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 FFmpeg.
9 *
10 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include <string.h>
26
27 #include "libavutil/imgutils.h"
28 #include "libavutil/internal.h"
29 #include "libavutil/intreadwrite.h"
30
31 #include "avcodec.h"
32 #include "codec_internal.h"
33 #include "internal.h"
34
35 typedef struct YopDecContext {
36 AVCodecContext *avctx;
37 AVFrame *frame;
38
39 int num_pal_colors;
40 int first_color[2];
41 int frame_data_length;
42
43 const uint8_t *low_nibble;
44 const uint8_t *srcptr;
45 const uint8_t *src_end;
46 uint8_t *dstptr;
47 uint8_t *dstbuf;
48 } YopDecContext;
49
50 // These tables are taken directly from:
51 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
52
53 /**
54 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
55 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
56 * Byte 3 contains the number of bytes consumed on the input,
57 * equal to max(bytes 0-2) + 1.
58 */
59 static const uint8_t paint_lut[15][4] =
60 {{1, 2, 3, 4}, {1, 2, 0, 3},
61 {1, 2, 1, 3}, {1, 2, 2, 3},
62 {1, 0, 2, 3}, {1, 0, 0, 2},
63 {1, 0, 1, 2}, {1, 1, 2, 3},
64 {0, 1, 2, 3}, {0, 1, 0, 2},
65 {1, 1, 0, 2}, {0, 1, 1, 2},
66 {0, 0, 1, 2}, {0, 0, 0, 1},
67 {1, 1, 1, 2},
68 };
69
70 /**
71 * Lookup table for copying macroblocks. Each entry contains the respective
72 * x and y pixel offset for the copy source.
73 */
74 static const int8_t motion_vector[16][2] =
75 {{-4, -4}, {-2, -4},
76 { 0, -4}, { 2, -4},
77 {-4, -2}, {-4, 0},
78 {-3, -3}, {-1, -3},
79 { 1, -3}, { 3, -3},
80 {-3, -1}, {-2, -2},
81 { 0, -2}, { 2, -2},
82 { 4, -2}, {-2, 0},
83 };
84
yop_decode_close(AVCodecContext * avctx)85 static av_cold int yop_decode_close(AVCodecContext *avctx)
86 {
87 YopDecContext *s = avctx->priv_data;
88
89 av_frame_free(&s->frame);
90
91 return 0;
92 }
93
yop_decode_init(AVCodecContext * avctx)94 static av_cold int yop_decode_init(AVCodecContext *avctx)
95 {
96 YopDecContext *s = avctx->priv_data;
97 s->avctx = avctx;
98
99 if (avctx->width & 1 || avctx->height & 1 ||
100 av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
101 av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
102 return AVERROR_INVALIDDATA;
103 }
104
105 if (avctx->extradata_size < 3) {
106 av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
107 return AVERROR_INVALIDDATA;
108 }
109
110 avctx->pix_fmt = AV_PIX_FMT_PAL8;
111
112 s->num_pal_colors = avctx->extradata[0];
113 s->first_color[0] = avctx->extradata[1];
114 s->first_color[1] = avctx->extradata[2];
115
116 if (s->num_pal_colors + s->first_color[0] > 256 ||
117 s->num_pal_colors + s->first_color[1] > 256) {
118 av_log(avctx, AV_LOG_ERROR,
119 "Palette parameters invalid, header probably corrupt\n");
120 return AVERROR_INVALIDDATA;
121 }
122
123 s->frame = av_frame_alloc();
124 if (!s->frame)
125 return AVERROR(ENOMEM);
126
127 return 0;
128 }
129
130 /**
131 * Paint a macroblock using the pattern in paint_lut.
132 * @param s codec context
133 * @param tag the tag that was in the nibble
134 */
yop_paint_block(YopDecContext * s,int linesize,int tag)135 static int yop_paint_block(YopDecContext *s, int linesize, int tag)
136 {
137 if (s->src_end - s->srcptr < paint_lut[tag][3]) {
138 av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
139 return AVERROR_INVALIDDATA;
140 }
141
142 s->dstptr[0] = s->srcptr[0];
143 s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
144 s->dstptr[linesize] = s->srcptr[paint_lut[tag][1]];
145 s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];
146
147 // The number of src bytes consumed is in the last part of the lut entry.
148 s->srcptr += paint_lut[tag][3];
149 return 0;
150 }
151
152 /**
153 * Copy a previously painted macroblock to the current_block.
154 * @param copy_tag the tag that was in the nibble
155 */
yop_copy_previous_block(YopDecContext * s,int linesize,int copy_tag)156 static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
157 {
158 uint8_t *bufptr;
159
160 // Calculate position for the copy source
161 bufptr = s->dstptr + motion_vector[copy_tag][0] +
162 linesize * motion_vector[copy_tag][1];
163 if (bufptr < s->dstbuf) {
164 av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");
165 return AVERROR_INVALIDDATA;
166 }
167
168 s->dstptr[0] = bufptr[0];
169 s->dstptr[1] = bufptr[1];
170 s->dstptr[linesize] = bufptr[linesize];
171 s->dstptr[linesize + 1] = bufptr[linesize + 1];
172
173 return 0;
174 }
175
176 /**
177 * Return the next nibble in sequence, consuming a new byte on the input
178 * only if necessary.
179 */
yop_get_next_nibble(YopDecContext * s)180 static uint8_t yop_get_next_nibble(YopDecContext *s)
181 {
182 int ret;
183
184 if (s->low_nibble) {
185 ret = *s->low_nibble & 0xf;
186 s->low_nibble = NULL;
187 }else {
188 s->low_nibble = s->srcptr++;
189 ret = *s->low_nibble >> 4;
190 }
191 return ret;
192 }
193
yop_decode_frame(AVCodecContext * avctx,AVFrame * rframe,int * got_frame,AVPacket * avpkt)194 static int yop_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
195 int *got_frame, AVPacket *avpkt)
196 {
197 YopDecContext *s = avctx->priv_data;
198 AVFrame *frame = s->frame;
199 int tag, firstcolor, is_odd_frame;
200 int ret, i, x, y;
201 uint32_t *palette;
202
203 if (avpkt->size < 4 + 3 * s->num_pal_colors) {
204 av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
205 return AVERROR_INVALIDDATA;
206 }
207
208 if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
209 return ret;
210
211 if (!avctx->frame_number)
212 memset(frame->data[1], 0, AVPALETTE_SIZE);
213
214 s->dstbuf = frame->data[0];
215 s->dstptr = frame->data[0];
216 s->srcptr = avpkt->data + 4;
217 s->src_end = avpkt->data + avpkt->size;
218 s->low_nibble = NULL;
219
220 is_odd_frame = avpkt->data[0];
221 if(is_odd_frame>1){
222 av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
223 return AVERROR_INVALIDDATA;
224 }
225 firstcolor = s->first_color[is_odd_frame];
226 palette = (uint32_t *)frame->data[1];
227
228 for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {
229 palette[i + firstcolor] = (s->srcptr[0] << 18) |
230 (s->srcptr[1] << 10) |
231 (s->srcptr[2] << 2);
232 palette[i + firstcolor] |= 0xFFU << 24 |
233 (palette[i + firstcolor] >> 6) & 0x30303;
234 }
235
236 frame->palette_has_changed = 1;
237
238 for (y = 0; y < avctx->height; y += 2) {
239 for (x = 0; x < avctx->width; x += 2) {
240 if (s->srcptr - avpkt->data >= avpkt->size) {
241 av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
242 return AVERROR_INVALIDDATA;
243 }
244
245 tag = yop_get_next_nibble(s);
246
247 if (tag != 0xf) {
248 ret = yop_paint_block(s, frame->linesize[0], tag);
249 if (ret < 0)
250 return ret;
251 } else {
252 tag = yop_get_next_nibble(s);
253 ret = yop_copy_previous_block(s, frame->linesize[0], tag);
254 if (ret < 0)
255 return ret;
256 }
257 s->dstptr += 2;
258 }
259 s->dstptr += 2*frame->linesize[0] - x;
260 }
261
262 if ((ret = av_frame_ref(rframe, s->frame)) < 0)
263 return ret;
264
265 *got_frame = 1;
266 return avpkt->size;
267 }
268
269 const FFCodec ff_yop_decoder = {
270 .p.name = "yop",
271 .p.long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
272 .p.type = AVMEDIA_TYPE_VIDEO,
273 .p.id = AV_CODEC_ID_YOP,
274 .priv_data_size = sizeof(YopDecContext),
275 .init = yop_decode_init,
276 .close = yop_decode_close,
277 FF_CODEC_DECODE_CB(yop_decode_frame),
278 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
279 };
280