- <title>Measuring the speaker frequency response using the AUDMES free software GUI - nice free software</title>
- <link>http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html</guid>
- <pubDate>Mon, 22 Oct 2018 08:40:00 +0200</pubDate>
- <description><p><img src="http://people.skolelinux.org/pere/blog/images/2018-10-22-audmes-measure-speakers.png" align="right" width="40%"/></p>
-
-<p>My current home stereo is a patchwork of various pieces I got on
-flee markeds over the years. It is amazing what kind of equipment
-show up there. I've been wondering for a while if it was possible to
-measure how well this equipment is working together, and decided to
-see how far I could get using free software. After trawling the web I
-came across an article from DIY Audio and Video on
-<a href="https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/">Speaker
-Testing and Analysis</a> describing how to test speakers, and it listing
-several software options, among them
-<a href="https://sourceforge.net/projects/audmes/">AUDio MEasurement
-System (AUDMES)</a>. It is the only free software system I could find
-focusing on measuring speakers and audio frequency response. In the
-process I also found an interesting article from NOVO on
-<a href="http://novo.press/understanding-speaker-specifications-and-frequency-response/">Understanding
-Speaker Specifications and Frequency Response</a> and an article from
-ecoustics on
-<a href="https://www.ecoustics.com/articles/understanding-speaker-frequency-response/">Understanding
-Speaker Frequency Response</a>, with a lot of information on what to
-look for and how to interpret the graphs. Armed with this knowledge,
-I set out to measure the state of my speakers.</p>
-
-<p>The first hurdle was that AUDMES hadn't seen a commit for 10 years
-and did not build with current compilers and libraries. I got in
-touch with its author, who no longer was spending time on the program
-but gave me write access to the subversion repository on Sourceforge.
-The end result is that now the code build on Linux and is capable of
-saving and loading the collected frequency response data in CSV
-format. The application is quite nice and flexible, and I was able to
-select the input and output audio interfaces independently. This made
-it possible to use a USB mixer as the input source, while sending
-output via my laptop headphone connection. I lacked the hardware and
-cabling to figure out a different way to get independent cabling to
-speakers and microphone.</p>
-
-<p>Using this setup I could see how a large range of high frequencies
-apparently were not making it out of my speakers. The picture show
-the frequency response measurement of one of the speakers. Note the
-frequency lines seem to be slightly misaligned, compared to the CSV
-output from the program. I can not hear several of these are high
-frequencies, according to measurement from
-<a href="http://freehearingtestsoftware.com">Free Hearing Test
-Software</a>, an freeware system to measure your hearing (still
-looking for a free software alternative), so I do not know if they are
-coming out out the speakers. I thus do not quite know how to figure
-out if the missing frequencies is a problem with the microphone, the
-amplifier or the speakers, but I managed to rule out the audio card in my
-PC by measuring my Bose noise canceling headset using its own
-microphone. This setup was able to see the high frequency tones, so
-the problem with my stereo had to be in the amplifier or speakers.</p>
-
-<p>Anyway, to try to role out one factor I ended up picking up a new
-set of speakers at a flee marked, and these work a lot better than the
-old speakers, so I guess the microphone and amplifier is OK. If you
-need to measure your own speakers, check out AUDMES. If more people
-get involved, perhaps the project could become good enough to
-<a href="https://bugs.debian.org/910876">include in Debian</a>? And if
-you know of some other free software to measure speakers and amplifier
-performance, please let me know. I am aware of the freeware option
-<a href="https://www.roomeqwizard.com/">REW</a>, but I want something
-that can be developed also when the vendor looses interest.</p>
+ <title>What would it cost to store all 2018 phone calls in Norway?</title>
+ <link>http://people.skolelinux.org/pere/blog/What_would_it_cost_to_store_all_2018_phone_calls_in_Norway_.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/What_would_it_cost_to_store_all_2018_phone_calls_in_Norway_.html</guid>
+ <pubDate>Mon, 25 Nov 2019 20:15:00 +0100</pubDate>
+ <description><p>Four years ago, I did a back of the envelope calculation on
+<a href="http://people.skolelinux.org/pere/blog/What_would_it_cost_to_store_all_phone_calls_in_Norway_.html">how
+much it would cost to store audio recordings of all the phone calls in
+Norway</a>, and came up with NOK 2.1 million / EUR 250 000 for the
+year 2013. It is time to repeat the calculation using updated
+numbers. The calculation is based on how much data storage is needed
+for each minute of audio, how many minutes all the calls in Norway
+sums up to, multiplied by the cost of data storage.</p>
+
+<p>The number of phone call minutes for 2018 was fetched from
+<a href="https://ekomstatistikken.nkom.no/">the NKOM statistics
+site</a>, and for 2018, land line calls are listed as 434 238 000
+minutes, while mobile phone calls are listed with 7 542 006 000
+minutes. The total number of minutes is thus 7 976 244 000. For
+simplicity, I decided to ignore any advantages in audio compression the
+last four years, and continue to assume 60 Kbytes/min as the last
+time.</p>
+
+<p>Storage prices still varies a lot, but as last time, I decide to
+take a reasonable big and cheap hard drive, and double its price to
+include the surrounding costs into account. A 10 TB disk cost less
+than 4500 NOK / 450 EUR these days, and doubling it give 9000 NOK per
+10 TB.</p>
+
+<p>So, with the parameters in place, lets update the old table
+estimating cost for calls in a given year:</p>
+
+<table border="1">
+<tr><th>Year</th><th>Call minutes</th><th>Size</th><th>Price in NOK / EUR</th></tr>
+<tr><td>2005</td><td align="right">24 000 000 000</td><td align="right">1.3 PiB</td><td align="right">1 170 000 / 117 000</td></tr>
+
+<tr><td>2012</td><td align="right">18 000 000 000</td><td align="right">1.0 PiB</td><td align="right">900 000 / 90 000</td></tr>
+
+<tr><td>2013</td><td align="right">17 000 000 000</td><td align="right">950 TiB</td><td align="right">855 000 / 85 500</td></tr>
+
+<tr><td>2018</td><td align="right">7 976 244 000</td><td align="right">445 TiB</td><td align="right">401 100 / 40 110</td></tr>
+</table>
+
+<p>Both the cost of storage and the number of phone call minutes have
+dropped since the last time, bringing the cost down to a level where I
+guess even small organizations can afford to store the audio recording
+from every phone call taken in a year in Norway. Of course, this is
+just the cost of buying the storage equipment. Maintenance, need to
+be included as well, but the volume of a single year is about a single
+rack of hard drives, so it is not much more than I could fit in my own
+home. Wonder how much the electricity bill would raise if I had that
+kind of storage? I doubt it would be more than a few tens of thousand
+NOK per year.</p>
+</description>
+ </item>
+
+ <item>
+ <title>Norwegian movies that might be legal to share on the Internet</title>
+ <link>http://people.skolelinux.org/pere/blog/Norwegian_movies_that_might_be_legal_to_share_on_the_Internet.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Norwegian_movies_that_might_be_legal_to_share_on_the_Internet.html</guid>
+ <pubDate>Sun, 1 Sep 2019 11:10:00 +0200</pubDate>
+ <description><p>While working on identifying and counting movies that can be
+legally shared on the Internet, I also looked at the Norwegian movies
+listed in IMDb. So far I have identified 54 candidates published
+before 1940 that might no longer be protected by norwegian copyright
+law. Of these, only 29 are available at least in part from the
+Norwegian National Library. It can be assumed that the remaining 25
+movies are lost. It seem most useful to identify the copyright status
+of movies that are not lost. To verify that the movie is really no
+longer protected, one need to verify the list of copyright holders and
+figure out if and when they died. I've been able to identify some of
+them, but for some it is hard to figure out when they died.</p>
+
+</p>This is the list of 29 movies both available from the library and
+possibly no longer protected by copyright law. The year range
+(1909-1979 on the first line) is year of publication and last year
+with copyright protection.</p>
+
+<pre>
+1909-1979 ( 70 year) NSB Bergensbanen 1909 - http://www.imdb.com/title/tt0347601/
+1910-1980 ( 70 year) Bjørnstjerne Bjørnsons likfærd - http://www.imdb.com/title/tt9299304/
+1910-1980 ( 70 year) Bjørnstjerne Bjørnsons begravelse - http://www.imdb.com/title/tt9299300/
+1912-1998 ( 86 year) Roald Amundsens Sydpolsferd (1910-1912) - http://www.imdb.com/title/tt9237500/
+1913-2006 ( 93 year) Roald Amundsen på sydpolen - http://www.imdb.com/title/tt0347886/
+1917-1987 ( 70 year) Fanden i nøtten - http://www.imdb.com/title/tt0346964/
+1919-2018 ( 99 year) Historien om en gut - http://www.imdb.com/title/tt0010259/
+1920-1990 ( 70 year) Kaksen på Øverland - http://www.imdb.com/title/tt0011361/
+1923-1993 ( 70 year) Norge - en skildring i 6 akter - http://www.imdb.com/title/tt0014319/
+1925-1997 ( 72 year) Roald Amundsen - Ellsworths flyveekspedition 1925 - http://www.imdb.com/title/tt0016295/
+1925-1995 ( 70 year) En verdensreise, eller Da knold og tott vaskede negrene hvite med 13 sæpen - http://www.imdb.com/title/tt1018948/
+1926-1996 ( 70 year) Luftskibet 'Norge's flugt over polhavet - http://www.imdb.com/title/tt0017090/
+1926-1996 ( 70 year) Med 'Maud' over Polhavet - http://www.imdb.com/title/tt0017129/
+1927-1997 ( 70 year) Den store sultan - http://www.imdb.com/title/tt1017997/
+1928-1998 ( 70 year) Noahs ark - http://www.imdb.com/title/tt1018917/
+1928-1998 ( 70 year) Skjæbnen - http://www.imdb.com/title/tt1002652/
+1928-1998 ( 70 year) Chefens cigarett - http://www.imdb.com/title/tt1019896/
+1929-1999 ( 70 year) Se Norge - http://www.imdb.com/title/tt0020378/
+1929-1999 ( 70 year) Fra Chr. Michelsen til Kronprins Olav og Prinsesse Martha - http://www.imdb.com/title/tt0019899/
+1930-2000 ( 70 year) Mot ukjent land - http://www.imdb.com/title/tt0021158/
+1930-2000 ( 70 year) Det er natt - http://www.imdb.com/title/tt1017904/
+1930-2000 ( 70 year) Over Besseggen på motorcykel - http://www.imdb.com/title/tt0347721/
+1931-2001 ( 70 year) Glimt fra New York og den Norske koloni - http://www.imdb.com/title/tt0021913/
+1932-2007 ( 75 year) En glad gutt - http://www.imdb.com/title/tt0022946/
+1934-2004 ( 70 year) Den lystige radio-trio - http://www.imdb.com/title/tt1002628/
+1935-2005 ( 70 year) Kronprinsparets reise i Nord Norge - http://www.imdb.com/title/tt0268411/
+1935-2005 ( 70 year) Stormangrep - http://www.imdb.com/title/tt1017998/
+1936-2006 ( 70 year) En fargesymfoni i blått - http://www.imdb.com/title/tt1002762/
+1939-2009 ( 70 year) Til Vesterheimen - http://www.imdb.com/title/tt0032036/
+</pre>
+
+To be sure which one of these can be legally shared on the Internet,
+in addition to verifying the right holders list is complete, one need
+to verify the death year of these persons:
+
+<pre>
+Bjørnstjerne Bjørnson (dead 1910) - http://www.imdb.com/name/nm0085085/
+Gustav Adolf Olsen (missing death year) - http://www.imdb.com/name/nm0647652/
+Gustav Lund (missing death year) - http://www.imdb.com/name/nm0526168/
+John W. Brunius (dead 1937) - http://www.imdb.com/name/nm0116307/
+Ola Cornelius (missing death year) - http://www.imdb.com/name/nm1227236/
+Oskar Omdal (dead 1927) - http://www.imdb.com/name/nm3116241/
+Paul Berge (missing death year) - http://www.imdb.com/name/nm0074006/
+Peter Lykke-Seest (dead 1948) - http://www.imdb.com/name/nm0528064/
+Roald Amundsen (dead 1928) - https://www.imdb.com/name/nm0025468/
+Sverre Halvorsen (dead 1936) - http://www.imdb.com/name/nm1299757/
+Thomas W. Schwartz (missing death year) - http://www.imdb.com/name/nm2616250/
+</pre>
+
+<p>Perhaps you can help me figuring death year of those missing it, or
+right holders if some are missing in IMDb? It would be nice to have a
+definite list of Norwegian movies that are legal to share on the
+Internet.</p>
+
+</p>This is the list of 25 movies not available from the library and
+possibly no longer protected by copyright law:</p>
+
+<pre>
+1907-2009 (102 year) Fiskerlivets farer - http://www.imdb.com/title/tt0121288/
+1912-2018 (106 year) Historien omen moder - http://www.imdb.com/title/tt0382852/
+1912-2002 ( 90 year) Anny - en gatepiges roman - http://www.imdb.com/title/tt0002026/
+1916-1986 ( 70 year) The Mother Who Paid - http://www.imdb.com/title/tt3619226/
+1917-2018 (101 year) En vinternat - http://www.imdb.com/title/tt0008740/
+1917-2018 (101 year) Unge hjerter - http://www.imdb.com/title/tt0008719/
+1917-2018 (101 year) De forældreløse - http://www.imdb.com/title/tt0007972/
+1918-2018 (100 year) Vor tids helte - http://www.imdb.com/title/tt0009769/
+1918-2018 (100 year) Lodsens datter - http://www.imdb.com/title/tt0009314/
+1919-2018 ( 99 year) Æresgjesten - http://www.imdb.com/title/tt0010939/
+1921-2006 ( 85 year) Det nye year? - http://www.imdb.com/title/tt0347686/
+1921-1991 ( 70 year) Under Polarkredsens himmel - http://www.imdb.com/title/tt0012789/
+1923-1993 ( 70 year) Nordenfor polarcirkelen - http://www.imdb.com/title/tt0014318/
+1925-1995 ( 70 year) Med 'Stavangerfjord' til Nordkap - http://www.imdb.com/title/tt0016098/
+1926-1996 ( 70 year) Over Atlanterhavet og gjennem Amerika - http://www.imdb.com/title/tt0017241/
+1926-1996 ( 70 year) Hallo! Amerika! - http://www.imdb.com/title/tt0016945/
+1926-1996 ( 70 year) Tigeren Teodors triumf - http://www.imdb.com/title/tt1008052/
+1927-1997 ( 70 year) Rød sultan - http://www.imdb.com/title/tt1017979/
+1927-1997 ( 70 year) Søndagsfiskeren Flag - http://www.imdb.com/title/tt1018002/
+1930-2000 ( 70 year) Ro-ro til fiskeskjær - http://www.imdb.com/title/tt1017973/
+1933-2003 ( 70 year) I kongens klær - http://www.imdb.com/title/tt0024164/
+1934-2004 ( 70 year) Eventyret om de tre bukkene bruse - http://www.imdb.com/title/tt1007963/
+1934-2004 ( 70 year) Pål sine høner - http://www.imdb.com/title/tt1017966/
+1937-2007 ( 70 year) Et mesterverk - http://www.imdb.com/title/tt1019937/
+1938-2008 ( 70 year) En Harmony - http://www.imdb.com/title/tt1007975/
+</pre>
+
+<p>Several of these movies completely lack right holder information in
+IMDb and elsewhere. Without access to a copy of the movie, it is
+often impossible to get the list of people involved in making the
+movie, making it impossible to figure out the correct copyright
+status.</p>
+
+<p>Not listed here are the movies still protected by copyright law.
+Their copyright terms varies from 79 to 144 years, according to the
+information I have available so far. One of the non-lost movies might
+change status next year,
+<a href="https://www.imdb.com/title/tt1008007/">Mustads Mono from 1920</a>.
+The next one might be
+<a href="https://www.imdb.com/title/tt0347215/">Hvor isbjørnen ferdes
+from 1935</a> in 2024.</p>