WebM VP8/VP9 Encoder
Supported Codecs » VP8

## Files

file | vp8cx.h
| Provides definitions for using VP8 or VP9 encoder algorithm within the vpx Codec Interface.

## Data Structures

struct | vpx_roi_map
| vpx region of interest map More...
struct | vpx_active_map
| vpx active region map More...
struct | vpx_scaling_mode
| vpx image scaling mode More...
struct | vpx_svc_layer_id
| vp9 svc layer parameters More...
struct | vpx_svc_ref_frame_config
| vp9 svc frame flag parameters. More...
struct | vpx_svc_frame_drop
| vp9 svc frame dropping parameters. More...
struct | vpx_svc_spatial_layer_sync
| vp9 svc spatial layer sync parameters. More...

## Macros

#define | VP8_EFLAG_NO_REF_LAST (1 << 16)
| Don't reference the last frame.
#define | VP8_EFLAG_NO_REF_GF (1 << 17)
| Don't reference the golden frame.
#define | VP8_EFLAG_NO_REF_ARF (1 << 21)
| Don't reference the alternate reference frame.
#define | VP8_EFLAG_NO_UPD_LAST (1 << 18)
| Don't update the last frame.
#define | VP8_EFLAG_NO_UPD_GF (1 << 22)
| Don't update the golden frame.
#define | VP8_EFLAG_NO_UPD_ARF (1 << 23)
| Don't update the alternate reference frame.
#define | VP8_EFLAG_FORCE_GF (1 << 19)
| Force golden frame update.
#define | VP8_EFLAG_FORCE_ARF (1 << 24)
| Force alternate reference frame update.
#define | VP8_EFLAG_NO_UPD_ENTROPY (1 << 20)
| Disable entropy update.

## Typedefs

typedef enum vpx_scaling_mode_1d | VPX_SCALING_MODE
| vpx 1-D scaling mode
typedef enum vp9e_temporal_layering_mode | VP9E_TEMPORAL_LAYERING_MODE
| Temporal layering mode enum for VP9 SVC.
typedef struct vpx_roi_map | vpx_roi_map_t
| vpx region of interest map
typedef struct vpx_active_map | vpx_active_map_t
| vpx active region map
typedef struct vpx_scaling_mode | vpx_scaling_mode_t
| vpx image scaling mode
typedef struct vpx_svc_layer_id | vpx_svc_layer_id_t
| vp9 svc layer parameters
typedef struct vpx_svc_ref_frame_config | vpx_svc_ref_frame_config_t
| vp9 svc frame flag parameters.
typedef struct vpx_svc_frame_drop | vpx_svc_frame_drop_t
| vp9 svc frame dropping parameters.
typedef struct vpx_svc_spatial_layer_sync | vpx_svc_spatial_layer_sync_t
| vp9 svc spatial layer sync parameters.

## Enumerations

enum

vp8e_enc_control_id {
VP8E_SET_ROI_MAP = 8 , VP8E_SET_ACTIVEMAP , VP8E_SET_SCALEMODE = 11 , VP8E_SET_CPUUSED = 13 ,
VP8E_SET_ENABLEAUTOALTREF , VP8E_SET_NOISE_SENSITIVITY , VP8E_SET_SHARPNESS , VP8E_SET_STATIC_THRESHOLD ,
VP8E_SET_TOKEN_PARTITIONS , VP8E_GET_LAST_QUANTIZER , VP8E_GET_LAST_QUANTIZER_64 , VP8E_SET_ARNR_MAXFRAMES ,
VP8E_SET_ARNR_STRENGTH , VP8E_SET_ARNR_TYPE , VP8E_SET_TUNING , VP8E_SET_CQ_LEVEL ,
VP8E_SET_MAX_INTRA_BITRATE_PCT , VP8E_SET_FRAME_FLAGS , VP9E_SET_MAX_INTER_BITRATE_PCT , VP9E_SET_GF_CBR_BOOST_PCT ,
VP8E_SET_TEMPORAL_LAYER_ID , VP8E_SET_SCREEN_CONTENT_MODE , VP9E_SET_LOSSLESS , VP9E_SET_TILE_COLUMNS ,
VP9E_SET_TILE_ROWS , VP9E_SET_FRAME_PARALLEL_DECODING , VP9E_SET_AQ_MODE , VP9E_SET_FRAME_PERIODIC_BOOST ,
VP9E_SET_NOISE_SENSITIVITY , VP9E_SET_SVC , VP9E_SET_ROI_MAP , VP9E_SET_SVC_PARAMETERS ,
VP9E_SET_SVC_LAYER_ID , VP9E_SET_TUNE_CONTENT , VP9E_GET_SVC_LAYER_ID , VP9E_REGISTER_CX_CALLBACK ,
VP9E_SET_COLOR_SPACE , VP9E_SET_MIN_GF_INTERVAL = 48 , VP9E_SET_MAX_GF_INTERVAL , VP9E_GET_ACTIVEMAP ,
VP9E_SET_COLOR_RANGE , VP9E_SET_SVC_REF_FRAME_CONFIG , VP9E_SET_RENDER_SIZE , VP9E_SET_TARGET_LEVEL ,
VP9E_SET_ROW_MT , VP9E_GET_LEVEL , VP9E_SET_ALT_REF_AQ , VP8E_SET_GF_CBR_BOOST_PCT ,
VP9E_ENABLE_MOTION_VECTOR_UNIT_TEST , VP9E_SET_SVC_INTER_LAYER_PRED , VP9E_SET_SVC_FRAME_DROP_LAYER , VP9E_GET_SVC_REF_FRAME_CONFIG ,
VP9E_SET_SVC_GF_TEMPORAL_REF , VP9E_SET_SVC_SPATIAL_LAYER_SYNC , VP9E_SET_TPL , VP9E_SET_KEY_FRAME_FILTERING ,
VP9E_SET_POSTENCODE_DROP , VP9E_SET_DELTA_Q_UV , VP9E_SET_DISABLE_OVERSHOOT_MAXQ_CBR , VP9E_SET_DISABLE_LOOPFILTER ,
VP9E_SET_EXTERNAL_RATE_CONTROL , VP9E_SET_RTC_EXTERNAL_RATECTRL , VP9E_GET_LOOPFILTER_LEVEL , VP9E_GET_LAST_QUANTIZER_SVC_LAYERS ,
VP8E_SET_RTC_EXTERNAL_RATECTRL , VP9E_SET_QUANTIZER_ONE_PASS
}

| VPx encoder control functions. More...
enum | vpx_scaling_mode_1d { VP8E_NORMAL = 0 , VP8E_FOURFIVE = 1 , VP8E_THREEFIVE = 2 , VP8E_ONETWO = 3 }
| vpx 1-D scaling mode More...
enum | vp9e_temporal_layering_mode { VP9E_TEMPORAL_LAYERING_MODE_NOLAYERING = 0 , VP9E_TEMPORAL_LAYERING_MODE_BYPASS = 1 , VP9E_TEMPORAL_LAYERING_MODE_0101 = 2 , VP9E_TEMPORAL_LAYERING_MODE_0212 = 3 }
| Temporal layering mode enum for VP9 SVC. More...
enum | vp8e_token_partitions { VP8_ONE_TOKENPARTITION = 0 , VP8_TWO_TOKENPARTITION = 1 , VP8_FOUR_TOKENPARTITION = 2 , VP8_EIGHT_TOKENPARTITION = 3 }
| VP8 token partition mode. More...
enum | vp9e_tune_content { VP9E_CONTENT_DEFAULT , VP9E_CONTENT_SCREEN , VP9E_CONTENT_FILM , VP9E_CONTENT_INVALID }
enum | vp8e_tuning { VP8_TUNE_PSNR , VP8_TUNE_SSIM }
| VP8 model tuning parameters. More...
enum | SVC_LAYER_DROP_MODE { CONSTRAINED_LAYER_DROP , LAYER_DROP , FULL_SUPERFRAME_DROP , CONSTRAINED_FROM_ABOVE_DROP }
| VP9 svc frame dropping mode. More...

## Algorithm interface for VP8

This interface provides the capability to encode raw VP8 streams.
vpx_codec_iface_t | vpx_codec_vp8_cx_algo
| A single instance of the VP8 encoder.
vpx_codec_iface_t * | vpx_codec_vp8_cx (void)
| The interface to the VP8 encoder.

## Algorithm interface for VP9

This interface provides the capability to encode raw VP9 streams.
vpx_codec_iface_t | vpx_codec_vp9_cx_algo
| A single instance of the VP9 encoder.
vpx_codec_iface_t * | vpx_codec_vp9_cx (void)
| The interface to the VP9 encoder.

## Detailed Description

## Macro Definition Documentation

## VP8_EFLAG_NO_REF_LAST

#define VP8_EFLAG_NO_REF_LAST (1 << 16)

Don't reference the last frame.

When this flag is set, the encoder will not use the last frame as a predictor. When not set, the encoder will choose whether to use the last frame or not automatically.

## VP8_EFLAG_NO_REF_GF

#define VP8_EFLAG_NO_REF_GF (1 << 17)

Don't reference the golden frame.

When this flag is set, the encoder will not use the golden frame as a predictor. When not set, the encoder will choose whether to use the golden frame or not automatically.

## VP8_EFLAG_NO_REF_ARF

#define VP8_EFLAG_NO_REF_ARF (1 << 21)

Don't reference the alternate reference frame.

When this flag is set, the encoder will not use the alt ref frame as a predictor. When not set, the encoder will choose whether to use the alt ref frame or not automatically.

## VP8_EFLAG_NO_UPD_LAST

#define VP8_EFLAG_NO_UPD_LAST (1 << 18)

Don't update the last frame.

When this flag is set, the encoder will not update the last frame with the contents of the current frame.

## VP8_EFLAG_NO_UPD_GF

#define VP8_EFLAG_NO_UPD_GF (1 << 22)

Don't update the golden frame.

When this flag is set, the encoder will not update the golden frame with the contents of the current frame.

## VP8_EFLAG_NO_UPD_ARF

#define VP8_EFLAG_NO_UPD_ARF (1 << 23)

Don't update the alternate reference frame.

When this flag is set, the encoder will not update the alt ref frame with the contents of the current frame.

## VP8_EFLAG_FORCE_GF

#define VP8_EFLAG_FORCE_GF (1 << 19)

Force golden frame update.

When this flag is set, the encoder copy the contents of the current frame to the golden frame buffer.

## VP8_EFLAG_FORCE_ARF

#define VP8_EFLAG_FORCE_ARF (1 << 24)

Force alternate reference frame update.

When this flag is set, the encoder copy the contents of the current frame to the alternate reference frame buffer.

## VP8_EFLAG_NO_UPD_ENTROPY

#define VP8_EFLAG_NO_UPD_ENTROPY (1 << 20)

Disable entropy update.

When this flag is set, the encoder will not update its internal entropy model based on the entropy of this frame.

## Typedef Documentation

## VPX_SCALING_MODE

typedef enum vpx_scaling_mode_1d VPX_SCALING_MODE

vpx 1-D scaling mode

This set of constants define 1-D vpx scaling modes

## VP9E_TEMPORAL_LAYERING_MODE

typedef enum vp9e_temporal_layering_mode VP9E_TEMPORAL_LAYERING_MODE

Temporal layering mode enum for VP9 SVC.

This set of macros define the different temporal layering modes. Supported codecs: VP9 (in SVC mode)

## vpx_roi_map_t

typedef struct vpx_roi_map vpx_roi_map_t

vpx region of interest map

These defines the data structures for the region of interest map

## vpx_active_map_t

typedef struct vpx_active_map vpx_active_map_t

vpx active region map

These defines the data structures for active region map

## vpx_scaling_mode_t

typedef struct vpx_scaling_mode vpx_scaling_mode_t

vpx image scaling mode

This defines the data structure for image scaling mode

## vpx_svc_layer_id_t

typedef struct vpx_svc_layer_id vpx_svc_layer_id_t

vp9 svc layer parameters

This defines the spatial and temporal layer id numbers for svc encoding. This is used with the VP9E_SET_SVC_LAYER_ID control to set the spatial and temporal layer id for the current frame.

## vpx_svc_ref_frame_config_t

typedef struct vpx_svc_ref_frame_config vpx_svc_ref_frame_config_t

vp9 svc frame flag parameters.

This defines the frame flags and buffer indices for each spatial layer for svc encoding. This is used with the VP9E_SET_SVC_REF_FRAME_CONFIG control to set frame flags and buffer indices for each spatial layer for the current (super)frame.

## vpx_svc_frame_drop_t

typedef struct vpx_svc_frame_drop vpx_svc_frame_drop_t

vp9 svc frame dropping parameters.

This defines the frame drop thresholds for each spatial layer, and the frame dropping mode: 0 = layer based frame dropping (default), 1 = constrained dropping where current layer drop forces all upper spatial layers to drop.

## vpx_svc_spatial_layer_sync_t

typedef struct vpx_svc_spatial_layer_sync vpx_svc_spatial_layer_sync_t

vp9 svc spatial layer sync parameters.

This defines the spatial layer sync flag, defined per spatial layer.

## Enumeration Type Documentation

## vp8e_enc_control_id

enum vp8e_enc_control_id

VPx encoder control functions.

This set of macros define the control functions available for VPx encoder interface.

See also
  vpx_codec_control

Enumerator
VP8E_SET_ROI_MAP | Codec control function to pass an ROI map to encoder. Supported in codecs: VP8
VP8E_SET_ACTIVEMAP | Codec control function to pass an Active map to encoder. Supported in codecs: VP8, VP9
VP8E_SET_SCALEMODE | Codec control function to set encoder scaling mode. Supported in codecs: VP8, VP9

VP8E_SET_CPUUSED

Codec control function to set encoder internal speed settings.

Changes in this value influences, among others, the encoder's selection of motion estimation methods. Values greater than 0 will increase encoder speed at the expense of quality.

Note
  Valid range for VP8: -16..16
  Valid range for VP9: -9..9
  A negative value (-n) is treated as its absolute value (n) in VP9.

Supported in codecs: VP8, VP9

VP8E_SET_ENABLEAUTOALTREF

Codec control function to enable automatic use of arf frames.

Note
  Valid range for VP8: 0..1
  Valid range for VP9: 0..6

Supported in codecs: VP8, VP9

VP8E_SET_NOISE_SENSITIVITY | control function to set noise sensitivity 0: off, 1: OnYOnly, 2: OnYUV, 3: OnYUVAggressive, 4: Adaptive Supported in codecs: VP8

VP8E_SET_SHARPNESS

Codec control function to set higher sharpness at the expense of a lower PSNR.

Note
  Valid range: 0..7

Supported in codecs: VP8, VP9

VP8E_SET_STATIC_THRESHOLD | Codec control function to set the threshold for MBs treated static. Supported in codecs: VP8, VP9
VP8E_SET_TOKEN_PARTITIONS | Codec control function to set the number of token partitions. Supported in codecs: VP8
VP8E_GET_LAST_QUANTIZER | Codec control function to get last quantizer chosen by the encoder. Return value uses internal quantizer scale defined by the codec. Supported in codecs: VP8, VP9
VP8E_GET_LAST_QUANTIZER_64 | Codec control function to get last quantizer chosen by the encoder. Return value uses the 0..63 scale as used by the rc_*_quantizer config parameters. Supported in codecs: VP8, VP9
VP8E_SET_ARNR_MAXFRAMES | Codec control function to set the max no of frames to create arf. Supported in codecs: VP8, VP9
VP8E_SET_ARNR_STRENGTH | Codec control function to set the filter strength for the arf. Supported in codecs: VP8, VP9

VP8E_SET_ARNR_TYPE

Deprecated:
  control function to set the filter type to use for the arf.

VP8E_SET_TUNING | Codec control function to set visual tuning. Supported in codecs: VP8, VP9

VP8E_SET_CQ_LEVEL

Codec control function to set constrained / constant quality level.

Attention
  For this value to be used vpx_codec_enc_cfg_t::rc_end_usage must be set to VPX_CQ or VPX_Q

Note
  Valid range: 0..63

Supported in codecs: VP8, VP9

VP8E_SET_MAX_INTRA_BITRATE_PCT

Codec control function to set Max data rate for Intra frames.

This value controls additional clamping on the maximum size of a keyframe. It is expressed as a percentage of the average per-frame bitrate, with the special (and default) value 0 meaning unlimited, or no additional clamping beyond the codec's built-in algorithm.

For example, to allocate no more than 4.5 frames worth of bitrate to a keyframe, set this to 450.

Supported in codecs: VP8, VP9

VP8E_SET_FRAME_FLAGS | Codec control function to set reference and update frame flags. Supported in codecs: VP8

VP9E_SET_MAX_INTER_BITRATE_PCT

Codec control function to set max data rate for Inter frames.

This value controls additional clamping on the maximum size of an inter frame. It is expressed as a percentage of the average per-frame bitrate, with the special (and default) value 0 meaning unlimited, or no additional clamping beyond the codec's built-in algorithm.

For example, to allow no more than 4.5 frames worth of bitrate to an inter frame, set this to 450.

Supported in codecs: VP9

VP9E_SET_GF_CBR_BOOST_PCT

Boost percentage for Golden Frame in CBR mode.

This value controls the amount of boost given to Golden Frame in CBR mode. It is expressed as a percentage of the average per-frame bitrate, with the special (and default) value 0 meaning the feature is off, i.e., no golden frame boost in CBR mode and average bitrate target is used.

For example, to allow 100% more bits, i.e., 2X, in a golden frame than average frame, set this to 100.

Supported in codecs: VP9

VP8E_SET_TEMPORAL_LAYER_ID | Codec control function to set the temporal layer id. For temporal scalability: this control allows the application to set the layer id for each frame to be encoded. Note that this control must be set for every frame prior to encoding. The usage of this control function supersedes the internal temporal pattern counter, which is now deprecated. Supported in codecs: VP8
VP8E_SET_SCREEN_CONTENT_MODE | Codec control function to set encoder screen content mode. 0: off, 1: On, 2: On with more aggressive rate control. Supported in codecs: VP8

VP9E_SET_LOSSLESS

Codec control function to set lossless encoding mode.

VP9 can operate in lossless encoding mode, in which the bitstream produced will be able to decode and reconstruct a perfect copy of input source. This control function provides a mean to switch encoder into lossless coding mode(1) or normal coding mode(0) that may be lossy. 0 = lossy coding mode 1 = lossless coding mode

By default, encoder operates in normal coding mode (maybe lossy).

Supported in codecs: VP9

VP9E_SET_TILE_COLUMNS

Codec control function to set number of tile columns.

In encoding and decoding, VP9 allows an input image frame be partitioned into separated vertical tile columns, which can be encoded or decoded independently. This enables easy implementation of parallel encoding and decoding. This control requests the encoder to use column tiles in encoding an input frame, with number of tile columns (in Log2 unit) as the parameter: 0 = 1 tile column 1 = 2 tile columns 2 = 4 tile columns ..... n = 2**n tile columns The requested tile columns will be capped by the encoder based on image size limitations (The minimum width of a tile column is 256 pixels, the maximum is 4096).

By default, the value is 6, i.e., the maximum number of tiles supported by the resolution.

Supported in codecs: VP9

VP9E_SET_TILE_ROWS

Codec control function to set number of tile rows.

In encoding and decoding, VP9 allows an input image frame be partitioned into separated horizontal tile rows. Tile rows are encoded or decoded sequentially. Even though encoding/decoding of later tile rows depends on earlier ones, this allows the encoder to output data packets for tile rows prior to completely processing all tile rows in a frame, thereby reducing the latency in processing between input and output. The parameter for this control describes the number of tile rows, which has a valid range [0, 2]: 0 = 1 tile row 1 = 2 tile rows 2 = 4 tile rows

By default, the value is 0, i.e. one single row tile for entire image.

Supported in codecs: VP9

VP9E_SET_FRAME_PARALLEL_DECODING

Codec control function to enable frame parallel decoding feature.

VP9 has a bitstream feature to reduce decoding dependency between frames by turning off backward update of probability context used in encoding and decoding. This allows staged parallel processing of more than one video frame in the decoder. This control function provides a means to turn this feature on or off for bitstreams produced by encoder.

By default, this feature is on.

Supported in codecs: VP9

VP9E_SET_AQ_MODE

Codec control function to set adaptive quantization mode.

VP9 has a segment based feature that allows encoder to adaptively change quantization parameter for each segment within a frame to improve the subjective quality. This control makes encoder operate in one of the several AQ_modes supported.

By default, encoder operates with AQ_Mode 0(adaptive quantization off).

Supported in codecs: VP9

VP9E_SET_FRAME_PERIODIC_BOOST | Codec control function to enable/disable periodic Q boost. One VP9 encoder speed feature is to enable quality boost by lowering frame level Q periodically. This control function provides a mean to turn on/off this feature. 0 = off 1 = on By default, the encoder is allowed to use this feature for appropriate encoding modes. Supported in codecs: VP9
VP9E_SET_NOISE_SENSITIVITY | Codec control function to set noise sensitivity. 0: off, 1: On(YOnly), 2: For SVC only, on top two spatial layers(YOnly) Supported in codecs: VP9

VP9E_SET_SVC

Codec control function to turn on/off SVC in encoder.

Note
  Return value is VPX_CODEC_INVALID_PARAM if the encoder does not support SVC in its current encoding mode 0: off, 1: on

Supported in codecs: VP9

VP9E_SET_ROI_MAP | Codec control function to pass an ROI map to encoder. Supported in codecs: VP9

VP9E_SET_SVC_PARAMETERS

Codec control function to set parameters for SVC.

Note
  Parameters contain min_q, max_q, scaling factor for each of the SVC layers.

Supported in codecs: VP9

VP9E_SET_SVC_LAYER_ID

Codec control function to set svc layer for spatial and temporal.

Note
  Valid ranges: 0..vpx_codec_enc_cfg::ss_number_layers for spatial layer and 0..vpx_codec_enc_cfg::ts_number_layers for temporal layer.

Supported in codecs: VP9

VP9E_SET_TUNE_CONTENT

Codec control function to set content type.

Note
  Valid parameter range: VP9E_CONTENT_DEFAULT = Regular video content (Default) VP9E_CONTENT_SCREEN = Screen capture content VP9E_CONTENT_FILM = Film content: improves grain retention

Supported in codecs: VP9

VP9E_GET_SVC_LAYER_ID

Codec control function to get svc layer ID.

Note
  The layer ID returned is for the data packet from the registered callback function.

Supported in codecs: VP9

VP9E_REGISTER_CX_CALLBACK

Codec control function to register callback to get per layer packet.

Note
  Parameter for this control function is a structure with a callback function and a pointer to private data used by the callback.

Supported in codecs: VP9

VP9E_SET_COLOR_SPACE

Codec control function to set color space info.

Note
  Valid ranges: 0..7, default is "UNKNOWN". 0 = UNKNOWN, 1 = BT_601 2 = BT_709 3 = SMPTE_170 4 = SMPTE_240 5 = BT_2020 6 = RESERVED 7 = SRGB

Supported in codecs: VP9

VP9E_SET_MIN_GF_INTERVAL | Codec control function to set minimum interval between GF/ARF frames. By default the value is set as 4. Supported in codecs: VP9
VP9E_SET_MAX_GF_INTERVAL | Codec control function to set minimum interval between GF/ARF frames. By default the value is set as 16. Supported in codecs: VP9
VP9E_GET_ACTIVEMAP | Codec control function to get an Active map back from the encoder. Supported in codecs: VP9

VP9E_SET_COLOR_RANGE

Codec control function to set color range bit.

Note
  Valid ranges: 0..1, default is 0 0 = Limited range (16..235 or HBD equivalent) 1 = Full range (0..255 or HBD equivalent)

Supported in codecs: VP9

VP9E_SET_SVC_REF_FRAME_CONFIG | Codec control function to set the frame flags and buffer indices for spatial layers. The frame flags and buffer indices are set using the struct vpx_svc_ref_frame_config defined below. Supported in codecs: VP9
VP9E_SET_RENDER_SIZE | Codec control function to set intended rendering image size. By default, this is identical to the image size in pixels. Supported in codecs: VP9
VP9E_SET_TARGET_LEVEL | Codec control function to set target level. 255: off (default); 0: only keep level stats; 10: target for level 1.0; 11: target for level 1.1; ... 62: target for level 6.2 Supported in codecs: VP9
VP9E_SET_ROW_MT | Codec control function to set row level multi-threading. 0 : off, 1 : on Supported in codecs: VP9
VP9E_GET_LEVEL | Codec control function to get bitstream level. Supported in codecs: VP9
VP9E_SET_ALT_REF_AQ | Codec control function to enable/disable special mode for altref adaptive quantization. You can use it with –aq-mode concurrently. Enable special adaptive quantization for altref frames based on their expected prediction quality for the future frames. Supported in codecs: VP9

VP8E_SET_GF_CBR_BOOST_PCT

Boost percentage for Golden Frame in CBR mode.

This value controls the amount of boost given to Golden Frame in CBR mode. It is expressed as a percentage of the average per-frame bitrate, with the special (and default) value 0 meaning the feature is off, i.e., no golden frame boost in CBR mode and average bitrate target is used.

For example, to allow 100% more bits, i.e., 2X, in a golden frame than average frame, set this to 100.

Supported in codecs: VP8

VP9E_ENABLE_MOTION_VECTOR_UNIT_TEST | Codec control function to enable the extreme motion vector unit test in VP9. Please note that this is only used in motion vector unit test. 0 : off, 1 : MAX_EXTREME_MV, 2 : MIN_EXTREME_MV Supported in codecs: VP9
VP9E_SET_SVC_INTER_LAYER_PRED | Codec control function to constrain the inter-layer prediction (prediction of lower spatial resolution) in VP9 SVC. 0 : inter-layer prediction on, 1 : off, 2 : off only on non-key frames Supported in codecs: VP9
VP9E_SET_SVC_FRAME_DROP_LAYER | Codec control function to set mode and thresholds for frame dropping in SVC. Drop frame thresholds are set per-layer. Mode is set as: 0 : layer-dependent dropping, 1 : constrained dropping, current layer drop forces drop on all upper layers. Default mode is 0. Supported in codecs: VP9
VP9E_GET_SVC_REF_FRAME_CONFIG | Codec control function to get the refresh and reference flags and the buffer indices, up to the last encoded spatial layer. Supported in codecs: VP9
VP9E_SET_SVC_GF_TEMPORAL_REF | Codec control function to enable/disable use of golden reference as a second temporal reference for SVC. Only used when inter-layer prediction is disabled on INTER frames. 0: Off, 1: Enabled (default) Supported in codecs: VP9

VP9E_SET_SVC_SPATIAL_LAYER_SYNC

Codec control function to enable spatial layer sync frame, for any spatial layer. Enabling it for layer k means spatial layer k will disable all temporal prediction, but keep the inter-layer prediction. It will refresh any temporal reference buffer for that layer, and reset the temporal layer for the superframe to 0. Setting the layer sync for base spatial layer forces a key frame. Default is off (0) for all spatial layers. Spatial layer sync flag is reset to 0 after each encoded layer, so when control is invoked it is only used for the current superframe.

0: Off (default), 1: Enabled

Supported in codecs: VP9

VP9E_SET_TPL

Codec control function to enable temporal dependency model.

Vp9 allows the encoder to run temporal dependency model and use it to improve the compression performance. To enable, set this parameter to be

1. The default value is set to be 1.

VP9E_SET_KEY_FRAME_FILTERING

Codec control function to enable key frame temporal filtering.

Vp9 allows the encoder to run key frame temporal filtering and use it to improve the compression performance. To enable, set this parameter to be

1. The default value is set to be 0.

VP9E_SET_POSTENCODE_DROP | Codec control function to enable postencode frame drop. This will allow encoder to drop frame after it's encoded. 0: Off (default), 1: Enabled Supported in codecs: VP9
VP9E_SET_DELTA_Q_UV | Codec control function to set delta q for uv. Cap it at +/-15. Supported in codecs: VP9
VP9E_SET_DISABLE_OVERSHOOT_MAXQ_CBR | Codec control function to disable increase Q on overshoot in CBR. 0: On (default), 1: Disable. Supported in codecs: VP9
VP9E_SET_DISABLE_LOOPFILTER | Codec control function to disable loopfilter. 0: Loopfilter on all frames, 1: Disable on non reference frames. 2: Disable on all frames. Supported in codecs: VP9
VP9E_SET_EXTERNAL_RATE_CONTROL | Codec control function to enable external rate control library. args[0]: path of the rate control library args[1]: private config of the rate control library Supported in codecs: VP9

VP9E_SET_RTC_EXTERNAL_RATECTRL

Codec control to disable internal features in rate control.

This will do 3 things, only for 1 pass:

- Turn off low motion computation
- Turn off gf update constraint on key frame frequency
- Turn off content mode for cyclic refresh

With those, the rate control is expected to work exactly the same as the interface provided in ratectrl_rtc.cc/h

Supported in codecs: VP9

VP9E_GET_LOOPFILTER_LEVEL | Codec control function to get loopfilter level in the encoder. Supported in codecs: VP9
VP9E_GET_LAST_QUANTIZER_SVC_LAYERS | Codec control to get last quantizers for all spatial layers. Return value uses an array of internal quantizers scale defined by the codec, for all spatial layers. The size of the array passed in should be VPX_SS_MAX_LAYERS. Supported in codecs: VP9
VP8E_SET_RTC_EXTERNAL_RATECTRL | Codec control to disable internal features in rate control. This will turn off cyclic refresh for vp8. With this, the rate control is expected to work exactly the same as the interface provided in vp8_ratectrl_rtc.cc/h Supported in codecs: VP8
VP9E_SET_QUANTIZER_ONE_PASS | Codec control to set quantizer for the next frame. This will turn off cyclic refresh. Only applicable to 1-pass without spatial layers. Supported in codecs: VP9

## vpx_scaling_mode_1d

enum vpx_scaling_mode_1d

vpx 1-D scaling mode

This set of constants define 1-D vpx scaling modes

## vp9e_temporal_layering_mode

enum vp9e_temporal_layering_mode

Temporal layering mode enum for VP9 SVC.

This set of macros define the different temporal layering modes. Supported codecs: VP9 (in SVC mode)

Enumerator
VP9E_TEMPORAL_LAYERING_MODE_NOLAYERING | No temporal layering. Used when only spatial layering is used.
VP9E_TEMPORAL_LAYERING_MODE_BYPASS | Bypass mode. Used when application needs to control temporal layering. This will only work when the number of spatial layers equals 1.
VP9E_TEMPORAL_LAYERING_MODE_0101 | 0-1-0-1... temporal layering scheme with two temporal layers.
VP9E_TEMPORAL_LAYERING_MODE_0212 | 0-2-1-2... temporal layering scheme with three temporal layers.

## vp8e_token_partitions

enum vp8e_token_partitions

VP8 token partition mode.

This defines VP8 partitioning mode for compressed data, i.e., the number of sub-streams in the bitstream. Used for parallelized decoding.

## vp9e_tune_content

enum vp9e_tune_content

brief VP9 encoder content type

## vp8e_tuning

enum vp8e_tuning

VP8 model tuning parameters.

Changes the encoder to tune for certain types of input material.

## SVC_LAYER_DROP_MODE

enum SVC_LAYER_DROP_MODE

VP9 svc frame dropping mode.

This defines the frame drop mode for SVC.

Enumerator
CONSTRAINED_LAYER_DROP | Upper layers are constrained to drop if current layer drops.
LAYER_DROP | Any spatial layer can drop.
FULL_SUPERFRAME_DROP | Only full superframe can drop.
CONSTRAINED_FROM_ABOVE_DROP | Lower layers are constrained to drop if current layer drops.

## Variable Documentation

## vpx_codec_vp8_cx_algo

vpx_codec_iface_t vpx_codec_vp8_cx_algo

extern

A single instance of the VP8 encoder.

Deprecated:
  This access mechanism is provided for backwards compatibility; prefer vpx_codec_vp8_cx().

## vpx_codec_vp9_cx_algo

vpx_codec_iface_t vpx_codec_vp9_cx_algo

extern

A single instance of the VP9 encoder.

Deprecated:
  This access mechanism is provided for backwards compatibility; prefer vpx_codec_vp9_cx().