Loop Restoration

Collaboration diagram for Loop Restoration:

Functions
void	av1_loop_restoration_filter_unit (const RestorationTileLimits *limits, const RestorationUnitInfo *rui, const RestorationStripeBoundaries *rsb, RestorationLineBuffers *rlbs, int plane_w, int plane_h, int ss_x, int ss_y, int highbd, int bit_depth, uint8_t *data8, int stride, uint8_t *dst8, int dst_stride, int32_t *tmpbuf, int optimized_lr, struct aom_internal_error_info *error_info)
	Function for applying loop restoration filter to a single unit. More...
void	av1_loop_restoration_filter_frame (YV12_BUFFER_CONFIG *frame, struct AV1Common *cm, int optimized_lr, void *lr_ctxt)
	Function for applying loop restoration filter to a frame. More...
void	av1_pick_filter_restoration (const YV12_BUFFER_CONFIG *sd, AV1_COMP *cpi)
	Algorithm for AV1 loop restoration search and estimation. More...

Detailed Description

This module describes the loop restoration search and estimation algorithm in AV1. More details will be added.

Function Documentation

av1_loop_restoration_filter_unit()

void av1_loop_restoration_filter_unit	(	const RestorationTileLimits *	limits,
		const RestorationUnitInfo *	rui,
		const RestorationStripeBoundaries *	rsb,
		RestorationLineBuffers *	rlbs,
		int	plane_w,
		int	plane_h,
		int	ss_x,
		int	ss_y,
		int	highbd,
		int	bit_depth,
		uint8_t *	data8,
		int	stride,
		uint8_t *	dst8,
		int	dst_stride,
		int32_t *	tmpbuf,
		int	optimized_lr,
		struct aom_internal_error_info *	error_info
	)

Function for applying loop restoration filter to a single unit.

This function applies the loop restoration filter to a single loop restoration unit.

Parameters

[in]	limits	Limits of the unit
[in]	rui	The parameters to use for this unit and its coefficients
[in]	rsb	Deblocked pixels to use for stripe boundaries
[in]	rlbs	Space to use as a scratch buffer
[in]	ss_x	Horizontal subsampling for plane
[in]	ss_y	Vertical subsampling for plane
[in]	plane_w	Width of the current plane
[in]	plane_h	Height of the current plane
[in]	highbd	Whether high bitdepth pipeline is used
[in]	bit_depth	Bit-depth of the video
[in]	data8	Frame data (pointing at the top-left corner of the frame, not the restoration unit).
[in]	stride	Stride of data8
[out]	dst8	Buffer where the results will be written. Like data8, dst8 should point at the top-left corner of the frame
[in]	dst_stride	Stride of dst8
[in]	tmpbuf	Scratch buffer used by the sgrproj filter which should be at least SGRPROJ_TMPBUF_SIZE big.
[in]	optimized_lr	Whether to use fast optimized Loop Restoration
[in,out]	error_info	Error info for reporting errors

Remarks

Nothing is returned. Instead, the filtered unit is output in dst8 at the proper restoration unit offset.

av1_loop_restoration_filter_frame()

void av1_loop_restoration_filter_frame	(	YV12_BUFFER_CONFIG *	frame,
		struct AV1Common *	cm,
		int	optimized_lr,
		void *	lr_ctxt
	)

Function for applying loop restoration filter to a frame.

This function applies the loop restoration filter to a frame.

Parameters

[in,out]	frame	Compressed frame buffer
[in,out]	cm	Pointer to top level common structure
[in]	optimized_lr	Whether to use fast optimized Loop Restoration
[in]	lr_ctxt	Loop restoration context

Remarks

Nothing is returned. Instead, the filtered frame is output in frame.

av1_pick_filter_restoration()

void av1_pick_filter_restoration	(	const YV12_BUFFER_CONFIG *	sd,
		AV1_COMP *	cpi
	)

Algorithm for AV1 loop restoration search and estimation.

This function determines proper restoration filter types and associated parameters for each restoration unit in a frame.

Parameters

[in]	sd	Source frame buffer
[in,out]	cpi	Top-level encoder structure

Remarks

Nothing is returned. Instead, chosen restoration filter types and parameters are stored per plane in the rst_info structure of type RestorationInfo inside cpi->common:

• rst_info[ 0 ]: Chosen parameters for Y plane
• rst_info[ 1 ]: Chosen parameters for U plane if it exists
• rst_info[ 2 ]: Chosen parameters for V plane if it exists

The following fields in each rst_info[ p], p = 0, 1, 2 are populated:

• rst_info[ p ].frame_restoration_type
• rst_info[ p ].unit_info[ u ], for each u in 0, 1, ..., n( p ) - 1, where n( p ) is the number of restoration units in plane p.

The following fields in each rst_info[ p ].unit_info[ u ], p = 0, 1, 2 and u = 0, 1, ..., n( p ) - 1, of type RestorationUnitInfo are populated:

• rst_info[ p ].unit_info[ u ].restoration_type
• rst_info[ p ].unit_info[ u ].wiener_info OR rst_info[ p ].unit_info[ u ].sgrproj_info OR neither, depending on rst_info[ p ].unit_info[ u ].restoration_type