Edward provided an initial patch to improve the behavior of timestamps and seeking in GNonLin, while Nicolas “Stormer” Dufresne fixed two bugs causing deadlocks. Nicolas spent a lot of time discussing with Wim Taymans, Edward Hervey, Sebastian Dröge and other hackfesters about the architecture of GNonLin in light of GStreamer 1.x. He also fixed looping for the Ogg demuxer in pull mode and, with some help from Mathieu “Forest Ranger” Duponchelle, fleshed out the design for a new tree data structure for GNonLin.

Mathieu the Moustached Avenger worked on implementing keyframes in GES, paving the way for him to create a user interface to animate any effect property in PiTiVi. That user interface will most likely depend on him working on the clutter timeline canvas, so I’m looking forward to improvements in that area.

Thibault “Keyboard Crusher” Saunier finished the implementation of GES Containers and clip groups, then worked on implementing — at long last — audio mixing in GES. This is an essential feature of multitrack audio/video editing, and I’m really happy to see that feature make its comeback for the next release of PiTiVi. This work will also depend on Mathieu’s keyframes UI. A proper reimplementation of video mixing remains to be done, however.

There are lots of outstanding things to solve in GNonLin and GES. Nicolas has a bunch of ideas for things to improve and redesign in GNonLin and I expect much collaboration between Thibault and him to optimize the entire stack for better reliability and performance (for example, adding caps filters to allow realtime downscaling of videos to improve preview performance, configurable downstream buffering for playback to avoid frame drops in CPU-intensive parts of a timeline, etc.). GNonLin and GES have much potential to allow us to be a lot smarter than before.

Personally, I spent most of my time testing, discussing and hacking on some new features for PiTiVi.

• I added a button in the timeline toolbar that toggles the “gapless mode” (automatic ripple edits), which makes your clips behave like magnets and prevents needing to re-arrange them manually all the time. The feature works and will be merged after a customary code review.
• I made some progress on the custom effects UI branch. Once it’s complete, you will be able to easily create custom user interfaces for effects that require it, simply by using a glade/gtkbuilder .ui file (or, if you prefer, a set of widgets from your own python module). Of course, for the majority of effects, our automatically generated user interfaces are still good enough, so we can keep using them and avoid unnecessary work.

(See my previous blog post for a situation report on where we stood with PiTiVi before the hackfest)

I also spent a bit of time setting up my film making gear and shooting various interesting moments of the hackfest. Here’s my montage, which will tell the story much better than a long blog post. Hope you’ll like it:

I would like to thank Collabora for allowing many GStreamer contributors to attend the hackfest, which I consider vital to the health of the GStreamer community. I was happy to meet again with many friends and help push the Free multimedia stack forward. Props to Christian Schaller and Alessandro Decina for organizing the whole thing, too!

Aside from Collabora and Fluendo sponsoring two of our dinners (thanks!), I would also like to thank you, PiTiVi supporters, for making it possible for me to spend some money to thank GStreamer contributors with some food and beer — maximum boost to the GStreamer community! Full disclosure: I used 84 euros worth of PiTiVi donations for that purpose.

Here’s a list of fixes in Pitivi since my last blog post:

• Fixes for our automated UI tests, including interaction with the filechooser dialogs, the spinbutton widgets (see this bug report), the typing speed, etc.
• Fixes and cleanup for backend tests
• Enforce unicode in preset names, preventing a bug with non-ASCII chars are used in the name of a preset
• Allow presets with “/” in their name
• Fix drag and drop from the media library’s listview mode
• Prevent playing back clip previews in double (that was a subtle one, since windows were exactly on top of each other)
• Make the media library clip previewer work even when the application is in fullscreen mode
• Make effect properties work again
• Take into account project settings in the main window when loading a project
• Conform to the new version of the Freedesktop specification for thumbnail directories
• Make special characters show up correctly in the media library’s iconview mode, remove the ancient filename shortening code and rely on Pango instead.
• Properly handle clip URIs encoding, ensuring that we can find the thumbnails for all files. Also do last-minute checks for that encoding before computing thumbnail hashes.
• Avoid excessive work when searching clips in the media library, improving performance
• Handle special characters in the media library’s search entry
• Force calculating the toolbar height at the last minute to properly handle all screen setups in fullscreen
• Scale down effects thumbnails to fit better in the new listview arrangement
• Fix a race between clicks on the preview widget’s slider and position updates. When using it in the media library/file chooser, the slider would often “jump” back to its previous position instead of seeking. The new behavior is now smooth and reliable.
• Ensure the welcome dialog is initially centered on its parent
• Bring back the checkbox to enable/disable effects
• Initialize GES to prevent a segfault from occurring on some machines at startup
• Make rectangle selection work again in the media library’s iconview mode
• Make the “Restore from backup” dialog modal to the main window

New features:

• Automatically adjust the zoom when inserting to the end of the timeline
• When the viewer is undocked, provide a button to toggle fullscreen mode
• New icons for split, group/ungroup and align
• Specify the duration of missing/moved files when prompting the user about their new location
• Update effect categories, merge “Noise” and “Blur”, add a “Compositing” category, categorize new effects
• Automatically save the last used render directory
• Stop rendering when the user presses Escape
• Use symbolic icons everywhere where it makes sense (in the media library toolbar, property reset buttons, lists, etc.)
• Use the system’s default image viewer to preview images from the media library
• Update the preview widget slider on a more frequent basis, giving it a snappier feeling
• Automatically save and restore the main window’s position. This is especially useful when using detached utility windows.
• Hide the effects toolbar when nothing is selected
• Add a contextual help button in the render dialog to explain container formats
• Allow entering a frame number into the time widget

Architectural changes and cleanups:

• Clean up the build, prune useless files, simplify and centralize the list of dependencies
• Refactor dependency checks to be more reliable and provide a faster application startup
• GES Assets (implemented in GES and integrated in Pitivi), including the notion of GES Project among other things. This paves the way to many other improvements.
• A revised and simplified API has been implemented in GES and integrated in Pitivi. You can see this new API online in the GES API hierarchy documentation.

So yeah, that’s the summarized version… with refactoring and cleanup all over the place, there’s more than a hundred commits (excluding translations).

Stuff that still needs to be done (as always, we need your help here):

• Need to refactor the timeline UI code and the clip transformation UI
• Undo/redo
• Improving/expanding the UI tests, see the test suite wishlist
• Figure out how to better integrate the “welcome dialog”
• Figure out how to shave off the menu bar and how GTK AppMenu will work with accessibility technologies (and Dogtail)
• Improve the title editor UI
• Improve the timeline thumbnailer
• Reimplement the notion of grouping in GES
• Reimplement video compositing and audio mixing. Properly. In GES.
• Make a new keyframe UI that doesn’t suck. Integrate it for audio volume curves and to provide animatable effect properties.
• Fix… all the bugs! _o/
• Insert your own itch to scratch here

Ongoing work in my own/personal repository:

• Custom effect UIs
• New high-resolution icon (pictured above), new mimetypes
• Automatic rippling
• Resurrecting the codecs installer

No, really! It’s an incredibly productive and motivating event to participate in.

One of the major items we would like to accomplish is to fix GNonLin as much as possible. As you know, the GStreamer 1.x series is a major departure from the 7 years old 0.10 series’ design, and GNonLin needs to be rethought for the new world order. The current state of GNonLin makes it impossible for nonlinear audio/video editing applications to behave properly in GStreamer 1.x. This affects Pitivi, Jokosher, Novacut, and perhaps others.

If you want to work on PiTiVi’s UI at the hackfest, you are of course welcome to do so. I always have nice projects to play with, such as the need for a new keyframe UI, fixing undo/redo, improving the performance of the thumbnail system, helping Pēteris with the GStreamer waveforms library implementation, or porting the timeline and viewer canvases to Clutter.

Following up on the 2012.9 “Amazon” release, this SDK release, codenamed “Brahmaputra”, reveals a natural pattern: akin to the river of the same name, it streams down from the Himalayas, brings the coolness downstream, keeps flowing and breathes life onto the lands.

Evening on the Brahmaputra River, by Vikramjit Kakati

A particularly interesting piece of land that now gets irrigated by the flow of GStreamer is the Android plateau (some say platform, but that’s less geographically-fitting!).

Yep, you heard that right, pioneers of the open world! The land of Android is now fertile, free and wide open to rapid development of multimedia applications with GStreamer. Go ahead and try it out today, let us know how it helps you Get Things Done—and how GStreamer can be made even better!

The SDK currently supports a bunch of Linux distributions, Windows (from XP to 8), Mac OS, and Android 2.3.1 and newer (some features such as hardware acceleration will require Android 4.1 or newer). It is fully documented, free as in both, and has a sexy website (what more could you ask for?).

Recently, a significant piece of the puzzle has been fully solved in PulseAudio 2.0: real, rock-solid acoustic echo cancelling. Echo cancelling is not to be confused with echo concealment/suppression, which is basically just muting the other person while you’re talking (most phones and software applications—including Skype—do that, and it sucks).

As Christian nicely summarized, audio/video calls over the past few years have been a complex story. Unless you are close to GStreamer and Telepathy developers, it’s hard to see the big picture. Christian’s blog post is thus helpful, but I think it does not truly express how mindboggingly awesome this feature is, from a “What? Computers can do that? With Free Software?!” perspective.

A test call through XMPP/Jabber with Google Talk accounts. Notice that the echo-cancelled virtual device shows up in the GNOME volume control panel during the call. Yes, I cheated and used gnome-tweak-tool to change the control center’s colors to the dark variant.

Let me put it this way: I unplugged the headphones, called my laptop, put it into the garage, closed the door and went back to the previous room with the phone. I spoke, and I thought it was broken because the echo cancellation was working too well. I could not hear myself nor any audio artifacts. When I fetched someone else to go speak in front of the computer, it turned out that there was simply no echo whatsoever. Jaw on the floor. And that was with the laptop’s crappy 1-watt speakers; I then called across the globe to Bangalore, with my trusty USB microphone and 5.1 sound system, and it felt just like the other person was in the same room as me.

It works even if there’s ambient noise. The only way to confuse the echo canceller is to be in the same room with both the phone and the laptop. Not likely, unless you like talking to yourself.

Finally, no more fumbling around to pick up a call when your gear is not plugged in. Conference calls the way they were meant to be. Hands-free discussions while cooking or in a car. Holy smokes, we’re only missing holograms and flying cars… Folks, you know what to do.