FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/c93.c
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 107 127 84.3%
Branches: 58 80 72.5%

Line Branch Exec Source
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 C93DecoderContext {
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 2 static av_cold int decode_end(AVCodecContext *avctx)
50 {
51 2 C93DecoderContext * const c93 = avctx->priv_data;
52
53 2 av_frame_free(&c93->pictures[0]);
54 2 av_frame_free(&c93->pictures[1]);
55
56 2 return 0;
57 }
58
59 2 static av_cold int decode_init(AVCodecContext *avctx)
60 {
61 2 C93DecoderContext *s = avctx->priv_data;
62 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
63
64 2 s->pictures[0] = av_frame_alloc();
65 2 s->pictures[1] = av_frame_alloc();
66
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2 if (!s->pictures[0] || !s->pictures[1])
67 return AVERROR(ENOMEM);
68
69 2 return 0;
70 }
71
72 98205 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
73 uint8_t *from, int offset, int height, int stride)
74 {
75 int i;
76 98205 int width = height;
77 98205 int from_x = offset % WIDTH;
78 98205 int from_y = offset / WIDTH;
79 98205 int overflow = from_x + width - WIDTH;
80
81
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98205 if (!from) {
82 /* silently ignoring predictive blocks in first frame */
83 return 0;
84 }
85
86
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98205 if (from_y + height > HEIGHT) {
87 av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
88 offset);
89 return AVERROR_INVALIDDATA;
90 }
91
92
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98205 if (overflow > 0) {
93 width -= overflow;
94 for (i = 0; i < height; i++) {
95 memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
96 }
97 }
98
99
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573461 for (i = 0; i < height; i++) {
100 475256 memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
101 }
102
103 98205 return 0;
104 }
105
106 2576 static inline void draw_n_color(uint8_t *out, int stride, int width,
107 int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
108 {
109 int x, y;
110
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11584 for (y = 0; y < height; y++) {
111
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9008 if (grps)
112 480 cols[0] = grps[3 * (y >> 1)];
113
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46768 for (x = 0; x < width; x++) {
114
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37760 if (grps)
115 1920 cols[1]= grps[(x >> 1) + 1];
116 37760 out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
117 37760 col >>= bpp;
118 }
119 }
120 2576 }
121
122 45 static int decode_frame(AVCodecContext *avctx, void *data,
123 int *got_frame, AVPacket *avpkt)
124 {
125 45 const uint8_t *buf = avpkt->data;
126 45 int buf_size = avpkt->size;
127 45 C93DecoderContext * const c93 = avctx->priv_data;
128 45 AVFrame * const newpic = c93->pictures[c93->currentpic];
129 45 AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
130 GetByteContext gb;
131 uint8_t *out;
132 45 int stride, ret, i, x, y, b, bt = 0;
133
134
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45 if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
135 return ret;
136
137 45 c93->currentpic ^= 1;
138
139
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45 if ((ret = ff_reget_buffer(avctx, newpic, 0)) < 0)
140 return ret;
141
142 45 stride = newpic->linesize[0];
143
144 45 bytestream2_init(&gb, buf, buf_size);
145 45 b = bytestream2_get_byte(&gb);
146
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45 if (b & C93_FIRST_FRAME) {
147 1 newpic->pict_type = AV_PICTURE_TYPE_I;
148 1 newpic->key_frame = 1;
149 } else {
150 44 newpic->pict_type = AV_PICTURE_TYPE_P;
151 44 newpic->key_frame = 0;
152 }
153
154
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1125 for (y = 0; y < HEIGHT; y += 8) {
155 1080 out = newpic->data[0] + y * stride;
156
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44280 for (x = 0; x < WIDTH; x += 8) {
157 43200 uint8_t *copy_from = oldpic->data[0];
158 unsigned int offset, j;
159 uint8_t cols[4], grps[4];
160 C93BlockType block_type;
161
162
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43200 if (!bt)
163 21600 bt = bytestream2_get_byte(&gb);
164
165 43200 block_type= bt & 0x0F;
166
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43200 switch (block_type) {
167 20609 case C93_8X8_FROM_PREV:
168 20609 offset = bytestream2_get_le16(&gb);
169
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20609 if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
170 return ret;
171 20609 break;
172
173 621 case C93_4X4_FROM_CURR:
174 621 copy_from = newpic->data[0];
175 19399 case C93_4X4_FROM_PREV:
176
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58197 for (j = 0; j < 8; j += 4) {
177
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116394 for (i = 0; i < 8; i += 4) {
178 77596 int offset = bytestream2_get_le16(&gb);
179 77596 int from_x = offset % WIDTH;
180 77596 int from_y = offset / WIDTH;
181
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77596 if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
182 (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
183 avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
184 return AVERROR_INVALIDDATA;
185 }
186
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77596 if ((ret = copy_block(avctx, &out[j*stride+i],
187 copy_from, offset, 4, stride)) < 0)
188 return ret;
189 }
190 }
191 19399 break;
192
193 54 case C93_8X8_2COLOR:
194 54 bytestream2_get_buffer(&gb, cols, 2);
195
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486 for (i = 0; i < 8; i++) {
196 432 draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
197 NULL, bytestream2_get_byte(&gb));
198 }
199
200 54 break;
201
202 536 case C93_4X4_2COLOR:
203 case C93_4X4_4COLOR:
204 case C93_4X4_4COLOR_GRP:
205
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1608 for (j = 0; j < 8; j += 4) {
206
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3216 for (i = 0; i < 8; i += 4) {
207
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2144 if (block_type == C93_4X4_2COLOR) {
208 108 bytestream2_get_buffer(&gb, cols, 2);
209 108 draw_n_color(out + i + j*stride, stride, 4, 4,
210 1, cols, NULL, bytestream2_get_le16(&gb));
211
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2036 } else if (block_type == C93_4X4_4COLOR) {
212 1916 bytestream2_get_buffer(&gb, cols, 4);
213 1916 draw_n_color(out + i + j*stride, stride, 4, 4,
214 2, cols, NULL, bytestream2_get_le32(&gb));
215 } else {
216 120 bytestream2_get_buffer(&gb, grps, 4);
217 120 draw_n_color(out + i + j*stride, stride, 4, 4,
218 1, cols, grps, bytestream2_get_le16(&gb));
219 }
220 }
221 }
222 536 break;
223
224 case C93_NOOP:
225 break;
226
227 2602 case C93_8X8_INTRA:
228
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23418 for (j = 0; j < 8; j++)
229 20816 bytestream2_get_buffer(&gb, out + j*stride, 8);
230 2602 break;
231
232 default:
233 av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
234 block_type, x, y);
235 return AVERROR_INVALIDDATA;
236 }
237 43200 bt >>= 4;
238 43200 out += 8;
239 }
240 }
241
242
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45 if (b & C93_HAS_PALETTE) {
243 1 uint32_t *palette = (uint32_t *) newpic->data[1];
244
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257 for (i = 0; i < 256; i++) {
245 256 palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
246 }
247 1 newpic->palette_has_changed = 1;
248 } else {
249
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44 if (oldpic->data[1])
250 44 memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
251 }
252
253
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45 if ((ret = av_frame_ref(data, newpic)) < 0)
254 return ret;
255 45 *got_frame = 1;
256
257 45 return buf_size;
258 }
259
260 const AVCodec ff_c93_decoder = {
261 .name = "c93",
262 .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
263 .type = AVMEDIA_TYPE_VIDEO,
264 .id = AV_CODEC_ID_C93,
265 .priv_data_size = sizeof(C93DecoderContext),
266 .init = decode_init,
267 .close = decode_end,
268 .decode = decode_frame,
269 .capabilities = AV_CODEC_CAP_DR1,
270 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
271 };
272