gstreamer2.py

# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the 'License');
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an 'AS IS' BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import sys
from functools import partial
import svgwrite
import numpy as np

import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstBase', '1.0')
from gi.repository import GLib, GObject, Gst, GstBase
from PIL import Image

GObject.threads_init()
Gst.init(None)


def on_bus_message(bus, message, loop):
    t = message.type
    if t == Gst.MessageType.EOS:
        loop.quit()
    elif t == Gst.MessageType.WARNING:
        err, debug = message.parse_warning()
        sys.stderr.write('Warning: %s: %s\n' % (err, debug))
    elif t == Gst.MessageType.ERROR:
        err, debug = message.parse_error()
        sys.stderr.write('Error: %s: %s\n' % (err, debug))
        loop.quit()
    return True


def on_new_sample(sink, overlay, screen_size, appsink_size,
                  user_function):
    sample = sink.emit('pull-sample')
    buf = sample.get_buffer()
    result, mapinfo = buf.map(Gst.MapFlags.READ)
    if result:
        img = np.frombuffer(mapinfo.data, np.uint8)
        img = np.reshape(img, [appsink_size[1], appsink_size[0], -1])
        svg_canvas = svgwrite.Drawing('', size=(screen_size[0], screen_size[1]))
        appsrc_image = user_function(img, svg_canvas)
        overlay.set_property('data', svg_canvas.tostring())
    buf.unmap(mapinfo)
    return Gst.FlowReturn.OK


def run_pipeline(user_function,
                 src_size=(640, 480),
                 appsink_size=(320, 180),
                 camera='ip'):
    if camera == 'ip':
        SRC = """rtspsrc location=rtsp://admin:1Bigred1@192.168.0.51:554//h264Preview_01_sub
        ! {src_caps} ! rtpjitterbuffer latency=300 ! rtph264depay ! h264parse ! omxh264dec"""
        SRC_CAPS = "application/x-rtp,media=(string)video,encoding-name=(string)H264,payload=(int)96,width=(int){width},height=(int){height}"
        FINAL_Q = "queue"
    elif camera == 'built-in':
        SRC = """nvarguscamerasrc ! {src_caps}"""
        SRC_CAPS = "video/x-raw(memory:NVMM),format=(string)NV12,framerate=(fraction)120/1,width=(int){width},height=(int){height}"
        FINAL_Q = "{leaky_q}"
    elif camera == 'realsense':
        SRC = """v4l2src device=/dev/video3 do-timestamp=true ! {src_caps}"""
        SRC_CAPS = "video/x-raw,format=(string)YUY2,framerate=(fraction)30/1,width=(int){width},height=(int){height}"
        FINAL_Q = "{leaky_q}"

    PIPELINE = """ {src} 
        ! tee name=t
        t. ! nvvidconv ! video/x-raw(memory:NVMM) ! nvvidconv ! {accelerated_sink_caps} ! videoconvert ! {sink_caps} ! {leaky_q} ! {sink_element}
        t. ! nvvidconv ! video/x-raw(memory:NVMM),format=(string)BGRx ! nvvidconv ! video/x-raw ! videoconvert ! rsvgoverlay name=overlay ! videoconvert ! nvvidconv
           ! {final_q} ! nvegltransform ! nveglglessink window-width={width} window-height={height}
    """

    ACCELERATED_SINK_CAPS = "video/x-raw,format=RGBA,width={width},height={height}"
    LEAKY_Q = 'queue max-size-buffers=1 leaky=downstream'
    SINK_ELEMENT = 'appsink name=appsink sync=false emit-signals=true max-buffers=1 drop=true'

    SINK_CAPS = "video/x-raw,format=RGB,width={width},height={height}"

    src_caps = SRC_CAPS.format(width=src_size[0], height=src_size[1])
    src = SRC.format(src_caps=src_caps)
    accelerated_sink_caps = ACCELERATED_SINK_CAPS.format(width=appsink_size[0], height=appsink_size[1])
    sink_caps = SINK_CAPS.format(width=appsink_size[0], height=appsink_size[1])
    final_q = FINAL_Q.format(leaky_q=LEAKY_Q)

    pipeline = PIPELINE.format(width=src_size[0], height=src_size[1], leaky_q=LEAKY_Q, src=src, src_caps=src_caps,
                               accelerated_sink_caps=accelerated_sink_caps,
                               sink_caps=sink_caps, sink_element=SINK_ELEMENT,
                               final_q=final_q)

    print('Gstreamer pipeline: ', pipeline)
    pipeline = Gst.parse_launch(pipeline)
    appsink = pipeline.get_by_name('appsink')
    overlay = pipeline.get_by_name('overlay')

    appsink.connect('new-sample', partial(on_new_sample,
                                          overlay=overlay,
                                          screen_size=src_size, appsink_size=appsink_size,
                                          user_function=user_function))
    loop = GObject.MainLoop()

    # Set up a pipeline bus watch to catch errors.
    bus = pipeline.get_bus()
    bus.add_signal_watch()
    bus.connect('message', on_bus_message, loop)

    # Run pipeline.
    pipeline.set_state(Gst.State.PLAYING)
    try:
        loop.run()
    except:
        pass

    # Clean up.
    pipeline.set_state(Gst.State.NULL)
    while GLib.MainContext.default().iteration(False):
        pass