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FFmpeg/libavcodec/cdtoons.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

458 lines
15 KiB
C

/*
* CDToons video decoder
* Copyright (C) 2020 Alyssa Milburn <amilburn@zall.org>
*
* 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
* CDToons video decoder
* @author Alyssa Milburn <amilburn@zall.org>
*/
#include <stdint.h>
#include "libavutil/attributes.h"
#include "libavutil/internal.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#define CDTOONS_HEADER_SIZE 44
#define CDTOONS_MAX_SPRITES 1200
typedef struct CDToonsSprite {
uint16_t flags;
uint16_t owner_frame;
uint16_t start_frame;
uint16_t end_frame;
unsigned int alloc_size;
uint32_t size;
uint8_t *data;
int active;
} CDToonsSprite;
typedef struct CDToonsContext {
AVFrame *frame;
uint16_t last_pal_id; ///< The index of the active palette sprite.
uint32_t pal[256]; ///< The currently-used palette data.
CDToonsSprite sprites[CDTOONS_MAX_SPRITES];
} CDToonsContext;
static int cdtoons_render_sprite(AVCodecContext *avctx, const uint8_t *data,
uint32_t data_size,
int dst_x, int dst_y, int width, int height)
{
CDToonsContext *c = avctx->priv_data;
const uint8_t *next_line = data;
const uint8_t *end = data + data_size;
uint16_t line_size;
uint8_t *dest;
int skip = 0, to_skip, x;
if (dst_x + width > avctx->width)
width = avctx->width - dst_x;
if (dst_y + height > avctx->height)
height = avctx->height - dst_y;
if (dst_x < 0) {
/* we need to skip the start of the scanlines */
skip = -dst_x;
if (width <= skip)
return 0;
dst_x = 0;
}
for (int y = 0; y < height; y++) {
/* one scanline at a time, size is provided */
data = next_line;
if (end - data < 2)
return 1;
line_size = bytestream_get_be16(&data);
if (end - data < line_size)
return 1;
next_line = data + line_size;
if (dst_y + y < 0)
continue;
dest = c->frame->data[0] + (dst_y + y) * c->frame->linesize[0] + dst_x;
to_skip = skip;
x = 0;
while (x < width - skip) {
int raw, size, step;
uint8_t val;
if (data >= end)
return 1;
val = bytestream_get_byte(&data);
raw = !(val & 0x80);
size = (int)(val & 0x7F) + 1;
/* skip the start of a scanline if it is off-screen */
if (to_skip >= size) {
to_skip -= size;
if (raw) {
step = size;
} else {
step = 1;
}
if (next_line - data < step)
return 1;
data += step;
continue;
} else if (to_skip) {
size -= to_skip;
if (raw) {
if (next_line - data < to_skip)
return 1;
data += to_skip;
}
to_skip = 0;
}
if (x + size >= width - skip)
size = width - skip - x;
/* either raw data, or a run of a single color */
if (raw) {
if (next_line - data < size)
return 1;
memcpy(dest + x, data, size);
data += size;
} else {
uint8_t color = bytestream_get_byte(&data);
/* ignore transparent runs */
if (color)
memset(dest + x, color, size);
}
x += size;
}
}
return 0;
}
static int cdtoons_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
CDToonsContext *c = avctx->priv_data;
const uint8_t *buf = avpkt->data;
const uint8_t *eod = avpkt->data + avpkt->size;
const int buf_size = avpkt->size;
uint16_t frame_id;
uint8_t background_color;
uint16_t sprite_count, sprite_offset;
uint8_t referenced_count;
uint16_t palette_id;
uint8_t palette_set;
int ret;
int saw_embedded_sprites = 0;
if (buf_size < CDTOONS_HEADER_SIZE)
return AVERROR_INVALIDDATA;
if ((ret = ff_reget_buffer(avctx, c->frame, 0)) < 0)
return ret;
/* a lot of the header is useless junk in the absence of
* dirty rectangling etc */
buf += 2; /* version? (always 9?) */
frame_id = bytestream_get_be16(&buf);
buf += 2; /* blocks_valid_until */
buf += 1;
background_color = bytestream_get_byte(&buf);
buf += 16; /* clip rect, dirty rect */
buf += 4; /* flags */
sprite_count = bytestream_get_be16(&buf);
sprite_offset = bytestream_get_be16(&buf);
buf += 2; /* max block id? */
referenced_count = bytestream_get_byte(&buf);
buf += 1;
palette_id = bytestream_get_be16(&buf);
palette_set = bytestream_get_byte(&buf);
buf += 5;
if (sprite_offset > buf_size)
return AVERROR_INVALIDDATA;
/* read new sprites introduced in this frame */
buf = avpkt->data + sprite_offset;
while (sprite_count--) {
uint32_t size;
uint16_t sprite_id;
if (buf + 14 > eod)
return AVERROR_INVALIDDATA;
sprite_id = bytestream_get_be16(&buf);
if (sprite_id >= CDTOONS_MAX_SPRITES) {
av_log(avctx, AV_LOG_ERROR,
"Sprite ID %d is too high.\n", sprite_id);
return AVERROR_INVALIDDATA;
}
if (c->sprites[sprite_id].active) {
av_log(avctx, AV_LOG_ERROR,
"Sprite ID %d is a duplicate.\n", sprite_id);
return AVERROR_INVALIDDATA;
}
c->sprites[sprite_id].flags = bytestream_get_be16(&buf);
size = bytestream_get_be32(&buf);
if (size < 14) {
av_log(avctx, AV_LOG_ERROR,
"Sprite only has %d bytes of data.\n", size);
return AVERROR_INVALIDDATA;
}
size -= 14;
c->sprites[sprite_id].size = size;
c->sprites[sprite_id].owner_frame = frame_id;
c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf);
c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf);
buf += 2;
if (size > buf_size || buf + size > eod)
return AVERROR_INVALIDDATA;
av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size);
if (!c->sprites[sprite_id].data)
return AVERROR(ENOMEM);
c->sprites[sprite_id].active = 1;
bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size);
}
/* render any embedded sprites */
while (buf < eod) {
uint32_t tag, size;
if (buf + 8 > eod) {
av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n");
return AVERROR_INVALIDDATA;
}
tag = bytestream_get_be32(&buf);
size = bytestream_get_be32(&buf);
if (tag == MKBETAG('D', 'i', 'f', 'f')) {
uint16_t diff_count;
if (buf + 10 > eod) {
av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n");
return AVERROR_INVALIDDATA;
}
diff_count = bytestream_get_be16(&buf);
buf += 8; /* clip rect? */
for (int i = 0; i < diff_count; i++) {
int16_t top, left;
uint16_t diff_size, width, height;
if (buf + 16 > eod) {
av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n");
return AVERROR_INVALIDDATA;
}
top = bytestream_get_be16(&buf);
left = bytestream_get_be16(&buf);
buf += 4; /* bottom, right */
diff_size = bytestream_get_be32(&buf);
width = bytestream_get_be16(&buf);
height = bytestream_get_be16(&buf);
if (diff_size < 8 || diff_size - 4 > eod - buf) {
av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n");
return AVERROR_INVALIDDATA;
}
if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8,
left, top, width, height)) {
av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
}
buf += diff_size - 4;
}
saw_embedded_sprites = 1;
} else {
/* we don't care about any other entries */
if (size < 8 || size - 8 > eod - buf) {
av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf));
return AVERROR_INVALIDDATA;
}
buf += (size - 8);
}
}
/* was an intra frame? */
if (saw_embedded_sprites)
goto done;
/* render any referenced sprites */
buf = avpkt->data + CDTOONS_HEADER_SIZE;
eod = avpkt->data + sprite_offset;
for (int i = 0; i < referenced_count; i++) {
const uint8_t *block_data;
uint16_t sprite_id, width, height;
int16_t top, left, right;
if (buf + 10 > eod) {
av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n");
return AVERROR_INVALIDDATA;
}
sprite_id = bytestream_get_be16(&buf);
top = bytestream_get_be16(&buf);
left = bytestream_get_be16(&buf);
buf += 2; /* bottom */
right = bytestream_get_be16(&buf);
if ((i == 0) && (sprite_id == 0)) {
/* clear background */
memset(c->frame->data[0], background_color,
c->frame->linesize[0] * avctx->height);
}
if (!right)
continue;
if (sprite_id >= CDTOONS_MAX_SPRITES) {
av_log(avctx, AV_LOG_ERROR,
"Sprite ID %d is too high.\n", sprite_id);
return AVERROR_INVALIDDATA;
}
block_data = c->sprites[sprite_id].data;
if (!c->sprites[sprite_id].active) {
/* this can happen when seeking around */
av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id);
continue;
}
if (c->sprites[sprite_id].size < 14) {
av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id);
continue;
}
height = bytestream_get_be16(&block_data);
width = bytestream_get_be16(&block_data);
block_data += 10;
if (cdtoons_render_sprite(avctx, block_data,
c->sprites[sprite_id].size - 14,
left, top, width, height)) {
av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
}
}
if (palette_id && (palette_id != c->last_pal_id)) {
if (palette_id >= CDTOONS_MAX_SPRITES) {
av_log(avctx, AV_LOG_ERROR,
"Palette ID %d is too high.\n", palette_id);
return AVERROR_INVALIDDATA;
}
if (!c->sprites[palette_id].active) {
/* this can happen when seeking around */
av_log(avctx, AV_LOG_WARNING,
"Palette ID %d is missing.\n", palette_id);
goto done;
}
if (c->sprites[palette_id].size != 256 * 2 * 3) {
av_log(avctx, AV_LOG_ERROR,
"Palette ID %d is wrong size (%d).\n",
palette_id, c->sprites[palette_id].size);
return AVERROR_INVALIDDATA;
}
c->last_pal_id = palette_id;
if (!palette_set) {
uint8_t *palette_data = c->sprites[palette_id].data;
for (int i = 0; i < 256; i++) {
/* QuickTime-ish palette: 16-bit RGB components */
unsigned r, g, b;
r = *palette_data;
g = *(palette_data + 2);
b = *(palette_data + 4);
c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
palette_data += 6;
}
/* first palette entry indicates transparency */
c->pal[0] = 0;
c->frame->palette_has_changed = 1;
}
}
done:
/* discard outdated blocks */
for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
if (c->sprites[i].end_frame > frame_id)
continue;
c->sprites[i].active = 0;
}
memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE);
if ((ret = av_frame_ref(data, c->frame)) < 0)
return ret;
*got_frame = 1;
/* always report that the buffer was completely consumed */
return buf_size;
}
static av_cold int cdtoons_decode_init(AVCodecContext *avctx)
{
CDToonsContext *c = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
c->last_pal_id = 0;
c->frame = av_frame_alloc();
if (!c->frame)
return AVERROR(ENOMEM);
return 0;
}
static void cdtoons_flush(AVCodecContext *avctx)
{
CDToonsContext *c = avctx->priv_data;
c->last_pal_id = 0;
for (int i = 0; i < CDTOONS_MAX_SPRITES; i++)
c->sprites[i].active = 0;
}
static av_cold int cdtoons_decode_end(AVCodecContext *avctx)
{
CDToonsContext *c = avctx->priv_data;
for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
av_freep(&c->sprites[i].data);
c->sprites[i].active = 0;
}
av_frame_free(&c->frame);
return 0;
}
const AVCodec ff_cdtoons_decoder = {
.name = "cdtoons",
.long_name = NULL_IF_CONFIG_SMALL("CDToons video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CDTOONS,
.priv_data_size = sizeof(CDToonsContext),
.init = cdtoons_decode_init,
.close = cdtoons_decode_end,
.decode = cdtoons_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
.flush = cdtoons_flush,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};