mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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468cb05597
Original commit message from CVS:
* gst/gstbuffer.override:
the GstBuffer overrides seem to be confused about whether they're
mini-objects or a GBoxed, and it makes copy_on_write no actually
return a usable gst.Buffer. Fix up places where GstBuffers are
treated as GBoxed to use pygstminiobject functions.
Makes gst.Buffer('blah').copy_on_write() work.
* testsuite/test_buffer.py:
Add test for copy-on-write writability
* examples/buffer-draw.py:
Add an example of drawing on a GStreamer buffer with cairo
* gst/gstpad.override:
Make function static
138 lines
4.5 KiB
Python
138 lines
4.5 KiB
Python
#!/usr/bin/env python
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import sys
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import traceback
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from math import pi
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import pygtk
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pygtk.require ("2.0")
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import gobject
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gobject.threads_init()
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import pygst
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pygst.require('0.10')
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import gst
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import cairo
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WIDTH, HEIGHT = 640, 480
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FRAMES = 300
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FRAMERATE = 15
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class PyGstBufferDraw(gst.Element):
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_sinkpadtemplate = gst.PadTemplate ("sink",
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gst.PAD_SINK,
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gst.PAD_ALWAYS,
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gst.caps_from_string ("video/x-raw-rgb,bpp=32,depth=32,blue_mask=-16777216,green_mask=16711680, red_mask=65280, alpha_mask=255,width=[ 1, 2147483647 ],height=[ 1, 2147483647 ],framerate=[ 0/1, 2147483647/1 ]"))
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_srcpadtemplate = gst.PadTemplate ("src",
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gst.PAD_SRC,
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gst.PAD_ALWAYS,
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gst.caps_from_string ("video/x-raw-rgb,bpp=32,depth=32,blue_mask=-16777216,green_mask=16711680, red_mask=65280, alpha_mask=255,width=[ 1, 2147483647 ],height=[ 1, 2147483647 ],framerate=[ 0/1, 2147483647/1 ]"))
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def __init__(self):
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gst.Element.__init__(self)
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self.sinkpad = gst.Pad(self._sinkpadtemplate, "sink")
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self.sinkpad.set_chain_function(self.chainfunc)
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self.sinkpad.set_event_function(self.eventfunc)
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self.sinkpad.set_getcaps_function(gst.Pad.proxy_getcaps)
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self.sinkpad.set_setcaps_function(gst.Pad.proxy_setcaps)
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self.add_pad (self.sinkpad)
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self.srcpad = gst.Pad(self._srcpadtemplate, "src")
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self.srcpad.set_event_function(self.srceventfunc)
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self.srcpad.set_query_function(self.srcqueryfunc)
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self.srcpad.set_getcaps_function(gst.Pad.proxy_getcaps)
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self.srcpad.set_setcaps_function(gst.Pad.proxy_setcaps)
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self.add_pad (self.srcpad)
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def chainfunc(self, pad, buffer):
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try:
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outbuf = buffer.copy_on_write ()
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self.draw_on (outbuf)
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return self.srcpad.push (outbuf)
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except:
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return GST_FLOW_ERROR
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def eventfunc(self, pad, event):
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return self.srcpad.push_event (event)
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def srcqueryfunc (self, pad, query):
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return self.sinkpad.query (query)
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def srceventfunc (self, pad, event):
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return self.sinkpad.push_event (event)
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def draw_on (self, buf):
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try:
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caps = buf.get_caps()
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width = caps[0]['width']
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height = caps[0]['height']
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framerate = caps[0]['framerate']
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surface = cairo.ImageSurface.create_for_data (buf, cairo.FORMAT_ARGB32, width, height, 4 * width)
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ctx = cairo.Context(surface)
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except:
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print "Failed to create cairo surface for buffer"
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traceback.print_exc()
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return
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try:
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center_x = width/4
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center_y = 3*height/4
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# draw a circle
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radius = float (min (width, height)) * 0.25
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ctx.set_source_rgba (0.0, 0.0, 0.0, 0.9)
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ctx.move_to (center_x, center_y)
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ctx.arc (center_x, center_y, radius, 0, 2.0*pi)
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ctx.close_path()
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ctx.fill()
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ctx.set_source_rgba (1.0, 1.0, 1.0, 1.0)
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ctx.set_font_size(0.3 * radius)
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txt = "Hello World"
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extents = ctx.text_extents (txt)
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ctx.move_to(center_x - extents[2]/2, center_y + extents[3]/2)
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ctx.text_path(txt)
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ctx.fill()
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except:
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print "Failed cairo render"
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traceback.print_exc()
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gobject.type_register(PyGstBufferDraw)
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pipe = gst.Pipeline()
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vt = gst.element_factory_make ("videotestsrc")
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cf = gst.element_factory_make ("capsfilter")
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c1 = PyGstBufferDraw()
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color = gst.element_factory_make ("ffmpegcolorspace")
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scale = gst.element_factory_make ("videoscale")
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q1 = gst.element_factory_make ("queue")
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sink = gst.element_factory_make ("autovideosink")
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caps = gst.caps_from_string ("video/x-raw-rgb,width=%d,height=%d,framerate=%d/1" % (WIDTH, HEIGHT, FRAMERATE))
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cf.set_property ("caps", caps)
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vt.set_property ("num-buffers", FRAMES)
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pipe.add (vt, cf, c1, q1, color, scale, sink)
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gst.element_link_many (vt, cf, c1, q1, color, scale, sink)
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def on_eos (bus, msg):
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mainloop.quit()
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bus = pipe.get_bus()
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bus.add_signal_watch()
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bus.connect('message::eos', on_eos)
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pipe.set_state (gst.STATE_PLAYING)
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mainloop = gobject.MainLoop()
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try:
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mainloop.run()
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except:
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pass
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pipe.set_state (gst.STATE_NULL)
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pipe.get_state (gst.CLOCK_TIME_NONE)
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