anm.c
/*
* 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"
typedef struct AnmContext {
AVFrame frame;
int x; ///< x coordinate position
} AnmContext;
static av_cold int decode_init(AVCodecContext *avctx)
{
AnmContext *s = avctx->priv_data;
const uint8_t *buf;
int i;
avctx->pix_fmt = PIX_FMT_PAL8;
if (avctx->extradata_size != 16*8 + 4*256)
return -1;
s->frame.reference = 1;
if (avctx->get_buffer(avctx, &s->frame) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
buf = avctx->extradata + 16*8;
for (i = 0; i < 256; i++)
((uint32_t*)s->frame.data[1])[i] = bytestream_get_le32(&buf);
return 0;
}
/**
* Perform decode operation
* @param dst, dst_end Destination image buffer
* @param buf, buf_end Source buffer (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 'buf' is set
* a fill operation is acheived when 'buf' is null and pixel is >= 0
* a skip operation is acheived when 'buf' is null and pixel is < 0
*/
static inline int op(uint8_t **dst, const uint8_t *dst_end,
const uint8_t **buf, const uint8_t *buf_end,
int pixel, int count,
int *x, int width, int linesize)
{
int remaining = width - *x;
while(count > 0) {
int striplen = FFMIN(count, remaining);
if (buf) {
striplen = FFMIN(striplen, buf_end - *buf);
memcpy(*dst, *buf, striplen);
*buf += 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 *data_size,
AVPacket *avpkt)
{
AnmContext *s = avctx->priv_data;
const uint8_t *buf = avpkt->data;
const int buf_size = avpkt->size;
const uint8_t *buf_end = buf + buf_size;
uint8_t *dst, *dst_end;
int count;
if(avctx->reget_buffer(avctx, &s->frame) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
dst = s->frame.data[0];
dst_end = s->frame.data[0] + s->frame.linesize[0]*avctx->height;
if (buf[0] != 0x42) {
av_log_ask_for_sample(avctx, "unknown record type\n");
return buf_size;
}
if (buf[1]) {
av_log_ask_for_sample(avctx, "padding bytes not supported\n");
return buf_size;
}
buf += 4;
s->x = 0;
do {
/* if statements are ordered by probability */
#define OP(buf, pixel, count) \
op(&dst, dst_end, (buf), buf_end, (pixel), (count), &s->x, avctx->width, s->frame.linesize[0])
int type = bytestream_get_byte(&buf);
count = type & 0x7F;
type >>= 7;
if (count) {
if (OP(type ? NULL : &buf, -1, count)) break;
} else if (!type) {
int pixel;
count = bytestream_get_byte(&buf); /* count==0 gives nop */
pixel = bytestream_get_byte(&buf);
if (OP(NULL, pixel, count)) break;
} else {
int pixel;
type = bytestream_get_le16(&buf);
count = type & 0x3FFF;
type >>= 14;
if (!count) {
if (type == 0)
break; // stop
if (type == 2) {
av_log_ask_for_sample(avctx, "unknown opcode");
return AVERROR_INVALIDDATA;
}
continue;
}
pixel = type == 3 ? bytestream_get_byte(&buf) : -1;
if (type == 1) count += 0x4000;
if (OP(type == 2 ? &buf : NULL, pixel, count)) break;
}
} while (buf + 1 < buf_end);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
return buf_size;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
AnmContext *s = avctx->priv_data;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec ff_anm_decoder = {
"anm",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_ANM,
sizeof(AnmContext),
decode_init,
NULL,
decode_end,
decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
};