a53a068c152144ed5ecb220b5b48e4120c77724f
[libav.git] / libavcodec / avs.c
1 /*
2 * AVS video decoder.
3 * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "avcodec.h"
23 #include "get_bits.h"
24
25
26 typedef struct {
27 AVFrame picture;
28 } AvsContext;
29
30 typedef enum {
31 AVS_VIDEO = 0x01,
32 AVS_AUDIO = 0x02,
33 AVS_PALETTE = 0x03,
34 AVS_GAME_DATA = 0x04,
35 } AvsBlockType;
36
37 typedef enum {
38 AVS_I_FRAME = 0x00,
39 AVS_P_FRAME_3X3 = 0x01,
40 AVS_P_FRAME_2X2 = 0x02,
41 AVS_P_FRAME_2X3 = 0x03,
42 } AvsVideoSubType;
43
44
45 static int
46 avs_decode_frame(AVCodecContext * avctx,
47 void *data, int *data_size, AVPacket *avpkt)
48 {
49 const uint8_t *buf = avpkt->data;
50 int buf_size = avpkt->size;
51 AvsContext *const avs = avctx->priv_data;
52 AVFrame *picture = data;
53 AVFrame *const p = (AVFrame *) & avs->picture;
54 const uint8_t *table, *vect;
55 uint8_t *out;
56 int i, j, x, y, stride, vect_w = 3, vect_h = 3;
57 AvsVideoSubType sub_type;
58 AvsBlockType type;
59 GetBitContext change_map;
60
61 if (avctx->reget_buffer(avctx, p)) {
62 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
63 return -1;
64 }
65 p->reference = 1;
66 p->pict_type = FF_P_TYPE;
67 p->key_frame = 0;
68
69 out = avs->picture.data[0];
70 stride = avs->picture.linesize[0];
71
72 sub_type = buf[0];
73 type = buf[1];
74 buf += 4;
75
76 if (type == AVS_PALETTE) {
77 int first, last;
78 uint32_t *pal = (uint32_t *) avs->picture.data[1];
79
80 first = AV_RL16(buf);
81 last = first + AV_RL16(buf + 2);
82 buf += 4;
83 for (i=first; i<last; i++, buf+=3)
84 pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);
85
86 sub_type = buf[0];
87 type = buf[1];
88 buf += 4;
89 }
90
91 if (type != AVS_VIDEO)
92 return -1;
93
94 switch (sub_type) {
95 case AVS_I_FRAME:
96 p->pict_type = FF_I_TYPE;
97 p->key_frame = 1;
98 case AVS_P_FRAME_3X3:
99 vect_w = 3;
100 vect_h = 3;
101 break;
102
103 case AVS_P_FRAME_2X2:
104 vect_w = 2;
105 vect_h = 2;
106 break;
107
108 case AVS_P_FRAME_2X3:
109 vect_w = 2;
110 vect_h = 3;
111 break;
112
113 default:
114 return -1;
115 }
116
117 table = buf + (256 * vect_w * vect_h);
118 if (sub_type != AVS_I_FRAME) {
119 int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);
120 init_get_bits(&change_map, table, map_size);
121 table += map_size;
122 }
123
124 for (y=0; y<198; y+=vect_h) {
125 for (x=0; x<318; x+=vect_w) {
126 if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) {
127 vect = &buf[*table++ * (vect_w * vect_h)];
128 for (j=0; j<vect_w; j++) {
129 out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];
130 out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];
131 if (vect_h == 3)
132 out[(y + 2) * stride + x + j] =
133 vect[(2 * vect_w) + j];
134 }
135 }
136 }
137 if (sub_type != AVS_I_FRAME)
138 align_get_bits(&change_map);
139 }
140
141 *picture = *(AVFrame *) & avs->picture;
142 *data_size = sizeof(AVPicture);
143
144 return buf_size;
145 }
146
147 static av_cold int avs_decode_init(AVCodecContext * avctx)
148 {
149 avctx->pix_fmt = PIX_FMT_PAL8;
150 return 0;
151 }
152
153 AVCodec avs_decoder = {
154 "avs",
155 CODEC_TYPE_VIDEO,
156 CODEC_ID_AVS,
157 sizeof(AvsContext),
158 avs_decode_init,
159 NULL,
160 NULL,
161 avs_decode_frame,
162 CODEC_CAP_DR1,
163 .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"),
164 };