1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/avs.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

191 lines
5.2 KiB
C

/*
* AVS video decoder.
* Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* 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
*/
#include "avcodec.h"
#include "get_bits.h"
#include "internal.h"
typedef struct AvsContext {
AVFrame *frame;
} 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 *got_frame, 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 = avs->frame;
const uint8_t *table, *vect;
uint8_t *out;
int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3;
AvsVideoSubType sub_type;
AvsBlockType type;
GetBitContext change_map = {0}; //init to silence warning
if ((ret = ff_reget_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_P;
p->key_frame = 0;
out = p->data[0];
stride = p->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 *) p->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);
pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303;
}
sub_type = buf[0];
type = buf[1];
buf += 4;
}
if (type != AVS_VIDEO)
return AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
}
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);
}
if ((ret = av_frame_ref(picture, p)) < 0)
return ret;
*got_frame = 1;
return buf_size;
}
static av_cold int avs_decode_init(AVCodecContext * avctx)
{
AvsContext *s = avctx->priv_data;
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
avctx->pix_fmt = AV_PIX_FMT_PAL8;
return ff_set_dimensions(avctx, 318, 198);
}
static av_cold int avs_decode_end(AVCodecContext *avctx)
{
AvsContext *s = avctx->priv_data;
av_frame_free(&s->frame);
return 0;
}
const AVCodec ff_avs_decoder = {
.name = "avs",
.long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_AVS,
.priv_data_size = sizeof(AvsContext),
.init = avs_decode_init,
.decode = avs_decode_frame,
.close = avs_decode_end,
.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};