encodebin

encodebin — Convenience encoding/muxing element

Synopsis

                    GstEncodeBin;

Object Hierarchy

  GObject
   +----GInitiallyUnowned
         +----GstObject
               +----GstElement
                     +----GstBin
                           +----GstEncodeBin

Implemented Interfaces

GstEncodeBin implements GstChildProxy.

Properties

  "audio-jitter-tolerance"   guint64               : Read / Write
  "avoid-reencoding"         gboolean              : Read / Write
  "profile"                  GstEncodingProfile*   : Read / Write
  "queue-buffers-max"        guint                 : Read / Write
  "queue-bytes-max"          guint                 : Read / Write
  "queue-time-max"           guint64               : Read / Write
  "flags"                    GstEncodeBinFlags     : Read / Write

Signals

  "request-pad"                                    : Action
  "request-profile-pad"                            : Action

Description

EncodeBin provides a bin for encoding/muxing various streams according to a specified GstEncodingProfile.

Based on the profile that was set (via the "profile" property), EncodeBin will internally select and configure the required elements (encoders, muxers, but also audio and video converters) so that you can provide it raw or pre-encoded streams of data in input and have your encoded/muxed/converted stream in output.

Features

  • Automatic encoder and muxer selection based on elements available on the system.
  • Conversion of raw audio/video streams (scaling, framerate conversion, colorspace conversion, samplerate conversion) to conform to the profile output format.
  • Variable number of streams. If the presence property for a stream encoding profile is 0, you can request any number of sink pads for it via the standard request pad gstreamer API or the "request-pad" action signal.
  • Avoid reencoding (passthrough). If the input stream is already encoded and is compatible with what the GstEncodingProfile expects, then the stream won't be re-encoded but just passed through downstream to the muxer or the output.
  • Mix pre-encoded and raw streams as input. In addition to the passthrough feature above, you can feed both raw audio/video *AND* already-encoded data to a pad. GstEncodeBin will take care of passing through the compatible segments and re-encoding the segments of media that need encoding.
  • Standard behaviour is to use a GstEncodingContainerProfile to have both encoding and muxing performed. But you can also provide a single stream profile (like GstEncodingAudioProfile) to only have the encoding done and handle the encoded output yourself.
  • Audio imperfection corrections. Incoming audio streams can have non perfect timestamps (jitter), like the streams coming from ASF files. GstEncodeBin will automatically fix those imperfections for you. See "audio-jitter-tolerance" for more details.
  • Variable or Constant video framerate. If your GstEncodingVideoProfile has the variableframerate property deactivated (default), then the incoming raw video stream will be retimestampped in order to produce a constant framerate.
  • Cross-boundary re-encoding. When feeding compatible pre-encoded streams that fall on segment boundaries, and for supported formats (right now only H263), the GOP will be decoded/reencoded when needed to produce an encoded output that fits exactly within the request GstSegment.
  • Missing plugin support. If a GstElement is missing to encode/mux to the request profile formats, a missing-plugin GstMessage will be posted on the GstBus, allowing systems that support the missing-plugin system to offer the user a way to install the missing element.

Synopsis

Element Information

plugin

encoding

author

Edward Hervey <edward.hervey@collabora.co.uk>

class

Generic/Bin/Encoder

Element Pads

name

audio_%u

direction

sink

presence

request

details

ANY

name

private_%u

direction

sink

presence

request

details

ANY

name

video_%u

direction

sink

presence

request

details

ANY

name

src

direction

source

presence

always

details

ANY

Details

GstEncodeBin

typedef struct _GstEncodeBin GstEncodeBin;

Property Details

The "audio-jitter-tolerance" property

  "audio-jitter-tolerance"   guint64               : Read / Write

Amount of timestamp jitter/imperfection to allow on audio streams before inserting/dropping samples (ns).

Default value: 20000000


The "avoid-reencoding" property

  "avoid-reencoding"         gboolean              : Read / Write

Whether to re-encode portions of compatible video streams that lay on segment boundaries.

Default value: FALSE


The "profile" property

  "profile"                  GstEncodingProfile*   : Read / Write

The GstEncodingProfile to use. This property must be set before going to GST_STATE_PAUSED or higher.


The "queue-buffers-max" property

  "queue-buffers-max"        guint                 : Read / Write

Max. number of buffers in the queue (0=disable).

Default value: 200


The "queue-bytes-max" property

  "queue-bytes-max"          guint                 : Read / Write

Max. amount of data in the queue (bytes, 0=disable).

Default value: 10485760


The "queue-time-max" property

  "queue-time-max"           guint64               : Read / Write

Max. amount of data in the queue (in ns, 0=disable).

Default value: 1000000000


The "flags" property

  "flags"                    GstEncodeBinFlags     : Read / Write

Control the behaviour of encodebin.

Signal Details

The "request-pad" signal

GstPad*             user_function                      (GstEncodeBin *encodebin,
                                                        GstCaps      *caps,
                                                        gpointer      user_data)      : Action

Use this method to request an unused sink request GstPad that can take the provided caps as input. You must release the pad with gst_element_release_request_pad() when you are done with it.

encodebin :

a GstEncodeBin instance

caps :

a GstCaps

user_data :

user data set when the signal handler was connected.

Returns :

A compatible GstPad, or NULL if no compatible GstPad could be created or is available.

The "request-profile-pad" signal

GstPad*             user_function                      (GstEncodeBin *encodebin,
                                                        gchar        *profilename,
                                                        gpointer      user_data)        : Action

Use this method to request an unused sink request GstPad from the profile profilename. You must release the pad with gst_element_release_request_pad() when you are done with it.

encodebin :

a GstEncodeBin instance

profilename :

the name of a GstEncodingProfile

user_data :

user data set when the signal handler was connected.

Returns :

A compatible GstPad, or NULL if no compatible GstPad could be created or is available.