Element that encodes a VP9 stream.

This element can receive a Membrane.KeyframeRequestEvent on it's :output pad to force the next frame to be a keyframe.

Buffers produced by this element will have the following metadata that inform whether the buffer contains a keyframe:

%{vp9: %{is_keyframe: is_keyframe :: boolean()}}

Element options

Passed via struct Membrane.VP9.Encoder.t/0

• encoding_deadline

  Membrane.Time.t() | :auto

  Default value: :auto
  Determines how long should it take the encoder to encode a frame. The longer the encoding takes the better the quality will be. If set to 0 the encoder will take as long as it needs to produce the best frame possible. Note that this is a soft limit, there is no guarantee that the encoding process will never exceed it. If set to :auto the deadline will be calculated based on the framerate provided by incoming stream format. If the framerate is nil a fixed deadline of 10ms will be set.

• rc_target_bitrate

  pos_integer() | :auto

  Default value: :auto
  Gives the encoder information about the target bitrate (in kb/s). If set to :auto the target bitrate will be calculated automatically based on the resolution and framerate of the incoming stream. Some reference recommended bitrates can be also found here

• g_lag_in_frames

  non_neg_integer()

  Default value: 5
  The number of input frames the encoder is allowed to consume before producing output frames. This allows the encoder to base decisions for the current frame on future frames. This does increase the latency of the encoding pipeline, so it is not appropriate in all situations (ex: realtime encoding).

  Note that this is a maximum value -- the encoder may produce frames sooner than the given limit. If set to 0 this feature will be disabled.

Pads

:input

Accepted formats:

Membrane.RawVideo

:output

Accepted formats:

VP9