GStreamer Keyframe question

[wanting2learn]

I m trying to detect keyframes in a buffer. From the following link:
http://old.nabble.com/keyframes-from-a-video-td24641321.html

it says to use the following code:

if(!buffer->flag_is_set(Gst::BUFFER_FLAG_DELTA_UNIT))
{
// it's a keyframe
} I am using the following bit of code in my application like so:


static void onVideoHandoff( GstElement *object, GstBuffer *buffer,
gpointer user_data )
{

if(!buffer->flag_is_set(Gst::BUFFER_FLAG_DELTA_UNIT))
{
// it's a keyframe
}

//blah blah

}
I get the error:
error: ‘struct _GstBuffer’ has no member named ‘flag_is_set’

Does anyone know what I am doing wrong??

Thanks

[Zugzwang]

I get the error:
error: ‘struct _GstBuffer’ has no member named ‘flag_is_set’

Does anyone know what I am doing wrong??

Thanks

The post you refer to is from august. Maybe the library version of your Ubuntu is older and doesn't yet have this function? Even if you use karmic, the function may not have made it into Ubuntu's version yet. Download the latest source code of the library, extract it somewhere (e.g. to /tmp) and search for the definition of "_GstBuffer". See if it contains this function. Then compare that piece of code to the library version you have installed. Is it different wrt. to "flag_is_set"?

[SledgeHammer_999]

The post you are linking to most likely uses gstreamermm(C++ bindings), but I suppose you use the C API. So try this instead:


if(!GST_BUFFER_FLAG_IS_SET(buffer, GST_BUFFER_FLAG_DELTA_UNIT))
{
// it's a keyframe
}



doc link (http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GST-BUFFER-FLAG-IS-SET--CAPS)

[wanting2learn]

I have done the following which seems to work.


GstBufferFlag flag;
flag = GST_BUFFER_FLAG_DELTA_UNIT;

if( !GST_BUFFER_FLAG_IS_SET(buffer, flag ))
//if(!buffer->flag_is_set(Gst::BUFFER_FLAG_DELTA_UNIT))
{
fprintf( stderr, "DEBUG:onVideoHandoff - **********KEYFRAME**********\n");
//This is a keyframe
}
else
{
fprintf( stderr, "DEBUG:onVideoHandoff - DELTAFRAME\n");
}


I am getting 28 delta frames for every keyframe. Does this mean the GOP for the stream is 28?? )


Thanks for your help.

[SledgeHammer_999]

Your welcome.
Unfortunately I don't know nothing about video/audio terminology/encoding...