Is it a good way to separate pipelines in order to dynamically change properties?

s_kamiya at toa.co.jp s_kamiya at toa.co.jp
Thu Aug 10 16:45:57 UTC 2023


Hi,
Mr.Nicolas.

I'm Kamiya.

I resolved the problem with the following code.
The changing point is return type. I changed  GStrv* to  GStrv. 

--------------------------------------------------
static GStrv formatLocationHandler(GstElement *src, gpointer udata)
{
   GStrv locations = (GStrv)g_new0(gchar*, 4);

   locations[0] = g_strdup("C:/Rec/2023/07/26/1808_28911.mp4");
   locations[1] = g_strdup("C:/Rec/2023/07/26/1808_38919.mp4");
   locations[2] = g_strdup("C:/Rec/2023/07/26/1808_47902.mp4");
   locations[3] = nullptr;

   return locations;
}
--------------------------------------------------

Is this  a correct way?
If it is correct way, the following document and the gst-inspect of 
splitmuxsrc seems incorrect.
https://gstreamer.freedesktop.org/documentation/multifile/splitmuxsrc.html

Best regards,
Kamiya.


SHIGEHARU KAMIYA/TOA wrote on 2023/08/08 10:32:52:
> 
> Hi,
> Mr.Nicolas.
> 
> I'm Kamiya.
> 
> Thank your for your advice.
> I changed to "GStrv *ret   = (GStrv*)g_new0(GStrv, 4);" like below 
> and no longer crashes.
> 
> -------------------------------------------
> static GStrv* formatLocationHandler(GstElement *splitmux, gpointer 
udata)
> {
>     gchar **locations = (gchar**)g_new0(gchar*, 4);
> 
>     locations[0] = g_strdup("C:/Rec/2023/07/26/1808_28911.mp4");
>     locations[1] = g_strdup("C:/Rec/2023/07/26/1808_38919.mp4");
>     locations[2] = g_strdup("C:/Rec/2023/07/26/1808_47902.mp4");
>     locations[3] = nullptr;
> 
>     GStrv *ret  = (GStrv*)g_new0(GStrv, 4);
>     std::memcpy(ret, &locations, sizeof(locations));
> 
>     return ret;
> }
> -------------------------------------------
> 
> However, splitmuxsrc output the below error.
> 
> 0:00:01.696729000 69832 000001B40D38E600 DEBUG 
> splitmuxsrc gstsplitmuxsrc.c:
> 880:gst_splitmux_src_prepare_next_part:<splitmuxsrc0> Preparing file
> part nエ (0)
> 0:00:01.697042000 69832 000001B40D38E600 ERROR 
> splitmuxpartreader gstsplitmuxpartreader.c:
> 1410:bus_handler:<splitmuxpartreader0> Got error message from child 
> <filesrc0> marking this reader as failed
> 
> "Preparing file part nエ (0)" in the log should be "Preparing file 
> part C:/Rec/2023/07/26/1808_28911.mp4 (0)".
> It seems that it's still not referenced correctly.
> 
> I also tried below code, but the result was the same.
> 
> -------------------------------------------
> static GStrv* formatLocationHandler(GstElement *src, FileLoader *obj)
> {
>    GStrv *locations = (GStrv*)g_new0(GStrv, 4);
>    *locations = (gchar**)g_new0(gchar*, 4);
> 
>    (*locations)[0] = g_strdup("C:/TOA/NR/Rec/2023/07/26/CH0001/
> 1808_28911.mp4");
>    (*locations)[1] = g_strdup("C:/TOA/NR/Rec/2023/07/26/CH0001/
> 1808_38919.mp4");
>    (*locations)[2] = g_strdup("C:/TOA/NR/Rec/2023/07/26/CH0001/
> 1808_47902.mp4");
>    (*locations)[3] = nullptr;
> 
>    return locations;
> }
> -------------------------------------------
> 
> I'm embarrassed for not understanding pointers correctly.
> Could you give me some advice or example code once more?
> 
> Best regards,
> Kamiya.
> 
> "Nicolas Dufresne" <nicolas at ndufresne.ca> wrote on 2023/08/08 03:35:25:
> > Le lundi 07 ao?t 2023 ? 20:07 +0900, geysee via gstreamer-devel a 
?crit :
> > > Hi,
> > >
> > > Mr. Nicolas.
> > >
> > >
> > > I'm Kamiya.
> > >
> > >
> > > I'm trying to combine multiple files with the splitmuxsrc signal
> > > "format_location" you advised.
> > >
> > > I haven't tried concat element yet. I thought that splitmuxsrc 
> would be more
> > > suitable because of the large number of files.
> > >
> > >
> > > It succeeded when the return value of GStrv* type was initialized as 
an
> > > array.(code below)
> > >
> > >
> > > -----------------------------
> > >
> > > static GStrv* formatLocationHandler(GstElement *splitmux, gpointer 
udata)
> > >
> > > {
> > >
> > >     gchar *locations[4];
> > >
> > >
> > >     locations[0] = g_strdup("C:/Rec/2023/07/26/1808_28911.mp4");
> > >
> > >     locations[1] = g_strdup("C:/Rec/2023/07/26/1808_38919.mp4");
> > >
> > >     locations[2] = g_strdup("C:/Rec/2023/07/26/1808_47902.mp4");
> > >
> > >     locations[3] = nullptr;
> > >
> > >
> > >     GStrv *ret  = (GStrv*)g_new0(GStrv, 1);
> > >
> > >     std::memcpy(ret, &locations, sizeof(locations));

> > You have 1 pointer allocated, but memcopy 4, this is going to 
overflow.

> > >
> > >
> > >
> > >     return ret;
> > >
> > > }
> > >
> > > -----------------------------
> > >
> > >
> > > On the other hand, if the return value was dynamically 
> allocated, it will be
> > > crashed after exiting formatLocationHandler.(code below)
> > >
> > >
> > > -----------------------------
> > >
> > > static GStrv* formatLocationHandler(GstElement *splitmux, gpointer 
udata)
> > >
> > > {
> > >
> > >     gchar **locations = (gchar**)g_new0(gchar*, 4);
> > >
> > >
> > >     locations[0] = g_strdup("C:/Rec/2023/07/26/1808_28911.mp4");
> > >
> > >     locations[1] = g_strdup("C:/Rec/2023/07/26/1808_38919.mp4");
> > >
> > >     locations[2] = g_strdup("C:/Rec/2023/07/26/1808_47902.mp4");
> > >
> > >     locations[3] = nullptr;
> > >
> > >
> > >     GStrv *ret  = (GStrv*)g_new0(GStrv, 1);
> > >
> > >     std::memcpy(ret, &locations, sizeof(locations));

> > Same bug, it just worked by accident previously.

> > >
> > >
> > >
> > >     return ret;
> > >
> > > }
> > >
> > > -----------------------------
> > >
> > >
> > > Could you tell me how to dynamically allocate the file list in
> > > formatLocationHandler ?
> > >
> > > I am very embarrassed that it may be a basic problem with C 
> > language or GLib,
> > > but I have been unable to solve it for a long time, so I would 
> > appreciate your
> > > help.
> > >
> > >
> > > Best regards,
> > >
> > > Kamiya.
> > >
> > >
> > >
> > > SHIGEHARU KAMIYA/TOA wrote on 2023/08/03 12:04:11:
> > >
> > > >
> > > > Hi,
> > >
> > > > Mr. Nicolas.
> > >
> > > >
> > > > Thank you for your reply.
> > >
> > > > Your way looks nice!
> > >
> > > >
> > > > I am trying it now.
> > >
> > > > I will let you know the results later.
> > >
> > > >
> > > > Thank you.
> > >
> > > > Kamiya.
> > >
> > > >
> > > > "gstreamer-devel" <gstreamer-devel-bounces at lists.freedesktop.org>
> > > > wrote on 2023/08/03 07:09:52:
> > >
> > > > >
> > > > > Hi,
> > >
> > > > > Le mar. 1 ao?t 2023, 03 h 15, geysee via gstreamer-devel <
> > > > > gstreamer-devel at lists.freedesktop.org> a ?crit :
> > >
> > > > > > Hello
> > > > > > I am Kamiya.
> > > > > >
> > > > > > I have a question.
> > > > > >
> > > > > > Is it a good way to separate pipelines in order to 
> dynamically change
> > > > > > properties
> > > > > > that cannot be changed in the PLAYING state, such as the 
location
> > > property
> > > > > > in filesrc?
> > >
> > > > >
> > > > > It can be a good method. But from what you described below, 
> you may get
> > > > > easier results with concat element instead. splitmuxsrc should
> > work, there
> > > > > is a signal to query the filename from your app instead of 
> > using the glob.
> > >
> > > > >
> > > > > >
> > > > > > I'm sorry for the long post, but the background of the 
> question is as
> > > > > > follows.
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > 
> > 
----------------------------------------------------------------------------
> > > -----------------------------------------------------
> > > > > > I'm making a system that records video from a network camera 
while
> > > > > > dividing it into files.
> > > > > > If the file is split at 10 minute intervals, the file pathwill 
be as
> > > > > > follows.
> > > > > >
> > > > > > C:/Rec/2023/07/31/1330_00000.mp4
> > > > > > C:/Rec/2023/07/31/1340_00000.mp4
> > > > > > C:/Rec/2023/07/31/1350_00000.mp4
> > > > > >
> > > > > > With gstreamer C++ coding, I am trying to export as a single 
file by
> > > > > > specifying the date and time range from the divided recording 
files.
> > > > > >
> > > > > > If the date and time range is in one file, like 13:32 - 13:
> > 34, then the
> > > > > > pipeline below has been successful. (Properties are omitted)
> > > > > >
> > > > > > pileline : filesrc ! qtdemux ! h265parse ! queue ! qtmux ! 
filesink
> > > > > >
> > > > > > On the other hand, if the date and time range is split into 
multiple
> > > > > > files, like 7/31 20:00 - 8/1 10:00, this pipeline fails.
> > > > > >
> > > > > > First, I tried multifilesrc and splitmuxsrc, but the 
> location property
> > > is
> > > > > > a glob pattern, it didn't fit the file path of date and time.
> > > > > > Next, I tried updating the location property of filesrc 
> sequentially,
> > > but
> > > > > > I couldn't change the location when this state is PLAYING.
> > > > > >
> > > > > > So now I'm trying to divide the pipeline into two as follows.
> > > > > >
> > > > > > pipeline1 : filesrc ! qtdemux ! h265parse ! appsink
> > > > > > pipeline2 : appsrc ! queue ! qtmux ! filesink
> > > > > >
> > > > > > When pipeline1 reaches the end of stream, I change the state 
of
> > > pipeline1
> > > > > > to Ready.
> > > > > > Next I change the location of filesrc. Finaly I change 
> stateto PLAYING
> > > > > > again.
> > > > > > The State of pipeline2 is not changed.
> > > > > >
> > > > > > However this way has not been successful yet. There are 
> more problems
> > > than
> > > > > > single pipeline.
> > > > > >
> > > > > > Currently looking into the following issues:
> > > > > > If there was single pipeline it was processed at high 
> speed,but if the
> > > > > > pipeline is divided, the processing time will be as per 
> the timestamp.
> > > > > >
> > > > > > Is it a good way to split the pipeline like this?
> > > > > > I would appreciate if you give me some advice.
> > > > > >
> > > > > >
> > > > >
> > > > 
> > 
----------------------------------------------------------------------------
> > > -----------------------------------------------------
> > > > > >
> > > > > > Best regards,
> > > > > > Kamiya.
> > >
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