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/*
* Tiertex Limited SEQ Video Decoder
* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
*
* 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
* Tiertex Limited SEQ video decoder
*/
#include "avcodec.h"
#define BITSTREAM_READER_LE
#include "get_bits.h"
#include "internal.h"
typedef struct SeqVideoContext {
AVCodecContext *avctx;
AVFrame *frame;
} SeqVideoContext;
static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
const unsigned char *src_end,
unsigned char *dst, int dst_size)
{
int i, len, sz;
GetBitContext gb;
int code_table[64];
/* get the rle codes */
init_get_bits(&gb, src, (src_end - src) * 8);
for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
if (get_bits_left(&gb) < 4)
return NULL;
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;
if (src_end - src < 1)
return NULL;
memset(dst, *src++, FFMIN(len, dst_size));
} else {
if (src_end - src < len)
return NULL;
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,
const unsigned char *src_end,
unsigned char *dst)
{
const unsigned char *color_table;
int b, i, len, bits;
GetBitContext gb;
unsigned char block[8 * 8];
if (src_end - src < 1)
return NULL;
len = *src++;
if (len & 0x80) {
switch (len & 3) {
case 1:
src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
for (b = 0; b < 8; b++) {
memcpy(dst, &block[b * 8], 8);
dst += seq->frame->linesize[0];
}
break;
case 2:
src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
for (i = 0; i < 8; i++) {
for (b = 0; b < 8; b++)
dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
++dst;
}
break;
}
} else {
if (len <= 0)
return NULL;
bits = ff_log2_tab[len - 1] + 1;
if (src_end - src < len + 8 * bits)
return NULL;
color_table = src;
src += len;
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,
const unsigned char *src_end,
unsigned char *dst)
{
int i;
if (src_end - src < 8 * 8)
return NULL;
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,
const unsigned char *src_end,
unsigned char *dst)
{
int pos, offset;
do {
if (src_end - src < 2)
return NULL;
pos = *src++;
offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
dst[offset] = *src++;
} while (!(pos & 0x80));
return src;
}
static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
{
const unsigned char *data_end = data + data_size;
GetBitContext gb;
int flags, i, j, x, y, op;
unsigned char c[3];
unsigned char *dst;
uint32_t *palette;
flags = *data++;
if (flags & 1) {
palette = (uint32_t *)seq->frame->data[1];
if (data_end - data < 256 * 3)
return AVERROR_INVALIDDATA;
for (i = 0; i < 256; i++) {
for (j = 0; j < 3; j++, data++)
c[j] = (*data << 2) | (*data >> 4);
palette[i] = AV_RB24(c);
}
seq->frame->palette_has_changed = 1;
}
if (flags & 2) {
if (data_end - data < 128)
return AVERROR_INVALIDDATA;
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, data_end, dst);
break;
case 2:
data = seq_decode_op2(seq, data, data_end, dst);
break;
case 3:
data = seq_decode_op3(seq, data, data_end, dst);
break;
}
if (!data)
return AVERROR_INVALIDDATA;
}
}
return 0;
}
static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
{
SeqVideoContext *seq = avctx->priv_data;
seq->avctx = avctx;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
seq->frame = av_frame_alloc();
if (!seq->frame)
return AVERROR(ENOMEM);
return 0;
}
static int seqvideo_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int ret;
SeqVideoContext *seq = avctx->priv_data;
if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) {
av_log(seq->avctx, AV_LOG_ERROR, "tiertexseqvideo: reget_buffer() failed\n");
return ret;
}
if (seqvideo_decode(seq, buf, buf_size))
return AVERROR_INVALIDDATA;
if ((ret = av_frame_ref(data, seq->frame)) < 0)
return ret;
*got_frame = 1;
return buf_size;
}
static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
{
SeqVideoContext *seq = avctx->priv_data;
av_frame_free(&seq->frame);
return 0;
}
AVCodec ff_tiertexseqvideo_decoder = {
.name = "tiertexseqvideo",
.long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TIERTEXSEQVIDEO,
.priv_data_size = sizeof(SeqVideoContext),
.init = seqvideo_decode_init,
.close = seqvideo_decode_end,
.decode = seqvideo_decode_frame,
.capabilities = CODEC_CAP_DR1,
};
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