Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / c93.c
1 /*
2 * Interplay C93 video decoder
3 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 "bytestream.h"
24 #include "internal.h"
25
26 typedef struct {
27 AVFrame *pictures[2];
28 int currentpic;
29 } C93DecoderContext;
30
31 typedef enum {
32 C93_8X8_FROM_PREV = 0x02,
33 C93_4X4_FROM_PREV = 0x06,
34 C93_4X4_FROM_CURR = 0x07,
35 C93_8X8_2COLOR = 0x08,
36 C93_4X4_2COLOR = 0x0A,
37 C93_4X4_4COLOR_GRP = 0x0B,
38 C93_4X4_4COLOR = 0x0D,
39 C93_NOOP = 0x0E,
40 C93_8X8_INTRA = 0x0F,
41 } C93BlockType;
42
43 #define WIDTH 320
44 #define HEIGHT 192
45
46 #define C93_HAS_PALETTE 0x01
47 #define C93_FIRST_FRAME 0x02
48
49 static av_cold int decode_end(AVCodecContext *avctx)
50 {
51 C93DecoderContext * const c93 = avctx->priv_data;
52
53 av_frame_free(&c93->pictures[0]);
54 av_frame_free(&c93->pictures[1]);
55
56 return 0;
57 }
58
59 static av_cold int decode_init(AVCodecContext *avctx)
60 {
61 C93DecoderContext *s = avctx->priv_data;
62 avctx->pix_fmt = AV_PIX_FMT_PAL8;
63
64 s->pictures[0] = av_frame_alloc();
65 s->pictures[1] = av_frame_alloc();
66 if (!s->pictures[0] || !s->pictures[1]) {
67 decode_end(avctx);
68 return AVERROR(ENOMEM);
69 }
70
71 return 0;
72 }
73
74 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
75 uint8_t *from, int offset, int height, int stride)
76 {
77 int i;
78 int width = height;
79 int from_x = offset % WIDTH;
80 int from_y = offset / WIDTH;
81 int overflow = from_x + width - WIDTH;
82
83 if (!from) {
84 /* silently ignoring predictive blocks in first frame */
85 return 0;
86 }
87
88 if (from_y + height > HEIGHT) {
89 av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
90 offset);
91 return AVERROR_INVALIDDATA;
92 }
93
94 if (overflow > 0) {
95 width -= overflow;
96 for (i = 0; i < height; i++) {
97 memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
98 }
99 }
100
101 for (i = 0; i < height; i++) {
102 memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
103 }
104
105 return 0;
106 }
107
108 static inline void draw_n_color(uint8_t *out, int stride, int width,
109 int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
110 {
111 int x, y;
112 for (y = 0; y < height; y++) {
113 if (grps)
114 cols[0] = grps[3 * (y >> 1)];
115 for (x = 0; x < width; x++) {
116 if (grps)
117 cols[1]= grps[(x >> 1) + 1];
118 out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
119 col >>= bpp;
120 }
121 }
122 }
123
124 static int decode_frame(AVCodecContext *avctx, void *data,
125 int *got_frame, AVPacket *avpkt)
126 {
127 const uint8_t *buf = avpkt->data;
128 int buf_size = avpkt->size;
129 C93DecoderContext * const c93 = avctx->priv_data;
130 AVFrame * const newpic = c93->pictures[c93->currentpic];
131 AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
132 GetByteContext gb;
133 uint8_t *out;
134 int stride, ret, i, x, y, b, bt = 0;
135
136 if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
137 return ret;
138
139 c93->currentpic ^= 1;
140
141 if ((ret = ff_reget_buffer(avctx, newpic)) < 0)
142 return ret;
143
144 stride = newpic->linesize[0];
145
146 bytestream2_init(&gb, buf, buf_size);
147 b = bytestream2_get_byte(&gb);
148 if (b & C93_FIRST_FRAME) {
149 newpic->pict_type = AV_PICTURE_TYPE_I;
150 newpic->key_frame = 1;
151 } else {
152 newpic->pict_type = AV_PICTURE_TYPE_P;
153 newpic->key_frame = 0;
154 }
155
156 for (y = 0; y < HEIGHT; y += 8) {
157 out = newpic->data[0] + y * stride;
158 for (x = 0; x < WIDTH; x += 8) {
159 uint8_t *copy_from = oldpic->data[0];
160 unsigned int offset, j;
161 uint8_t cols[4], grps[4];
162 C93BlockType block_type;
163
164 if (!bt)
165 bt = bytestream2_get_byte(&gb);
166
167 block_type= bt & 0x0F;
168 switch (block_type) {
169 case C93_8X8_FROM_PREV:
170 offset = bytestream2_get_le16(&gb);
171 if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
172 return ret;
173 break;
174
175 case C93_4X4_FROM_CURR:
176 copy_from = newpic->data[0];
177 case C93_4X4_FROM_PREV:
178 for (j = 0; j < 8; j += 4) {
179 for (i = 0; i < 8; i += 4) {
180 int offset = bytestream2_get_le16(&gb);
181 int from_x = offset % WIDTH;
182 int from_y = offset / WIDTH;
183 if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
184 (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
185 avpriv_request_sample(avctx, "block overlap %d %d %d %d\n", from_x, x+i, from_y, y+j);
186 return AVERROR_INVALIDDATA;
187 }
188 if ((ret = copy_block(avctx, &out[j*stride+i],
189 copy_from, offset, 4, stride)) < 0)
190 return ret;
191 }
192 }
193 break;
194
195 case C93_8X8_2COLOR:
196 bytestream2_get_buffer(&gb, cols, 2);
197 for (i = 0; i < 8; i++) {
198 draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
199 NULL, bytestream2_get_byte(&gb));
200 }
201
202 break;
203
204 case C93_4X4_2COLOR:
205 case C93_4X4_4COLOR:
206 case C93_4X4_4COLOR_GRP:
207 for (j = 0; j < 8; j += 4) {
208 for (i = 0; i < 8; i += 4) {
209 if (block_type == C93_4X4_2COLOR) {
210 bytestream2_get_buffer(&gb, cols, 2);
211 draw_n_color(out + i + j*stride, stride, 4, 4,
212 1, cols, NULL, bytestream2_get_le16(&gb));
213 } else if (block_type == C93_4X4_4COLOR) {
214 bytestream2_get_buffer(&gb, cols, 4);
215 draw_n_color(out + i + j*stride, stride, 4, 4,
216 2, cols, NULL, bytestream2_get_le32(&gb));
217 } else {
218 bytestream2_get_buffer(&gb, grps, 4);
219 draw_n_color(out + i + j*stride, stride, 4, 4,
220 1, cols, grps, bytestream2_get_le16(&gb));
221 }
222 }
223 }
224 break;
225
226 case C93_NOOP:
227 break;
228
229 case C93_8X8_INTRA:
230 for (j = 0; j < 8; j++)
231 bytestream2_get_buffer(&gb, out + j*stride, 8);
232 break;
233
234 default:
235 av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
236 block_type, x, y);
237 return AVERROR_INVALIDDATA;
238 }
239 bt >>= 4;
240 out += 8;
241 }
242 }
243
244 if (b & C93_HAS_PALETTE) {
245 uint32_t *palette = (uint32_t *) newpic->data[1];
246 for (i = 0; i < 256; i++) {
247 palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
248 }
249 newpic->palette_has_changed = 1;
250 } else {
251 if (oldpic->data[1])
252 memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
253 }
254
255 if ((ret = av_frame_ref(data, newpic)) < 0)
256 return ret;
257 *got_frame = 1;
258
259 return buf_size;
260 }
261
262 AVCodec ff_c93_decoder = {
263 .name = "c93",
264 .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
265 .type = AVMEDIA_TYPE_VIDEO,
266 .id = AV_CODEC_ID_C93,
267 .priv_data_size = sizeof(C93DecoderContext),
268 .init = decode_init,
269 .close = decode_end,
270 .decode = decode_frame,
271 .capabilities = CODEC_CAP_DR1,
272 };