Instead of the audiodecoder one. The OMX audioo decoders have their
valid input in the template pad, so just check against that to
avoid doing a query downstream.
{
gst_audio_decoder_set_needs_format (GST_AUDIO_DECODER (self), TRUE);
gst_audio_decoder_set_drainable (GST_AUDIO_DECODER (self), TRUE);
+ gst_audio_decoder_set_use_default_pad_acceptcaps (GST_AUDIO_DECODER_CAST
+ (self), TRUE);
+ GST_PAD_SET_ACCEPT_TEMPLATE (GST_AUDIO_DECODER_SINK_PAD (self));
g_mutex_init (&self->drain_lock);
g_cond_init (&self->drain_cond);