Directory: | ../../../ffmpeg/ |
---|---|
File: | src/libavcodec/idcinvideo.c |
Date: | 2022-07-07 01:21:54 |
Exec | Total | Coverage | |
---|---|---|---|
Lines: | 75 | 81 | 92.6% |
Branches: | 32 | 36 | 88.9% |
Line | Branch | Exec | Source |
---|---|---|---|
1 | /* | ||
2 | * id Quake II CIN Video Decoder | ||
3 | * Copyright (C) 2003 The FFmpeg project | ||
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 | /** | ||
23 | * @file | ||
24 | * id Quake II Cin Video Decoder by Dr. Tim Ferguson | ||
25 | * For more information about the id CIN format, visit: | ||
26 | * http://www.csse.monash.edu.au/~timf/ | ||
27 | * | ||
28 | * This video decoder outputs PAL8 colorspace data. Interacting with this | ||
29 | * decoder is a little involved. During initialization, the demuxer must | ||
30 | * transmit the 65536-byte Huffman table(s) to the decoder via extradata. | ||
31 | * Then, whenever a palette change is encountered while demuxing the file, | ||
32 | * the demuxer must use the same extradata space to transmit an | ||
33 | * AVPaletteControl structure. | ||
34 | * | ||
35 | * id CIN video is purely Huffman-coded, intraframe-only codec. It achieves | ||
36 | * a little more compression by exploiting the fact that adjacent pixels | ||
37 | * tend to be similar. | ||
38 | * | ||
39 | * Note that this decoder could use libavcodec's optimized VLC facilities | ||
40 | * rather than naive, tree-based Huffman decoding. However, there are 256 | ||
41 | * Huffman tables. Plus, the VLC bit coding order is right -> left instead | ||
42 | * or left -> right, so all of the bits would have to be reversed. Further, | ||
43 | * the original Quake II implementation likely used a similar naive | ||
44 | * decoding algorithm and it worked fine on much lower spec machines. | ||
45 | */ | ||
46 | |||
47 | #include <stdio.h> | ||
48 | #include <stdlib.h> | ||
49 | #include <string.h> | ||
50 | |||
51 | #include "avcodec.h" | ||
52 | #include "codec_internal.h" | ||
53 | #include "decode.h" | ||
54 | #include "internal.h" | ||
55 | #include "libavutil/internal.h" | ||
56 | |||
57 | #define HUFFMAN_TABLE_SIZE 64 * 1024 | ||
58 | #define HUF_TOKENS 256 | ||
59 | #define PALETTE_COUNT 256 | ||
60 | |||
61 | typedef struct hnode { | ||
62 | int count; | ||
63 | unsigned char used; | ||
64 | int children[2]; | ||
65 | } hnode; | ||
66 | |||
67 | typedef struct IdcinContext { | ||
68 | |||
69 | AVCodecContext *avctx; | ||
70 | |||
71 | const unsigned char *buf; | ||
72 | int size; | ||
73 | |||
74 | hnode huff_nodes[256][HUF_TOKENS*2]; | ||
75 | int num_huff_nodes[256]; | ||
76 | |||
77 | uint32_t pal[256]; | ||
78 | } IdcinContext; | ||
79 | |||
80 | /** | ||
81 | * Find the lowest probability node in a Huffman table, and mark it as | ||
82 | * being assigned to a higher probability. | ||
83 | * @return the node index of the lowest unused node, or -1 if all nodes | ||
84 | * are used. | ||
85 | */ | ||
86 | 36984 | static int huff_smallest_node(hnode *hnodes, int num_hnodes) { | |
87 | int i; | ||
88 | int best, best_node; | ||
89 | |||
90 | 36984 | best = 99999999; | |
91 | 36984 | best_node = -1; | |
92 |
2/2✓ Branch 0 taken 10787968 times.
✓ Branch 1 taken 36984 times.
|
10824952 | for(i = 0; i < num_hnodes; i++) { |
93 |
2/2✓ Branch 0 taken 2658518 times.
✓ Branch 1 taken 8129450 times.
|
10787968 | if(hnodes[i].used) |
94 | 2658518 | continue; | |
95 |
2/2✓ Branch 0 taken 6790996 times.
✓ Branch 1 taken 1338454 times.
|
8129450 | if(!hnodes[i].count) |
96 | 6790996 | continue; | |
97 |
2/2✓ Branch 0 taken 132488 times.
✓ Branch 1 taken 1205966 times.
|
1338454 | if(hnodes[i].count < best) { |
98 | 132488 | best = hnodes[i].count; | |
99 | 132488 | best_node = i; | |
100 | } | ||
101 | } | ||
102 | |||
103 |
2/2✓ Branch 0 taken 512 times.
✓ Branch 1 taken 36472 times.
|
36984 | if(best_node == -1) |
104 | 512 | return -1; | |
105 | 36472 | hnodes[best_node].used = 1; | |
106 | 36472 | return best_node; | |
107 | } | ||
108 | |||
109 | /* | ||
110 | * Build the Huffman tree using the generated/loaded probabilities histogram. | ||
111 | * | ||
112 | * On completion: | ||
113 | * huff_nodes[prev][i < HUF_TOKENS] - are the nodes at the base of the tree. | ||
114 | * huff_nodes[prev][i >= HUF_TOKENS] - are used to construct the tree. | ||
115 | * num_huff_nodes[prev] - contains the index to the root node of the tree. | ||
116 | * That is: huff_nodes[prev][num_huff_nodes[prev]] is the root node. | ||
117 | */ | ||
118 | 512 | static av_cold void huff_build_tree(IdcinContext *s, int prev) { | |
119 | hnode *node, *hnodes; | ||
120 | int num_hnodes, i; | ||
121 | |||
122 | 512 | num_hnodes = HUF_TOKENS; | |
123 | 512 | hnodes = s->huff_nodes[prev]; | |
124 |
2/2✓ Branch 0 taken 262144 times.
✓ Branch 1 taken 512 times.
|
262656 | for(i = 0; i < HUF_TOKENS * 2; i++) |
125 | 262144 | hnodes[i].used = 0; | |
126 | |||
127 | while (1) { | ||
128 | 18594 | node = &hnodes[num_hnodes]; /* next free node */ | |
129 | |||
130 | /* pick two lowest counts */ | ||
131 | 18594 | node->children[0] = huff_smallest_node(hnodes, num_hnodes); | |
132 |
2/2✓ Branch 0 taken 204 times.
✓ Branch 1 taken 18390 times.
|
18594 | if(node->children[0] == -1) |
133 | 204 | break; /* reached the root node */ | |
134 | |||
135 | 18390 | node->children[1] = huff_smallest_node(hnodes, num_hnodes); | |
136 |
2/2✓ Branch 0 taken 308 times.
✓ Branch 1 taken 18082 times.
|
18390 | if(node->children[1] == -1) |
137 | 308 | break; /* reached the root node */ | |
138 | |||
139 | /* combine nodes probability for new node */ | ||
140 | 18082 | node->count = hnodes[node->children[0]].count + | |
141 | 18082 | hnodes[node->children[1]].count; | |
142 | 18082 | num_hnodes++; | |
143 | } | ||
144 | |||
145 | 512 | s->num_huff_nodes[prev] = num_hnodes - 1; | |
146 | 512 | } | |
147 | |||
148 | 2 | static av_cold int idcin_decode_init(AVCodecContext *avctx) | |
149 | { | ||
150 | 2 | IdcinContext *s = avctx->priv_data; | |
151 | 2 | int i, j, histogram_index = 0; | |
152 | unsigned char *histograms; | ||
153 | |||
154 | 2 | s->avctx = avctx; | |
155 | 2 | avctx->pix_fmt = AV_PIX_FMT_PAL8; | |
156 | |||
157 | /* make sure the Huffman tables make it */ | ||
158 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 2 times.
|
2 | if (s->avctx->extradata_size != HUFFMAN_TABLE_SIZE) { |
159 | ✗ | av_log(s->avctx, AV_LOG_ERROR, " id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE); | |
160 | ✗ | return -1; | |
161 | } | ||
162 | |||
163 | /* build the 256 Huffman decode trees */ | ||
164 | 2 | histograms = (unsigned char *)s->avctx->extradata; | |
165 |
2/2✓ Branch 0 taken 512 times.
✓ Branch 1 taken 2 times.
|
514 | for (i = 0; i < 256; i++) { |
166 |
2/2✓ Branch 0 taken 131072 times.
✓ Branch 1 taken 512 times.
|
131584 | for(j = 0; j < HUF_TOKENS; j++) |
167 | 131072 | s->huff_nodes[i][j].count = histograms[histogram_index++]; | |
168 | 512 | huff_build_tree(s, i); | |
169 | } | ||
170 | |||
171 | 2 | return 0; | |
172 | } | ||
173 | |||
174 | 52 | static int idcin_decode_vlcs(IdcinContext *s, AVFrame *frame) | |
175 | { | ||
176 | hnode *hnodes; | ||
177 | long x, y; | ||
178 | int prev; | ||
179 | 52 | unsigned char v = 0; | |
180 | int bit_pos, node_num, dat_pos; | ||
181 | |||
182 | 52 | prev = bit_pos = dat_pos = 0; | |
183 |
2/2✓ Branch 0 taken 12480 times.
✓ Branch 1 taken 52 times.
|
12532 | for (y = 0; y < (frame->linesize[0] * s->avctx->height); |
184 | 12480 | y += frame->linesize[0]) { | |
185 |
2/2✓ Branch 0 taken 3993600 times.
✓ Branch 1 taken 12480 times.
|
4006080 | for (x = y; x < y + s->avctx->width; x++) { |
186 | 3993600 | node_num = s->num_huff_nodes[prev]; | |
187 | 3993600 | hnodes = s->huff_nodes[prev]; | |
188 | |||
189 |
2/2✓ Branch 0 taken 13464208 times.
✓ Branch 1 taken 3993600 times.
|
17457808 | while(node_num >= HUF_TOKENS) { |
190 |
2/2✓ Branch 0 taken 1683045 times.
✓ Branch 1 taken 11781163 times.
|
13464208 | if(!bit_pos) { |
191 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 1683045 times.
|
1683045 | if(dat_pos >= s->size) { |
192 | ✗ | av_log(s->avctx, AV_LOG_ERROR, "Huffman decode error.\n"); | |
193 | ✗ | return -1; | |
194 | } | ||
195 | 1683045 | bit_pos = 8; | |
196 | 1683045 | v = s->buf[dat_pos++]; | |
197 | } | ||
198 | |||
199 | 13464208 | node_num = hnodes[node_num].children[v & 0x01]; | |
200 | 13464208 | v = v >> 1; | |
201 | 13464208 | bit_pos--; | |
202 | } | ||
203 | |||
204 | 3993600 | frame->data[0][x] = node_num; | |
205 | 3993600 | prev = node_num; | |
206 | } | ||
207 | } | ||
208 | |||
209 | 52 | return 0; | |
210 | } | ||
211 | |||
212 | 52 | static int idcin_decode_frame(AVCodecContext *avctx, AVFrame *frame, | |
213 | int *got_frame, AVPacket *avpkt) | ||
214 | { | ||
215 | 52 | const uint8_t *buf = avpkt->data; | |
216 | 52 | int buf_size = avpkt->size; | |
217 | 52 | IdcinContext *s = avctx->priv_data; | |
218 | int ret; | ||
219 | |||
220 | 52 | s->buf = buf; | |
221 | 52 | s->size = buf_size; | |
222 | |||
223 |
1/2✗ Branch 1 not taken.
✓ Branch 2 taken 52 times.
|
52 | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
224 | ✗ | return ret; | |
225 | |||
226 |
1/2✗ Branch 1 not taken.
✓ Branch 2 taken 52 times.
|
52 | if (idcin_decode_vlcs(s, frame)) |
227 | ✗ | return AVERROR_INVALIDDATA; | |
228 | |||
229 | 52 | frame->palette_has_changed = ff_copy_palette(s->pal, avpkt, avctx); | |
230 | /* make the palette available on the way out */ | ||
231 | 52 | memcpy(frame->data[1], s->pal, AVPALETTE_SIZE); | |
232 | |||
233 | 52 | *got_frame = 1; | |
234 | |||
235 | /* report that the buffer was completely consumed */ | ||
236 | 52 | return buf_size; | |
237 | } | ||
238 | |||
239 | static const FFCodecDefault idcin_defaults[] = { | ||
240 | { "max_pixels", "320*240" }, | ||
241 | { NULL }, | ||
242 | }; | ||
243 | |||
244 | const FFCodec ff_idcin_decoder = { | ||
245 | .p.name = "idcinvideo", | ||
246 | .p.long_name = NULL_IF_CONFIG_SMALL("id Quake II CIN video"), | ||
247 | .p.type = AVMEDIA_TYPE_VIDEO, | ||
248 | .p.id = AV_CODEC_ID_IDCIN, | ||
249 | .priv_data_size = sizeof(IdcinContext), | ||
250 | .init = idcin_decode_init, | ||
251 | FF_CODEC_DECODE_CB(idcin_decode_frame), | ||
252 | .p.capabilities = AV_CODEC_CAP_DR1, | ||
253 | .defaults = idcin_defaults, | ||
254 | .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, | ||
255 | }; | ||
256 |