blob: 06c5fd6b09d8d728ef1d38ff5a33a601d9d9b930
1 | /* |
2 | * Tiertex Limited SEQ Video Decoder |
3 | * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net) |
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 | * Tiertex Limited SEQ video decoder |
25 | */ |
26 | |
27 | #define BITSTREAM_READER_LE |
28 | #include "avcodec.h" |
29 | #include "get_bits.h" |
30 | #include "internal.h" |
31 | |
32 | |
33 | typedef struct SeqVideoContext { |
34 | AVCodecContext *avctx; |
35 | AVFrame *frame; |
36 | } SeqVideoContext; |
37 | |
38 | |
39 | static const unsigned char *seq_unpack_rle_block(const unsigned char *src, |
40 | const unsigned char *src_end, |
41 | unsigned char *dst, int dst_size) |
42 | { |
43 | int i, len, sz; |
44 | GetBitContext gb; |
45 | int code_table[64]; |
46 | |
47 | /* get the rle codes */ |
48 | init_get_bits(&gb, src, (src_end - src) * 8); |
49 | for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) { |
50 | if (get_bits_left(&gb) < 4) |
51 | return NULL; |
52 | code_table[i] = get_sbits(&gb, 4); |
53 | sz += FFABS(code_table[i]); |
54 | } |
55 | src += (get_bits_count(&gb) + 7) / 8; |
56 | |
57 | /* do the rle unpacking */ |
58 | for (i = 0; i < 64 && dst_size > 0; i++) { |
59 | len = code_table[i]; |
60 | if (len < 0) { |
61 | len = -len; |
62 | if (src_end - src < 1) |
63 | return NULL; |
64 | memset(dst, *src++, FFMIN(len, dst_size)); |
65 | } else { |
66 | if (src_end - src < len) |
67 | return NULL; |
68 | memcpy(dst, src, FFMIN(len, dst_size)); |
69 | src += len; |
70 | } |
71 | dst += len; |
72 | dst_size -= len; |
73 | } |
74 | return src; |
75 | } |
76 | |
77 | static const unsigned char *seq_decode_op1(SeqVideoContext *seq, |
78 | const unsigned char *src, |
79 | const unsigned char *src_end, |
80 | unsigned char *dst) |
81 | { |
82 | const unsigned char *color_table; |
83 | int b, i, len, bits; |
84 | GetBitContext gb; |
85 | unsigned char block[8 * 8]; |
86 | |
87 | if (src_end - src < 1) |
88 | return NULL; |
89 | len = *src++; |
90 | if (len & 0x80) { |
91 | switch (len & 3) { |
92 | case 1: |
93 | src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
94 | for (b = 0; b < 8; b++) { |
95 | memcpy(dst, &block[b * 8], 8); |
96 | dst += seq->frame->linesize[0]; |
97 | } |
98 | break; |
99 | case 2: |
100 | src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
101 | for (i = 0; i < 8; i++) { |
102 | for (b = 0; b < 8; b++) |
103 | dst[b * seq->frame->linesize[0]] = block[i * 8 + b]; |
104 | ++dst; |
105 | } |
106 | break; |
107 | } |
108 | } else { |
109 | if (len <= 0) |
110 | return NULL; |
111 | bits = ff_log2_tab[len - 1] + 1; |
112 | if (src_end - src < len + 8 * bits) |
113 | return NULL; |
114 | color_table = src; |
115 | src += len; |
116 | init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8; |
117 | for (b = 0; b < 8; b++) { |
118 | for (i = 0; i < 8; i++) |
119 | dst[i] = color_table[get_bits(&gb, bits)]; |
120 | dst += seq->frame->linesize[0]; |
121 | } |
122 | } |
123 | |
124 | return src; |
125 | } |
126 | |
127 | static const unsigned char *seq_decode_op2(SeqVideoContext *seq, |
128 | const unsigned char *src, |
129 | const unsigned char *src_end, |
130 | unsigned char *dst) |
131 | { |
132 | int i; |
133 | |
134 | if (src_end - src < 8 * 8) |
135 | return NULL; |
136 | |
137 | for (i = 0; i < 8; i++) { |
138 | memcpy(dst, src, 8); |
139 | src += 8; |
140 | dst += seq->frame->linesize[0]; |
141 | } |
142 | |
143 | return src; |
144 | } |
145 | |
146 | static const unsigned char *seq_decode_op3(SeqVideoContext *seq, |
147 | const unsigned char *src, |
148 | const unsigned char *src_end, |
149 | unsigned char *dst) |
150 | { |
151 | int pos, offset; |
152 | |
153 | do { |
154 | if (src_end - src < 2) |
155 | return NULL; |
156 | pos = *src++; |
157 | offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7); |
158 | dst[offset] = *src++; |
159 | } while (!(pos & 0x80)); |
160 | |
161 | return src; |
162 | } |
163 | |
164 | static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size) |
165 | { |
166 | const unsigned char *data_end = data + data_size; |
167 | GetBitContext gb; |
168 | int flags, i, j, x, y, op; |
169 | unsigned char c[3]; |
170 | unsigned char *dst; |
171 | uint32_t *palette; |
172 | |
173 | flags = *data++; |
174 | |
175 | if (flags & 1) { |
176 | palette = (uint32_t *)seq->frame->data[1]; |
177 | if (data_end - data < 256 * 3) |
178 | return AVERROR_INVALIDDATA; |
179 | for (i = 0; i < 256; i++) { |
180 | for (j = 0; j < 3; j++, data++) |
181 | c[j] = (*data << 2) | (*data >> 4); |
182 | palette[i] = 0xFFU << 24 | AV_RB24(c); |
183 | } |
184 | seq->frame->palette_has_changed = 1; |
185 | } |
186 | |
187 | if (flags & 2) { |
188 | if (data_end - data < 128) |
189 | return AVERROR_INVALIDDATA; |
190 | init_get_bits(&gb, data, 128 * 8); data += 128; |
191 | for (y = 0; y < 128; y += 8) |
192 | for (x = 0; x < 256; x += 8) { |
193 | dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x]; |
194 | op = get_bits(&gb, 2); |
195 | switch (op) { |
196 | case 1: |
197 | data = seq_decode_op1(seq, data, data_end, dst); |
198 | break; |
199 | case 2: |
200 | data = seq_decode_op2(seq, data, data_end, dst); |
201 | break; |
202 | case 3: |
203 | data = seq_decode_op3(seq, data, data_end, dst); |
204 | break; |
205 | } |
206 | if (!data) |
207 | return AVERROR_INVALIDDATA; |
208 | } |
209 | } |
210 | return 0; |
211 | } |
212 | |
213 | static av_cold int seqvideo_decode_init(AVCodecContext *avctx) |
214 | { |
215 | SeqVideoContext *seq = avctx->priv_data; |
216 | |
217 | seq->avctx = avctx; |
218 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
219 | |
220 | seq->frame = av_frame_alloc(); |
221 | if (!seq->frame) |
222 | return AVERROR(ENOMEM); |
223 | |
224 | return 0; |
225 | } |
226 | |
227 | static int seqvideo_decode_frame(AVCodecContext *avctx, |
228 | void *data, int *got_frame, |
229 | AVPacket *avpkt) |
230 | { |
231 | const uint8_t *buf = avpkt->data; |
232 | int buf_size = avpkt->size; |
233 | int ret; |
234 | |
235 | SeqVideoContext *seq = avctx->priv_data; |
236 | |
237 | if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) |
238 | return ret; |
239 | |
240 | if (seqvideo_decode(seq, buf, buf_size)) |
241 | return AVERROR_INVALIDDATA; |
242 | |
243 | if ((ret = av_frame_ref(data, seq->frame)) < 0) |
244 | return ret; |
245 | *got_frame = 1; |
246 | |
247 | return buf_size; |
248 | } |
249 | |
250 | static av_cold int seqvideo_decode_end(AVCodecContext *avctx) |
251 | { |
252 | SeqVideoContext *seq = avctx->priv_data; |
253 | |
254 | av_frame_free(&seq->frame); |
255 | |
256 | return 0; |
257 | } |
258 | |
259 | AVCodec ff_tiertexseqvideo_decoder = { |
260 | .name = "tiertexseqvideo", |
261 | .long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"), |
262 | .type = AVMEDIA_TYPE_VIDEO, |
263 | .id = AV_CODEC_ID_TIERTEXSEQVIDEO, |
264 | .priv_data_size = sizeof(SeqVideoContext), |
265 | .init = seqvideo_decode_init, |
266 | .close = seqvideo_decode_end, |
267 | .decode = seqvideo_decode_frame, |
268 | .capabilities = AV_CODEC_CAP_DR1, |
269 | }; |
270 |