vaapih264enc

Encodes raw video streams into H.264 bitstreams.

The GstVaapiEncodeH264:rate-control property controls the type of encoding. In case of Constant Bitrate Encoding (CBR), the GstVaapiEncodeH264:bitrate will determine the quality of the encoding. Alternatively, one may choose to perform Constant Quantizer or Variable Bitrate Encoding (VBR), in which case the GstVaapiEncodeH264:bitrate is the maximum bitrate.

The H264 profile that is eventually used depends on a few settings. If GstVaapiEncodeH264:dct8x8 is enabled, then High profile is used. Otherwise, if GstVaapiEncodeH264:cabac entropy coding is enabled or GstVaapiEncodeH264:max-bframes are allowed, then Main Profile is in effect. The element will alway go with the maximal profile available in the caps negotation and otherwise Baseline profile applies. But in some cases (e.g. hardware platforms) a more restrictedprofile/level may be necessary. The recommended way to set a profile is to set it in the downstream caps.

You can also set parameters to adjust the latency of encoding: GstVaapiEncodeH264:quality-level is a number between 1-7, in the case of the Intel VAAPI driver, where a lower value will produce a higher quality output but with more latency; meanwhile a hihg number will produce a lower quality output with less latency. Also you can set GstVaapiEncodeH264:tune, if your backend supports it, for low-power mode or high compression.

Example launch line

  gst-launch-1.0 -ev videotestsrc num-buffers=60 ! timeoverlay ! vaapih264enc ! h264parse ! mp4mux ! filesink location=test.mp4

Hierarchy

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstElement
                ╰──GstVideoEncoder
                    ╰──GstVaapiEncode
                        ╰──vaapih264enc

Implemented interfaces

Factory details

Authors: – Wind Yuan

Classification:Codec/Encoder/Video/Hardware

Rank – primary

Plugin – vaapi

Package – gstreamer-vaapi

Pad Templates

sink

video/x-raw:
         format: { NV12, YV12, I420 }
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
 interlace-mode: progressive

video/x-raw(memory:VASurface):
         format: { NV12, YV12, I420 }
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
 interlace-mode: progressive

Presencealways

Directionsink

Object typeGstPad


src

video/x-h264:
  stream-format: { (string)avc, (string)byte-stream }
      alignment: au
        profile: { (string)constrained-baseline, (string)baseline, (string)main, (string)high, (string)multiview-high, (string)stereo-high }

Presencealways

Directionsrc

Object typeGstPad


Properties

bitrate

“bitrate” guint

The desired bitrate expressed in kbps (0: auto-calculate)

Flags : Read / Write

Default value : 0


cabac

“cabac” gboolean

Enable CABAC entropy coding mode

Flags : Read / Write

Default value : false


compliance-mode

“compliance-mode” Vaapi-encoder-h264compliance-mode *

Tune Encode quality/performance by relaxing specification compliance restrictions

Flags : Read / Write

Default value : strict (0)


cpb-length

“cpb-length” guint

Length of the CPB buffer in milliseconds

Flags : Read / Write

Default value : 1500


dct8x8

“dct8x8” gboolean

Enable adaptive use of 8x8 transforms in I-frames

Flags : Read / Write

Default value : false


default-roi-delta-qp

“default-roi-delta-qp” gint

The default delta-qp to apply to each Region of Interest(lower value means higher-quality, higher value means lower-quality)

Flags : Read / Write

Default value : -10


init-qp

“init-qp” guint

Initial quantizer value

Flags : Read / Write

Default value : 26


keyframe-period

“keyframe-period” guint

Maximal distance between two keyframes (0: auto-calculate)

Flags : Read / Write

Default value : 30


max-bframes

“max-bframes” guint

Number of B-frames between I and P

Flags : Read / Write

Default value : 0


max-qp

“max-qp” guint

Maximum quantizer value

Flags : Read / Write

Default value : 51


mbbrc

“mbbrc” GstVaapiEncoderMbbrc *

Macroblock level Bitrate Control

Flags : Read / Write

Default value : auto (0)


min-qp

“min-qp” guint

Minimum quantizer value

Flags : Read / Write

Default value : 1


num-slices

“num-slices” guint

Number of slices per frame

Flags : Read / Write

Default value : 1


num-views

“num-views” guint

Number of Views for MVC encoding

Flags : Read / Write

Default value : 1


prediction-type

“prediction-type” Vaapi-encoder-h264prediction-type *

Reference Picture Selection Modes

Flags : Read / Write

Default value : default (0)


qp-ib

“qp-ib” gint

Difference of QP between I and B frame (available only on CQP)

Flags : Read / Write

Default value : 0


qp-ip

“qp-ip” gint

Difference of QP between I and P frame (available only on CQP)

Flags : Read / Write

Default value : 0


quality-factor

“quality-factor” guint

quality factor for ICQ/QVBR bitrate control mode(low value means higher-quality, higher value means lower-quality)

Flags : Read / Write

Default value : 26


quality-level

“quality-level” guint

Encoding Quality Level (lower value means higher-quality/slow-encode, higher value means lower-quality/fast-encode)

Flags : Read / Write

Default value : 4


rate-control

“rate-control” Vaapi-rate-control-h264 *

Rate control mode

Flags : Read / Write

Default value : cqp (1)


refs

“refs” guint

Number of reference frames

Flags : Read / Write

Default value : 1


target-percentage

“target-percentage” guint

The desired target percentage of bitrate for variable rate controls.

Flags : Read / Write

Default value : 70


temporal-levels

“temporal-levels” guint

Number of temporal levels in the encoded stream

Flags : Read / Write

Default value : 1


trellis

“trellis” gboolean

The Trellis Quantization Method of Encoder

Flags : Read / Write

Default value : false


tune

“tune” Vaapi-encoder-tune-h264 *

Encoder tuning option

Flags : Read / Write

Default value : none (0)


view-ids

“view-ids” GstValueArray *

Set of View Ids used for MVC encoding

Flags : Read / Write


Named constants

Vaapi-encoder-h264compliance-mode

Members

strict (0) – Strict compliance to the H264 Specification
restrict-buf-alloc (1) – Restrict the allocation size of coded-buffer

Vaapi-encoder-h264prediction-type

Members

default (0) – Default encode, prev/next frame as ref
hierarchical-p (1) – Hierarchical P frame encode
hierarchical-b (2) – Hierarchical B frame encode

Vaapi-encoder-tune-h264

Members

none (0) – None
high-compression (1) – High compression
low-power (3) – Low power mode

Vaapi-rate-control-h264

Members

cqp (1) – Constant QP
cbr (2) – Constant bitrate
vbr (4) – Variable bitrate
vbr_constrained (5) – Variable bitrate - Constrained
icq (7) – Constant QP - Intelligent
qvbr (8) – Variable bitrate - Quality defined

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