According to Qt, props must have a read method

And more :)

hack adapted from the qt interface.

close #7876

avcodec contains codecs that don't like variable size frames, so feed
avcodec with frame_size chunks and and handle leftovers ourself. This
functionality was dropped when flushing was introduced and seemed to
work without just fine, I was proven wrong.

avcodec: aout_BitsPerSample uses  vlc_fourcc_GetCodec itself, so no need to call it ourselves in here

Doing it in the callback cause deadlocks.

It seems that standard OpenGL 2.0 requires version number to be equal to 120 contrary to OpenGL ES 2.0 that requires it to be equal to 100.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

This avoid leaks at segment changes.

minor announcement stuff left to do