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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-12 19:18:44 +02:00
FFmpeg/libavcodec/xfaceenc.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

224 lines
7.0 KiB
C

/*
* 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 "codec_internal.h"
#include "encode.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_get_encode_buffer(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;
*got_packet = 1;
return 0;
}
const FFCodec ff_xface_encoder = {
.p.name = "xface",
.p.long_name = NULL_IF_CONFIG_SMALL("X-face image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_XFACE,
.p.capabilities = AV_CODEC_CAP_DR1,
.p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
.priv_data_size = sizeof(XFaceContext),
.encode2 = xface_encode_frame,
};