av1/common/mv.h - aom - Git at Google

 /*
  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
  *
  * This source code is subject to the terms of the BSD 2 Clause License and
  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
  * was not distributed with this source code in the LICENSE file, you can
  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
  * Media Patent License 1.0 was not distributed with this source code in the
  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  */

 #ifndef AV1_COMMON_MV_H_
 #define AV1_COMMON_MV_H_

 #include "av1/common/common.h"
 #include "aom_dsp/aom_filter.h"

 #ifdef __cplusplus
 extern "C" {
 #endif

 typedef struct mv {
   int16_t row;
   int16_t col;
 } MV;

 typedef union int_mv {
   uint32_t as_int;
   MV as_mv;
 } int_mv; /* facilitates faster equality tests and copies */

 typedef struct mv32 {
   int32_t row;
   int32_t col;
 } MV32;

 #if CONFIG_GLOBAL_MOTION || CONFIG_WARPED_MOTION
 // Bits of precision used for the model
 #define WARPEDMODEL_PREC_BITS 16
 #define WARPEDMODEL_ROW3HOMO_PREC_BITS 16

 // Bits of subpel precision for warped interpolation
 #define WARPEDPIXEL_PREC_BITS 6
 #define WARPEDPIXEL_PREC_SHIFTS (1 << WARPEDPIXEL_PREC_BITS)

 // Taps for ntap filter
 #define WARPEDPIXEL_FILTER_TAPS 6

 // Precision of filter taps
 #define WARPEDPIXEL_FILTER_BITS 7

 #define WARPEDDIFF_PREC_BITS (WARPEDMODEL_PREC_BITS - WARPEDPIXEL_PREC_BITS)

 /* clang-format off */
 typedef enum {
   IDENTITY = 0,     // identity transformation, 0-parameter
   TRANSLATION = 1,  // translational motion 2-parameter
   ROTZOOM = 2,      // simplified affine with rotation + zoom only, 4-parameter
   AFFINE = 3,       // affine, 6-parameter
   HOMOGRAPHY = 4,   // homography, 8-parameter
   TRANS_TYPES = 5,
 } TransformationType;
 /* clang-format on */

 // Number of types used for global motion (must be >= 3 and <= TRANS_TYPES)
 #define GLOBAL_TRANS_TYPES 3

 // number of parameters used by each transformation in TransformationTypes
 static const int n_trans_model_params[TRANS_TYPES] = { 0, 2, 4, 6, 8 };

 // The order of values in the wmmat matrix below is best described
 // by the homography:
 // [x'     (m2 m3 m0   [x
 //  y'  =   m4 m5 m1 *  y
 //  1]      m6 m7 1)    1]
 typedef struct {
   TransformationType wmtype;
   int32_t wmmat[8];
 } WarpedMotionParams;
 #endif  // CONFIG_GLOBAL_MOTION || CONFIG_WARPED_MOTION

 #if CONFIG_GLOBAL_MOTION
 // ALPHA here refers to parameters a and b in rotzoom model:
 // | a   b|
 // |-b   a|
 //
 // and a, b, c, d in affine model:
 // | a   b|
 // | c   d|
 //
 // Anything ending in PREC_BITS is the number of bits of precision
 // to maintain when converting from double to integer.
 //
 // The ABS parameters are used to create an upper and lower bound
 // for each parameter. In other words, after a parameter is integerized
 // it is clamped between -(1 << ABS_XXX_BITS) and (1 << ABS_XXX_BITS).
 //
 // XXX_PREC_DIFF and XXX_DECODE_FACTOR
 // are computed once here to prevent repetitive
 // computation on the decoder side. These are
 // to allow the global motion parameters to be encoded in a lower
 // precision than the warped model precision. This means that they
 // need to be changed to warped precision when they are decoded.
 //
 // XX_MIN, XX_MAX are also computed to avoid repeated computation

 #define GM_TRANS_PREC_BITS 3
 #define GM_ABS_TRANS_BITS 9
 #define GM_TRANS_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_TRANS_PREC_BITS)
 #define GM_TRANS_DECODE_FACTOR (1 << GM_TRANS_PREC_DIFF)

 #define GM_ALPHA_PREC_BITS 15
 #define GM_ABS_ALPHA_BITS 12
 #define GM_ALPHA_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_ALPHA_PREC_BITS)
 #define GM_ALPHA_DECODE_FACTOR (1 << GM_ALPHA_PREC_DIFF)

 #define GM_ROW3HOMO_PREC_BITS 16
 #define GM_ABS_ROW3HOMO_BITS 11
 #define GM_ROW3HOMO_PREC_DIFF \
   (WARPEDMODEL_ROW3HOMO_PREC_BITS - GM_ROW3HOMO_PREC_BITS)
 #define GM_ROW3HOMO_DECODE_FACTOR (1 << GM_ROW3HOMO_PREC_DIFF)

 #define GM_TRANS_MAX (1 << GM_ABS_TRANS_BITS)
 #define GM_ALPHA_MAX (1 << GM_ABS_ALPHA_BITS)
 #define GM_ROW3HOMO_MAX (1 << GM_ABS_ROW3HOMO_BITS)

 #define GM_TRANS_MIN -GM_TRANS_MAX
 #define GM_ALPHA_MIN -GM_ALPHA_MAX
 #define GM_ROW3HOMO_MIN -GM_ROW3HOMO_MAX

 // Bits used for different models
 #define GM_IDENTITY_BITS 0
 #define GM_TRANSLATION_BITS ((GM_ABS_TRANS_BITS + 1) * 2)
 #define GM_ROTZOOM_BITS (GM_TRANSLATION_BITS + (GM_ABS_ALPHA_BITS + 1) * 2)
 #define GM_AFFINE_BITS (GM_ROTZOOM_BITS + (GM_ABS_ALPHA_BITS + 1) * 2)
 #define GM_HOMOGRAPHY_BITS (GM_AFFINE_BITS + (GM_ABS_ROW3HOMO_BITS + 1) * 2)

 // Convert a global motion translation vector (which may have more bits than a
 // regular motion vector) into a motion vector
 static INLINE int_mv gm_get_motion_vector(const WarpedMotionParams *gm,
                                           int allow_hp) {
   int_mv res;
   res.as_mv.row = allow_hp ? (int16_t)ROUND_POWER_OF_TWO_SIGNED(
                                  gm->wmmat[1], WARPEDMODEL_PREC_BITS - 3)
                            : (int16_t)ROUND_POWER_OF_TWO_SIGNED(
                                  gm->wmmat[1], WARPEDMODEL_PREC_BITS - 2) *
                                  2;
   res.as_mv.col = allow_hp ? (int16_t)ROUND_POWER_OF_TWO_SIGNED(
                                  gm->wmmat[0], WARPEDMODEL_PREC_BITS - 3)
                            : (int16_t)ROUND_POWER_OF_TWO_SIGNED(
                                  gm->wmmat[0], WARPEDMODEL_PREC_BITS - 2) *
                                  2;
   return res;
 }

 static INLINE TransformationType get_gmtype(const WarpedMotionParams *gm) {
   // if (gm->wmmat[6] != 0 || gm->wmmat[7] != 0) return HOMOGRAPHY;
   if (gm->wmmat[5] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[4] &&
       gm->wmmat[2] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[3]) {
     return ((!gm->wmmat[1] && !gm->wmmat[0]) ? IDENTITY : TRANSLATION);
   }
   if (gm->wmmat[2] == gm->wmmat[5] && gm->wmmat[3] == -gm->wmmat[4])
     return ROTZOOM;
   else
     return AFFINE;
 }

 static INLINE void set_default_gmparams(WarpedMotionParams *wm) {
   static const int32_t default_wm_mat[8] = {
     0, 0, (1 << WARPEDMODEL_PREC_BITS), 0, 0, (1 << WARPEDMODEL_PREC_BITS), 0, 0
   };
   memcpy(wm->wmmat, default_wm_mat, sizeof(wm->wmmat));
   wm->wmtype = IDENTITY;
 }
 #endif  // CONFIG_GLOBAL_MOTION

 #if CONFIG_REF_MV
 typedef struct candidate_mv {
   int_mv this_mv;
   int_mv comp_mv;
   uint8_t pred_diff[2];
   int weight;
 } CANDIDATE_MV;
 #endif

 static INLINE int is_zero_mv(const MV *mv) {
   return *((const uint32_t *)mv) == 0;
 }

 static INLINE int is_equal_mv(const MV *a, const MV *b) {
   return *((const uint32_t *)a) == *((const uint32_t *)b);
 }

 static INLINE void clamp_mv(MV *mv, int min_col, int max_col, int min_row,
                             int max_row) {
   mv->col = clamp(mv->col, min_col, max_col);
   mv->row = clamp(mv->row, min_row, max_row);
 }

 static INLINE int mv_has_subpel(const MV *mv) {
   return (mv->row & SUBPEL_MASK) || (mv->col & SUBPEL_MASK);
 }
 #ifdef __cplusplus
 }  // extern "C"
 #endif

 #endif  // AV1_COMMON_MV_H_
	/*
	* Copyright (c) 2016, Alliance for Open Media. All rights reserved
	*
	* This source code is subject to the terms of the BSD 2 Clause License and
	* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
	* was not distributed with this source code in the LICENSE file, you can
	* obtain it at www.aomedia.org/license/software. If the Alliance for Open
	* Media Patent License 1.0 was not distributed with this source code in the
	* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
	*/

	#ifndef AV1_COMMON_MV_H_
	#define AV1_COMMON_MV_H_

	#include "av1/common/common.h"
	#include "aom_dsp/aom_filter.h"

	#ifdef __cplusplus
	extern "C" {
	#endif

	typedef struct mv {
	int16_t row;
	int16_t col;
	} MV;

	typedef union int_mv {
	uint32_t as_int;
	MV as_mv;
	} int_mv; /* facilitates faster equality tests and copies */

	typedef struct mv32 {
	int32_t row;
	int32_t col;
	} MV32;

	#if CONFIG_GLOBAL_MOTION \|\| CONFIG_WARPED_MOTION
	// Bits of precision used for the model
	#define WARPEDMODEL_PREC_BITS 16
	#define WARPEDMODEL_ROW3HOMO_PREC_BITS 16

	// Bits of subpel precision for warped interpolation
	#define WARPEDPIXEL_PREC_BITS 6
	#define WARPEDPIXEL_PREC_SHIFTS (1 << WARPEDPIXEL_PREC_BITS)

	// Taps for ntap filter
	#define WARPEDPIXEL_FILTER_TAPS 6

	// Precision of filter taps
	#define WARPEDPIXEL_FILTER_BITS 7

	#define WARPEDDIFF_PREC_BITS (WARPEDMODEL_PREC_BITS - WARPEDPIXEL_PREC_BITS)

	/* clang-format off */
	typedef enum {
	IDENTITY = 0, // identity transformation, 0-parameter
	TRANSLATION = 1, // translational motion 2-parameter
	ROTZOOM = 2, // simplified affine with rotation + zoom only, 4-parameter
	AFFINE = 3, // affine, 6-parameter
	HOMOGRAPHY = 4, // homography, 8-parameter
	TRANS_TYPES = 5,
	} TransformationType;
	/* clang-format on */

	// Number of types used for global motion (must be >= 3 and <= TRANS_TYPES)
	#define GLOBAL_TRANS_TYPES 3

	// number of parameters used by each transformation in TransformationTypes
	static const int n_trans_model_params[TRANS_TYPES] = { 0, 2, 4, 6, 8 };

	// The order of values in the wmmat matrix below is best described
	// by the homography:
	// [x' (m2 m3 m0 [x
	// y' = m4 m5 m1 * y
	// 1] m6 m7 1) 1]
	typedef struct {
	TransformationType wmtype;
	int32_t wmmat[8];
	} WarpedMotionParams;
	#endif // CONFIG_GLOBAL_MOTION \|\| CONFIG_WARPED_MOTION

	#if CONFIG_GLOBAL_MOTION
	// ALPHA here refers to parameters a and b in rotzoom model:
	// \| a b\|
	// \|-b a\|
	//
	// and a, b, c, d in affine model:
	// \| a b\|
	// \| c d\|
	//
	// Anything ending in PREC_BITS is the number of bits of precision
	// to maintain when converting from double to integer.
	//
	// The ABS parameters are used to create an upper and lower bound
	// for each parameter. In other words, after a parameter is integerized
	// it is clamped between -(1 << ABS_XXX_BITS) and (1 << ABS_XXX_BITS).
	//
	// XXX_PREC_DIFF and XXX_DECODE_FACTOR
	// are computed once here to prevent repetitive
	// computation on the decoder side. These are
	// to allow the global motion parameters to be encoded in a lower
	// precision than the warped model precision. This means that they
	// need to be changed to warped precision when they are decoded.
	//
	// XX_MIN, XX_MAX are also computed to avoid repeated computation

	#define GM_TRANS_PREC_BITS 3
	#define GM_ABS_TRANS_BITS 9
	#define GM_TRANS_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_TRANS_PREC_BITS)
	#define GM_TRANS_DECODE_FACTOR (1 << GM_TRANS_PREC_DIFF)

	#define GM_ALPHA_PREC_BITS 15
	#define GM_ABS_ALPHA_BITS 12
	#define GM_ALPHA_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_ALPHA_PREC_BITS)
	#define GM_ALPHA_DECODE_FACTOR (1 << GM_ALPHA_PREC_DIFF)

	#define GM_ROW3HOMO_PREC_BITS 16
	#define GM_ABS_ROW3HOMO_BITS 11
	#define GM_ROW3HOMO_PREC_DIFF \
	(WARPEDMODEL_ROW3HOMO_PREC_BITS - GM_ROW3HOMO_PREC_BITS)
	#define GM_ROW3HOMO_DECODE_FACTOR (1 << GM_ROW3HOMO_PREC_DIFF)

	#define GM_TRANS_MAX (1 << GM_ABS_TRANS_BITS)
	#define GM_ALPHA_MAX (1 << GM_ABS_ALPHA_BITS)
	#define GM_ROW3HOMO_MAX (1 << GM_ABS_ROW3HOMO_BITS)

	#define GM_TRANS_MIN -GM_TRANS_MAX
	#define GM_ALPHA_MIN -GM_ALPHA_MAX
	#define GM_ROW3HOMO_MIN -GM_ROW3HOMO_MAX

	// Bits used for different models
	#define GM_IDENTITY_BITS 0
	#define GM_TRANSLATION_BITS ((GM_ABS_TRANS_BITS + 1) * 2)
	#define GM_ROTZOOM_BITS (GM_TRANSLATION_BITS + (GM_ABS_ALPHA_BITS + 1) * 2)
	#define GM_AFFINE_BITS (GM_ROTZOOM_BITS + (GM_ABS_ALPHA_BITS + 1) * 2)
	#define GM_HOMOGRAPHY_BITS (GM_AFFINE_BITS + (GM_ABS_ROW3HOMO_BITS + 1) * 2)

	// Convert a global motion translation vector (which may have more bits than a
	// regular motion vector) into a motion vector
	static INLINE int_mv gm_get_motion_vector(const WarpedMotionParams *gm,
	int allow_hp) {
	int_mv res;
	res.as_mv.row = allow_hp ? (int16_t)ROUND_POWER_OF_TWO_SIGNED(
	gm->wmmat[1], WARPEDMODEL_PREC_BITS - 3)
	: (int16_t)ROUND_POWER_OF_TWO_SIGNED(
	gm->wmmat[1], WARPEDMODEL_PREC_BITS - 2) *
	2;
	res.as_mv.col = allow_hp ? (int16_t)ROUND_POWER_OF_TWO_SIGNED(
	gm->wmmat[0], WARPEDMODEL_PREC_BITS - 3)
	: (int16_t)ROUND_POWER_OF_TWO_SIGNED(
	gm->wmmat[0], WARPEDMODEL_PREC_BITS - 2) *
	2;
	return res;
	}

	static INLINE TransformationType get_gmtype(const WarpedMotionParams *gm) {
	// if (gm->wmmat[6] != 0 \|\| gm->wmmat[7] != 0) return HOMOGRAPHY;
	if (gm->wmmat[5] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[4] &&
	gm->wmmat[2] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[3]) {
	return ((!gm->wmmat[1] && !gm->wmmat[0]) ? IDENTITY : TRANSLATION);
	}
	if (gm->wmmat[2] == gm->wmmat[5] && gm->wmmat[3] == -gm->wmmat[4])
	return ROTZOOM;
	else
	return AFFINE;
	}

	static INLINE void set_default_gmparams(WarpedMotionParams *wm) {
	static const int32_t default_wm_mat[8] = {
	0, 0, (1 << WARPEDMODEL_PREC_BITS), 0, 0, (1 << WARPEDMODEL_PREC_BITS), 0, 0
	};
	memcpy(wm->wmmat, default_wm_mat, sizeof(wm->wmmat));
	wm->wmtype = IDENTITY;
	}
	#endif // CONFIG_GLOBAL_MOTION

	#if CONFIG_REF_MV
	typedef struct candidate_mv {
	int_mv this_mv;
	int_mv comp_mv;
	uint8_t pred_diff[2];
	int weight;
	} CANDIDATE_MV;
	#endif

	static INLINE int is_zero_mv(const MV *mv) {
	return ((const uint32_t )mv) == 0;
	}

	static INLINE int is_equal_mv(const MV a, const MV b) {
	return ((const uint32_t )a) == ((const uint32_t )b);
	}

	static INLINE void clamp_mv(MV *mv, int min_col, int max_col, int min_row,
	int max_row) {
	mv->col = clamp(mv->col, min_col, max_col);
	mv->row = clamp(mv->row, min_row, max_row);
	}

	static INLINE int mv_has_subpel(const MV *mv) {
	return (mv->row & SUBPEL_MASK) \|\| (mv->col & SUBPEL_MASK);
	}
	#ifdef __cplusplus
	} // extern "C"
	#endif

	#endif // AV1_COMMON_MV_H_