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/*
* Tiertex Limited SEQ Video Decoder
* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
*
* 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 tiertexseqv.c
* Tiertex Limited SEQ video decoder
*/
#include "avcodec.h"
#define ALT_BITSTREAM_READER_LE
#include "bitstream.h"
typedef struct SeqVideoContext {
AVCodecContext *avctx;
AVFrame frame;
unsigned int palette[256];
unsigned char block[8 * 8];
} SeqVideoContext;
static const unsigned char *seq_unpack_rle_block(const unsigned char *src, unsigned char *dst, int dst_size)
{
int i, len, sz;
GetBitContext gb;
int code_table[64];
/* get the rle codes (at most 64 bytes) */
init_get_bits(&gb, src, 64 * 8);
for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
code_table[i] = get_sbits(&gb, 4);
sz += FFABS(code_table[i]);
}
src += (get_bits_count(&gb) + 7) / 8;
/* do the rle unpacking */
for (i = 0; i < 64 && dst_size > 0; i++) {
len = code_table[i];
if (len < 0) {
len = -len;
memset(dst, *src++, FFMIN(len, dst_size));
} else {
memcpy(dst, src, FFMIN(len, dst_size));
src += len;
}
dst += len;
dst_size -= len;
}
return src;
}
static const unsigned char *seq_decode_op1(SeqVideoContext *seq, const unsigned char *src, unsigned char *dst)
{
const unsigned char *color_table;
int b, i, len, bits;
GetBitContext gb;
len = *src++;
if (len & 0x80) {
switch (len & 3) {
case 1:
src = seq_unpack_rle_block(src, seq->block, sizeof(seq->block));
for (b = 0; b < 8; b++) {
memcpy(dst, &seq->block[b * 8], 8);
dst += seq->frame.linesize[0];
}
break;
case 2:
src = seq_unpack_rle_block(src, seq->block, sizeof(seq->block));
for (i = 0; i < 8; i++) {
for (b = 0; b < 8; b++)
dst[b * seq->frame.linesize[0]] = seq->block[i * 8 + b];
++dst;
}
break;
}
} else {
color_table = src;
src += len;
bits = ff_log2_tab[len - 1] + 1;
init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
for (b = 0; b < 8; b++) {
for (i = 0; i < 8; i++)
dst[i] = color_table[get_bits(&gb, bits)];
dst += seq->frame.linesize[0];
}
}
return src;
}
static const unsigned char *seq_decode_op2(SeqVideoContext *seq, const unsigned char *src, unsigned char *dst)
{
int i;
for (i = 0; i < 8; i++) {
memcpy(dst, src, 8);
src += 8;
dst += seq->frame.linesize[0];
}
return src;
}
static const unsigned char *seq_decode_op3(SeqVideoContext *seq, const unsigned char *src, unsigned char *dst)
{
int pos, offset;
do {
pos = *src++;
offset = ((pos >> 3) & 7) * seq->frame.linesize[0] + (pos & 7);
dst[offset] = *src++;
} while (!(pos & 0x80));
return src;
}
static void seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
{
GetBitContext gb;
int flags, i, j, x, y, op;
unsigned char c[3];
unsigned char *dst;
flags = *data++;
if (flags & 1) {
for (i = 0; i < 256; i++) {
for (j = 0; j < 3; j++, data++)
c[j] = (*data << 2) | (*data >> 4);
seq->palette[i] = AV_RB24(c);
}
memcpy(seq->frame.data[1], seq->palette, sizeof(seq->palette));
seq->frame.palette_has_changed = 1;
}
if (flags & 2) {
init_get_bits(&gb, data, 128 * 8); data += 128;
for (y = 0; y < 128; y += 8)
for (x = 0; x < 256; x += 8) {
dst = &seq->frame.data[0][y * seq->frame.linesize[0] + x];
op = get_bits(&gb, 2);
switch (op) {
case 1:
data = seq_decode_op1(seq, data, dst);
break;
case 2:
data = seq_decode_op2(seq, data, dst);
break;
case 3:
data = seq_decode_op3(seq, data, dst);
break;
}
}
}
}
static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
{
SeqVideoContext *seq = avctx->priv_data;
seq->avctx = avctx;
avctx->pix_fmt = PIX_FMT_PAL8;
seq->frame.data[0] = NULL;
return 0;
}
static av_cold int seqvideo_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
SeqVideoContext *seq = avctx->priv_data;
seq->frame.reference = 1;
seq->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, &seq->frame)) {
av_log(seq->avctx, AV_LOG_ERROR, "tiertexseqvideo: reget_buffer() failed\n");
return -1;
}
seqvideo_decode(seq, buf, buf_size);
*data_size = sizeof(AVFrame);
*(AVFrame *)data = seq->frame;
return buf_size;
}
static int seqvideo_decode_end(AVCodecContext *avctx)
{
SeqVideoContext *seq = avctx->priv_data;
if (seq->frame.data[0])
avctx->release_buffer(avctx, &seq->frame);
return 0;
}
AVCodec tiertexseqvideo_decoder = {
"tiertexseqvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_TIERTEXSEQVIDEO,
sizeof(SeqVideoContext),
seqvideo_decode_init,
NULL,
seqvideo_decode_end,
seqvideo_decode_frame,
CODEC_CAP_DR1,
};
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