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• ffmpeg drops the moov atom when coverting mp4 to ogg, flv, or webm

  31 janvier 2014, par user1370897

  I'm using processor qtfaststart and the gem paperclip-ffmpeg in Rails to convert an mp4 file to either ogg, webm, or flv. However, I haven't had any success converting the mp4 file to these formats for streaming purposes because the moov atom gets dropped (converting mp4 to mp4 keeps its moov atom though*).

  I did a $ qtfaststart -l on the original mp4 file and I get this :

  ftyp (24 bytes)
  
  moov (5691 bytes)
  
  free (399309 bytes)
  
  mdat (12312760 bytes)

  Which shows me that the mp4 file has an moov atom in there. The command that paperclip-ffmpeg is executing is something like this :

  $ ffmpeg -i ~/Movies/VID_20140119_134445.mp4 -acodec libvorbis -ac 2 -ab 96k -ar 44100 -s 640x360 -y ~/tmp/iguana.webm

  However, doing a qtfaststart on the new file (iguana.webm) I get the following :

  $ qtfaststart -l ~/tmp/iguana.webm 
  
  moov atom not found, is this a valid MOV/MP4 file?
  
  Traceback (most recent call last):
  
  File "/usr/local/bin/qtfaststart", line 5, in <module>
  
  pkg_resources.run_script(&#39;qtfaststart==1.8&#39;, &#39;qtfaststart&#39;)
  
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 489, in run_script
  
  self.require(requires)[0].run_script(script_name, ns)
  
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources.py", line 1214, in run_script
  
  exec script_code in namespace, namespace
  
  File "/Library/Python/2.7/site-packages/qtfaststart-1.8-py2.7.egg/EGG-INFO/scripts/qtfaststart", line 17, in <module>
  
  
  
  File "build/bdist.macosx-10.9-intel/egg/qtfaststart/command.py", line 44, in run
  
  File "build/bdist.macosx-10.9-intel/egg/qtfaststart/processor.py", line 65, in get_index
  
  File "build/bdist.macosx-10.9-intel/egg/qtfaststart/processor.py", line 106, in _ensure_valid_index
  
  qtfaststart.exceptions.FastStartException
  
  </module></module>

  I've also tried adding the option -movflags faststart to the command ffmpeg but ffmpeg still keeps dropping the moov atom to the output file.

  I'm using Rails 4, paperclip-ffmpeg 1.0.1, ffmpeg 2.1.3 Built on Jan 28 2014. Any help would be greatly appreciated.

• 11 ways Piwik Analytics helps you to protect your visitors privacy

  11 janvier 2017, par InnoCraft — Community

  At Piwik and at InnoCraft, we think Privacy matters. From the beginning, Piwik has had a strong focus on privacy and ensures the privacy of your visitors and analytics data. As a result, Piwik has been recommended as a privacy-compliant analytics tool for example by the Independent Center for Privacy Protection in Germany (ULD) and by the Center for Data Privacy Protection in France (CNIL). In France, Piwik is the only web analytics tool that does not require Cookie Consent.

  Here are some ways how you can ensure your users and visitors privacy by using Piwik.

  1. You own the data

  Whether you host Piwik on premise yourself, managed on premise by InnoCraft, or whether you use our Piwik cloud, when you use Piwik, YOU keep control of your data and nobody else. This also means you can decide where your data should be located physically.

  2. Anonymized IP addresses

  For better privacy by default, Piwik will not record the full IP address of your visitors because otherwise the browsing history could be easily tracked across several days and even across websites within the same Piwik server. Some countries even require to anonymize the IP address, considered Personally Identifiable Information (PII).

  To change the IP anonymization settings go to “Administration > Privacy”. Optionally, you can use the full IP to still get for example accurate location data.

  

  3. Delete old visitor logs

  The visitor logs contain information all the collected raw data about every visitor and every action. You can configure Piwik to automatically delete logs from the database. When you delete old logs, only the real time and visitor log reports will no longer work for this old time period, all other aggregated reports will still work.

  For privacy reasons, we highly recommend that you keep the detailed Piwik logs for only 3 to 6 months and delete older log data. This has one other nice side effect : it will free significant database space, which will, in turn, slightly increase performance !

  

  4. Support Do Not Track preference

  Do Not Track enables users to opt out of any tracking by websites they do not visit, including analytics services, advertising networks, and social platforms. By default, Piwik respects users preference and will not track visitors which have specified “I do not want to be tracked” in their web browsers. Get more information about DoNotTrack.

  To make sure Do Not Track is respected, go to “Administration => Privacy”.

  5. Include an Opt-Out Feature on your website or app

  By embedding the Opt-Out feature in your website, you give your visitors the possibility to opt-out of the tracking. When you go to “Administration > Privacy”, you will be able to copy and paste an HTML Iframe code to embed the opt-out feature for example into your privacy policy page or in your ‘Legal’ page. Your users can then click on a link to opt-out.

  On the Piwik Marketplace there are also some plugins available to customize the Opt-Out experience. For example AjaxOptOut and CustomOptOut.

  

  6. Disable Live features

  The Real-Time, Visitor Log and Visitor Profile features give you insights into the tracked raw data by showing you details about every visitor and every action they performed. To protect the privacy of your visitors you may decide to prevent access to such features by disabling the “Live” plugin in “Administration => Plugins”. This way only aggregated reports will be shown in your Piwik.

  7. Disable fingerprinting across websites

  By default, when one of your visitors visits several of your websites, Piwik will create a fingerprint for this user that will be different across the websites to increase the visitors’ privacy. You can make sure that this feature is disabled by going to “Administration => Config file” and verifying that the value of “enable_fingerprinting_across_websites” is set to zero.

  8. Disable tracking cookies

  Piwik uses cookies to store some information about visitors between visits. In some countries, the legislation requires websites to provide a way for users to opt-out of all tracking, in particular tracking cookies. You can disable cookies by adding one line in the Piwik Javascript code.

  9. Custom development

  Piwik is an open platform that lets you extend and customize the tracking, the reporting and the Piwik user interface to your needs and to protect your visitors’ privacy the way you want or need it. Learn more in the Piwik Developer Zone. You may also have a look at our Piwik Marketplace where you can find several free and premium features to extend your Piwik.

  10. Transparency

  By default, all information and all collected data in your Piwik server are protected and nobody can access it. However, Piwik allows you to optionally make your collected data public and you can export any Piwik report including the whole dashboard to embed it into your website. This way you can show your users exactly which information you track. When you decide to make reports public, we do our best to protect privacy and automatically hide any Personally Identifiable Information such as the Visitor Profile and we make sure to not show any Visitor IP address and the Visitor ID.

  11. Privacy policy

  When you use Piwik to track your visitors, we recommend to update your Privacy Policy to explain how Piwik is used and what data it gathers. We provide a Privacy Policy template for Piwik users that you can copy on your site.

  Continuous privacy improvements

  We are always interested in improving the privacy. If you miss any feature or have an idea on how to improve the privacy, please let us know.

  More information about all the Piwik features

  If you want to learn more about all the features in Piwik, have a look at our User Guides and FAQ entries.

• Dreamcast SD Adapter and DreamShell

  31 décembre 2014, par Multimedia Mike — Sega Dreamcast

  Nope ! I’m never going to let go of the Sega Dreamcast hacking. When I was playing around with Dreamcast hacking early last year, I became aware that there is such a thing as an SD card adapter for the DC that plugs into the port normally reserved for the odd DC link cable. Of course I wanted to see what I could do with it.

  The primary software that leverages the DC SD adapter is called DreamShell. Working with this adapter and the software requires some skill and guesswork. Searching for these topics tends to turn up results from various forums where people are trying to cargo-cult their way to solutions. I have a strange feeling that this post might become the unofficial English-language documentation on the matter.

  Use Cases
  What can you do with this thing ? Undoubtedly, the primary use is for backing up (ripping) the contents of GD-ROMs (the custom optical format used for the DC) and playing those backed up (ripped) copies. Presumably, users of this device leverage the latter use case more than the former, i.e., download ripped games, load them on the SD card, and launch them using DreamShell.

  However, there are other uses such as multimedia playback, system exploration, BIOS reprogramming, high-level programming, and probably a few other things I haven’t figured out yet.

  Delivery
  I put in an order via the dc-sd.com website and in about 2 short months, the item arrived from China. This marked my third lifetime delivery from China and curiously, all 3 of the shipments have pertained to the Sega Dreamcast.

  
  

  

  Click for larger image

  
  

  I thought it was very interesting that this adapter came in such complete packaging. The text is all in Chinese, though the back states “Windows 98 / ME / 2000 / XP, Mac OS 9.1, LINUX2.4”. That’s what tipped me off that they must have just cannibalized some old USB SD card readers and packaging in order to create these. Closer inspection of the internals through the translucent pink case confirms this.

  Usage
  According to its change log, DreamShell has been around for a long time with version 1.0.0 released in February of 2004. The current version is 4.0.0 RC3. There are several downloads available :

  1. DreamShell 4.0 RC 3 CDI Image
  2. DreamShell 4.0 RC 3 + Boot Loader
  3. DreamShell 4.0 RC 3 + Core CDI image

  Option #2 worked for me. It contains a CDI disc image and the DreamShell files in a directory named DS/.

  Burn the CDI to a CD-R in the normal way you would burn a bootable Dreamcast disc from a CDI image. This is open-ended and left as an exercise to the reader, since there are many procedures depending on platform. On Linux, I used a small script I found once called burncdi-dc.sh.

  Then, copy the contents of the DS/ folder to an SD card. As for filesystem, FAT16 and FAT32 are both known to work. The files in DS/ should land in the root of the SD card ; the folder DS/ should not be in the root.

  Plug the SD card into the DC SD adapter and plug the adapter in the link cable port on the back of the Dreamcast. Then, boot the disc. If it works, you will see this minor corruption of the usual Sega licensing screen :

  
  
  

  Then, there will be a brief white-on-black text screen that explains the booting process :
  

  
  
  

  Then, there will be the main DreamShell logo :

  
  
  

  Finally, you will land on the DreamShell main desktop :

  
  
  

  Skepticism
  At first, I was supremely skeptical of the idea that this SD adapter could perform speedily enough to play games reasonably. This was predicated on the observation that my DC coder’s cable that I used to use for homebrew development could not transfer faster than 115200 bits/second, amounting to about 11 kbytes/sec. I assumed that this was a fundamental limitation of the link port.

  In fact, I ripped a few of my Dreamcast discs over a decade ago and still have those rips lying around. So I copied the ISO image of Resident Evil : Code Veronica — the game I personally played most on the DC — to the SD card (anywhere works) and used the “ISO loader” icon seen on the desktop above to launch the game.

  It works :

  
  
  

  The opening FMV plays at full speed. Everything loads as fast as I remember. I was quite surprised.

  Digression : My assumptions about serial speeds have often been mistaken. 10 years ago, I heard stories about how we would soon be able to watch streaming video on our cell phones. I scoffed because I thought the 56K limitation of dialup modems was some sort of fundamental speed-of-light type of limitation for telephony bandwidth, wired or wireless.

  The desktop menu also includes a ‘speedtest’ tool that profiles the write and read performance of your preferred storage medium. For my fastest SD card (a PNY 2 GB card) :

  
  
  

  This is probably more representative of the true adapter bandwidth as reading and writing is a good deal faster through more modern interfaces on PC and Mac with this same card.

  Look at the other options on the speedtest console. Hard drive ? Apparently, it’s possible, but it requires a good deal more hardware hacking than just purchasing this SD adapter.

  Ripping
  As you can see from the Resident Evil screenshot, playing games works quite nicely. How about ripping ? I’m pleased to say that DreamShell has a beautiful ripping interface :

  
  
  

  Enter a name for the disc (or read the disc label), select the storage medium, and let it, well, rip. It indicates which track it’s working on and the Sega logo acts as a progress bar, shading blue as the track rip progresses.

  I’m finally, efficiently, archiving that collection of Sega Dreamcast demo discs ; I’m hoping they’ll eventually find a home at the Internet Archive. How is overall ripping performance ? Usually about 38-40 minutes to rip a full 900-1000 MB. That certainly beats the 27-28 hours that were required when I performed the ripping at 11 kbytes/sec via the DC coders cable.

  All is well until I get a sector reading error :

  
  
  

  That’s when it can come in handy to have 3 DC consoles (see ?! not crazy !).

  Other Uses
  There’s a file explorer. You can browse the filesystem of the SD card, visual memory unit, or the CD portion of the GD-ROM (would be more useful if it accessed the GD area). There are FFmpeg files included. So I threw a random Cinepak file and random MPEG-1 file at it to see what happens. MPEG-1 didn’t do anything, but this Cinepak file from some Sierra game played handily :

  
  
  

  If you must enter strings, it helps to have a Dreamcast keyboard (which I do). Failing that, here’s a glimpse of the onscreen keyboard that DreamShell equips :

  
  
  

  Learning to use it is a game in itself.

  There is an option of installing DreamShell in the BIOS. I did not attempt this. I don’t know if it’s possible (not like there’s a lot of documentation)– perhaps a custom BIOS modchip is needed. But here’s what the screen looks like :

  
  
  

  There is also a plain console to interact with (better have a physical keyboard). There are numerous file manipulation commands and custom system interaction commands. I see one interesting command called ‘addr’ that looks useful for dumping memory regions to a file.

  A Lua language interpreter is also built in. I would love to play with this if I could ascertain whether DreamShell provided Dreamcast-specific APIs.

  Tips And Troubleshooting
  I have 3 Dreamcast consoles, affectionately named Terran, Protoss, and Zerg after the StarCraft II stickers with which they are adorned. Some seem to work better than others. Protoss seemed to be able to boot the DreamShell disc more reliably than the others. However, I was alarmed when it couldn’t boot one morning when it was churning the previous day.

  I think the problem is that it was just cold. That seemed to be the issue. I put in a normal GD-ROM and let it warm up on that disc for awhile and then DreamShell booted fine. So that’s my piece of cargo-culting troubleshooting advice.