Herostratus’ legacy

words from a lazy coder

misc

Do you remember that I promised not to use a minimalist window manager? Well, sorry, another broken promise. Since I started to play around with imapfilter, I discovered lua. Moreover, a comment in a previous post made a mention of awesome, a minimalist window manager configured through lua. So, I installed it, play with it, and suddenly I got delighted with all of its features: Awesome comes along pretty well with Gnome and its panel, which I didn’t want to lose at all. Besides, Awesome provides its own panel (called widget box, a.k.a. wibox), which includes a systray (sadly, awesome systray steals the icons from the gnome-panel systray). I’ve found that a tidy desktop, which avoids to the user unnecessary mouse interactions, is much more relaxed and helps the user to focus on her task. We’ll see how this experiment ends.Meanwhile, Joaquin, a colleague from Dextra, told about they were having troubles with the gst-openmax JPEG decoder element, because it needed a JPEG parser, while the gst-goo one mimic the official JPEG decoder provided by GStreamer in gst-plugins-good. In other words, the last two elements actually parse the buffer and validates the presences of a complete image in a single buffer, while the first doesn’t, it just assumes it, relying thou on a parser after the data source, which will deliver the image meta-data through fixed capabilities in the parser’s source pad.

Loathed by HAM and all the release processes, I though it could be nice to wet my feet again in the GStreamer waters. Besides, I need to help Iago with his codec base classes, so this JPEG parser, would help me to ramp up.

As an historical note, the first element I took in charge when I get in the GStreamer development group in Dextra was, precisely, the JPEG decoder.

As soon as I chatted with Joaquin, I found a bug report about an element for that purpose, but it still missed a couple features to turn it useful for our needs. And start to hack it. First, I moved from gst-plugins-good, to gst-plugins-bad, and then parse the image header in order to find its properties such as width, height, if the image is progressive, color format, etc. And the set these data in a fixed capability. Also, the frame-rate is negotiated in the sink pad of the parser, such as in the official JPEG decoder.

Finally I got something which seems to work OK and posted it in the same bugzilla report. I hope to receive feedback soon.

On the other hand, I’m still waiting for the approval of my last patches to the GStreamer’s Vala bindings (592346, 592345 and 591979). 591979 can be particularly controversial, given that it changes a typical class method, into a static function. I guess I need to ping somebody.

On the Bacon Video Widget port to Vala, some advances had came, but still there’s nothing to show yet.