lavc: fix decode_frame() third parameter semantics for video decoders
[libav.git] / 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 Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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
25 typedef struct {
26 AVFrame pictures[2];
27 int currentpic;
28 } C93DecoderContext;
29
30 typedef enum {
31 C93_8X8_FROM_PREV = 0x02,
32 C93_4X4_FROM_PREV = 0x06,
33 C93_4X4_FROM_CURR = 0x07,
34 C93_8X8_2COLOR = 0x08,
35 C93_4X4_2COLOR = 0x0A,
36 C93_4X4_4COLOR_GRP = 0x0B,
37 C93_4X4_4COLOR = 0x0D,
38 C93_NOOP = 0x0E,
39 C93_8X8_INTRA = 0x0F,
40 } C93BlockType;
41
42 #define WIDTH 320
43 #define HEIGHT 192
44
45 #define C93_HAS_PALETTE 0x01
46 #define C93_FIRST_FRAME 0x02
47
48 static av_cold int decode_init(AVCodecContext *avctx)
49 {
50 avctx->pix_fmt = AV_PIX_FMT_PAL8;
51 return 0;
52 }
53
54 static av_cold int decode_end(AVCodecContext *avctx)
55 {
56 C93DecoderContext * const c93 = avctx->priv_data;
57
58 if (c93->pictures[0].data[0])
59 avctx->release_buffer(avctx, &c93->pictures[0]);
60 if (c93->pictures[1].data[0])
61 avctx->release_buffer(avctx, &c93->pictures[1]);
62 return 0;
63 }
64
65 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
66 uint8_t *from, int offset, int height, int stride)
67 {
68 int i;
69 int width = height;
70 int from_x = offset % WIDTH;
71 int from_y = offset / WIDTH;
72 int overflow = from_x + width - WIDTH;
73
74 if (!from) {
75 /* silently ignoring predictive blocks in first frame */
76 return 0;
77 }
78
79 if (from_y + height > HEIGHT) {
80 av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
81 offset);
82 return -1;
83 }
84
85 if (overflow > 0) {
86 width -= overflow;
87 for (i = 0; i < height; i++) {
88 memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
89 }
90 }
91
92 for (i = 0; i < height; i++) {
93 memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
94 }
95
96 return 0;
97 }
98
99 static inline void draw_n_color(uint8_t *out, int stride, int width,
100 int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
101 {
102 int x, y;
103 for (y = 0; y < height; y++) {
104 if (grps)
105 cols[0] = grps[3 * (y >> 1)];
106 for (x = 0; x < width; x++) {
107 if (grps)
108 cols[1]= grps[(x >> 1) + 1];
109 out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
110 col >>= bpp;
111 }
112 }
113 }
114
115 static int decode_frame(AVCodecContext *avctx, void *data,
116 int *got_frame, AVPacket *avpkt)
117 {
118 const uint8_t *buf = avpkt->data;
119 int buf_size = avpkt->size;
120 C93DecoderContext * const c93 = avctx->priv_data;
121 AVFrame * const newpic = &c93->pictures[c93->currentpic];
122 AVFrame * const oldpic = &c93->pictures[c93->currentpic^1];
123 AVFrame *picture = data;
124 GetByteContext gb;
125 uint8_t *out;
126 int stride, i, x, y, b, bt = 0;
127
128 c93->currentpic ^= 1;
129
130 newpic->reference = 1;
131 newpic->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
132 FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;
133 if (avctx->reget_buffer(avctx, newpic)) {
134 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
135 return -1;
136 }
137
138 stride = newpic->linesize[0];
139
140 bytestream2_init(&gb, buf, buf_size);
141 b = bytestream2_get_byte(&gb);
142 if (b & C93_FIRST_FRAME) {
143 newpic->pict_type = AV_PICTURE_TYPE_I;
144 newpic->key_frame = 1;
145 } else {
146 newpic->pict_type = AV_PICTURE_TYPE_P;
147 newpic->key_frame = 0;
148 }
149
150 for (y = 0; y < HEIGHT; y += 8) {
151 out = newpic->data[0] + y * stride;
152 for (x = 0; x < WIDTH; x += 8) {
153 uint8_t *copy_from = oldpic->data[0];
154 unsigned int offset, j;
155 uint8_t cols[4], grps[4];
156 C93BlockType block_type;
157
158 if (!bt)
159 bt = bytestream2_get_byte(&gb);
160
161 block_type= bt & 0x0F;
162 switch (block_type) {
163 case C93_8X8_FROM_PREV:
164 offset = bytestream2_get_le16(&gb);
165 if (copy_block(avctx, out, copy_from, offset, 8, stride))
166 return -1;
167 break;
168
169 case C93_4X4_FROM_CURR:
170 copy_from = newpic->data[0];
171 case C93_4X4_FROM_PREV:
172 for (j = 0; j < 8; j += 4) {
173 for (i = 0; i < 8; i += 4) {
174 offset = bytestream2_get_le16(&gb);
175 if (copy_block(avctx, &out[j*stride+i],
176 copy_from, offset, 4, stride))
177 return -1;
178 }
179 }
180 break;
181
182 case C93_8X8_2COLOR:
183 bytestream2_get_buffer(&gb, cols, 2);
184 for (i = 0; i < 8; i++) {
185 draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
186 NULL, bytestream2_get_byte(&gb));
187 }
188
189 break;
190
191 case C93_4X4_2COLOR:
192 case C93_4X4_4COLOR:
193 case C93_4X4_4COLOR_GRP:
194 for (j = 0; j < 8; j += 4) {
195 for (i = 0; i < 8; i += 4) {
196 if (block_type == C93_4X4_2COLOR) {
197 bytestream2_get_buffer(&gb, cols, 2);
198 draw_n_color(out + i + j*stride, stride, 4, 4,
199 1, cols, NULL, bytestream2_get_le16(&gb));
200 } else if (block_type == C93_4X4_4COLOR) {
201 bytestream2_get_buffer(&gb, cols, 4);
202 draw_n_color(out + i + j*stride, stride, 4, 4,
203 2, cols, NULL, bytestream2_get_le32(&gb));
204 } else {
205 bytestream2_get_buffer(&gb, grps, 4);
206 draw_n_color(out + i + j*stride, stride, 4, 4,
207 1, cols, grps, bytestream2_get_le16(&gb));
208 }
209 }
210 }
211 break;
212
213 case C93_NOOP:
214 break;
215
216 case C93_8X8_INTRA:
217 for (j = 0; j < 8; j++)
218 bytestream2_get_buffer(&gb, out + j*stride, 8);
219 break;
220
221 default:
222 av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
223 block_type, x, y);
224 return -1;
225 }
226 bt >>= 4;
227 out += 8;
228 }
229 }
230
231 if (b & C93_HAS_PALETTE) {
232 uint32_t *palette = (uint32_t *) newpic->data[1];
233 for (i = 0; i < 256; i++) {
234 palette[i] = bytestream2_get_be24(&gb);
235 }
236 } else {
237 if (oldpic->data[1])
238 memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
239 }
240
241 *picture = *newpic;
242 *got_frame = 1;
243
244 return buf_size;
245 }
246
247 AVCodec ff_c93_decoder = {
248 .name = "c93",
249 .type = AVMEDIA_TYPE_VIDEO,
250 .id = AV_CODEC_ID_C93,
251 .priv_data_size = sizeof(C93DecoderContext),
252 .init = decode_init,
253 .close = decode_end,
254 .decode = decode_frame,
255 .capabilities = CODEC_CAP_DR1,
256 .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
257 };