Ojisan Seiuchi

Halema'uma'u eruption and stars

(Sony A7 35/2.8 Zeiss)

One of the great things about shooting with a camera like the Sony A7 that has an advanced sensor is that you can shoot astrophotographs with less noise that ever before. This comes into play with the inevitably long exposures you encounter when shooting the night sky. On a recent trip to view Kilauea volcano as we’ve done many times, I wondered if it might be possible to capture both the volcano and the star-filled sky in the same shot; so I began to research a bit on astrophotography. I’m by no means an expert; but I’ve learned a bit.

Concatenating mp4 video files

May 08, 2015

Miscellaneous

I recently shot a recital with my Sony A7. While it’s a wonderful camera for stills and it produces some excellent video too, cameras like this are not meant for continuous video recording. There are limitations that are imposed by compression algorithm licensing requirements. And, it seems, there are limits that are imposed by thermal issues inside the camera.

To make a long story short, my A7 ended up giving me two video files instead of one for this event. What to do?

First I thought of making a round-trip through iMovie; but I so dislike that confusing dumbed-down piece of software that I’d rather doing anything other than that. Fortunately I stumbled upon ffmpeg.

Installing Homebrew and `ffmpeg`

On OS X, the easiest way to install ffmpeg is to use Homebrew. I do. I’m not going to walk through all of the steps for installing Homebrew as they are published elsewhere.

After installing Homebrew, you’ll need to install ffmpeg. I followed another set of instructions. I started by looking at all of the installation options available for ffmpeg:

~|⇒ brew options ffmpeg

Not being a audio/video codec guy, I found it too confusing; so I cut and pasted the command to install ffmpeg with all of the options:

brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-frei0r --with-libass --with-libvo-aacenc --with-libvorbis --with-libvpx --with-opencore-amr --with-openjpeg --with-opus --with-rtmpdump --with-schroedinger --with-speex --with-theora --with-tools

Concatenating files with `ffmpeg`

Now, you need to create a text file specifying the videos that you wish to join. The paths are relative to the text file path. So, I created a text file on the desktop and called it concatv.txt:

# videos to concatenate
file '2015_04_11_13_49_29.mp4'
file '2015_04_11_13_59_42.mp4'

Now, go to the Terminal (or iTerm like I use) and give the concatenation command for ffmpeg with your specification file and the output location and options:

~|⇒ ffmpeg -f concat -i ~/Desktop/concatv.txt -acodec ac3 -vcodec copy output.mp4

ffmpeg version 2.5 Copyright (c) 2000-2014 the FFmpeg developers
  built on May  7 2015 06:08:38 with Apple LLVM version 6.1.0 (clang-602.0.49) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.5 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libvpx --enable-librtmp --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-aacenc --enable-libass --enable-ffplay --enable-libspeex --enable-libschroedinger --enable-libfdk-aac --enable-libopus --enable-frei0r --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags='-I/usr/local/Cellar/openjpeg/1.5.1_1/include/openjpeg-1.5 ' --enable-nonfree --enable-vda
  libavutil      54. 15.100 / 54. 15.100
  libavcodec     56. 13.100 / 56. 13.100
  libavformat    56. 15.102 / 56. 15.102
  libavdevice    56.  3.100 / 56.  3.100
  libavfilter     5.  2.103 /  5.  2.103
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, concat, from '/Users/alan/Desktop/concatv.txt':
  Duration: N/A, start: 0.000000, bitrate: 15957 kb/s
    Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 15704 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 253 kb/s
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf56.15.102
    Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 15704 kb/s, 29.97 fps, 30k tbn, 30k tbc
    Stream #0:1: Audio: ac3 ([165][0][0][0] / 0x00A5), 48000 Hz, stereo, fltp, 192 kb/s
    Metadata:
      encoder         : Lavc56.13.100 ac3
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (aac (native) -> ac3 (native))
Press [q] to stop, [?] for help
frame= 1660 fps=0.0 q=-1.0 size=  170730kB time=00:00:55.35 bitrate=25266.2kbits/frame= 3300 fps=3299 q=-1.0 size=  338567kB time=00:01:50.07 bitrate=25196.4kbitsframe= 4820 fps=3213 q=-1.0 size=  494783kB time=00:02:40.79 bitrate=25207.8kbitsframe= 6470 fps=3235 q=-1.0 size=  663576kB time=00:03:35.84 bitrate=25184.3kbitsframe= 7880 fps=3152 q=-1.0 size=  808522kB time=00:04:22.89 bitrate=25194.0kbitsframe= 9520 fps=3173 q=-1.0 size=  977105kB time=00:05:17.62 bitrate=25200.8kbitsframe=10920 fps=3119 q=-1.0 size= 1120948kB time=00:06:04.34 bitrate=25203.5kbitsframe=12660 fps=3164 q=-1.0 size= 1298599kB time=00:07:02.38 bitrate=25185.6kbitsframe=14279 fps=3172 q=-1.0 size= 1464549kB time=00:07:56.40 bitrate=25183.4kbitsframe=16030 fps=3205 q=-1.0 size= 1644149kB time=00:08:54.83 bitrate=25183.3kbitsframe=17880 fps=3248 q=-1.0 size= 1833635kB time=00:09:56.56 bitrate=25179.5kbitsframe=19530 fps=3251 q=-1.0 size= 2004140kB time=00:10:51.64 bitrate=25194.7kbitsframe=21080 fps=3239 q=-1.0 size= 2162571kB time=00:11:43.33 bitrate=25188.2kbitsframe=22920 fps=3271 q=-1.0 size= 2351215kB time=00:12:44.73 bitrate=25186.9kbitsframe=24378 fps=3247 q=-1.0 size= 2500568kB time=00:13:33.37 bitrate=25184.6kbitsframe=26090 fps=3258 q=-1.0 size= 2676095kB time=00:14:30.50 bitrate=25183.8kbitsframe=27840 fps=3272 q=-1.0 size= 2856249kB time=00:15:28.89 bitrate=25189.5kbitsframe=29570 fps=3279 q=-1.0 size= 3032933kB time=00:16:26.61 bitrate=25182.8kbitsframe=31130 fps=3271 q=-1.0 size= 3178060kB time=00:17:18.67 bitrate=25065.4kbitsframe=35330 fps=3527 q=-1.0 size= 3182691kB time=00:19:38.81 bitrate=22117.7kbitsframe=39660 fps=3771 q=-1.0 size= 3187472kB time=00:22:03.28 bitrate=19732.5kbitsframe=43280 fps=3928 q=-1.0 size= 3191459kB time=00:24:04.07 bitrate=18104.6kbitsframe=47660 fps=4138 q=-1.0 size= 3196297kB time=00:26:30.22 bitrate=16465.7kbitsframe=50265 fps=4183 q=-1.0 size= 3288092kB time=00:27:57.18 bitrate=16060.2kbitsframe=51955 fps=4151 q=-1.0 size= 3461672kB time=00:28:53.57 bitrate=16358.1kbitsframe=53695 fps=4125 q=-1.0 size= 3640451kB time=00:29:51.63 bitrate=16645.4kbitsframe=55075 fps=4074 q=-1.0 size= 3782069kB time=00:30:37.69 bitrate=16859.6kbitsframe=56841 fps=4055 q=-1.0 size= 3962677kB time=00:31:36.60 bitrate=17116.0kbitsframe=58625 fps=4038 q=-1.0 size= 4145422kB time=00:32:36.13 bitrate=17360.4kbitsframe=60221 fps=4010 q=-1.0 size= 4309072kB time=00:33:29.38 bitrate=17567.5kbitsframe=61865 fps=3986 q=-1.0 size= 4478416kB time=00:34:24.25 bitrate=17772.6kbitsframe=63675 fps=3975 q=-1.0 size= 4663684kB time=00:35:24.63 bitrate=17981.9kbitsframe=65371 fps=3957 q=-1.0 size= 4837570kB time=00:36:21.22 bitrate=18168.4kbitsframe=66712 fps=3920 q=-1.0 size= 4975079kB time=00:37:05.96 bitrate=18309.3kbitsframe=69115 fps=3945 q=-1.0 size= 5090248kB time=00:38:26.14 bitrate=18081.8kbitsframe=73456 fps=4077 q=-1.0 size= 5095040kB time=00:40:51.00 bitrate=17029.2kbitsframe=77825 fps=4202 q=-1.0 size= 5099858kB time=00:43:16.77 bitrate=16088.4kbitsframe=82205 fps=4322 q=-1.0 size= 5104691kB time=00:45:42.91 bitrate=15245.7kbitsframe=86583 fps=4436 q=-1.0 size= 5109513kB time=00:48:08.99 bitrate=14488.5kbitsframe=90945 fps=4543 q=-1.0 size= 5114326kB time=00:50:34.54 bitrate=13806.5kbitsframe=95295 fps=4644 q=-1.0 size= 5119122kB time=00:52:59.68 bitrate=13188.7kbitsframe=98790 fps=4719 q=-1.0 Lsize= 5125570kB time=00:54:56.37 bitrate=12737.8kbits/s
video:5045729kB audio:77259kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.050416%

And you’re done.

Spring has finally arrived in Minnesota. So have dandelions.

On one of our walks, my daughter ViolinGirl exclaimed how much she loved the yellow “daisies” that dot some lawns. She wished our lawn could be covered with these beautiful flowers.

What a strange circumstance! We begin life appreciating the random beauty of these “weeds.” But once we reach adulthood, neighborhood peer pressure and cultural expectations have us spraying toxic chemicals - to our own detriment, no less - to eradicate these cherished flowers.

I have always been troubled in some ill-defined way by articles that assert the benefits of music in some tangible way. For example, kids with music training do better at math. (I don’t if that’s true or not; but you get the style of what I’m talking about.) The unwritten inference is something like this: “No one but a fool or the spectacularly talented would regard music as an economically-valid life path; but math might be. So have your kids play music so they will make good grades and get into an Ivy League school.”

Patricia Cohen’s piece “Middle Class, but Feeling Economically Insecure”¹ published yesterday in the New York Times raises several discrepancies between the economics of the middle class and one’s identification with that group. Reading the comments on the article I was struck by how divided Americans’ points of view are when it comes to the middle class and the causes of its distress. Clearly middle class wages have stagnated in the years immediately preceding and following 9/11. As the article points out, the median income in the US has not risen since 2000. Many of the commenters point to this and the feeling of insecurity and dispensability as a source of middle class angst. Others, fewer in number, point to a change in the baseline spending level. One commenter sums it up this way:

Politics is hopeless arena in which to enact individual values. Commercial interest will always win because of the enormous cost of modern politics. As I’ve written before¹ I think that voting is an inefficient way of effecting change in a way that aligns with personal values. Persons can only be elected when they affiliate themselves with a package of values whose source is largely commercial interest. For example, if I placed the highest values on a balanced federal budget, low defense spending, universal health care, and inclusive rights, who would I vote for?

This is how I do it. YMMV.

I’ve used DEVONthink since its early days. If you’re unfamiliar with DEVONthink, it’s a knowledge management tool that allows you to save information, tag it, cross-reference it and classify it. Since I use both a laptop and a desktop Mac Pro, I need to synchronize databases across machines. There are several ways to go about synchronization:

Direct connection This is not a bad option when both machines are turned on simultaneously and are connected to the same network.
Dropbox Obviously, you need a Dropbox account for this. Since databases can grow quite large, you may need a paid Dropbox account for it. I don’t like having my personal information in the cloud; so I don’t use this option.
WebDAV I don’t run a WebDAV server, so that was out.
Local sync store This was the best option for me, since I use BitTorrent Sync to synchronize certain content between machines using peer-to-peer connections.

Here’s how I do it.

Those darned Republicans just can’t catch a break these days. In the latest cultural eruption, the Indiana legislature passed a bill which its governor signed into law. The bill allows places of business to refuse to serve persons if doing would conflict with their sincerely-held religious beliefs. An avalanche of public outcry has Indiana’s governor making a hasty retreat.

Charles Blow of the New York Times weighs in about how we should deal with the juxtaposition of free exercise of religious beliefs and discrimination:

I use the excellent, dependable Pinboard service for managing my bookmarks. A one-time fee gives you lifetime access to the service; and there is an API that has fostered an ecosystem of desktop and mobile apps that interact with the service. Of course, Safari can synchronize bookmarks among devices; but it doesn’t allow tagging. Since tagging is a major part of my workflow, Safari bookmarks don’t work for me.

The Intergovernmental Panel on Climate Change just released a draft summary of a report to the UN. Unsurprisingly, the panel concluded both that the Earth’s warming is unequivocal but now expressed near certainty that human activity is the cause of the observed and predicted climate shifts.

Given the near universality of scientific opinion on climate change, I’ve begun to wonder what motivates climate change deniers. After all, on most topics, reasonable people who are inexpert in a discipline look to the opinions of experts to gain a better understanding. So what’s behind the extreme rejection of scientific consensus among climate change deniers.

First experience with astrophotography

Halema'uma'u eruption and stars

Concatenating mp4 video files

Installing Homebrew and `ffmpeg`

Concatenating files with `ffmpeg`

Dandelions and innocence

Nietzsche and the sublime purposeless of music

Nietzsche at the piano

Middle class economics and false dichotomies

Private virtues v. public life

Synchronizing DEVONthink databases across machines

This is how I do it. YMMV.

Commerce and discrimination

Spotlight-searchable pinboard bookmarks

What motivates climate change deniers?

Halema'uma'u eruption and stars

Installing Homebrew and ffmpeg

Concatenating files with ffmpeg

Nietzsche at the piano

This is how I do it. YMMV.

Installing Homebrew and `ffmpeg`

Concatenating files with `ffmpeg`