GStreamer and opencv player versions.

2026-07-03 16:58:35 +08:00 · 2011-07-17 17:45:17 +02:00
parent 06b0ddab67
commit 050f83bb23
1 changed files with 135 additions and 0 deletions
@@ -0,0 +1,135 @@
+import cv
+import numpy as np
+import pygst
+import os, time
+pygst.require("0.10")
+import gst, gobject
+gobject.threads_init()
+from gst.extend.discoverer import Discoverer
+
+class CvVideo(object):
+    """
+    Opencv-based video player.
+
+    Parameters
+    ----------
+    source : str
+        Media location.
+    size: tuple, optional
+        Size of returned array.
+    """
+    def __init__(self, source, size=None):
+        self.source = source
+        self.capture = cv.CreateFileCapture(self.source)
+        self.size = size
+        
+    def get(self):
+        """
+        Retrieve a video frame as a numpy array.
+        """
+        img = cv.QueryFrame(self.capture)
+        if not self.size:
+            self.size = cv.GetSize(img)
+        img_mat = np.empty((self.size[1], self.size[0], 3), dtype=np.uint8)
+        if cv.GetSize(img) == self.size:
+            cv.Copy(img, img_mat)
+        else:
+            cv.Resize(img, img_mat)
+        return img_mat
+    
+        
+class GstVideo(object):
+    """
+    GStreamer-based video player.
+
+    Parameters
+    ----------
+    source : str
+        Media location.
+    size: tuple, optional
+        Size of returned array.
+    sync: bool, optional
+        Frames are extracted per frame or per time basis.
+    """
+    def __init__(self, source, size=None, sync=False):
+        self.source = source
+        self.size = size
+        self.time_format = gst.Format(gst.FORMAT_TIME)
+
+        # extract video size
+        if not size: 
+            gobject.idle_add(self._discover_one)
+            self.mainloop = gobject.MainLoop()
+            self.mainloop.run()
+        if not self.size:
+            self.size = (640, 480)
+        if os.path.exists(self.source):
+            self.source = "file://" + self.source
+        self._create_main_pipeline(self.source, self.size, sync)
+
+    def _discover_one(self):
+        """
+        Callback to start media discovery process.
+        """
+        discoverer = Discoverer(self.source)
+        discoverer.connect('discovered', self._discovered)
+        discoverer.discover()          
+        return False
+
+    def _discovered(self, d, is_media):
+        """
+        Callback to on media discovery result.
+        """
+        if is_media:
+            self.size = (d.videowidth, d.videoheight)            
+        self.mainloop.quit()
+        return False
+    
+    def _create_main_pipeline(self, source, size, sync):
+        """ 
+        Create the frame extraction pipeline.
+        """
+        pipeline_string = "uridecodebin name=decoder uri=%s ! ffmpegcolorspace ! videoscale ! appsink name=play_sink" % self.source
+        self.pipeline = gst.parse_launch(pipeline_string)
+        caps = "video/x-raw-rgb, width=%d, height=%d, depth=24, bpp=24" % size
+        self.decoder = self.pipeline.get_by_name("decoder")
+        self.appsink = self.pipeline.get_by_name('play_sink')
+        self.appsink.set_property('emit-signals', True)
+        self.appsink.set_property('sync', sync)
+        self.appsink.set_property('drop', True)
+        self.appsink.set_property('max-buffers', 1)
+        self.appsink.set_property('caps', gst.caps_from_string(caps))
+        if self.pipeline.set_state(gst.STATE_PLAYING) == gst.STATE_CHANGE_FAILURE:
+            raise NameError("Failed to load video source %s" % self.source)
+	    buff = self.appsink.emit('pull-preroll')
+      
+    def get(self):
+        """
+        Retrieve a video frame as a numpy array.
+        """
+        buff = self.appsink.emit('pull-buffer')
+        img_mat = np.ndarray(shape=(self.size[1], self.size[0], 3), dtype='uint8', buffer=buff.data)
+        return img_mat
+
+   
+
+if __name__ == '__main__':
+    cv.NamedWindow ('display', cv.CV_WINDOW_AUTOSIZE)
+    cv.MoveWindow("display", 100, 100);
+    #camera = GstVideo(source="http://146.232.169.185/video.mjpg")
+    camera = GstVideo(source="/home/tzhau/hacking/video/ing1.avi", sync=1)
+    #camera = CvVideo(source="/home/tzhau/hacking/video/ing1.avi")
+    camera.seek_frame(200)
+    i = 0
+    while 1:
+        i += 1
+        #print 'hey'
+        #time.sleep(0.5)
+        #print 'hallo'
+        a = time.time()
+        img = camera.get()
+
+        b = time.time()
+        print b-a
+        cv.ShowImage('display', img)
+        cv.WaitKey(100)