change "location" of filesrc element without breaking tcpserversink connection

Mon Jul 29 14:24:22 PDT 2013

Thank you for answer,
 I have tried change the location in the thread and now I have only one
error:

Error: GStreamer encountered a general stream error. qtdemux.c(3891):
gst_qtdemux_loop ():
/GstPipeline:player/GstDecodeBin2:decoder/GstQTDemux:qtdemux0:
streaming stopped, reason not-negotiated

I just put to STATE_NULL decodebin2 and filesrc, change location, and put
them back to play.

Thank you for your help

2013/7/29 Sergio Ortega <sortegagamero at gmail.com>

> What kind of errors have you got? Could you put here the logs?
>
> When do you have to change the location? Well, basically when you want. If
> you want to play a video until its end then you have to wait for the EOS
> event. If you want to do it at second 20, then you must wait for the
> corresponding DTS buffer. I forgot to tell you one thing. You can't do a
> seek or set to NULL an element from within the event probe. You must start
> a thread ( usually a pthread or a GTask) and do it from outside of the
> probe. Of course the probe must wait for the operation, so that also
> implies using a semaphore.
>
> You're welcome!
>
> SERGIO
>
>
> 2013/7/29 Serhiy Stetskovych <patriotyk at gmail.com>
>
>> Thank you for so detailed explanation, I am not much familiar with
>> gstreamer so I don't understand some things. I was able to add event
>> hendler  and got all events. I was able to block and modify segment events.
>> But I can't understand when exactly I need to change the location, I get
>> two EOS events for video and audio. So when I am changing location in any
>> of them I got many errors.
>> Thank you
>>
>>
>> 2013/7/26 Sergio Ortega <sortegagamero at gmail.com>
>>
>>> Hi,
>>>
>>> What you are trying to do is simulating a live from a file, aren't you?
>>> You don't want to break the tcpserversink connection when you change the
>>> filesrc's location. Then you must do the next thing. You must install a
>>> pad-probe outside the decodebin or whatever demuxer you use. That pad probe
>>> must do several things.
>>>
>>> The first one is modifying the first segment event. That event will have
>>> the video's original duration. It must be modified to have 0 as start and
>>> -1 as end. In such way you won't let the final muxer to know the duration,
>>> and it will assume that video has no end ( you can, of course, put whatever
>>> duration you wan, of course, for example half of the first video and the
>>> whole of the second one).
>>>
>>> The second one is blocking the rest segment events which you will have
>>> when you replace the location. We will see later how to replace it.
>>>
>>> The third thing is blocking the flush events.
>>>
>>> The fourth thing is blocking the EOS events ( if you want to play a
>>> video until the end, of course).
>>>
>>> The fifth thing ( and this is very important) is modifying the  buffer's
>>> PTS and DTS. Several muxers ( like mp4mux or oggmux) will multiplex a video
>>> and an audio depending on each PTS and DTS frame. If they detect that
>>> repeated PTS's or DTS's, they will discard the buffer, so in the best case
>>> you will see the video delayed ( in the worst you will see nothing but
>>> errors in the logs). Think that video and audio have their own PTS's and
>>> DTS's, but they are related when you replace a file ( at the end both files
>>> must maintain the synchronization).
>>>
>>> And now how to change a file. First of all emit a flush start and a
>>> flush end in the filesrc to clean the buffers. After it, put filesrc and
>>> the demuxer or the decodebin to NULL, change filesrc's location and put
>>> those elements again into PLAYING state.
>>>
>>> Watch out with the events and the DTS's!!
>>>
>>> 2013/7/26 Serhiy Stetskovych <patriotyk at gmail.com>
>>>
>>>> I think the second option with locking might help me but I don't
>>>> understand how to use it.
>>>>
>>>>
>>>> 2013/7/25 Serhiy Stetskovych <patriotyk at gmail.com>
>>>>
>>>>> Just investigated and found that after changing location, stream
>>>>> begins with new webm header. So Is it possible to create one stream from
>>>>> several files?
>>>>>
>>>>>
>>>>> 2013/7/25 Serhiy Stetskovych <patriotyk at gmail.com>
>>>>>
>>>>>> Thank you,
>>>>>> I have tried with state READY and thought it don't work, but problem
>>>>>> wasn't in connection. Looks like when file reaches end, gstreamer sends
>>>>>> some end information, or there is some gap between streams or something
>>>>>> else. Because connections still alive, but video didn't displays in
>>>>>> browser, it begin playing again after refresh(reconnect)
>>>>>>
>>>>>>
>>>>>> 2013/7/25 Stirling Westrup <swestrup at gmail.com>
>>>>>>
>>>>>>>  On Thu, Jul 25, 2013 at 6:44 AM, Serhiy Stetskovych <
>>>>>>> patriotyk at gmail.com> wrote:
>>>>>>>
>>>>>>>> Hello, I have a problem with changing media file in filesrc. After
>>>>>>>> finishing playing one file I get event and in this point I need change
>>>>>>>> media file to another but without breaking clients connected to
>>>>>>>> tcpserversink. I can change file only after setting STATE_NULL, and  then
>>>>>>>> setting back to STATE_PLAYING. But this breaks all my connections.
>>>>>>>>
>>>>>>>> Actually I use multifdsink with writing to sockets, but in
>>>>>>>> explanation above I wrote about tcpserversink because It is easier to
>>>>>>>> explain, but I think it doesnt matter.
>>>>>>>> <http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>>>>>>>>
>>>>>>> You have two options. First, you can change the media file in
>>>>>>> filesrc when you are in STATE_READY rather than STATE_NULL. You only really
>>>>>>> need to go into STATE_NULL when you are about to dismantle your pipeline
>>>>>>> (ie for program cleanup).
>>>>>>>
>>>>>>> If for some reason you have to put filesrc in a state that causes
>>>>>>> your sink to perform an action you don't like, you can LOCK the state of
>>>>>>> the sink so it ignores requests to change state. This is done with one of
>>>>>>> the gst_element_... function calls.
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Stirling Westrup
>>>>>>> Programmer, Entrepreneur.
>>>>>>> https://www.linkedin.com/e/fpf/77228
>>>>>>> http://www.linkedin.com/in/swestrup
>>>>>>> http://technaut.livejournal.com
>>>>>>> http://sourceforge.net/users/stirlingwestrup
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> gstreamer-devel mailing list
>>>>>>> gstreamer-devel at lists.freedesktop.org
>>>>>>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
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