Whoops, you are starting your QProcess twice:
101: self.proc.start(command)
106: QtCore.QTimer.singleShot(100, partial(self.proc.start, command))
And also you aren't making use of that partial callback...
def dataReady(self, proc):
# make sure you are first converting the QByteArray
# to a string, and then stripping the string.
out = str(proc.readAllStandardOutput())
self.log.append(out.strip())
...
def export(self):
...
# probably dont need to save it as a member
# but pass it a parent
proc = QtCore.QProcess(self)
# connect signals first
proc.started.connect(self.started)
proc.readyReadStandardOutput.connect(partial(self.dataReady, proc))
proc.finished.connect(self.finished)
# start
proc.start(command)
On Tue, Mar 19, 2013 at 9:36 AM, Ricardo Viana <[email protected]> wrote:
> Thanks. i m trying Qprocess now.
> i can get the started and finished feedback. but nothing in between... :(
>
> i even changed from avconv to ffmpeg to see if its something w the command.
> maybe its something to do with the stdout from the command line app!?!?
>
> here is the latest.
>
> https://gist.github.com/RicardoViana/5190548
>
>
>
>
>
>
> On 03/18/2013 07:57 PM, Justin Israel wrote:
>
> This works fine as a test, when I change these lines:
>
> command = 'for i in {1..5}; do echo $i; sleep 1; done'
> self.proc=subprocess.Popen(command, shell=True,
> stdout=subprocess.PIPE)
>
> Also, you can just connect the button right to the slot:
>
> saveFile = QtGui.QPushButton('Export')
> saveFile.clicked.connect(self.export)
>
> Now here is a down side of the subprocess approach. What if the
> application takes a while to print a line? That means your application will
> still hang on that line, then process events, then wait on another line. I
> still think you should explore the QProcess approach.
>
>
>
>
> On Mar 19, 2013, at 8:06 AM, Ricardo Viana wrote:
>
> Thanks for the help man. Learning quite a lot of python just by joining
> this group.
>
> here is the link:
>
> https://gist.github.com/RicardoViana/5189872
>
>
> cheers
> Ricardo Viana
>
>
> On 03/18/2013 06:53 PM, Justin Israel wrote:
>
> Can you post a full example on pastsbin or gist? It sounds like something
> is happening before the event loop.
> Also for subprocess, you should pass the command as a list so you don't
> need shell=True
>
> command=["avconv", "-i", self.inputFile, "-b",
> self.bitRatesList[self.bitRate.currentIndex()], "-s",
> self.sizeList[self.sizeSel.cur rentIndex()], self.outputFile]
>
> Generally though, I think the QProcess approach is more robust as it plays
> nicely with the event loop.
>
> With the qtimer then reason I was using it plus a 100 ms timeout was to
> have the callback placed into the event loop and run after the app had
> fully started and signals would work. In a real case, the process would
> probably get started by some action in your running app. Like a button
> press or a response to some signal.
> On Mar 18, 2013 11:00 PM, "Ricardo Viana" <[email protected]> wrote:
>
>> Thank you very much for the help Justin.
>>
>> i followed your code on gist.
>>
>> here is what i have now:
>>
>> -----code----
>>
>>
>> def timer(self):
>> QtCore.QTimer.singleShot(100,self.export)
>>
>>
>>
>> def export(self):
>> self.log.append("started")
>>
>> self.proc=subprocess.Popen("avconv -i %s -b %s -s %s %s"
>> %(self.inputFile,self.bitRatesList[self.bitRate.currentIndex()],
>>
>> self.sizeList[self.sizeSel.currentIndex()],self.outputFile),shell=True,stdout=subprocess.PIPE)
>> while True:
>> output=self.proc.stdout.readline()
>> if not output:
>> break
>> QtGui.qApp.processEvents()
>> self.log.append(output.strip())
>>
>>
>>
>>
>> -----code----
>>
>>
>> what is happening is the following. The self.log.append("started") only
>> shows when the subprocess terminates and it should be the
>> other way around. Also i can't append the output.strip to the
>> QTextBrowser(self.log) i have. it shows nicely on the terminal but not in
>> the GUI.
>>
>> Another thing i can't figure is why i have to say to subprocess ->
>> Shell=True. In your code you don't have it. but if i run it that way
>> i get an error :
>>
>> File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
>> raise child_exception
>> OSError: [Errno 2] No such file or directory
>>
>>
>>
>>
>>
>>
>> On 03/16/2013 03:29 AM, Justin Israel wrote:
>>
>>> QProcess has signals that indicate when new data is ready to read from
>>> your process, allowing to to get line updates. Also, in your example, you
>>> are going to be blocking the event loop with your for loop.
>>>
>>> I put together an example of each of those for you here:
>>> https://gist.github.com/justinfx/5174795
>>>
>>> The first example shows how to monitor the QProcess for new output
>>>
>>> The second shows how to use subprocess in a way that you can loop over
>>> the output, but still pump the event loop. If your lines are being emitted
>>> quickly you probably don't need to make the call for every loop, but rather
>>> you could call on on every 10 lines...or 100 lines.. or whatever is
>>> appropriate to give your main gui thread a chance to process the pending
>>> events:
>>>
>>> i.e.
>>>
>>> i = 0
>>> while True:
>>> line = process.stdout.readline()
>>> if not line:
>>> break
>>>
>>> # process line
>>>
>>> # process event loop every 10 lines
>>> if i % 10 == 0:
>>> QtGui.qApp.processEvents()
>>> i +=1
>>>
>>>
>>> -- justin
>>>
>>>
>>>
>>> On Thursday, March 7, 2013 5:22:19 AM UTC+13, olheiros wrote:
>>>
>>>> Hi Fellas!
>>>>
>>>>
>>>>
>>>> i'm trying to build my own video converter gui on a Linux. Using Pyqt4.
>>>>
>>>> I'm using avconv command line converter.
>>>>
>>>>
>>>>
>>>> I have setup all parameters and it is working fine.
>>>>
>>>>
>>>>
>>>> The thing is i would like to have some kind of progress feedback.
>>>>
>>>> Does anyone know how to retrieve the command line feedback so
>>>>
>>>> i can hook it to some kind of expression to drive the QProgressBar?
>>>>
>>>>
>>>>
>>>> thank you very much
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> ////////////////////////////////////
>>>>
>>>> Ricardo Viana
>>>>
>>>> VFX Generalist
>>>>
>>>
>>
>> --
>> ////////////////////////////////////
>> Ricardo Viana
>> VFX Generalist
>>
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> --
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> VFX Generalist
>
>
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> --
> ////////////////////////////////////
> Ricardo Viana
> VFX Generalist
>
> --
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