[gst-devel] Caps problem when writing encoder/decoder

[sudarshan bisht]

I think you can't simply put any mimetype in the caps , it must be some
valid mimetype .

Please go through this link
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/pwg/html/section-types-definitions.html


On Tue, May 18, 2010 at 4:01 PM, Hunterwood <markus.jagerskogh at imentum.se>wrote:

>
> Hi,
>
> I have tried several different non-existing types: audio/x-test, audio/xyz,
> audio/x-xyz, audio/x-qwertyuiop, audio/x-test, ...
>
> Since my encoder is passing data to my decoder, I thought that the only
> imortant thing was that they have the same caps to make it work (when I'm
> finished, I want them to use a currently non-existing type), but it doesn't
> work.
> gst-inspect shows the same type for the source of the encoder and the sink
> of the decoder, but when trying with gst-launch, it doesn't work:
>
> C:\gstreamer\bin>gst-launch-0.10.exe audiotestsrc ! gtestenc ! gtestdec !
> audioresample ! autoaudiosink
> Setting pipeline to PAUSED ...
> Pipeline is PREROLLING ...
> ERROR: from element /GstPipeline:pipeline0/GstAudioTestSrc:audiotestsrc0:
> Internal data flow error.
> Additional debug info:
> ..\Source\gstreamer\libs\gst\base\gstbasesrc.c(2378): gst_base_src_loop ():
> /GstPipeline:pipeline0/GstAudioTestSrc:audiotestsrc0:
> streaming task paused, reason not-negotiated (-4)
> ERROR: pipeline doesn't want to preroll.
> Setting pipeline to NULL ...
> Freeing pipeline ...
> C:\gstreamer\bin>
>
> Since I couldn't make it work with non-existing types i tried several
> different existing types, but the only types that work are ANY and
> audio/x-raw-int:
>
> C:\gstreamer\bin>gst-launch-0.10.exe audiotestsrc ! gtestenc ! gtestdec !
> audioresample ! autoaudiosink
> Setting pipeline to PAUSED ...
> Pipeline is PREROLLING ...
> Pipeline is PREROLLED ...
> Setting pipeline to PLAYING ...
> New clock: GstAudioSinkClock
> ^C
> C:\gstreamer\bin>
>
> To isolate the problem with the caps, the code just passes on the incomming
> buffer (just as the gst-template, which I used as base), and the
> interresting parts of the encoder looks like this (I have omited
> gst_gtestenc_class_init and parts of gst_gtestenc_base_init bellow):
>
> static GstStaticPadTemplate gtest_enc_sink_factory =
> GST_STATIC_PAD_TEMPLATE
> ("sink",
>    GST_PAD_SINK,
>    GST_PAD_ALWAYS,
>    GST_STATIC_CAPS ("audio/x-raw-int, "
>        "rate = (int) { 48000 }, "
>        "channels = (int) { 1 }, "
>        "endianness = (int) BYTE_ORDER, "
>        "width = (int) 16, " "depth = (int) 16, " "signed = (boolean) True")
>    );
>
> static GstStaticPadTemplate gtest_enc_src_factory = GST_STATIC_PAD_TEMPLATE
> ("src",
>    GST_PAD_SRC,
>    GST_PAD_ALWAYS,
>    GST_STATIC_CAPS ("audio/x-test")
>    );
>
> GST_BOILERPLATE (Gstgtestenc, gst_gtestenc, GstElement, GST_TYPE_ELEMENT);
>
> static void gst_gtestenc_base_init (gpointer gclass)
> {
>  GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
>
> // ...
>
>  gst_element_class_add_pad_template (element_class,
>      gst_static_pad_template_get (&amp;gtest_enc_src_factory));
>  gst_element_class_add_pad_template (element_class,
>      gst_static_pad_template_get (&amp;gtest_enc_sink_factory));
> }
>
> static void gst_gtestenc_init (Gstgtestenc * filter,
>    GstgtestencClass * gclass)
> {
>  filter->sinkpad = gst_pad_new_from_static_template
> (&amp;gtest_enc_sink_factory, "sink");
>  gst_pad_set_chain_function (filter->sinkpad,
>                              GST_DEBUG_FUNCPTR(gst_gtestenc_chain));
>
>  filter->srcpad = gst_pad_new_from_static_template
> (&amp;gtest_enc_src_factory, "src");
>  gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
>  gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
>  gst_pad_use_fixed_caps (filter->sinkpad);
>  gst_pad_use_fixed_caps (filter->srcpad);
> }
>
> static GstFlowReturn gst_gtestenc_chain (GstPad * pad, GstBuffer * buf)
> {
>  Gstgtestenc *filter;
>
>  filter = GST_GtestENC (GST_OBJECT_PARENT (pad));
>
>  /* just push out the incoming buffer without touching it */
>  return gst_pad_push (filter->srcpad, buf);
> }
>
>
> The code in the decoder is basicly the same - pass on the incomming data.
> The main difference at the moment is the caps definitions:
>
>
> static GstStaticPadTemplate gtest_dec_sink_factory =
> GST_STATIC_PAD_TEMPLATE
> ("sink",
>    GST_PAD_SINK,
>    GST_PAD_ALWAYS,
>    GST_STATIC_CAPS ("audio/x-test")
>    );
>
> static GstStaticPadTemplate gtest_dec_src_factory = GST_STATIC_PAD_TEMPLATE
> ("src",
>    GST_PAD_SRC,
>    GST_PAD_ALWAYS,
>    GST_STATIC_CAPS ("audio/x-raw-int, "
>        "rate = (int) { 48000 }, "
>                "channels = (int) { 1 }, "
>        "endianness = (int) BYTE_ORDER, "
>        "width = (int) 16, " "depth = (int) 16, " "signed = (boolean) True")
>    );
>
>
>
> What am I doing wrong?
> Why is it working with audio/x-raw-int, but not with audio/x-test?
>
> Regards,
>  Markus
> --
> View this message in context:
> http://gstreamer-devel.966125.n4.nabble.com/Caps-problem-when-writing-encoder-decoder-tp2219436p2221067.html
>  Sent from the GStreamer-devel mailing list archive at Nabble.com.
>
>
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-- 
Regards,

Sudarshan Bisht
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