ffmpeg/libavcodec/anm.c

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/*
* Deluxe Paint Animation decoder
* Copyright (c) 2009 Peter Ross
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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];
GetByteContext gb;
int x; ///< x coordinate position
} AnmContext;
static av_cold int decode_init(AVCodecContext *avctx)
{
AnmContext *s = avctx->priv_data;
int i;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
if (bytestream2_get_bytes_left(&s->gb) < 16 * 8 + 4 * 256)
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return AVERROR_INVALIDDATA;
bytestream2_skipu(&s->gb, 16 * 8);
for (i = 0; i < 256; i++)
s->palette[i] = bytestream2_get_le32u(&s->gb);
return 0;
}
/**
* Perform decode operation
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* @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
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* 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;
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int count, ret;
if ((ret = ff_reget_buffer(avctx, s->frame)) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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return ret;
}
dst = s->frame->data[0];
dst_end = s->frame->data[0] + s->frame->linesize[0]*avctx->height;
bytestream2_init(&s->gb, avpkt->data, buf_size);
if (bytestream2_get_byte(&s->gb) != 0x42) {
avpriv_request_sample(avctx, "Unknown record type");
return buf_size;
}
if (bytestream2_get_byte(&s->gb)) {
avpriv_request_sample(avctx, "Padding bytes");
return buf_size;
}
bytestream2_skip(&s->gb, 2);
s->x = 0;
do {
/* if statements are ordered by probability */
#define OP(gb, pixel, count) \
op(&dst, dst_end, (gb), (pixel), (count), &s->x, avctx->width, s->frame->linesize[0])
int type = bytestream2_get_byte(&s->gb);
count = type & 0x7F;
type >>= 7;
if (count) {
if (OP(type ? NULL : &s->gb, -1, count)) break;
} else if (!type) {
int pixel;
count = bytestream2_get_byte(&s->gb); /* count==0 gives nop */
pixel = bytestream2_get_byte(&s->gb);
if (OP(NULL, pixel, count)) break;
} else {
int pixel;
type = bytestream2_get_le16(&s->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(&s->gb) : -1;
if (type == 1) count += 0x4000;
if (OP(type == 2 ? &s->gb : NULL, pixel, count)) break;
}
} while (bytestream2_get_bytes_left(&s->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;
}
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,
};