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/*
* Copyright (c) 1990 James Ashton - Sydney University
* Copyright (c) 2012 Stefano Sabatini
*
* 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
* X-Face encoder, based on libcompface, by James Ashton.
*/
#include "xface.h"
#include "avcodec.h"
#include "internal.h"
#include "libavutil/avassert.h"
typedef struct XFaceContext {
AVClass *class;
uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
int max_line_len; ///< max line length for compressed data
int set_header; ///< set X-Face header in the output
} XFaceContext;
static int all_same(char *bitmap, int w, int h)
{
char val, *row;
int x;
val = *bitmap;
while (h--) {
row = bitmap;
x = w;
while (x--)
if (*(row++) != val)
return 0;
bitmap += XFACE_WIDTH;
}
return 1;
}
static int all_black(char *bitmap, int w, int h)
{
if (w > 3) {
w /= 2;
h /= 2;
return (all_black(bitmap, w, h) && all_black(bitmap + w, w, h) &&
all_black(bitmap + XFACE_WIDTH * h, w, h) &&
all_black(bitmap + XFACE_WIDTH * h + w, w, h));
} else {
/* at least one pixel in the 2x2 grid is non-zero */
return *bitmap || *(bitmap + 1) ||
*(bitmap + XFACE_WIDTH) || *(bitmap + XFACE_WIDTH + 1);
}
}
static int all_white(char *bitmap, int w, int h)
{
return *bitmap == 0 && all_same(bitmap, w, h);
}
typedef struct {
ProbRange prob_ranges[XFACE_PIXELS*2];
int prob_ranges_idx;
} ProbRangesQueue;
static inline int pq_push(ProbRangesQueue *pq, const ProbRange *p)
{
if (pq->prob_ranges_idx >= XFACE_PIXELS * 2 - 1)
return -1;
pq->prob_ranges[pq->prob_ranges_idx++] = *p;
return 0;
}
static void push_greys(ProbRangesQueue *pq, char *bitmap, int w, int h)
{
if (w > 3) {
w /= 2;
h /= 2;
push_greys(pq, bitmap, w, h);
push_greys(pq, bitmap + w, w, h);
push_greys(pq, bitmap + XFACE_WIDTH * h, w, h);
push_greys(pq, bitmap + XFACE_WIDTH * h + w, w, h);
} else {
const ProbRange *p = ff_xface_probranges_2x2 +
*bitmap +
2 * *(bitmap + 1) +
4 * *(bitmap + XFACE_WIDTH) +
8 * *(bitmap + XFACE_WIDTH + 1);
pq_push(pq, p);
}
}
static void encode_block(char *bitmap, int w, int h, int level, ProbRangesQueue *pq)
{
if (all_white(bitmap, w, h)) {
pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_WHITE]);
} else if (all_black(bitmap, w, h)) {
pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_BLACK]);
push_greys(pq, bitmap, w, h);
} else {
pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_GREY]);
w /= 2;
h /= 2;
level++;
encode_block(bitmap, w, h, level, pq);
encode_block(bitmap + w, w, h, level, pq);
encode_block(bitmap + h * XFACE_WIDTH, w, h, level, pq);
encode_block(bitmap + w + h * XFACE_WIDTH, w, h, level, pq);
}
}
static void push_integer(BigInt *b, const ProbRange *prange)
{
uint8_t r;
ff_big_div(b, prange->range, &r);
ff_big_mul(b, 0);
ff_big_add(b, r + prange->offset);
}
static int xface_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *frame, int *got_packet)
{
XFaceContext *xface = avctx->priv_data;
ProbRangesQueue pq = {{{ 0 }}, 0};
uint8_t bitmap_copy[XFACE_PIXELS];
BigInt b = {0};
int i, j, k, ret = 0;
const uint8_t *buf;
uint8_t *p;
char intbuf[XFACE_MAX_DIGITS];
if (avctx->width || avctx->height) {
if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
av_log(avctx, AV_LOG_ERROR,
"Size value %dx%d not supported, only accepts a size of %dx%d\n",
avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
return AVERROR(EINVAL);
}
}
avctx->width = XFACE_WIDTH;
avctx->height = XFACE_HEIGHT;
/* convert image from MONOWHITE to 1=black 0=white bitmap */
buf = frame->data[0];
i = j = 0;
do {
for (k = 0; k < 8; k++)
xface->bitmap[i++] = (buf[j]>>(7-k))&1;
if (++j == XFACE_WIDTH/8) {
buf += frame->linesize[0];
j = 0;
}
} while (i < XFACE_PIXELS);
/* create a copy of bitmap */
memcpy(bitmap_copy, xface->bitmap, XFACE_PIXELS);
ff_xface_generate_face(xface->bitmap, bitmap_copy);
encode_block(xface->bitmap, 16, 16, 0, &pq);
encode_block(xface->bitmap + 16, 16, 16, 0, &pq);
encode_block(xface->bitmap + 32, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 16, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 16 + 16, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 16 + 32, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 32, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 32 + 16, 16, 16, 0, &pq);
encode_block(xface->bitmap + XFACE_WIDTH * 32 + 32, 16, 16, 0, &pq);
while (pq.prob_ranges_idx > 0)
push_integer(&b, &pq.prob_ranges[--pq.prob_ranges_idx]);
/* write the inverted big integer in b to intbuf */
i = 0;
av_assert0(b.nb_words < XFACE_MAX_WORDS);
while (b.nb_words) {
uint8_t r;
ff_big_div(&b, XFACE_PRINTS, &r);
av_assert0(i < sizeof(intbuf));
intbuf[i++] = r + XFACE_FIRST_PRINT;
}
if ((ret = ff_alloc_packet2(avctx, pkt, i+2, 0)) < 0)
return ret;
/* revert the number, and close the buffer */
p = pkt->data;
while (--i >= 0)
*(p++) = intbuf[i];
*(p++) = '\n';
*(p++) = 0;
pkt->flags |= AV_PKT_FLAG_KEY;
*got_packet = 1;
return 0;
}
const AVCodec ff_xface_encoder = {
.name = "xface",
.long_name = NULL_IF_CONFIG_SMALL("X-face image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_XFACE,
.priv_data_size = sizeof(XFaceContext),
.encode2 = xface_encode_frame,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
};
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