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/*
* Brute Force & Ignorance (BFI) video decoder
* Copyright (c) 2008 Sisir Koppaka
*
* 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 bfi.c
* @brief Brute Force & Ignorance (.bfi) video decoder
* @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
* @sa http://wiki.multimedia.cx/index.php?title=BFI
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "bytestream.h"
typedef struct BFIContext {
AVCodecContext *avctx;
AVFrame frame;
uint8_t *dst;
} BFIContext;
static int bfi_decode_init(AVCodecContext * avctx)
{
BFIContext *bfi = avctx->priv_data;
avctx->pix_fmt = PIX_FMT_PAL8;
bfi->dst = av_mallocz(avctx->width * avctx->height);
return 0;
}
static int bfi_decode_frame(AVCodecContext * avctx, void *data,
int *data_size, const uint8_t * buf,
int buf_size)
{
BFIContext *bfi = avctx->priv_data;
uint8_t *dst = bfi->dst;
uint8_t *src, *dst_offset, colour1, colour2;
uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
uint32_t *pal;
int i, j, height = avctx->height;
if (bfi->frame.data[0])
avctx->release_buffer(avctx, &bfi->frame);
bfi->frame.reference = 1;
if (avctx->get_buffer(avctx, &bfi->frame) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
/* Set frame parameters and palette, if necessary */
if (!avctx->frame_number) {
bfi->frame.pict_type = FF_I_TYPE;
bfi->frame.key_frame = 1;
/* Setting the palette */
if(avctx->extradata_size>768) {
av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
return -1;
}
pal = (uint32_t *) bfi->frame.data[1];
for (i = 0; i < avctx->extradata_size / 3; i++) {
int shift = 16;
*pal = 0;
for (j = 0; j < 3; j++, shift -= 8)
*pal +=
((avctx->extradata[i * 3 + j] << 2) |
(avctx->extradata[i * 3 + j] >> 4)) << shift;
pal++;
}
bfi->frame.palette_has_changed = 1;
} else {
bfi->frame.pict_type = FF_P_TYPE;
bfi->frame.key_frame = 0;
}
buf += 4; //Unpacked size, not required.
while (dst != frame_end) {
static const uint8_t lentab[4]={0,2,0,1};
unsigned int byte = *buf++, offset;
unsigned int code = byte >> 6;
unsigned int length = byte & ~0xC0;
/* Get length and offset(if required) */
if (length == 0) {
if (code == 1) {
length = bytestream_get_byte(&buf);
offset = bytestream_get_le16(&buf);
} else {
length = bytestream_get_le16(&buf);
if (code == 2 && length == 0)
break;
}
} else {
if (code == 1)
offset = bytestream_get_byte(&buf);
}
/* Do boundary check */
if (dst + (length<<lentab[code]) > frame_end)
break;
switch (code) {
case 0: //Normal Chain
bytestream_get_buffer(&buf, dst, length);
dst += length;
break;
case 1: //Back Chain
dst_offset = dst - offset;
length *= 4; //Convert dwords to bytes.
if (dst_offset < bfi->dst)
break;
while (length--)
*dst++ = *dst_offset++;
break;
case 2: //Skip Chain
dst += length;
break;
case 3: //Fill Chain
colour1 = bytestream_get_byte(&buf);
colour2 = bytestream_get_byte(&buf);
while (length--) {
*dst++ = colour1;
*dst++ = colour2;
}
break;
}
}
src = bfi->dst;
dst = bfi->frame.data[0];
while (height--) {
memcpy(dst, src, avctx->width);
src += avctx->width;
dst += bfi->frame.linesize[0];
}
*data_size = sizeof(AVFrame);
*(AVFrame *) data = bfi->frame;
return buf_size;
}
static int bfi_decode_close(AVCodecContext * avctx)
{
BFIContext *bfi = avctx->priv_data;
if (bfi->frame.data[0])
avctx->release_buffer(avctx, &bfi->frame);
av_free(bfi->dst);
return 0;
}
AVCodec bfi_decoder = {
.name = "bfi",
.type = CODEC_TYPE_VIDEO,
.id = CODEC_ID_BFI,
.priv_data_size = sizeof(BFIContext),
.init = bfi_decode_init,
.close = bfi_decode_close,
.decode = bfi_decode_frame,
.long_name = "Brute Force & Ignorance",
};
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