GstVideo.VideoDecoderClass

Fields

Name	Type	Access	Description
close	object	r	Optional. Called when the element changes to Gst.State.NULL. Allows closing external resources.
decide_allocation	object	r	Optional. Setup the allocation parameters for allocating output buffers. The passed in query contains the result of the downstream allocation query. Subclasses should chain up to the parent implementation to invoke the default handler.
drain	object	r	Optional. Called to request subclass to decode any data it can at this point, but that more data may arrive after. (e.g. at segment end). Sub-classes should be prepared to handle new data afterward, or seamless segment processing will break.
element_class	Gst.ElementClass	r
finish	object	r	Optional. Called to request subclass to dispatch any pending remaining data at EOS. Sub-classes can refuse to decode new data after.
flush	object	r	Optional. Flush all remaining data from the decoder without pushing it downstream.
getcaps	object	r	Optional. Allows for a custom sink getcaps implementation. If not implemented, default returns GstVideo.VideoDecoder.proxy_getcaps applied to sink template caps.
handle_frame	object	r	Provides input data frame to subclass. In subframe mode, the subclass needs to take ownership of GstVideoCodecFrame.input_buffer as it will be modified by the base class on the next subframe buffer receiving.
handle_missing_data	object	r
negotiate	object	r	Optional. Negotiate with downstream and configure buffer pools, etc. Subclasses should chain up to the parent implementation to invoke the default handler.
open	object	r	Optional. Called when the element changes to Gst.State.READY. Allows opening external resources.
padding	[object]	r
parse	object	r	Required for non-packetized input. Allows chopping incoming data into manageable units (frames) for subsequent decoding.
propose_allocation	object	r	Optional. Propose buffer allocation parameters for upstream elements. Subclasses should chain up to the parent implementation to invoke the default handler.
reset	object	r	Optional. Allows subclass (decoder) to perform post-seek semantics reset. Deprecated.
set_format	object	r	Notifies subclass of incoming data format (caps).
sink_event	object	r	Optional. Event handler on the sink pad. This function should return True if the event was handled and should be discarded (i.e. not unref’ed). Subclasses should chain up to the parent implementation to invoke the default handler.
sink_query	object	r	Optional. Query handler on the sink pad. This function should return True if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler.
src_event	object	r	Optional. Event handler on the source pad. This function should return True if the event was handled and should be discarded (i.e. not unref’ed). Subclasses should chain up to the parent implementation to invoke the default handler.
src_query	object	r	Optional. Query handler on the source pad. This function should return True if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler.
start	object	r	Optional. Called when the element starts processing. Allows opening external resources.
stop	object	r	Optional. Called when the element stops processing. Allows closing external resources.
transform_meta	object	r	Optional. Transform the metadata on the input buffer to the output buffer. By default this method is copies all meta without tags and meta with only the “video” tag. subclasses can implement this method and return True if the metadata is to be copied.

Methods

None

Details

class GstVideo.VideoDecoderClass

Subclasses can override any of the available virtual methods or not, as needed. At minimum handle_frame needs to be overridden, and set_format and likely as well. If non-packetized input is supported or expected, parse needs to be overridden as well.