diff options
Diffstat (limited to 'ext/directfb/dfbvideosink.c')
| -rw-r--r-- | ext/directfb/dfbvideosink.c | 68 |
1 files changed, 66 insertions, 2 deletions
diff --git a/ext/directfb/dfbvideosink.c b/ext/directfb/dfbvideosink.c index 47b2cd2f..84dd0407 100644 --- a/ext/directfb/dfbvideosink.c +++ b/ext/directfb/dfbvideosink.c @@ -17,6 +17,66 @@ * Boston, MA 02111-1307, USA. */ +/** + * SECTION:element-dfbvideosink + * + * <refsect2> + * <para> + * DfbVideoSink renders video frames using the + * <ulink url="http://www.directfb.org/">DirectFB</ulink> library. + * Rendering can happen in two different modes : + * <itemizedlist> + * <listitem> + * <para> + * Standalone: this mode will take complete control of the monitor forcing + * <ulink url="http://www.directfb.org/">DirectFB</ulink> to fullscreen layout. + * This is convenient to test using the gst-launch command line tool or + * other simple applications. It is possible to interrupt playback while + * being in this mode by pressing the Escape key. + * </para> + * <para> + * This mode handles navigation events for every input device supported by + * the <ulink url="http://www.directfb.org/">DirectFB</ulink> library, it will + * look for available video modes in the fb.modes file and try to switch + * the framebuffer video mode to the most suitable one. Depending on + * hardware acceleration capabilities the element will handle scaling or not. + * If no acceleration is available it will do clipping or centering of the + * video frames respecting the original aspect ratio. + * </para> + * </listitem> + * <listitem> + * <para> + * Embedded: this mode will render video frames in a + * <link linkend="GstDfbVideoSink--surface">surface</link> provided by the + * application developer. This is a more advanced usage of the element and + * it is required to integrate video playback in existing + * <ulink url="http://www.directfb.org/">DirectFB</ulink> applications. + * </para> + * <para> + * When using this mode the element just renders to the + * <link linkend="GstDfbVideoSink--surface">surface</link> provided by the + * application, that means it won't handle navigation events and won't resize + * the <link linkend="GstDfbVideoSink--surface">surface</link> to fit video + * frames geometry. Application has to implement the necessary code to grab + * informations about the negotiated geometry and resize there + * <link linkend="GstDfbVideoSink--surface">surface</link> accordingly. + * </para> + * </listitem> + * </itemizedlist> + * For both modes the element implements a buffer pool allocation system to + * optimize memory allocation time and handle reverse negotiation. Indeed if + * you insert an element like videoscale in the pipeline the video sink will + * negotiate with it to try get a scaled video for either the fullscreen layout + * or the application provided external + * <link linkend="GstDfbVideoSink--surface">surface</link>. + * </para> + * <title>Example application</title> + * <para> + * <include xmlns="http://www.w3.org/2003/XInclude" href="element-dfb-example.xml" /> + * </para> + * </refsect2> + */ + #ifdef HAVE_CONFIG_H #include "config.h" #endif @@ -1392,11 +1452,15 @@ gst_dfbvideosink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size, gst_structure_set (structure, "height", G_TYPE_INT, result.h, NULL); if (gst_pad_accept_caps (peer, desired_caps)) { - GST_DEBUG ("peed pad accepts our desired caps %" GST_PTR_FORMAT, - desired_caps); + gint bpp; + + bpp = size / height / width; rev_nego = TRUE; width = result.w; height = result.h; + size = bpp * width * height; + GST_DEBUG ("peed pad accepts our desired caps %" GST_PTR_FORMAT + " buffer size is now %d bytes", desired_caps, size); } else { GST_DEBUG ("peer pad does not accept our desired caps %" GST_PTR_FORMAT, desired_caps); |