +0200 + <p>Television loudness is the source of frustration for viewers +everywhere. Some channels are very load, others are less loud, and +ads tend to shout very high to get the attention of the viewers, and +the viewers do not like this. This fact is well known to the TV +channels. See for example the BBC white paper +"<a href="http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP202.pdf">Terminology +for loudness and level dBTP, LU, and all that</a>" from 2011 for a +summary of the problem domain. To better address the need for even +loadness, the TV channels got together several years ago to agree on a +new way to measure loudness in digital files as one step in +standardizing loudness. From this came the ITU-R standard BS.1770, +"<a href="http://www.itu.int/rec/R-REC-BS.1770/en">Algorithms to +measure audio programme loudness and true-peak audio level</a>".</p> + +<p>The ITU-R BS.1770 specification describe an algorithm to measure +loadness in LUFS (Loudness Units, referenced to Full Scale). But +having a way to measure is not enough. To get the same loudness +across TV channels, one also need to decide which value to standardize +on. For European TV channels, this was done in the EBU Recommondaton +R128, "<a href="https://tech.ebu.ch/docs/r/r128.pdf">Loudness +normalisation and permitted maximum level of audio signals</a>", which +specifies a recommended level of -23 LUFS. In Norway, I have been +told that NRK, TV2, MTG and SBS have decided among themselves to +follow the R128 recommondation for playout from 2016-03-01.</p> + +<p>There are free software available to measure and adjust the loudness +level using the LUFS. In Debian, I am aware of a library named +<a href="https://tracker.debian.org/pkg/libebur128">libebur128</a> +able to measure the loudness and since yesterday morning a new binary +named <a href="http://bs1770gain.sourceforge.net">bs1770gain</a> +capable of both measuring and adjusting was uploaded and is waiting +for NEW processing. I plan to maintain the latter in Debian under the +<a href="https://qa.debian.org/developer.php?email=pkg-multimedia-maintainers%40lists.alioth.debian.org">Debian +multimedia</a> umbrella.</p> + +<p>The free software based TV channel I am involved in, +<a href="http://www.frikanalen.no/">Frikanalen</a>, plan to follow the +R128 recommondation ourself as soon as we can adjust the software to +do so, and the bs1770gain tool seem like a good fit for that part of +the puzzle to measure loudness on new video uploaded to Frikanalen. +Personally, I plan to use bs1770gain to adjust the loudness of videos +I upload to Frikanalen on behalf of <a href="http://www.nuug.no/">the +NUUG member organisation</a>. The program seem to be able to measure +the LUFS value of any media file handled by ffmpeg, but I've only +successfully adjusted the LUFS value of WAV files. I suspect it +should be able to adjust it for all the formats handled by ffmpeg.</p> + + + Hva gjør at NRK kan distribuere H.264-video uten patentavtale med MPEG LA? http://people.skolelinux.org/pere/blog/Hva_gj_r_at_NRK_kan_distribuere_H_264_video_uten_patentavtale_med_MPEG_LA_.html @@ -1025,36 +1079,5 @@ know how to fix it using free software.</p> - - The Citizenfour documentary on the Snowden confirmations to Norway - http://people.skolelinux.org/pere/blog/The_Citizenfour_documentary_on_the_Snowden_confirmations_to_Norway.html - http://people.skolelinux.org/pere/blog/The_Citizenfour_documentary_on_the_Snowden_confirmations_to_Norway.html - Sat, 28 Feb 2015 22:10:00 +0100 - <p>Today I was happy to learn that the documentary -<a href="https://citizenfourfilm.com/">Citizenfour</a> by -<a href="https://en.wikipedia.org/wiki/Laura_Poitras">Laura Poitras</a> -finally will show up in Norway. According to the magazine -<a href="http://montages.no/">Montages</a>, a deal has finally been -made for -<a href="http://montages.no/nyheter/snowden-dokumentaren-citizenfour-far-norsk-kinodistribusjon/">Cinema -distribution in Norway</a> and the movie will have its premiere soon. -This is great news. As part of my involvement with -<a href="http://www.nuug.no/">the Norwegian Unix User Group</a>, me and -a friend have -<a href="http://www.nuug.no/news/Dokumentar_om_Snowdenbekreftelsene_til_Norge_.shtml">tried -to get the movie to Norway</a> ourselves, but obviously -<a href="http://www.nuug.no/news/Dokumentar_om_Snowdenbekreftelsene_endelig_til_Norge_.shtml">we -were too late</a> and Tor Fosse beat us to it. I am happy he did, as -the movie will make its way to the public and we do not have to make -it happen ourselves. -<a href="https://www.youtube.com/watch?v=XiGwAvd5mvM">The trailer</a> -can be seen on youtube, if you are curious what kind of film this -is.</p> - -<p>The whistle blower Edward Snowden really deserve political asylum -here in Norway, but I am afraid he would not be safe.</p> - - -