lavc: fix decode_frame() third parameter semantics for video decoders
[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 #include "internal.h"
31
32 typedef struct YopDecContext {
33 AVFrame frame;
34 AVCodecContext *avctx;
35
36 int num_pal_colors;
37 int first_color[2];
38 int frame_data_length;
39 int row_pos;
40
41 uint8_t *low_nibble;
42 uint8_t *srcptr;
43 uint8_t *dstptr;
44 uint8_t *dstbuf;
45 } YopDecContext;
46
47 // These tables are taken directly from:
48 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
49
50 /**
51 * Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
52 * the macroblock positions to be painted (taken as (0, B0, B1, B2)).
53 * Byte 3 contains the number of bytes consumed on the input,
54 * equal to max(bytes 0-2) + 1.
55 */
56 static const uint8_t paint_lut[15][4] =
57 {{1, 2, 3, 4}, {1, 2, 0, 3},
58 {1, 2, 1, 3}, {1, 2, 2, 3},
59 {1, 0, 2, 3}, {1, 0, 0, 2},
60 {1, 0, 1, 2}, {1, 1, 2, 3},
61 {0, 1, 2, 3}, {0, 1, 0, 2},
62 {1, 1, 0, 2}, {0, 1, 1, 2},
63 {0, 0, 1, 2}, {0, 0, 0, 1},
64 {1, 1, 1, 2},
65 };
66
67 /**
68 * Lookup table for copying macroblocks. Each entry contains the respective
69 * x and y pixel offset for the copy source.
70 */
71 static const int8_t motion_vector[16][2] =
72 {{-4, -4}, {-2, -4},
73 { 0, -4}, { 2, -4},
74 {-4, -2}, {-4, 0},
75 {-3, -3}, {-1, -3},
76 { 1, -3}, { 3, -3},
77 {-3, -1}, {-2, -2},
78 { 0, -2}, { 2, -2},
79 { 4, -2}, {-2, 0},
80 };
81
82 static av_cold int yop_decode_init(AVCodecContext *avctx)
83 {
84 YopDecContext *s = avctx->priv_data;
85 s->avctx = avctx;
86
87 if (avctx->width & 1 || avctx->height & 1 ||
88 av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
89 av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
90 return -1;
91 }
92
93 avctx->pix_fmt = AV_PIX_FMT_PAL8;
94
95 s->num_pal_colors = avctx->extradata[0];
96 s->first_color[0] = avctx->extradata[1];
97 s->first_color[1] = avctx->extradata[2];
98
99 if (s->num_pal_colors + s->first_color[0] > 256 ||
100 s->num_pal_colors + s->first_color[1] > 256) {
101 av_log(avctx, AV_LOG_ERROR,
102 "YOP: palette parameters invalid, header probably corrupt\n");
103 return AVERROR_INVALIDDATA;
104 }
105
106 return 0;
107 }
108
109 static av_cold int yop_decode_close(AVCodecContext *avctx)
110 {
111 YopDecContext *s = avctx->priv_data;
112 if (s->frame.data[0])
113 avctx->release_buffer(avctx, &s->frame);
114 return 0;
115 }
116
117 /**
118 * Paint a macroblock using the pattern in paint_lut.
119 * @param s codec context
120 * @param tag the tag that was in the nibble
121 */
122 static void yop_paint_block(YopDecContext *s, int tag)
123 {
124 s->dstptr[0] = s->srcptr[0];
125 s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
126 s->dstptr[s->frame.linesize[0]] = s->srcptr[paint_lut[tag][1]];
127 s->dstptr[s->frame.linesize[0] + 1] = s->srcptr[paint_lut[tag][2]];
128
129 // The number of src bytes consumed is in the last part of the lut entry.
130 s->srcptr += paint_lut[tag][3];
131 }
132
133 /**
134 * Copy a previously painted macroblock to the current_block.
135 * @param copy_tag the tag that was in the nibble
136 */
137 static int yop_copy_previous_block(YopDecContext *s, int copy_tag)
138 {
139 uint8_t *bufptr;
140
141 // Calculate position for the copy source
142 bufptr = s->dstptr + motion_vector[copy_tag][0] +
143 s->frame.linesize[0] * motion_vector[copy_tag][1];
144 if (bufptr < s->dstbuf) {
145 av_log(s->avctx, AV_LOG_ERROR,
146 "YOP: cannot decode, file probably corrupt\n");
147 return AVERROR_INVALIDDATA;
148 }
149
150 s->dstptr[0] = bufptr[0];
151 s->dstptr[1] = bufptr[1];
152 s->dstptr[s->frame.linesize[0]] = bufptr[s->frame.linesize[0]];
153 s->dstptr[s->frame.linesize[0] + 1] = bufptr[s->frame.linesize[0] + 1];
154
155 return 0;
156 }
157
158 /**
159 * Return the next nibble in sequence, consuming a new byte on the input
160 * only if necessary.
161 */
162 static uint8_t yop_get_next_nibble(YopDecContext *s)
163 {
164 int ret;
165
166 if (s->low_nibble) {
167 ret = *s->low_nibble & 0xf;
168 s->low_nibble = NULL;
169 }else {
170 s->low_nibble = s->srcptr++;
171 ret = *s->low_nibble >> 4;
172 }
173 return ret;
174 }
175
176 /**
177 * Take s->dstptr to the next macroblock in sequence.
178 */
179 static void yop_next_macroblock(YopDecContext *s)
180 {
181 // If we are advancing to the next row of macroblocks
182 if (s->row_pos == s->frame.linesize[0] - 2) {
183 s->dstptr += s->frame.linesize[0];
184 s->row_pos = 0;
185 }else {
186 s->row_pos += 2;
187 }
188 s->dstptr += 2;
189 }
190
191 static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
192 AVPacket *avpkt)
193 {
194 YopDecContext *s = avctx->priv_data;
195 int tag, firstcolor, is_odd_frame;
196 int ret, i;
197 uint32_t *palette;
198
199 if (s->frame.data[0])
200 avctx->release_buffer(avctx, &s->frame);
201
202 ret = ff_get_buffer(avctx, &s->frame);
203 if (ret < 0) {
204 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
205 return ret;
206 }
207
208 s->frame.linesize[0] = avctx->width;
209
210 s->dstbuf = s->frame.data[0];
211 s->dstptr = s->frame.data[0];
212 s->srcptr = avpkt->data + 4;
213 s->row_pos = 0;
214 s->low_nibble = NULL;
215
216 is_odd_frame = avpkt->data[0];
217 firstcolor = s->first_color[is_odd_frame];
218 palette = (uint32_t *)s->frame.data[1];
219
220 for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3)
221 palette[i + firstcolor] = (s->srcptr[0] << 18) |
222 (s->srcptr[1] << 10) |
223 (s->srcptr[2] << 2);
224
225 s->frame.palette_has_changed = 1;
226
227 while (s->dstptr - s->dstbuf <
228 avctx->width * avctx->height &&
229 s->srcptr - avpkt->data < avpkt->size) {
230
231 tag = yop_get_next_nibble(s);
232
233 if (tag != 0xf) {
234 yop_paint_block(s, tag);
235 }else {
236 tag = yop_get_next_nibble(s);
237 ret = yop_copy_previous_block(s, tag);
238 if (ret < 0) {
239 avctx->release_buffer(avctx, &s->frame);
240 return ret;
241 }
242 }
243 yop_next_macroblock(s);
244 }
245
246 *got_frame = 1;
247 *(AVFrame *) data = s->frame;
248 return avpkt->size;
249 }
250
251 AVCodec ff_yop_decoder = {
252 .name = "yop",
253 .type = AVMEDIA_TYPE_VIDEO,
254 .id = AV_CODEC_ID_YOP,
255 .priv_data_size = sizeof(YopDecContext),
256 .init = yop_decode_init,
257 .close = yop_decode_close,
258 .decode = yop_decode_frame,
259 .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
260 .capabilities = CODEC_CAP_DR1,
261 };