Author Archives: pb

OSCAL 2016: A role model for community events

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This year, I had the honor of being invited to give a talk and workshop at the “Open Source Conference ALbania” (OSCAL) in Tirana, again.
It was simply amazing. Again.

Over the years, I’ve attended many conferences of this kind – as speaker, as well as a visitor.
Yet, the OSCAL-experience from 2015 was quite outstanding in my memory – so my expectations to meet were even higher this year 😉

Community events need the right atmosphere:

Firstly, it’s amazing how well the voluntary team of organizers takes care of the speakers:
They’re not only incredibly nice, friendly and helpful wherever they can, but they just made every single one of us feel appreciated, welcome and being looked after.
It was the most amazing “all-awesome-feelaround-package”, even including pick-up from the airport, and a nice goodie-present with local delicacies.

Maybe it sounds strange to mention this, but this is a community event. Not a trade-show. (Although, there are business opportunities and networking connections to be made there too, of course)

I’ve seen other events like this, were the organizers had not understood that they’re mostly dealing with volunteers (also on the speaker side), who put a lot of their spare-time into this. I’ve been to events where they made you feel like a solicitant. Like you had to serve the organizers and be grateful that you were “allowed” to contribute.
This makes you feel bad – and in consequence, it makes people less interested, less cooperative, less open and greatly reduces the interest of participating next time.

The OSCAL team understood this, and managed to create a great event, where participants as well as contributors felt great:

This encourages people to embrace the ideas of Software Freedom even more, as it generates a great atmosphere where people want to ask, participate, communicate, collaborate and exchange themselves about ideas, projects and visions.

A wide range of interesting subjects:

The conference itself was well-organized, with multiple tracks of presentations, workshops and even “birds of feathers” (BoF) rooms, where participants could arrange ad-hoc meetings or working-groups on different topics.
The selection of topics covered a wide range of interesting subjects – ranging from programming, office or audiovisual – to graphics design.
The FSFE had an info-table with information material, and me standing there, offering additional information where needed.

Tech: Not only a male thing!

Something else thing that makes OSCAL special, is that the male/female ratio seems to be the inverse of what you usually see in our western world:
Just like last year, there were at least as many girls as guys!
Many of the girls there are studying computer science, programming or other subjects – and they’re having great fun.
Check out the speakers list, to see for yourselves.

Usually I keep hearing that “technical stuff is only interesting for men”, or even worse: “women can not understand these things” (and even some female friends of mine believe that).
OSCAL not only proves that this is complete nonsense.
At other “nerd events”, I’ve seen that girls might feel uncomfortable: Not only, because they stand out as rare exception, but also because some guys seem to not take them fully seriously – or even say inappropriate things to them…

So, OSCAL also stands out as a role model here again, when you see how people respectfully interact with each other – regardless of their sexual gender.
Therefore, I’d encourage the rest of the world to learn from Tirana how gender-equality is done better 🙂

After spending only this short time there, I learned that Albanian people will always find a way to make things happen.
You emerge in a world and atmosphere where you feel that anything is possible, if you envision it – and this again attracts and inspires others.

Looking forward to OSCAL 2017! 😀

MAGIX: Rescue Your Videotapes!

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Recently, I’m getting an increased number of requests if the package offered by MAGIX for digitization and archiving of old video tapes is any good.

As technician at the National Video-Archive, I probably have certain demands regarding digitization quality and archive suitability of video material, which might seem “overkill” for most end-users (e.g. lossless codecs).

In order to produce digital copies of analog videos, this product might hardly be underbid.
Yet, I strongly question the long-term archiving properties (and quality) of the output formats of the MAGIX suite.

I’ve done some research regarding this MAGIX product, and I’ve encountered several things that one should know/consider, before buying this product.

Summary / Overview

  • Questionable quality of the analog/digital (A/D) converter
  • Exclusively lossy output formats
  • WMV, as well as optical carriers (DVD, Blu-Ray, etc) are absolutely inadequate as archive format
  • Unclear number of generation losses during record/editing/export

Possible alternative hybrid solution:
Use the MAGIX A/D converter stick with VirtualDub (see below) and FFV1 or DV as video codec. PCM uncompressed for audio.
Store the original export files on harddisks and DVD/Blu-Ray only for access copies.
This enables you to re-create DVD/Blu-Rays later on, in case they decay. Or convert your videos in the future to “then-common” video formats for viewing.
Without additional generation loss.

Supported audio/video formats:
Under “Technical Data > Data Formats“, a list of supported formats for video/audio/image are listed.

The formats listed there are only listed according to their file suffixes (e.g. AVI, MOV, MP3, OGG). This may seem simple(r) on first sight, but it’s lacking concrete information about the actually supported codecs.

A video file always consists (at least) of 3 components:

  1. container
  2. video-codec
  3. audio-codec

Despite the fact, that the list of video formats given by MAGIX is a mixture of container formats (AVI/MOV) and codecs (DV, MPEG-1, MPEG-2, WMV), the only format for file-export is “WMV(HD)”.
Additionally, there is no information given about how the audio is stored.

The list of audio formats only lists lossy (!) codecs like MP3/WMA/Vorbis for import.

Analog-digital (A/D) converter:
The analog video signal is being converted using a small, sweet USB-stick with video inputs.
I was not able to find publicly accessible information about technical details about this converter.

Open questions:

  • Does the A/D converter provide the uncompressed digital signal – or only the already lossy compressed version?
  • Same question for audio…
  • Does it preserve video fields accurately?
  • Does it preserve color information, or the chroma subsampling (e.g. 4:2:2 to 4:2:0)?

Although the A/D converter stick seems to be usable by other video applications (e.g. VirtualDub), it’s unclear if recording to another codec already contains a generation loss.
This would be very relevant for eventual post-editing (e.g. cropping, color corrections, audio corrections, etc), since one would be to accept at least 3 generation losses:

  • Loss #1: Lossy compression in A/D converter
  • Loss #2: Image-/audio-recording in lossy codec (WMV/WMA?)
  • Loss #3: Export to a lossy format (DVD, Blu-Ray, etc)

UPDATE (26.Aug.2015):
I was told by a user that the program provided an export to MPEG-2 in recent versions.
Unfortunately, this “program bug” was “fixed” by MAGIX.

Quote MAGIX support (Translated from German to English):

“If MPEG-2 was listed as export option, that is a bug which was corrected automatically with the next program start.
So there is no possibility to export the video as MPEG-2. Additionally, this function can also not be activated.”

MAGIX support also gave us the tip that the MPEG, generated by the A/D converter stick, would intermediately be stored in the “My Record” folder.
At least with this option, you would have had only one generation loss.

Unfortunately, this “program bug” was also “fixed”:
The original MPEG-2 is not accessible any more – the video is now transcoded directly to a 16:9 WMV/WMA format.

So in the current version, this adds another 2 quality losses:

  • Loss #4: Interpolation by upscaling from SD to HD (720×576 auf 1920×1080)
  • Loss #5: If there are no black borders added left/right, then cropping occurs

I hope that at least the audio is stored lossless (e.g. uncompressed PCM) before export.
Yet, this is uncertain.

For those who would (still) like to copy and preserve their videos in a safe(r) way, I’ve written down some options and background informations here:

Formats (more) suitable for archiving:
The best option, of course, is if you can store audio/video uncompressed or in a mathematically lossless codec (e.g. FFV1).
Currently, this might still be an issue for end-users, due to the rather huge data size (compared to lossy).
For example, FFV1/PCM in AVI requires about 90 GB for 4h VHS (~370 MB/min).

Of course it’s tempting to have smaller files – but that has its price.

In case one decides to use compression without any loss, any other codec than Windows Media is to be preferred. Due to its Microsoft origin, WMV/WMA is strongly bound to Windows, and due to this format’s licensing- und patent-obstacles it’s unclear if (and under which conditions) one is able to open these formats in the future.
For Non-Windows environments, the license costs for creators of applications/devices that can play (or convert) WMV is currently at 300.000 USD per year.
See: “Windows Media Components Product Agreement, page 12.

The best compromise would probably be “DV” (=lossy, but widespread open standard) as video codec and PCM (=uncompressed. Quasi “WAV”) for audio in AVI. That would approximately be 55 GB for 4h VHS (~230 MB/min).
Within a reasonable value-for-money range, a A/D converter like the ADVC55 might make sense.

As recording program “VirtualDub” could be used.
Audio should be recorded uncompressed (PCM) – and also stored in that format in the video container file.
Presets for recording DV in the most exact way can be downloaded here.
These settings are part of DVA-Profession, and are used at the Austrian Mediathek (the National Audio/Video Archive).

A general rule of thumb for long-term preservation of media formats is, that the implementation of an open format/standard under a Free Software license (e.g. GPL) has the highest chance to “virtually immortal”.

For example, if a media format is supported by the tool “FFmpeg“, your changes are very good 🙂

DVD/Blu-ray as physical carrier:
Here a short quote from the product page (Translated from German to English):

“Digital is better: Advantages of DVDs & Blu-ray Discs In addition to the large disk space, long service life, and small size, they do not have any sensitive mechanical components, making them ideal for archiving!”

Of course, the part about the mechanical components is correct, but saying it’s “ideal for archiving?
Theoretically “yes” – practically “no”.

The times where archives stored everything on optical carriers are long gone.
Mainly, because it has quickly shown that self burned optical carriers are way more fragile and short-lived than analog material, hard disks or magnetic tapes.
Burned disks that are not readable without errors after 2 years are not the exception. The higher the density of the carrier, the more fragile of course are is the data stored on it…

Furthermore one should distinguish between “data disk” and “video disk” – the same applies to CD, as well as DVD and Blu-Ray.
If one stores their videos on a video-disk (e.g. Video-DVD), the audio/video format – including resolution and aspect ratio – is mostly fixed.
Currently, these are exclusively lossy video codecs:

  • CD: MPEG-1
  • DVD: MPEG-2
  • Blu-Ray: MPEG-4 (H.264)

At the moment, there is (currently) no perfect carrier. Especially not for digital data.
For the time being, I would suggest to store the originally captured files on hard disks – and a copy on DVD/Blu-Ray only as access copy.
This allows to choose the archiving format separately from the access format, increasing ones chances to more easily and without additional generation loss convert the videos for viewing.

Aspect ratio:
Analog video is stored in “standard definition” (SD) resolution, and was always recorded with the aspect ratio of 4:3 – and that’s also the way the image is stored on the tape.

In screenshots on the MAGIX Website however, the video is exclusively displayed in 16:9:

Even if you have black borders at top/bottom (=<a href="https://en.wikipedia.org/wiki/Letterboxing_(filming)"), the information on the tape originally isn't wide screen at all.

In Europe we have PAL as TV-/video norm.
If you digitize PAL-SD video, that usually results in a pixel resolution of 720×576. Due to quadratic pixel aspect ratio (PAR), that relates to 5:4 storage aspect ratio (SAR).

Even if one originally recorded 16:9 on e.g. DV (=”Digital Video”) or Digital Betacam, it is stored anamorph with 720×576 pixels (=5:4) – also not wide screen.

If 4:3 is stored as 16:9 full screen, information is always lost.

How does the MAGIX Rescue Your Videotapes handle that?
Does it automatically crop, or could one have black borders left/right (=”pillarbox“) instead?
That would at least offer a lossless video image format for archiving, in case one wants to convert to a 16:9 aspect ratio for viewing (e.g. Blu-Ray/HD).

I don’t even dare to ask how fields (half-images of a frame) and/or deinterlacing are handled…

MXV:
Justa short remark regarding the “MXV” format for video:
At my work at the national video archive, we encounter a variety of most diverse video formats as source. Until today, MXV was unknown to me.

During my recherche, I wasn’t able to find technical details about it, except of these:

  • It’s a MAGIX-internal format. Probably a container or project format
  • There are probably no tools (except for MAGIX’) that can open/convert it
  • It seems to store video in lossy-only formats (MPEG-2)
  • Which audio format is uses is completely unclear. PCM? MP3? WMA? MXA?

If you should have stored your videos in this format, I suggest to export/convert it to an open format as soon as possible. It is absolutely unclear if (and what-with) one can open MXV in the future at all.
Unfortunately, it is not impossible that one loses quality during that conversion (due to additional, lossy compression during export).

Please don’t send complaints to me, but to MAGIX 😉

GNU/Linux, an iPod and Clementine: becoming friends

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Yet another friend of mine came to me with the problem that they were stuck with the music collection they currently had on their iPod, because they’ve had to re-install the OS on their computer, and were now afraid to connect it with iTunes, since it might “synchronize” their not-on-the-harddrive-anymore collection and thereby wiping all the music from the iPod.

Hm.

Since that wasn’t the first time I’ve heard this, I offered that I “might take a look at it” – and try to hook it up with my all-time-favorite music player and operating system: Clementine on GNU/Linux (Xubuntu 12.04 LTS).

I was expecting the iPod to be accessible somehow on GNU/Linux, and expected to have to read some HowTos, etc – but I was amazed: It just worked! ™
I connected the iPod over USB, and it immediately showed up as mass-storage device (it’s labeled “PAN”):

I double-clicked it, and was served with the files on the device. The music collection is stored in a non-human readable way: The folders are labeled “FXX” (XX being a zero-padded number), and the music files had 4-letter names with some hex-IDs.

Hm… Let’s hope the files are tagged properly, and that Clementine can handle them.
So, I started Clementine and selected the option “Devices”. There it was!

Not only could I access (and therefore backup) all files on the iPod, but Clementine can read and even upload songs to it without problems – or any configuration necessary. Just select the tracks you want to upload to the iPod, right-click and select “Copy to device…”.
That actually makes way more sense for handling your music collection on your portable music player.

Summary:
So not only was I able to easily make a full backup of the data on the iPod, but I could easily manage handling the music collection, with the full convenience of Clementine for browsing, tagging and uploading the files.

That’s yet another situation where Free Software enables users to avoid the unnecessary lock-in by the original vendor.
I’m not suggesting anyone to get an iPod, but some people already have one – and it’s better to enable them to use it with Free Software, than have them throw it away.

It might be one of the few MP3 players that survive more than a few months, but it’s just too “restrictive/defective-by-design” for my taste. My all time favorite portable audio player is the “Sansa Clip+” on Rockbox 🙂
Once you’ve gone Rockbox, you just don’t want back (Especially as an audio engineer)!

MAGIX: Retten Sie Ihre Videokassetten!

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Seit einiger Zeit bekomme ich mehr und mehr Anfragen ob das von MAGIX angebotene Paket zur Digitalisierung und Archivierung von alten Videokassetten etwas taugt.

Als Techniker im nationalen Videoarchiv habe ich wahrscheinlich gewisse Ansprüche an die Digitalisierung und Archivtauglichkeit von Videomaterial, die für die meisten Endanwender_innen vielleicht “overkill” wären (z.B. verlustfreie Codecs).

Um analoge Videos einfach und billig zu überspielen ist dieses Produkt derzeit kaum zu unterbieten.
Die langfristige Archivierbarkeit (und Qualität) der Ausgabeformate stelle ich jedoch sehr in Frage.

Beim Nachlesen über dieses MAGIX-Paket fielen einige Dinge auf, die man vielleicht wissen/bedenken sollte, bevor man sich dieses Produkt zulegt.

Zusammenfassung / Überblick

  • Fragliche Qualität des Analog/Digitalwandlers
  • Ausschließlich verlustbehaftete Ausgabeformate
  • Sowohl WMV, als auch optische Speichermedien sind als Archivformat absolut unzulänglich
  • Unklare Generationsverluste bei Aufnahme/Bearbeitung/Export

Mögliche Hybridlösung:
MAGIX-Wandlerstick mit VirtualDub verwenden (siehe unten) und FFV1 oder DV als Videocodec verwenden. PCM für Audio.
Originaldateien auf Festplatte(n) speichern, und DVD/Blu-Ray lediglich für Ansichtskopien.
Somit kann man beschädigte DVD/Blu-Rays jederzeit neu erstellen, oder in Zukunft sogar in das-dann-gängige Videoformat zum Ansehen überspielen. Ohne zusätzlichen Generationsverlust.

Unterstützte Audio/Videoformate:
Unter “Technische Daten > Dateiformate” werden die unterstützten Formate für Video/Audio/Bild aufgelistet.

Die dort angegebenen Formate richten sich ausschließlich nach den Dateiendungen von Medienfiles (zB AVI, MOV, MP3, OGG). Das wirkt auf den ersten Blick zwar einfach(er), jedoch fehlen dadurch konkrete Informationen über die tatsächlich unterstützten Codecs.
Ein Videofile besteht immer aus 3 Komponenten:

  1. Container
  2. Video-Codec
  3. Audio-Codec

Abgesehen davon, dass die angegebenen “Videoformate” eine Mischung von Containern (AVI/MOV) und Codecs (DV, MPEG-1, MPEG-2, WMV) sind, wird ausschließlich “WMV(HD)” als Video-Exportformat aufgelistet.
Unter Anderem gibt es dort keine Information wie der Ton des Videos abgespeichert wird.

Die Liste an Audioformaten gibt lediglich an, dass man ausschließlich verlustbehaftete (!) Codecs wie MP3/WMA/Vorbis importieren kann.

Analog-Digital Wandler (AD-Konverter):
Das analoge Videosignal wird über einen kleinen, süßen USB-Stick mit Videoeingängen digital gewandelt.
Ich konnte noch keine öffentlich-zugänglichen Informationen über die technischen Details dieses Wandlers finden.

Offene Fragen:

  • Liefert der Wandler das unkomprimierte Digitalsignal – oder bereits eine verlustbehaftet (=lossy) komprimierte Version?
  • Selbe Frage für Audio…
  • Bleiben die Video-Halbbilder 1:1 erhalten?
  • Wird die Farbinformation beibehalten, oder das Subsampling verändert (zB 4:2:2 auf 4:2:0?)

Obwohl der Wandler-Stick von anderen Videoprogrammen (zB VirtualDub) als Eingang verwendet werden kann, ist unklar ob man bereits bei der Aufnahme in einen anderen Codec bereits einen Generationsverlust hat.
Das wäre für etwaige Nachbearbeitungen (zB Zuschneiden, Farbkorrekturen, Tonkorrekturen, etc) relevant, da man es sonst gleich mit mindestens 3 Generationsverlusten zu tun hätte:

  • Verlust 1: Lossy-Kompression im Wandler
  • Verlust 2: Bild-/Tonaufnahme in lossy Codec (WMV?)
  • Verlust 3: Export in lossy Codec/Format (DVD,Blu-Ray,etc)

UPDATE (26.Aug.2015):
Wie mir nun mitgeteilt wurde, gab es früher die Möglichkeit das MPEG-2 zu exportieren.
Dieser “Programmfehler” wurde jedoch von MAGIX behoben.

Zitat MAGIX Support:

“Wenn Ihnen als Exportformat MPEG2 angezeigt wurde, handelt es sich dabei um einen Bug, der nach dem nächsten Programmstart automatisch korrigiert wurde.
Es gibt also keine Möglichkeit, das Video in MPEG2 zu exportieren, diese Funktion lässt sich auch nicht aktivieren.”

Der Support gab jedoch den Tipp, dass das MPEG des Wandlersticks im Ordner “My Record” abgelegt wird.
Damit hätte man zumindest nur einen Verlust gehabt.

Dieser “Programmfehler” wurde jedoch ebenfalls behoben:
Das unberührte MPEG2 gibt es nicht mehr – es wird nun gleich in ein 16:9 HD WMV/WMA zwischengespeichert.

Damit kommen in der aktuellen Version noch 2 Verluste hinzu:

  • Verlust 4: Interpolation durch Skalierung von SD auf HD (720×576 auf 1920×1080)
  • Verlust 5: Wenn keine schwarzen Balken links/rechts, dann Cropping

Ich hoffe, dass zumindest der Ton bis zum Zeitpunkt des Exports unkomprimiert (PCM) abgespeichert wird.
Klar ist es nicht.

Für die, die ihre Videos in einem (immer noch) sinnvollen Preis/Leistungsverhältnis überspielen und sicher(er) aufbewahren möchten, habe ich hier ein paar Optionen und Hintergrundinfos zusammengefasst:

Archivtauglich(ere) Formate:
Am Besten ist natürlich, wenn man sich leisten kann Audio/Video unkomprimiert oder mit mathematisch verlustfreien (=lossless) Codecs (zB FFV1) abzulegen. Derzeit sind für Endanwender_innen die Datenmengen dabei jedoch wahrscheinlich noch zu groß.
Beispiel “FFV1/PCM in AVI” benötigt ca. 90 GB für 4h VHS (~370 MB/Min).

Verlockend ist natürlich kleinere Dateien zu erzeugen, aber das hat seinen Preis.

Sollte man sich entscheiden, verlustbehaftet zu komprimieren wäre so ziemlich jeder andere Codec ausser Windows Media zu bevorzugen. WMV/WMA ist aufgrund seines Microsoft-Ursprungs stark mit Windows verheiratet, und es ist aufgrund von lizenz- und patentrechtlichen Hürden unklar womit (und unter welchen Bedingungen) man diese Dateien in Zukunft öffnen kann. Für Nicht-Windows-Umgebungen liegen die Lizenzkosten für Hersteller von Programmen/Geräten, die WMV abspielen (oder umwandeln) möchten derzeit bei 300.000 USD pro Jahr. Siehe “Windows Media Components Product Agreement, Seite 12.

Der beste Kompromiss wäre wahrscheinlich “DV” (=verlustbehaftet, aber weit-verbreiteter offener Standard) als Videocodec mit PCM (=unkomprimiert. Quasi “WAV”) für Audio in AVI. Das wären ungefähr 55 GB für 4h VHS (~230 MB/Min).
Vom Preis/Leistungsverhältnis wäre zB ein Analog-zu-DV Wandler, wie zB der ADVC55 sinnvoll.

Als Aufnahmeprogramm kann “VirtualDub” verwendet werden. Der Ton sollte dabei unkomprimiert (PCM) aufgenommen und so auch im Videofile gespeichert werden. Voreinstellungen (=Presets) wie man damit DV am exaktesten aufnimmt, kann man sich von hier herunterladen.
Diese Einstellungen sind Teil von DVA-Profession, und werden in der Österreichischen Mediathek (dem nationalen Audio/Videoarchiv) verwendet.

Als generelle Faustregel für die Langzeitarchivierbarkeite von Medienformaten kann man sagen, dass eine Implementierung eines offenen Formats/Standards unter einer Freien Softwarelizenz (zB GPL) die besten Chancen hat quasi “für immer” zugänglich zu sein.
Wenn zum Beispiel ein offenes Medienformat vom Tool “FFmpeg” unterstützt wird, stehen die Chancen sehr sehr gut 🙂

DVD/Blu-ray als Trägerformat:
Hier ein kurzes Zitat von der Produktseite:

Digital ist besser: Vorteile von DVDs & Blu-ray Discs
Neben dem großen Speicherplatz, der langen Lebensdauer und der geringen Größe, besitzen sie keine sensiblen, mechanischen Bauteile und sind daher ideal zum Archivieren geeignet!

Das mit den mechanischen Bauteilen stimmt natürlich, aber “ideal zum Archivieren“?
Theoretisch “ja” – praktisch “nein”.

Die Zeit in der Archive alles auf optische Datenträger gespeicher haben sind vorbei. Größtenteils, da sich sehr schnell herausgestellt hat, dass gebrannte optische Datenträger noch viel anfälliger und kurzlebiger sind als Analogmaterial, Festplatten oder Magnetbänder. Gebrannte Scheiben die nach 2 Jahren schon nicht mehr fehlerfrei lesbar sind, sind nicht die Ausnahme. Je höher die Datendichte, desto fragiler natürlich auch die Daten darauf…

Weiters sollte man zwischen “Daten-Disk” und “Video-Disk” unterscheiden – das gilt für CD, wie DVD und Blu-Ray.
Wenn man seine Videos als Video-Disk brennt (zB Video-DVD), ist das Audio/Videoformat – inklusive Auflösung und Seitenverhältnis – größtenteils festgelegt. Derzeit sind das ausschließlich verlustbehaftete Videocodecs:

  • CD: MPEG-1
  • DVD: MPEG-2
  • Blu-Ray: MPEG-4 (H.264)

Es gibt (noch) keinen perfekten Träger. Schon gar nicht für Digitales.
Derzeit würde ich empfehlen, die Originaldateien auf Festplatte(n) zu speichern – und auf DVD/Blu-Ray lediglich Ansichtskopien.
Damit kann man auch das Archivformat und das Abspielformat des Videos trennen, und so seine Chancen erhöhen in Zukunft leichter und ohne zusätzlichen Generationsverlust auf zukünftige Formate für’s Ansehen der Videos zu konvertieren.

Seitenverhältnis:
Analoges Video in “Standard Definition” (SD) Auflösung, war immer für das Seitenverhältnis 4:3 aufgenommen – und so ist das Bild auch am Band gespeichert.
In den Screenshots auf der MAGIX Website wird das Video jedoch ausschließlich 16:9 angezeigt:

Sogar wenn man schwarze Balken oben und unten hat (=Letterbox), ist die Information am Band eigentlich nicht Breitbild.

In Europa haben wir PAL als Fernseh-/Videonorm.
Digitalisiert man PAL-SD-Video, ergibt sich dadurch in den meisten Fällen eine Pixelauflösung von 720×576. Aufgrund quadratischer Pixel entspricht das 5:4.

Auch wenn man 16:9 auf DV (=”Digital Video”) aufgenommen hat, wurde es anamorph mit 720×576 Pixel (=5:4) gespeichert – also ebenfalls nicht Breitbild.

Will man 4:3 auf 16:9 Vollbild abbilden, geht immer Information verloren.

Wie geht das MAGIX Videoprogramm damit um?
Beschneidet es automatisch, oder könnte man stattdessen schwarze Balken links/recht (=”Pillarbox“) haben? Das wäre das verlustfreie Video-Bildformat zur Archivierung, falls man auf ein 16:9-Anzeigeformat konvertieren will (zB Blu-Ray/HD).

Ich wage nicht zu fragen wie mit Halbbildern (=Fields) und/oder Deinterlacing umgegangen wird…

MXV:
Nur noch kurz eine Anmerkung zum “MXV” Format für Video:
In meiner Arbeit im nationalen Videoarchiv haben wir es tagtäglich mit den unterschiedlichsten Videodateiformaten als Quelle zu tun. MXV war mir bis dato unbekannt. Bei meiner Recherche fand’ ich wenig bis keine technischen Informationen darüber, abgesehen von diesen:

  • Es ist ein MAGIX-internes Format (wahrscheinlich ein Container)
  • Es gibt wahrscheinlich keine Tools (außer von MAGIX), die es öffnen/konvertieren können
  • Vielleicht ist es auch eine Projektdatei für MAGIX Videoprogramme
  • Angeblich enthält es MPEG-2 als Videocodec
  • Welches Audioformat es enthält ist völlig unklar. PCM? MP3? WMA? MXA?

Sollte man Videos in diesem Format abgelegt haben, empfehle ich sehr dringend sie bald-möglichst mit den MAGIX-Tools in ein offenes Format umzuwandeln. Es ist völlig unklar ob (und womit) man MXV überhaupt jemals wieder öffnen kann.
Leider kann bei einer Konvertierung nicht sichergestellt werden, dass man keine Qualität verliert (nochmalige, verlustbehaftere Kompression beim Export).

Beschwerden bitte nicht an mich, sondern an MAGIX 😉

Tears of Steel: New “Open Movie Project” movie is out!

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Last September, the “Open Movie Project” people released their newest movie called “Tears of Steel” (Codename: Mango).

Image from "Tears of Steel" movie

The interesting (and great) thing about this short film is that it’s made using Free Software – mainly the Blender 3D creation suite. The previous Open Movie releases were completely computer-generated (rendered), but this is the first Blender movie that features real video footage.

The image quality looks amazing, and I’d say it’s another fine proof of the high quality that can be produced with Free Software.

Worth checking it out.

Audio/video formats: Licensing and patents

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The video-domain is a tricky thing, but I’ll do my best 🙂

Containers

Before we proceed, let’s make sure we’re talking about the same things here:
AVI, MOV, MKV and OGG are merely audio/video containers. Not codecs.

When talking about digital videos, people often just refer to the container format, as this is what they “see” when they see the file. But digital video consists of 3 parts:

  1. video codec
  2. audio codec
  3. container format

There are hardly any patents or licensing issues regarding containers. AVI for example is, according to my knowledge free and open – even though it’s been specified by Microsoft ages ago, and MOV (=Quicktime container) licensing appears to be limited to their software, but not the container.

Ogg as container has gained popularity within the audio domain, but is hardly being used for video. I guess, because MKV (=Matroska) seems to be the best solution for the job at the moment. For web-applications, Google’s “WebM” might be a good thing in the (near) future.

As Matroska also supports to be used as audio-only container, I’d personally find it not unlikely, that the current popularity of MKV among consumers might lead to a broader adoption of that format for audio as well – but that’s difficult to say…

For video hardware it’s currently definitely the case that many of them support MKV out-of-the-box, but will very likely never see any reason to support OGV.

Codecs

So, when talking about patents and licensing issues in the audio/video domain, it’s about the codecs – or algorithms used by them.

Video codecs

Popular non-free lossy (consumer) video codecs at the moment are:

Free ones comparable to MPEG-4 at the moment are:

Audio Codecs

In the audio domain, the popular non-free ones are:

And the free ones:

NOTE: I’ll leave lossless codecs out of the game for the moment, as they are not as widely used/seen by regular consumers.

What is being compared?

Sorry for the detailed introduction, but I think it’s a good thing to make clear that for digital video you need to consider all 3 things:
video-codec, audio-codec and the container.

Usually, most people are actually comparing the most common/popular codecs used within the containers to each other, probably being:

  • AVI:
    • video: XviD/DivX (= MPEG4 ASP)
    • audio: MP3 [8]
  • MOV:
    • video: h264 (= MPEG4 AVC), sometimes “Quicktime” (=also the name of a codec)
    • audio: AAC (Advanced Audio Coding)
  • OGG:
    • video: Theora
    • audio: Vorbis

Freedom aspects:

All currently widely used non-free A/V codecs mentioned above cannot easily be implemented and shared as Free Software, because it might infringe licensing or patents of these codecs.
This means, that depending on the legislation of the countries where the software is downloaded from – and the country the software user is living in.

Nice example: VLC has a note on its website explaining why they are allowed to distribute their application freely:

“Neither French law nor European conventions recognize software as patentable (see French section below).
Therefore, software patents licenses do not apply on VideoLAN software.”

Their servers are located in France. If they’d be located in the U.S. things would be very different.

As Free Software developers could get sued for distributing patented software, most distributions and applications must be shipped without support for these formats. This is the reason why MP3, DVD-Playback, etc. doesn’t work out-of-the-box on Free Software OS (e.g. Ubuntu, Debian, …)

Even worse: Some licensing forbids implement things as Free Software, because then the inner-workings would be visible (although this applies mostly to media-related DRM issues)

With proprietary software, the users are already paying for the (partial!) use of these formats: The royalty fees are included in the price. Funny though, that noone really ever reads the licensing texts, as Apple’s Quicktime license for example, states that additional fees are are required for using MPEG-2/4 for other than personal- or non-commercial use:

“ANY USE OF THIS PRODUCT OTHER THAN CONSUMER PERSONAL USE IN ANY MANNER
THAT COMPLIES WITH THE MPEG-2 STANDARD FOR ENCODING VIDEO INFORMATION
FOR PACKAGED MEDIA IS EXPRESSLY PROHIBITED WITHOUT A LICENSE UNDER
APPLICABLE PATENTS IN THE MPEG-2 PATENT PORTFOLIO, WHICH LICENSE IS
AVAILABLE FROM MPEG LA, L.L.C, 250 STEELE STREET, SUITE 300, DENVER,
COLORADO 80206.”

So if you use your iStuff to make a video and then go-pro and make money with it: You could get sued… (But I’m not a lawyer)

Conclusion

As you can see, licensing and patent issues with A/V codecs mean that a developer can only join the game if they play by proprietary rules – and have (enough) money to do so. So, even if it’s technically possible to implement these formats as Free Software (e.g. LAME, x264, …), these legal barriers make it difficult (or impossible) to grant access to content encoded in these formats.

When talking about money, you might want to take a look at the MP3 licensing costs for starters (…and that’s an ancient format already!) – or the pricelist for Microsoft codecs.

I hope this cleared things up a bit? 😉

DFD 2010: rOGGing at ORANGE 94.0

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This year’s focus on the document freedom day wasn’t on printable document formats as the years before, but rather on multimedia formats. Why? Because those formats are “documents” as well, and are used daily for storing and exchanging information.

That’s why the FSFE has decided to award some radio stations that provide their program-stream in an open standard format. For audio, that’s “ogg/vorbis”.

In Vienna there is one radio station providing ogg-streams: ORANGE 94.0, an independent free radio station.

So, we (a small group of fellows) put on our newly made “rOGG on!” shirts, grabbed our perfectly designed DFD-cake and went over to the radio station of ORANGE 94.0 to congratulate them for their good work, and celebrate the DFD together.

We were received with a very warm welcome by the nice people at ORANGE 94.0 – including the news that they’ve taken the DFD-award as a reason to upgrade the bandwidth of their ogg/vorbis live stream. Wow! That’s great!

A member of ORANGE 94.0 said that they’re happy to receive the DFD-award and that they’re receiving it not only for them, but substitutionally also for other free radio stations in Austria, that also provide ogg-streams. Other free radio stations transmitting in ogg/vorbis are:

Surprisingly Manfred from Radio Netwatcher was waiting there with audio/video recording equipment in order to record and report about that event in one of the upcoming episodes of Radio Netwatcher.

Since, we assumed that the nice staff at ORANGE 94.0 knows what they’re doing – and why, we didn’t prepare a long speech, so Georg got caught a bit surprised, when Manfred asked him for a few words about “why we are here today”. 🙂 Nevertheless, he did a good job at providing that information instantly.

After we’ve finished the professional foto-shooting session, including highlights like:

  • handing over the DFD 2010 award certificate
  • opening the bottle of champagne
  • cutting the cake

…we’ve provided everyone with enough to eat and drink, and stayed for quite a while, having interesting conversations with ORANGE 94.0 staff members.

Images from the event can be found on the DFD-2010 page in our fellowship wiki:
http://wiki.fsfe.org/DFD-2010-BCV

Watching your own medical CT: Free Software makes it possible

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I’ve received my own CT (computer tomography) images on a CD-ROM from the hospital. Unfortunately, they were expecting their patients to run exclusively on Windows (Well, TDK – the manufacturer of the CT did), so it was filled with autorun.inf, .exe and .dll files. *sigh*
Long story short: The actual images were stored as “DICOM” files (a medical image standard, yeah!) – now all I had was to install a viewer.

“apt-cache search dicom” returns a handful of entries, but the most interesting ones for me where:
AMIDE (http://xmedcon.sourceforge.net/)
(X)MedCon (http://amide.sourceforge.net/documentation.html)

With the XMedCon app I could view the DICOM images, and with the medcon commandline tool, I did:
$ medcon -c PNG -f *.dcm
to convert the DICOMs to PNGs. No fuzz.

AMIDE however was really impressing me, because it takes the DICOM images of a CT, reads that they’re linked and renders 3 views, based on the top-only pictures:
top, front and side

I was now able to navigate through my own CT at home, without being forced to use proprietary tools. Great!

Play Ogg: Video of Shane Coughlan’s talk in Vienna now easily accessible

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Free formats are are very important thing these days and thanks to the publicity of the Firefox webbrowser, it’s now even more comfortable to listen to or watch media in the free Ogg/Vorbis/Theora format since Firefox v3.5.
I had to try that new feature out, and used the video we’ve taken from Shane’s visit to Vienna last year.

If you want to watch his talk about “The professionalisation of Free Software – Where we are going next” and try out Firefox’s awesome new builtin, plugin-less audio/video support try this link:

http://download.das-werkstatt.com/pb/fsfe/shane.ogv

Enjoy!