lavc: use designated initialisers for all codecs.
[libav.git] / libavcodec / yop.c
1 /*
2 * Psygnosis YOP decoder
3 *
4 * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
5 * derived from the code by
6 * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
7 *
8 * This file is part of Libav.
9 *
10 * Libav is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * Libav is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with Libav; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/imgutils.h"
27
28 #include "avcodec.h"
29 #include "get_bits.h"
30
31 typedef struct YopDecContext {
32 AVFrame frame;
33 AVCodecContext *avctx;
34
35 int num_pal_colors;
36 int first_color[2];
37 int frame_data_length;
38 int row_pos;
39
40 uint8_t *low_nibble;
41 uint8_t *srcptr;
42 uint8_t *dstptr;
43 uint8_t *dstbuf;
44 } YopDecContext;
45
46 // These tables are taken directly from:
47 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
48
49 /**
50 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
51 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
52 * Byte 3 contains the number of bytes consumed on the input,
53 * equal to max(bytes 0-2) + 1.
54 */
55 static const uint8_t paint_lut[15][4] =
56 {{1, 2, 3, 4}, {1, 2, 0, 3},
57 {1, 2, 1, 3}, {1, 2, 2, 3},
58 {1, 0, 2, 3}, {1, 0, 0, 2},
59 {1, 0, 1, 2}, {1, 1, 2, 3},
60 {0, 1, 2, 3}, {0, 1, 0, 2},
61 {1, 1, 0, 2}, {0, 1, 1, 2},
62 {0, 0, 1, 2}, {0, 0, 0, 1},
63 {1, 1, 1, 2},
64 };
65
66 /**
67 * Lookup table for copying macroblocks. Each entry contains the respective
68 * x and y pixel offset for the copy source.
69 */
70 static const int8_t motion_vector[16][2] =
71 {{-4, -4}, {-2, -4},
72 { 0, -4}, { 2, -4},
73 {-4, -2}, {-4, 0},
74 {-3, -3}, {-1, -3},
75 { 1, -3}, { 3, -3},
76 {-3, -1}, {-2, -2},
77 { 0, -2}, { 2, -2},
78 { 4, -2}, {-2, 0},
79 };
80
81 static av_cold int yop_decode_init(AVCodecContext *avctx)
82 {
83 YopDecContext *s = avctx->priv_data;
84 s->avctx = avctx;
85
86 if (avctx->width & 1 || avctx->height & 1 ||
87 av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
88 av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
89 return -1;
90 }
91
92 avctx->pix_fmt = PIX_FMT_PAL8;
93
94 s->num_pal_colors = avctx->extradata[0];
95 s->first_color[0] = avctx->extradata[1];
96 s->first_color[1] = avctx->extradata[2];
97
98 if (s->num_pal_colors + s->first_color[0] > 256 ||
99 s->num_pal_colors + s->first_color[1] > 256) {
100 av_log(avctx, AV_LOG_ERROR,
101 "YOP: palette parameters invalid, header probably corrupt\n");
102 return AVERROR_INVALIDDATA;
103 }
104
105 return 0;
106 }
107
108 static av_cold int yop_decode_close(AVCodecContext *avctx)
109 {
110 YopDecContext *s = avctx->priv_data;
111 if (s->frame.data[0])
112 avctx->release_buffer(avctx, &s->frame);
113 return 0;
114 }
115
116 /**
117 * Paint a macroblock using the pattern in paint_lut.
118 * @param s codec context
119 * @param tag the tag that was in the nibble
120 */
121 static void yop_paint_block(YopDecContext *s, int tag)
122 {
123 s->dstptr[0] = s->srcptr[0];
124 s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
125 s->dstptr[s->frame.linesize[0]] = s->srcptr[paint_lut[tag][1]];
126 s->dstptr[s->frame.linesize[0] + 1] = s->srcptr[paint_lut[tag][2]];
127
128 // The number of src bytes consumed is in the last part of the lut entry.
129 s->srcptr += paint_lut[tag][3];
130 }
131
132 /**
133 * Copy a previously painted macroblock to the current_block.
134 * @param copy_tag the tag that was in the nibble
135 */
136 static int yop_copy_previous_block(YopDecContext *s, int copy_tag)
137 {
138 uint8_t *bufptr;
139
140 // Calculate position for the copy source
141 bufptr = s->dstptr + motion_vector[copy_tag][0] +
142 s->frame.linesize[0] * motion_vector[copy_tag][1];
143 if (bufptr < s->dstbuf) {
144 av_log(s->avctx, AV_LOG_ERROR,
145 "YOP: cannot decode, file probably corrupt\n");
146 return AVERROR_INVALIDDATA;
147 }
148
149 s->dstptr[0] = bufptr[0];
150 s->dstptr[1] = bufptr[1];
151 s->dstptr[s->frame.linesize[0]] = bufptr[s->frame.linesize[0]];
152 s->dstptr[s->frame.linesize[0] + 1] = bufptr[s->frame.linesize[0] + 1];
153
154 return 0;
155 }
156
157 /**
158 * Return the next nibble in sequence, consuming a new byte on the input
159 * only if necessary.
160 */
161 static uint8_t yop_get_next_nibble(YopDecContext *s)
162 {
163 int ret;
164
165 if (s->low_nibble) {
166 ret = *s->low_nibble & 0xf;
167 s->low_nibble = NULL;
168 }else {
169 s->low_nibble = s->srcptr++;
170 ret = *s->low_nibble >> 4;
171 }
172 return ret;
173 }
174
175 /**
176 * Take s->dstptr to the next macroblock in sequence.
177 */
178 static void yop_next_macroblock(YopDecContext *s)
179 {
180 // If we are advancing to the next row of macroblocks
181 if (s->row_pos == s->frame.linesize[0] - 2) {
182 s->dstptr += s->frame.linesize[0];
183 s->row_pos = 0;
184 }else {
185 s->row_pos += 2;
186 }
187 s->dstptr += 2;
188 }
189
190 static int yop_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
191 AVPacket *avpkt)
192 {
193 YopDecContext *s = avctx->priv_data;
194 int tag, firstcolor, is_odd_frame;
195 int ret, i;
196 uint32_t *palette;
197
198 if (s->frame.data[0])
199 avctx->release_buffer(avctx, &s->frame);
200
201 ret = avctx->get_buffer(avctx, &s->frame);
202 if (ret < 0) {
203 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
204 return ret;
205 }
206
207 s->frame.linesize[0] = avctx->width;
208
209 s->dstbuf = s->frame.data[0];
210 s->dstptr = s->frame.data[0];
211 s->srcptr = avpkt->data + 4;
212 s->row_pos = 0;
213 s->low_nibble = NULL;
214
215 is_odd_frame = avpkt->data[0];
216 firstcolor = s->first_color[is_odd_frame];
217 palette = (uint32_t *)s->frame.data[1];
218
219 for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3)
220 palette[i + firstcolor] = (s->srcptr[0] << 18) |
221 (s->srcptr[1] << 10) |
222 (s->srcptr[2] << 2);
223
224 s->frame.palette_has_changed = 1;
225
226 while (s->dstptr - s->dstbuf <
227 avctx->width * avctx->height &&
228 s->srcptr - avpkt->data < avpkt->size) {
229
230 tag = yop_get_next_nibble(s);
231
232 if (tag != 0xf) {
233 yop_paint_block(s, tag);
234 }else {
235 tag = yop_get_next_nibble(s);
236 ret = yop_copy_previous_block(s, tag);
237 if (ret < 0) {
238 avctx->release_buffer(avctx, &s->frame);
239 return ret;
240 }
241 }
242 yop_next_macroblock(s);
243 }
244
245 *data_size = sizeof(AVFrame);
246 *(AVFrame *) data = s->frame;
247 return avpkt->size;
248 }
249
250 AVCodec ff_yop_decoder = {
251 .name = "yop",
252 .type = AVMEDIA_TYPE_VIDEO,
253 .id = CODEC_ID_YOP,
254 .priv_data_size = sizeof(YopDecContext),
255 .init = yop_decode_init,
256 .close = yop_decode_close,
257 .decode = yop_decode_frame,
258 .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
259 };