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ラズベリーパイのgstreamer-1.0 pythonスクリプトを実行しようとしています（以下、ウブントノートPCでうまく動作します）。しかし、ストリームをデコードすることができないようだ。ラズベリーPiのgstreamer-1.0：H.264ストリームをデコードできません
0:00:11.237415476 9605 0xafb0cc60 ERROR vaapidecode ../../../gst/vaapi/gstvaapidecode.c:1025:gst_vaapidecode_ensure_allowed_caps: failed to retrieve VA display
0:00:11.239490439 9605 0xafb0cc60 WARN decodebin gstdecodebin2.c:2087:connect_pad:<decodebin0> Link failed on pad vaapidecode0:sink
0:00:11.244097356 9605 0xafb0cc60 WARN uridecodebin gsturidecodebin.c:939:unknown_type_cb:<decoder> warning: No decoder available for type 'video/x-h264, stream-format=(string)byte-stream, alignment=(string)nal, width=(int)426, height=(int)240, framerate=(fraction)30/1, parsed=(boolean)true, pixel-aspect-ratio=(fraction)1/1, level=(string)2.1, profile=(string)main'.
私はエラーに関する情報検索（結果は私を啓発していない）と警告が、実際にインストールするよりも、他の多くのアドバイスを見つけることができませんでしたすでにインストールされているgstreamer1.0-libavです。その結果、デコーダが利用可能になるはずです。
ここで間違っている可能性がありますが、どうすれば修正できますか？
これはスクリプトです：あなたが設定した
#!/usr/bin/env python
# GST_DEBUG=3,python:5,gnl*:5 python 01_parsepipeline.py http://www.ustream.tv/channel/17074538 worst novideo.png
from __future__ import print_function
import sys
import gi
from gi.repository import GObject as gobject, Gst as gst
from livestreamer import Livestreamer, StreamError, PluginError, NoPluginError
import cv2
import numpy
def exit(msg):
print(msg, file=sys.stderr)
sys.exit()
class Player(object):
def __init__(self):
self.fd = None
self.mainloop = gobject.MainLoop()
# This creates a playbin pipeline and using the appsrc source
# we can feed it our stream data
self.pipeline = gst.parse_launch('uridecodebin uri=appsrc:// name=decoder \
decoder. ! videorate ! video/x-raw,framerate=1/1 ! tee name=t \
t. ! queue ! videoconvert ! video/x-raw,format=RGB ! appsink name=appsink \
decoder. ! queue ! audioconvert ! fakesink')
if self.pipeline is None:
exit("couldn't build pipeline")
decoder = self.pipeline.get_by_name('decoder')
if decoder is None:
exit("couldn't get decoder")
decoder.connect("source-setup", self.on_source_setup)
vsink = self.pipeline.get_by_name('appsink')
if vsink is None:
exit("couldn't get sink")
vsink.set_property("emit-signals", True)
vsink.set_property("max-buffers", 1)
vsink.connect("new-sample", self.on_new_sample)
# Creates a bus and set callbacks to receive errors
self.bus = self.pipeline.get_bus()
self.bus.add_signal_watch()
self.bus.connect("message::eos", self.on_eos)
self.bus.connect("message::error", self.on_error)
def on_new_sample(self, sink):
sample = sink.emit("pull-sample")
buf = sample.get_buffer()
caps = sample.get_caps()
height = caps.get_structure(0).get_value('height')
width = caps.get_structure(0).get_value('width')
(result, mapinfo) = buf.map(gst.MapFlags.READ)
if result == True:
arr = numpy.ndarray(
(height,
width,
3),
buffer=buf.extract_dup(0, buf.get_size()),
dtype=numpy.uint8)
resized_refimage = cv2.resize(refArray, (width, height))
diff = cv2.norm(arr, resized_refimage, cv2.NORM_L2)
buf.unmap(mapinfo)
s = "diff = " + str(diff)
print(s)
return gst.FlowReturn.OK
def exit(self, msg):
self.stop()
exit(msg)
def stop(self):
# Stop playback and exit mainloop
self.pipeline.set_state(gst.State.NULL)
self.mainloop.quit()
# Close the stream
if self.fd:
self.fd.close()
def play(self, stream):
# Attempt to open the stream
try:
self.fd = stream.open()
except StreamError as err:
self.exit("Failed to open stream: {0}".format(err))
# Start playback
self.pipeline.set_state(gst.State.PLAYING)
self.mainloop.run()
def on_source_setup(self, element, source):
# When this callback is called the appsrc expects
# us to feed it more data
print("source setup")
source.connect("need-data", self.on_source_need_data)
print("done")
def on_pad_added(self, element, pad):
string = pad.query_caps(None).to_string()
print(string)
if string.startswith('video/'):
#type = pad.get_caps()[0].get_name()
#print(type)
#if type.startswith("video"):
pad.link(self.vconverter.get_static_pad("sink"))
def on_source_need_data(self, source, length):
# Attempt to read data from the stream
try:
data = self.fd.read(length)
except IOError as err:
self.exit("Failed to read data from stream: {0}".format(err))
# If data is empty it's the end of stream
if not data:
source.emit("end-of-stream")
return
# Convert the Python bytes into a GStreamer Buffer
# and then push it to the appsrc
buf = gst.Buffer.new_wrapped(data)
source.emit("push-buffer", buf)
#print("sent " + str(length) + " bytes")
def on_eos(self, bus, msg):
# Stop playback on end of stream
self.stop()
def on_error(self, bus, msg):
# Print error message and exit on error
error = msg.parse_error()[1]
self.exit(error)
def main():
if len(sys.argv) < 4:
exit("Usage: {0} <url> <quality> <reference png image path>".format(sys.argv[0]))
# Initialize and check GStreamer version
gi.require_version("Gst", "1.0")
gobject.threads_init()
gst.init(None)
# Collect arguments
url = sys.argv[1]
quality = sys.argv[2]
refImage = sys.argv[3]
global refArray
image = cv2.imread(refImage)
refArray = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
# refArray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
refArray = cv2.blur(refArray, (3,3))
# Create the Livestreamer session
livestreamer = Livestreamer()
# Enable logging
livestreamer.set_loglevel("debug")
livestreamer.set_logoutput(sys.stdout)
# Attempt to fetch streams
try:
streams = livestreamer.streams(url)
except NoPluginError:
exit("Livestreamer is unable to handle the URL '{0}'".format(url))
except PluginError as err:
exit("Plugin error: {0}".format(err))
if not streams:
exit("No streams found on URL '{0}'".format(url))
# Look for specified stream
if quality not in streams:
exit("Unable to find '{0}' stream on URL '{1}'".format(quality, url))
# We found the stream
stream = streams[quality]
# Create the player and start playback
player = Player()
# Blocks until playback is done
player.play(stream)
if __name__ == "__main__":
main()