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FFmpeg/libavcodec/anm.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

204 lines
6.0 KiB
C

/*
* Deluxe Paint Animation decoder
* Copyright (c) 2009 Peter Ross
*
* 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
* Deluxe Paint Animation decoder
*/
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
typedef struct AnmContext {
AVFrame *frame;
int palette[AVPALETTE_COUNT];
} AnmContext;
static av_cold int decode_init(AVCodecContext *avctx)
{
AnmContext *s = avctx->priv_data;
GetByteContext gb;
int i;
if (avctx->extradata_size < 16 * 8 + 4 * 256)
return AVERROR_INVALIDDATA;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
bytestream2_init(&gb, avctx->extradata, avctx->extradata_size);
bytestream2_skipu(&gb, 16 * 8);
for (i = 0; i < 256; i++)
s->palette[i] = (0xFFU << 24) | bytestream2_get_le32u(&gb);
return 0;
}
/**
* Perform decode operation
* @param dst pointer to destination image buffer
* @param dst_end pointer to end of destination image buffer
* @param gb GetByteContext (optional, see below)
* @param pixel Fill color (optional, see below)
* @param count Pixel count
* @param x Pointer to x-axis counter
* @param width Image width
* @param linesize Destination image buffer linesize
* @return non-zero if destination buffer is exhausted
*
* a copy operation is achieved when 'gb' is set
* a fill operation is achieved when 'gb' is null and pixel is >= 0
* a skip operation is achieved when 'gb' is null and pixel is < 0
*/
static inline int op(uint8_t **dst, const uint8_t *dst_end,
GetByteContext *gb,
int pixel, int count,
int *x, int width, int linesize)
{
int remaining = width - *x;
while(count > 0) {
int striplen = FFMIN(count, remaining);
if (gb) {
if (bytestream2_get_bytes_left(gb) < striplen)
goto exhausted;
bytestream2_get_bufferu(gb, *dst, striplen);
} else if (pixel >= 0)
memset(*dst, pixel, striplen);
*dst += striplen;
remaining -= striplen;
count -= striplen;
if (remaining <= 0) {
*dst += linesize - width;
remaining = width;
}
if (linesize > 0) {
if (*dst >= dst_end) goto exhausted;
} else {
if (*dst <= dst_end) goto exhausted;
}
}
*x = width - remaining;
return 0;
exhausted:
*x = width - remaining;
return 1;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
AnmContext *s = avctx->priv_data;
const int buf_size = avpkt->size;
uint8_t *dst, *dst_end;
GetByteContext gb;
int count, ret, x = 0;
if (buf_size < 7)
return AVERROR_INVALIDDATA;
if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
return ret;
dst = s->frame->data[0];
dst_end = s->frame->data[0] + s->frame->linesize[0]*avctx->height;
bytestream2_init(&gb, avpkt->data, buf_size);
if (bytestream2_get_byte(&gb) != 0x42) {
avpriv_request_sample(avctx, "Unknown record type");
return AVERROR_INVALIDDATA;
}
if (bytestream2_get_byte(&gb)) {
avpriv_request_sample(avctx, "Padding bytes");
return AVERROR_PATCHWELCOME;
}
bytestream2_skip(&gb, 2);
do {
/* if statements are ordered by probability */
#define OP(gb, pixel, count) \
op(&dst, dst_end, (gb), (pixel), (count), &x, avctx->width, s->frame->linesize[0])
int type = bytestream2_get_byte(&gb);
count = type & 0x7F;
type >>= 7;
if (count) {
if (OP(type ? NULL : &gb, -1, count)) break;
} else if (!type) {
int pixel;
count = bytestream2_get_byte(&gb); /* count==0 gives nop */
pixel = bytestream2_get_byte(&gb);
if (OP(NULL, pixel, count)) break;
} else {
int pixel;
type = bytestream2_get_le16(&gb);
count = type & 0x3FFF;
type >>= 14;
if (!count) {
if (type == 0)
break; // stop
if (type == 2) {
avpriv_request_sample(avctx, "Unknown opcode");
return AVERROR_PATCHWELCOME;
}
continue;
}
pixel = type == 3 ? bytestream2_get_byte(&gb) : -1;
if (type == 1) count += 0x4000;
if (OP(type == 2 ? &gb : NULL, pixel, count)) break;
}
} while (bytestream2_get_bytes_left(&gb) > 0);
memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
*got_frame = 1;
if ((ret = av_frame_ref(data, s->frame)) < 0)
return ret;
return buf_size;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
AnmContext *s = avctx->priv_data;
av_frame_free(&s->frame);
return 0;
}
const AVCodec ff_anm_decoder = {
.name = "anm",
.long_name = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_ANM,
.priv_data_size = sizeof(AnmContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};