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• fate : Add basic tests for WebM Dash Manifest

  26 août 2014, par Vignesh Venkatasubramanian

  fate : Add basic tests for WebM Dash Manifest
  Add fate tests that test out the functionality of WebM DASH
  
  Manifest XML generation. This patch contains the vpx.mak file
  
  changes and the reference gold XML files.
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] tests/fate/vpx.mak
  • [DH] tests/ref/fate/webm-dash-manifest
  • [DH] tests/ref/fate/webm-dash-manifest-unaligned-audio-streams
  • [DH] tests/ref/fate/webm-dash-manifest-unaligned-video-streams

• 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.

• How to create a custom theme in Piwik – Introducing the Piwik Platform

  23 août 2014, par Thomas Steur — Development

  This is the start of a new blog series where we introduce the capabilities of the Piwik platform. You’ll learn how to write custom plugins & themes, how to use our HTTP APIs and more.

  We have been greatly simplifying our APIs over the last year focusing primarily on one design principle :

  The complexity of our API should never exceed the complexity of your use case.

  In other words, if you have a simple use for our API, we want it to be simple for you to accomplish it. If you have a complex, big, hairy, change-the-world idea, then maybe we can’t make it simple for you to accomplish it, but we want it to be possible.

  Over the next weeks and months you will learn what exactly we mean by this and how we accomplished it.

  FYI, don’t worry if you’re currently using our APIs, we keep them backwards compatible and we announce breaking changes in our platform changelog.

  Getting started

  In this series of posts, we assume that you have already set up your development environment. If not, visit the Piwik Developer Zone where you’ll find the tutorial Setting up Piwik.

  To summarize the things you have to do to get setup :

  • Install Piwik (for instance via git).
  • Activate the developer mode : ./console development:enable --full.
  • And if you want, generate some test data : ./console visitorgenerator:generate-visits --idsite=1 --limit-fake-visits=600. This can take a while and requires the VisitorGenerator plugin from the Marketplace.

  Let’s start creating our own theme

  We start by using the Piwik Console to create a blank theme :

  ./console generate:theme

  The command will ask you to enter a name, description and version number for your theme. I will simply use “CustomTheme” as the name of the theme. There should now be a folder plugins/CustomTheme which contains some files to get you started easily.

  Before we modify our theme, we have to activate it by visiting the Settings => Themes admin page in our Piwik installation, or alternatively by running the command ./console core:plugin activate YourCustomTheme. If the theme is not activated, we won’t see any changes.

  Theme Contents

  The most important files in our theme are plugins/CustomTheme/stylesheets/theme.less, plugins/CustomTheme/stylesheets/_colors.less and plugins/CustomTheme/stylesheets/_variables.less :

  • theme.less is the file that will be included when your theme is activated. In this file you would include other stylesheet files and overwrite CSS styles.
  • _colors.less contains many less variables allowing you to easily change the colors Piwik uses.
  • _variables.less contains currently only one variable to change the font family. More variables will be added in the future. Note : This is a new feature and the file will be only there in case you have installed Piwik using Git or at least Piwik 2.6.0.

  Changing the font family

  To change the font family simply overwrite the variable @theme-fontFamily-base: Verdana, sans-serif; in _variables.less. That’s it.

  Changing colors

  To change a color, uncomment the less variables of the colors you want to change in _colors.less. I will shortly explain some of them. Usually changing only these colors will be enough to adjust Piwik’s look to your corporate design or to create a look that pleases you :

  @theme-color-brand:                    #d4291f; // The Piwik red which is for instance used in the menu, it also defines the color of buttons, the little arrows and more
  
  @theme-color-brand-contrast:           #ffffff; // Contrast color to the Piwik red. Usually you need to change it only in case you define a light brand color. For instance to change the text color of buttons
  
  @theme-color-link:                     #1e93d1; // The link color which is usually a light blue
  
  
  
  @theme-color-widget-title-text:        #0d0d0d; // The text and background color of the header of a widget (Dashboard)
  
  @theme-color-widget-title-background:  #f2f2f2;
  
  
  
  @theme-color-menu-contrast-text:       #666666; // The text color of a menu item in the reporting sub menu and the admin menu
  
  @theme-color-menu-contrast-textActive: #0d0d0d; // The text color of an active menu item
  
  @theme-color-menu-contrast-background: #f2f2f2; // The background color of a menu item
  
  
  
  @graph-colors-data-series[1-8]:        #000000; // The different colors used in graphs

  Making the change visible

  To make a color or font change actually visible when you reload a page in Piwik you will have to delete the compiled CSS file after each change like this :

  rm tmp/assets/asset_manager_global_css.css

  Publishing your Theme on the Marketplace

  In case you want to share your theme with other Piwik users you can do this by pushing your theme to GitHub and creating a tag. Easy as that. Read more about how to distribute a theme.

  Advanced features

  Isn’t it easy to create a custom theme ? All we had to do is to change some less variables. We never even created a file ! Of course, based on our API design principle, you can accomplish more if you want. For instance, you can change icons, CSS stylesheets, templates and more.

  For further customising your Piwik, you can even change the logo and favicon in the Settings => General settings page.

  Would you like to know more about theming ? Go to our Theme guide in the Piwik Developer Zone.

  If you have any feedback regarding our APIs or our guides in the Developer Zone feel free to send it to us.

  PS : see also this related FAQ : How do I White Label Piwik ?