<link>http://people.skolelinux.org/pere/blog/</link>
+ <item>
+ <title>Measuring and adjusting the loudness of a TV channel using bs1770gain</title>
+ <link>http://people.skolelinux.org/pere/blog/Measuring_and_adjusting_the_loudness_of_a_TV_channel_using_bs1770gain.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Measuring_and_adjusting_the_loudness_of_a_TV_channel_using_bs1770gain.html</guid>
+ <pubDate>Thu, 11 Jun 2015 13:40:00 +0200</pubDate>
+ <description><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>
+</description>
+ </item>
+
<item>
<title>Hva gjør at NRK kan distribuere H.264-video uten patentavtale med MPEG LA?</title>
<link>http://people.skolelinux.org/pere/blog/Hva_gj_r_at_NRK_kan_distribuere_H_264_video_uten_patentavtale_med_MPEG_LA_.html</link>
projects / homepage.git / blobdiff