mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-07 11:13:41 +02:00
bb98212930
This improves performance: For msvideo1, the performance improved by 4.8% when encoding the sample from the fate-vsynth1-msvideo1 test; when encoding the sample from fate-vsynth1-cinepak, performance improved by 2%. The compiler user was GCC 10 and the calls to encode2 have been timed. Reviewed-by: Tomas Härdin <tjoppen@acc.umu.se> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
515 lines
16 KiB
C
515 lines
16 KiB
C
/*
|
|
* Copyright (C) 2007 Vitor Sessak <vitor1001@gmail.com>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* Codebook Generator using the ELBG algorithm
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
#include "libavutil/avassert.h"
|
|
#include "libavutil/common.h"
|
|
#include "libavutil/lfg.h"
|
|
#include "elbg.h"
|
|
|
|
#define DELTA_ERR_MAX 0.1 ///< Precision of the ELBG algorithm (as percentage error)
|
|
|
|
/**
|
|
* In the ELBG jargon, a cell is the set of points that are closest to a
|
|
* codebook entry. Not to be confused with a RoQ Video cell. */
|
|
typedef struct cell_s {
|
|
int index;
|
|
struct cell_s *next;
|
|
} cell;
|
|
|
|
/**
|
|
* ELBG internal data
|
|
*/
|
|
typedef struct ELBGContext {
|
|
int64_t error;
|
|
int dim;
|
|
int num_cb;
|
|
int *codebook;
|
|
cell **cells;
|
|
int64_t *utility;
|
|
int64_t *utility_inc;
|
|
int *nearest_cb;
|
|
int *points;
|
|
int *temp_points;
|
|
int *size_part;
|
|
AVLFG *rand_state;
|
|
int *scratchbuf;
|
|
cell *cell_buffer;
|
|
|
|
/* Sizes for the buffers above. Pointers without such a field
|
|
* are not allocated by us and only valid for the duration
|
|
* of a single call to avpriv_elbg_do(). */
|
|
unsigned utility_allocated;
|
|
unsigned utility_inc_allocated;
|
|
unsigned size_part_allocated;
|
|
unsigned cells_allocated;
|
|
unsigned scratchbuf_allocated;
|
|
unsigned cell_buffer_allocated;
|
|
unsigned temp_points_allocated;
|
|
} ELBGContext;
|
|
|
|
static inline int distance_limited(int *a, int *b, int dim, int limit)
|
|
{
|
|
int i, dist=0;
|
|
for (i=0; i<dim; i++) {
|
|
dist += (a[i] - b[i])*(a[i] - b[i]);
|
|
if (dist > limit)
|
|
return INT_MAX;
|
|
}
|
|
|
|
return dist;
|
|
}
|
|
|
|
static inline void vect_division(int *res, int *vect, int div, int dim)
|
|
{
|
|
int i;
|
|
if (div > 1)
|
|
for (i=0; i<dim; i++)
|
|
res[i] = ROUNDED_DIV(vect[i],div);
|
|
else if (res != vect)
|
|
memcpy(res, vect, dim*sizeof(int));
|
|
|
|
}
|
|
|
|
static int eval_error_cell(ELBGContext *elbg, int *centroid, cell *cells)
|
|
{
|
|
int error=0;
|
|
for (; cells; cells=cells->next)
|
|
error += distance_limited(centroid, elbg->points + cells->index*elbg->dim, elbg->dim, INT_MAX);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int get_closest_codebook(ELBGContext *elbg, int index)
|
|
{
|
|
int pick = 0;
|
|
for (int i = 0, diff_min = INT_MAX; i < elbg->num_cb; i++)
|
|
if (i != index) {
|
|
int diff;
|
|
diff = distance_limited(elbg->codebook + i*elbg->dim, elbg->codebook + index*elbg->dim, elbg->dim, diff_min);
|
|
if (diff < diff_min) {
|
|
pick = i;
|
|
diff_min = diff;
|
|
}
|
|
}
|
|
return pick;
|
|
}
|
|
|
|
static int get_high_utility_cell(ELBGContext *elbg)
|
|
{
|
|
int i=0;
|
|
/* Using linear search, do binary if it ever turns to be speed critical */
|
|
uint64_t r;
|
|
|
|
if (elbg->utility_inc[elbg->num_cb - 1] < INT_MAX) {
|
|
r = av_lfg_get(elbg->rand_state) % (unsigned int)elbg->utility_inc[elbg->num_cb - 1] + 1;
|
|
} else {
|
|
r = av_lfg_get(elbg->rand_state);
|
|
r = (av_lfg_get(elbg->rand_state) + (r<<32)) % elbg->utility_inc[elbg->num_cb - 1] + 1;
|
|
}
|
|
|
|
while (elbg->utility_inc[i] < r) {
|
|
i++;
|
|
}
|
|
|
|
av_assert2(elbg->cells[i]);
|
|
|
|
return i;
|
|
}
|
|
|
|
/**
|
|
* Implementation of the simple LBG algorithm for just two codebooks
|
|
*/
|
|
static int simple_lbg(ELBGContext *elbg,
|
|
int dim,
|
|
int *centroid[3],
|
|
int newutility[3],
|
|
int *points,
|
|
cell *cells)
|
|
{
|
|
int i, idx;
|
|
int numpoints[2] = {0,0};
|
|
int *newcentroid[2] = {
|
|
elbg->scratchbuf + 3*dim,
|
|
elbg->scratchbuf + 4*dim
|
|
};
|
|
cell *tempcell;
|
|
|
|
memset(newcentroid[0], 0, 2 * dim * sizeof(*newcentroid[0]));
|
|
|
|
newutility[0] =
|
|
newutility[1] = 0;
|
|
|
|
for (tempcell = cells; tempcell; tempcell=tempcell->next) {
|
|
idx = distance_limited(centroid[0], points + tempcell->index*dim, dim, INT_MAX)>=
|
|
distance_limited(centroid[1], points + tempcell->index*dim, dim, INT_MAX);
|
|
numpoints[idx]++;
|
|
for (i=0; i<dim; i++)
|
|
newcentroid[idx][i] += points[tempcell->index*dim + i];
|
|
}
|
|
|
|
vect_division(centroid[0], newcentroid[0], numpoints[0], dim);
|
|
vect_division(centroid[1], newcentroid[1], numpoints[1], dim);
|
|
|
|
for (tempcell = cells; tempcell; tempcell=tempcell->next) {
|
|
int dist[2] = {distance_limited(centroid[0], points + tempcell->index*dim, dim, INT_MAX),
|
|
distance_limited(centroid[1], points + tempcell->index*dim, dim, INT_MAX)};
|
|
int idx = dist[0] > dist[1];
|
|
newutility[idx] += dist[idx];
|
|
}
|
|
|
|
return newutility[0] + newutility[1];
|
|
}
|
|
|
|
static void get_new_centroids(ELBGContext *elbg, int huc, int *newcentroid_i,
|
|
int *newcentroid_p)
|
|
{
|
|
cell *tempcell;
|
|
int *min = newcentroid_i;
|
|
int *max = newcentroid_p;
|
|
int i;
|
|
|
|
for (i=0; i< elbg->dim; i++) {
|
|
min[i]=INT_MAX;
|
|
max[i]=0;
|
|
}
|
|
|
|
for (tempcell = elbg->cells[huc]; tempcell; tempcell = tempcell->next)
|
|
for(i=0; i<elbg->dim; i++) {
|
|
min[i]=FFMIN(min[i], elbg->points[tempcell->index*elbg->dim + i]);
|
|
max[i]=FFMAX(max[i], elbg->points[tempcell->index*elbg->dim + i]);
|
|
}
|
|
|
|
for (i=0; i<elbg->dim; i++) {
|
|
int ni = min[i] + (max[i] - min[i])/3;
|
|
int np = min[i] + (2*(max[i] - min[i]))/3;
|
|
newcentroid_i[i] = ni;
|
|
newcentroid_p[i] = np;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Add the points in the low utility cell to its closest cell. Split the high
|
|
* utility cell, putting the separated points in the (now empty) low utility
|
|
* cell.
|
|
*
|
|
* @param elbg Internal elbg data
|
|
* @param indexes {luc, huc, cluc}
|
|
* @param newcentroid A vector with the position of the new centroids
|
|
*/
|
|
static void shift_codebook(ELBGContext *elbg, int *indexes,
|
|
int *newcentroid[3])
|
|
{
|
|
cell *tempdata;
|
|
cell **pp = &elbg->cells[indexes[2]];
|
|
|
|
while(*pp)
|
|
pp= &(*pp)->next;
|
|
|
|
*pp = elbg->cells[indexes[0]];
|
|
|
|
elbg->cells[indexes[0]] = NULL;
|
|
tempdata = elbg->cells[indexes[1]];
|
|
elbg->cells[indexes[1]] = NULL;
|
|
|
|
while(tempdata) {
|
|
cell *tempcell2 = tempdata->next;
|
|
int idx = distance_limited(elbg->points + tempdata->index*elbg->dim,
|
|
newcentroid[0], elbg->dim, INT_MAX) >
|
|
distance_limited(elbg->points + tempdata->index*elbg->dim,
|
|
newcentroid[1], elbg->dim, INT_MAX);
|
|
|
|
tempdata->next = elbg->cells[indexes[idx]];
|
|
elbg->cells[indexes[idx]] = tempdata;
|
|
tempdata = tempcell2;
|
|
}
|
|
}
|
|
|
|
static void evaluate_utility_inc(ELBGContext *elbg)
|
|
{
|
|
int64_t inc=0;
|
|
|
|
for (int i = 0; i < elbg->num_cb; i++) {
|
|
if (elbg->num_cb * elbg->utility[i] > elbg->error)
|
|
inc += elbg->utility[i];
|
|
elbg->utility_inc[i] = inc;
|
|
}
|
|
}
|
|
|
|
|
|
static void update_utility_and_n_cb(ELBGContext *elbg, int idx, int newutility)
|
|
{
|
|
cell *tempcell;
|
|
|
|
elbg->utility[idx] = newutility;
|
|
for (tempcell=elbg->cells[idx]; tempcell; tempcell=tempcell->next)
|
|
elbg->nearest_cb[tempcell->index] = idx;
|
|
}
|
|
|
|
/**
|
|
* Evaluate if a shift lower the error. If it does, call shift_codebooks
|
|
* and update elbg->error, elbg->utility and elbg->nearest_cb.
|
|
*
|
|
* @param elbg Internal elbg data
|
|
* @param idx {luc (low utility cell, huc (high utility cell), cluc (closest cell to low utility cell)}
|
|
*/
|
|
static void try_shift_candidate(ELBGContext *elbg, int idx[3])
|
|
{
|
|
int j, k, cont=0;
|
|
int64_t olderror=0, newerror;
|
|
int newutility[3];
|
|
int *newcentroid[3] = {
|
|
elbg->scratchbuf,
|
|
elbg->scratchbuf + elbg->dim,
|
|
elbg->scratchbuf + 2*elbg->dim
|
|
};
|
|
cell *tempcell;
|
|
|
|
for (j=0; j<3; j++)
|
|
olderror += elbg->utility[idx[j]];
|
|
|
|
memset(newcentroid[2], 0, elbg->dim*sizeof(int));
|
|
|
|
for (k=0; k<2; k++)
|
|
for (tempcell=elbg->cells[idx[2*k]]; tempcell; tempcell=tempcell->next) {
|
|
cont++;
|
|
for (j=0; j<elbg->dim; j++)
|
|
newcentroid[2][j] += elbg->points[tempcell->index*elbg->dim + j];
|
|
}
|
|
|
|
vect_division(newcentroid[2], newcentroid[2], cont, elbg->dim);
|
|
|
|
get_new_centroids(elbg, idx[1], newcentroid[0], newcentroid[1]);
|
|
|
|
newutility[2] = eval_error_cell(elbg, newcentroid[2], elbg->cells[idx[0]]);
|
|
newutility[2] += eval_error_cell(elbg, newcentroid[2], elbg->cells[idx[2]]);
|
|
|
|
newerror = newutility[2];
|
|
|
|
newerror += simple_lbg(elbg, elbg->dim, newcentroid, newutility, elbg->points,
|
|
elbg->cells[idx[1]]);
|
|
|
|
if (olderror > newerror) {
|
|
shift_codebook(elbg, idx, newcentroid);
|
|
|
|
elbg->error += newerror - olderror;
|
|
|
|
for (j=0; j<3; j++)
|
|
update_utility_and_n_cb(elbg, idx[j], newutility[j]);
|
|
|
|
evaluate_utility_inc(elbg);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Implementation of the ELBG block
|
|
*/
|
|
static void do_shiftings(ELBGContext *elbg)
|
|
{
|
|
int idx[3];
|
|
|
|
evaluate_utility_inc(elbg);
|
|
|
|
for (idx[0]=0; idx[0] < elbg->num_cb; idx[0]++)
|
|
if (elbg->num_cb * elbg->utility[idx[0]] < elbg->error) {
|
|
if (elbg->utility_inc[elbg->num_cb - 1] == 0)
|
|
return;
|
|
|
|
idx[1] = get_high_utility_cell(elbg);
|
|
idx[2] = get_closest_codebook(elbg, idx[0]);
|
|
|
|
if (idx[1] != idx[0] && idx[1] != idx[2])
|
|
try_shift_candidate(elbg, idx);
|
|
}
|
|
}
|
|
|
|
static void do_elbg(ELBGContext *av_restrict elbg, int *points, int numpoints,
|
|
int max_steps)
|
|
{
|
|
int *const size_part = elbg->size_part;
|
|
int i, j, steps = 0;
|
|
int best_idx = 0;
|
|
int64_t last_error;
|
|
|
|
elbg->error = INT64_MAX;
|
|
elbg->points = points;
|
|
|
|
do {
|
|
cell *free_cells = elbg->cell_buffer;
|
|
last_error = elbg->error;
|
|
steps++;
|
|
memset(elbg->utility, 0, elbg->num_cb * sizeof(*elbg->utility));
|
|
memset(elbg->cells, 0, elbg->num_cb * sizeof(*elbg->cells));
|
|
|
|
elbg->error = 0;
|
|
|
|
/* This loop evaluate the actual Voronoi partition. It is the most
|
|
costly part of the algorithm. */
|
|
for (i=0; i < numpoints; i++) {
|
|
int best_dist = distance_limited(elbg->points + i * elbg->dim,
|
|
elbg->codebook + best_idx * elbg->dim,
|
|
elbg->dim, INT_MAX);
|
|
for (int k = 0; k < elbg->num_cb; k++) {
|
|
int dist = distance_limited(elbg->points + i * elbg->dim,
|
|
elbg->codebook + k * elbg->dim,
|
|
elbg->dim, best_dist);
|
|
if (dist < best_dist) {
|
|
best_dist = dist;
|
|
best_idx = k;
|
|
}
|
|
}
|
|
elbg->nearest_cb[i] = best_idx;
|
|
elbg->error += best_dist;
|
|
elbg->utility[elbg->nearest_cb[i]] += best_dist;
|
|
free_cells->index = i;
|
|
free_cells->next = elbg->cells[elbg->nearest_cb[i]];
|
|
elbg->cells[elbg->nearest_cb[i]] = free_cells;
|
|
free_cells++;
|
|
}
|
|
|
|
do_shiftings(elbg);
|
|
|
|
memset(size_part, 0, elbg->num_cb * sizeof(*size_part));
|
|
|
|
memset(elbg->codebook, 0, elbg->num_cb * elbg->dim * sizeof(*elbg->codebook));
|
|
|
|
for (i=0; i < numpoints; i++) {
|
|
size_part[elbg->nearest_cb[i]]++;
|
|
for (j=0; j < elbg->dim; j++)
|
|
elbg->codebook[elbg->nearest_cb[i]*elbg->dim + j] +=
|
|
elbg->points[i*elbg->dim + j];
|
|
}
|
|
|
|
for (int i = 0; i < elbg->num_cb; i++)
|
|
vect_division(elbg->codebook + i*elbg->dim,
|
|
elbg->codebook + i*elbg->dim, size_part[i], elbg->dim);
|
|
|
|
} while(((last_error - elbg->error) > DELTA_ERR_MAX*elbg->error) &&
|
|
(steps < max_steps));
|
|
}
|
|
|
|
#define BIG_PRIME 433494437LL
|
|
|
|
/**
|
|
* Initialize the codebook vector for the elbg algorithm.
|
|
* If numpoints <= 24 * num_cb this function fills codebook with random numbers.
|
|
* If not, it calls do_elbg for a (smaller) random sample of the points in
|
|
* points.
|
|
*/
|
|
static void init_elbg(ELBGContext *av_restrict elbg, int *points, int *temp_points,
|
|
int numpoints, int max_steps)
|
|
{
|
|
int dim = elbg->dim;
|
|
|
|
if (numpoints > 24LL * elbg->num_cb) {
|
|
/* ELBG is very costly for a big number of points. So if we have a lot
|
|
of them, get a good initial codebook to save on iterations */
|
|
for (int i = 0; i < numpoints / 8; i++) {
|
|
int k = (i*BIG_PRIME) % numpoints;
|
|
memcpy(temp_points + i*dim, points + k*dim, dim * sizeof(*temp_points));
|
|
}
|
|
|
|
/* If anything is changed in the recursion parameters,
|
|
* the allocated size of temp_points will also need to be updated. */
|
|
init_elbg(elbg, temp_points, temp_points + numpoints / 8 * dim,
|
|
numpoints / 8, 2 * max_steps);
|
|
do_elbg(elbg, temp_points, numpoints / 8, 2 * max_steps);
|
|
} else // If not, initialize the codebook with random positions
|
|
for (int i = 0; i < elbg->num_cb; i++)
|
|
memcpy(elbg->codebook + i * dim, points + ((i*BIG_PRIME)%numpoints)*dim,
|
|
dim * sizeof(*elbg->codebook));
|
|
}
|
|
|
|
int avpriv_elbg_do(ELBGContext **elbgp, int *points, int dim, int numpoints,
|
|
int *codebook, int num_cb, int max_steps,
|
|
int *closest_cb, AVLFG *rand_state, uintptr_t flags)
|
|
{
|
|
ELBGContext *const av_restrict elbg = *elbgp ? *elbgp : av_mallocz(sizeof(*elbg));
|
|
|
|
if (!elbg)
|
|
return AVERROR(ENOMEM);
|
|
*elbgp = elbg;
|
|
|
|
elbg->nearest_cb = closest_cb;
|
|
elbg->rand_state = rand_state;
|
|
elbg->codebook = codebook;
|
|
elbg->num_cb = num_cb;
|
|
elbg->dim = dim;
|
|
|
|
#define ALLOCATE_IF_NECESSARY(field, new_elements, multiplicator) \
|
|
if (elbg->field ## _allocated < new_elements) { \
|
|
av_freep(&elbg->field); \
|
|
elbg->field = av_malloc_array(new_elements, \
|
|
multiplicator * sizeof(*elbg->field)); \
|
|
if (!elbg->field) { \
|
|
elbg->field ## _allocated = 0; \
|
|
return AVERROR(ENOMEM); \
|
|
} \
|
|
elbg->field ## _allocated = new_elements; \
|
|
}
|
|
/* Allocating the buffers for do_elbg() here once relies
|
|
* on their size being always the same even when do_elbg()
|
|
* is called from init_elbg(). It also relies on do_elbg()
|
|
* never calling itself recursively. */
|
|
ALLOCATE_IF_NECESSARY(cells, num_cb, 1)
|
|
ALLOCATE_IF_NECESSARY(utility, num_cb, 1)
|
|
ALLOCATE_IF_NECESSARY(utility_inc, num_cb, 1)
|
|
ALLOCATE_IF_NECESSARY(size_part, num_cb, 1)
|
|
ALLOCATE_IF_NECESSARY(cell_buffer, numpoints, 1)
|
|
ALLOCATE_IF_NECESSARY(scratchbuf, dim, 5)
|
|
if (numpoints > 24LL * elbg->num_cb) {
|
|
/* The first step in the recursion in init_elbg() needs a buffer with
|
|
* (numpoints / 8) * dim elements; the next step needs numpoints / 8 / 8
|
|
* * dim elements etc. The geometric series leads to an upper bound of
|
|
* numpoints / 8 * 8 / 7 * dim elements. */
|
|
uint64_t prod = dim * (uint64_t)(numpoints / 7U);
|
|
if (prod > INT_MAX)
|
|
return AVERROR(ERANGE);
|
|
ALLOCATE_IF_NECESSARY(temp_points, prod, 1)
|
|
}
|
|
|
|
init_elbg(elbg, points, elbg->temp_points, numpoints, max_steps);
|
|
do_elbg (elbg, points, numpoints, max_steps);
|
|
return 0;
|
|
}
|
|
|
|
av_cold void avpriv_elbg_free(ELBGContext **elbgp)
|
|
{
|
|
ELBGContext *elbg = *elbgp;
|
|
if (!elbg)
|
|
return;
|
|
|
|
av_freep(&elbg->size_part);
|
|
av_freep(&elbg->utility);
|
|
av_freep(&elbg->cell_buffer);
|
|
av_freep(&elbg->cells);
|
|
av_freep(&elbg->utility_inc);
|
|
av_freep(&elbg->scratchbuf);
|
|
av_freep(&elbg->temp_points);
|
|
|
|
av_freep(elbgp);
|
|
}
|