Timo Jyrinki: MotionPhoto / MicroVideo File Formats on Pixel Phones
Google Pixel phones support what they call Motion Photo which is essentially a photo with a short video clip attached to it. They are quite nice since they bring the moment alive, especially as the capturing of the video starts a small moment before the shutter button is pressed. For most viewing programs they simply show as static JPEG photos, but there is more to the files. There are actually two different formats, an old one that is already obsolete, and a newer current format. The older ones are those that your Pixel phone recorded as MVIMG_[datetime].jpg", and they have the following meta-data:
Xmp.GCamera.MicroVideo XmpText 1 1
Xmp.GCamera.MicroVideoVersion XmpText 1 1
Xmp.GCamera.MicroVideoOffset XmpText 7 4022143
Xmp.GCamera.MicroVideoPresentationTimestampUs XmpText 7 1331607
The offset is actually from the end of the file, so one needs to calculate accordingly. But it is exact otherwise, so one simply extract a file with that meta-data information:#!/bin/bash
#
# Extracts the microvideo from a MVIMG_*.jpg file
# The offset is from the ending of the file, so calculate accordingly
offset=$(exiv2 -p X "$1" grep MicroVideoOffset sed 's/.*\"\(.*\)"/\1/')
filesize=$(du --apparent-size --block=1 "$1" sed 's/^\([0-9]*\).*/\1/')
extractposition=$(expr $filesize - $offset)
echo offset: $offset
echo filesize: $filesize
echo extractposition=$extractposition
dd if="$1" skip=1 bs=$extractposition of="$(basename -s .jpg $1).mp4"
Xmp.GCamera.MotionPhoto XmpText 1 1
Xmp.GCamera.MotionPhotoVersion XmpText 1 1
Xmp.GCamera.MotionPhotoPresentationTimestampUs XmpText 6 233320
Xmp.xmpNote.HasExtendedXMP XmpText 32 E1F7505D2DD64EA6948D2047449F0FFA
Xmp.Container.Directory XmpText 0 type="Seq"
Xmp.Container.Directory[1] XmpText 0 type="Struct"
Xmp.Container.Directory[1]/Container:Item XmpText 0 type="Struct"
Xmp.Container.Directory[1]/Container:Item/Item:Mime XmpText 10 image/jpeg
Xmp.Container.Directory[1]/Container:Item/Item:Semantic XmpText 7 Primary
Xmp.Container.Directory[1]/Container:Item/Item:Length XmpText 1 0
Xmp.Container.Directory[1]/Container:Item/Item:Padding XmpText 1 0
Xmp.Container.Directory[2] XmpText 0 type="Struct"
Xmp.Container.Directory[2]/Container:Item XmpText 0 type="Struct"
Xmp.Container.Directory[2]/Container:Item/Item:Mime XmpText 9 video/mp4
Xmp.Container.Directory[2]/Container:Item/Item:Semantic XmpText 11 MotionPhoto
Xmp.Container.Directory[2]/Container:Item/Item:Length XmpText 7 1679555
Xmp.Container.Directory[2]/Container:Item/Item:Padding XmpText 1 0
Sounds like fun and lots of information. However I didn t see why the length in first item is 0 and I didn t see how to use the latter Length info. But I can use the mp4 headers to extract it:#!/bin/bash
#
# Extracts the motion part of a MotionPhoto file PXL_*.MP.mp4
extractposition=$(grep --binary --byte-offset --only-matching --text \
-P "\x00\x00\x00\x18\x66\x74\x79\x70\x6d\x70\x34\x32" $1 sed 's/^\([0-9]*\).*/\1/')
dd if="$1" skip=1 bs=$extractposition of="$(basename -s .jpg $1).mp4"

TLDR: Freexian s success means that we have resources to invest into Debian projects. Plainly offering money has not worked so far, so I am looking to hire a project manager whose work would be to help spend that money in useful ways. At the same time, Freexian needs to adapt to cope with the growth: with new employees, with new infrastructure and a new offering. I want to give an idea of where we are headed, to try to inspire persons that share our values and our desire to improve Debian. Read on if you are interested.
Note: The original text has been split into 4 blog posts that will be published over a few days.
Introduction


Kubernetes is
Too much has been written, a war of support letters is going on, Debian is heading head first like Lemmings into the same war. And then, there is this by the first female President of the American Civil Liberties Union (ACLU):
A long time, no blog entries. What's prompted a new missive?
Two things:
In 14 years since starting this blog, I changed the software several times,
with each iteration simplifying requirements and setup.
Wordpress
In 2007, I
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from 2018, their
The
Ten years ago, I
Today, we are pleased to announce that
I've talked about