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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 decoder, based on libcompface, by James Ashton.
*/
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "xface.h"
static int pop_integer(BigInt *b, const ProbRange *pranges)
{
uint8_t r;
int i;
/* extract the last byte into r, and shift right b by 8 bits */
ff_big_div(b, 0, &r);
i = 0;
while (r < pranges->offset || r >= pranges->range + pranges->offset) {
pranges++;
i++;
}
ff_big_mul(b, pranges->range);
ff_big_add(b, r - pranges->offset);
return i;
}
static void pop_greys(BigInt *b, char *bitmap, int w, int h)
{
if (w > 3) {
w /= 2;
h /= 2;
pop_greys(b, bitmap, w, h);
pop_greys(b, bitmap + w, w, h);
pop_greys(b, bitmap + XFACE_WIDTH * h, w, h);
pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h);
} else {
w = pop_integer(b, ff_xface_probranges_2x2);
if (w & 1) bitmap[0] = 1;
if (w & 2) bitmap[1] = 1;
if (w & 4) bitmap[XFACE_WIDTH] = 1;
if (w & 8) bitmap[XFACE_WIDTH + 1] = 1;
}
}
static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
{
switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) {
case XFACE_COLOR_WHITE:
return;
case XFACE_COLOR_BLACK:
pop_greys(b, bitmap, w, h);
return;
default:
w /= 2;
h /= 2;
level++;
decode_block(b, bitmap, w, h, level);
decode_block(b, bitmap + w, w, h, level);
decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level);
decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level);
return;
}
}
typedef struct XFaceContext {
uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
} XFaceContext;
static av_cold int xface_decode_init(AVCodecContext *avctx)
{
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;
avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
return 0;
}
static int xface_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
XFaceContext *xface = avctx->priv_data;
int ret, i, j, k;
uint8_t byte;
BigInt b = {0};
char *buf;
int64_t c;
AVFrame *frame = data;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
for (i = 0, k = 0; i < avpkt->size && avpkt->data[i]; i++) {
c = avpkt->data[i];
/* ignore invalid digits */
if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT)
continue;
if (++k > XFACE_MAX_DIGITS) {
av_log(avctx, AV_LOG_WARNING,
"Buffer is longer than expected, truncating at byte %d\n", i);
break;
}
ff_big_mul(&b, XFACE_PRINTS);
ff_big_add(&b, c - XFACE_FIRST_PRINT);
}
/* decode image and put it in bitmap */
memset(xface->bitmap, 0, XFACE_PIXELS);
buf = xface->bitmap;
decode_block(&b, buf, 16, 16, 0);
decode_block(&b, buf + 16, 16, 16, 0);
decode_block(&b, buf + 32, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0);
decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0);
ff_xface_generate_face(xface->bitmap, xface->bitmap);
/* convert image from 1=black 0=white bitmap to MONOWHITE */
buf = frame->data[0];
for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) {
byte += xface->bitmap[i];
if (k == 7) {
buf[j++] = byte;
byte = k = 0;
} else {
k++;
byte <<= 1;
}
if (j == XFACE_WIDTH/8) {
j = 0;
buf += frame->linesize[0];
}
}
*got_frame = 1;
return avpkt->size;
}
AVCodec ff_xface_decoder = {
.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),
.init = xface_decode_init,
.decode = xface_decode_frame,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
};
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