I'm developing a GStreamer plugin following the GStreamer Plugin Writer's Guide and using gst-element-maker from the gst-plugins-bad repository with the base class set to basetransform. As a starting point I have developed a plugin named MyFilter that simply passes the data along the chain. The plugin is working, but when I run gst-launch with the debug level set to 2, I get the following error: alsa gstalsa.c:124:gst_alsa_detect_formats: skipping non-int format. I am executing the command: gst-launch --gst-debug-level=2 --gst-plugin-load=./src/<a href="http://libgstmyfilter.la">libgstmyfilter.la</a> filesrc location=./song.mp3 ! flump3dec ! audioconvert ! audioresample ! myfilter ! alsasink From the base class that was created by gst-element-maker I have removed calls to gst_pad_new_from_static_template() because the calls were returning errors reporting that the sink and source pad were already created, I have set the chain function using gst_pad_set_chain_function(), have implemented the function gst_myfilter_transform_caps(), and have added code to handle the GST_EVENT_NEWSEGMENT event. The STATIC_CAPS string I am using for source and sink are: "audio/x-raw-int, " "rate = (int) { 16000, 32000, 44100, 48000 }, " "channels = (int) [ 1, 2 ], " "endianness = (int) BYTE_ORDER, " "signed = (boolean) true, " "width = (int) 16, " "depth = (int) 16" I return the caps from gst_myfilter_transform_caps() using gst_pad_get_fixed_caps_func(GST_BASE_TRANSFORM_SRC[[/SINK]]_PAD(trans)). The pad caps are set using the default code created by gst-element-maker in gst_myfilter_base_init() using: gst_element_class_add_pad_template(element_class, gst_static_pad_template_get(&gst_myfilter_sink_template)); Is there a problem with the GstBaseTransform class? I have another custom filter which does not use the GstBaseTransform class and does not have this problem. I am using GStreamer v0.10.36 with Ubuntu 12.04.