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/*
* AVS video decoder.
* Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* 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
*/
#include "avcodec.h"
#include "get_bits.h"
typedef struct {
AVFrame picture;
} AvsContext;
typedef enum {
AVS_VIDEO = 0x01,
AVS_AUDIO = 0x02,
AVS_PALETTE = 0x03,
AVS_GAME_DATA = 0x04,
} AvsBlockType;
typedef enum {
AVS_I_FRAME = 0x00,
AVS_P_FRAME_3X3 = 0x01,
AVS_P_FRAME_2X2 = 0x02,
AVS_P_FRAME_2X3 = 0x03,
} AvsVideoSubType;
static int
avs_decode_frame(AVCodecContext * avctx,
void *data, int *data_size, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
const uint8_t *buf_end = avpkt->data + avpkt->size;
int buf_size = avpkt->size;
AvsContext *const avs = avctx->priv_data;
AVFrame *picture = data;
AVFrame *const p = (AVFrame *) & avs->picture;
const uint8_t *table, *vect;
uint8_t *out;
int i, j, x, y, stride, vect_w = 3, vect_h = 3;
AvsVideoSubType sub_type;
AvsBlockType type;
GetBitContext change_map;
if (avctx->reget_buffer(avctx, p)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
p->reference = 1;
p->pict_type = AV_PICTURE_TYPE_P;
p->key_frame = 0;
out = avs->picture.data[0];
stride = avs->picture.linesize[0];
if (buf_end - buf < 4)
return AVERROR_INVALIDDATA;
sub_type = buf[0];
type = buf[1];
buf += 4;
if (type == AVS_PALETTE) {
int first, last;
uint32_t *pal = (uint32_t *) avs->picture.data[1];
first = AV_RL16(buf);
last = first + AV_RL16(buf + 2);
if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first))
return AVERROR_INVALIDDATA;
buf += 4;
for (i=first; i<last; i++, buf+=3)
pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);
sub_type = buf[0];
type = buf[1];
buf += 4;
}
if (type != AVS_VIDEO)
return -1;
switch (sub_type) {
case AVS_I_FRAME:
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
case AVS_P_FRAME_3X3:
vect_w = 3;
vect_h = 3;
break;
case AVS_P_FRAME_2X2:
vect_w = 2;
vect_h = 2;
break;
case AVS_P_FRAME_2X3:
vect_w = 2;
vect_h = 3;
break;
default:
return -1;
}
if (buf_end - buf < 256 * vect_w * vect_h)
return AVERROR_INVALIDDATA;
table = buf + (256 * vect_w * vect_h);
if (sub_type != AVS_I_FRAME) {
int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);
if (buf_end - table < map_size)
return AVERROR_INVALIDDATA;
init_get_bits(&change_map, table, map_size * 8);
table += map_size;
}
for (y=0; y<198; y+=vect_h) {
for (x=0; x<318; x+=vect_w) {
if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) {
if (buf_end - table < 1)
return AVERROR_INVALIDDATA;
vect = &buf[*table++ * (vect_w * vect_h)];
for (j=0; j<vect_w; j++) {
out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];
out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];
if (vect_h == 3)
out[(y + 2) * stride + x + j] =
vect[(2 * vect_w) + j];
}
}
}
if (sub_type != AVS_I_FRAME)
align_get_bits(&change_map);
}
*picture = *(AVFrame *) & avs->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
static av_cold int avs_decode_init(AVCodecContext * avctx)
{
avctx->pix_fmt = PIX_FMT_PAL8;
avcodec_set_dimensions(avctx, 318, 198);
return 0;
}
AVCodec ff_avs_decoder = {
"avs",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_AVS,
sizeof(AvsContext),
avs_decode_init,
NULL,
NULL,
avs_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"),
};
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