FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/tiertexseqv.c
Date: 2026-01-23 19:11:46
Exec Total Coverage
Lines: 110 129 85.3%
Functions: 8 8 100.0%
Branches: 54 77 70.1%
Line Branch Exec Source
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 "codec_internal.h"
30 #include "decode.h"
31 #include "get_bits.h"
32
33
34 typedef struct SeqVideoContext {
35 AVCodecContext *avctx;
36 AVFrame *frame;
37 } SeqVideoContext;
38
39
40 2508 static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
41 const unsigned char *src_end,
42 unsigned char *dst, int dst_size)
43 {
44 int i, len, sz;
45 GetBitContext gb;
46 int code_table[64];
47
48 /* get the rle codes */
49 2508 init_get_bits(&gb, src, (src_end - src) * 8);
50
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 53386 for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
51
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 50878 if (get_bits_left(&gb) < 4)
52 ✗ return NULL;
53 50878 code_table[i] = get_sbits(&gb, 4);
54 50878 sz += FFABS(code_table[i]);
55 }
56 2508 src += (get_bits_count(&gb) + 7) / 8;
57
58 /* do the rle unpacking */
59
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 53386 for (i = 0; i < 64 && dst_size > 0; i++) {
60 50878 len = code_table[i];
61
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 50878 if (len < 0) {
62 50878 len = -len;
63
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 50878 if (src_end - src < 1)
64 ✗ return NULL;
65 50878 memset(dst, *src++, FFMIN(len, dst_size));
66 } else {
67 ✗ if (src_end - src < len)
68 ✗ return NULL;
69 ✗ memcpy(dst, src, FFMIN(len, dst_size));
70 ✗ src += len;
71 }
72 50878 dst += len;
73 50878 dst_size -= len;
74 }
75 2508 return src;
76 }
77
78 6758 static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
79 const unsigned char *src,
80 const unsigned char *src_end,
81 unsigned char *dst)
82 {
83 const unsigned char *color_table;
84 int b, i, len, bits;
85 GetBitContext gb;
86 unsigned char block[8 * 8];
87
88
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 6758 if (src_end - src < 1)
89 ✗ return NULL;
90 6758 len = *src++;
91
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 6758 if (len & 0x80) {
92
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 2508 switch (len & 3) {
93 1099 case 1:
94 1099 src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
95
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 9891 for (b = 0; b < 8; b++) {
96 8792 memcpy(dst, &block[b * 8], 8);
97 8792 dst += seq->frame->linesize[0];
98 }
99 1099 break;
100 1409 case 2:
101 1409 src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
102
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 12681 for (i = 0; i < 8; i++) {
103
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 101448 for (b = 0; b < 8; b++)
104 90176 dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
105 11272 ++dst;
106 }
107 1409 break;
108 }
109 } else {
110
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 4250 if (len <= 0)
111 ✗ return NULL;
112 4250 bits = ff_log2_tab[len - 1] + 1;
113
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 4250 if (src_end - src < len + 8 * bits)
114 ✗ return NULL;
115 4250 color_table = src;
116 4250 src += len;
117 4250 init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
118
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 38250 for (b = 0; b < 8; b++) {
119
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 306000 for (i = 0; i < 8; i++)
120 272000 dst[i] = color_table[get_bits(&gb, bits)];
121 34000 dst += seq->frame->linesize[0];
122 }
123 }
124
125 6758 return src;
126 }
127
128 197 static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
129 const unsigned char *src,
130 const unsigned char *src_end,
131 unsigned char *dst)
132 {
133 int i;
134
135
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 197 if (src_end - src < 8 * 8)
136 ✗ return NULL;
137
138
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 1773 for (i = 0; i < 8; i++) {
139 1576 memcpy(dst, src, 8);
140 1576 src += 8;
141 1576 dst += seq->frame->linesize[0];
142 }
143
144 197 return src;
145 }
146
147 595 static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
148 const unsigned char *src,
149 const unsigned char *src_end,
150 unsigned char *dst)
151 {
152 int pos, offset;
153
154 do {
155
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 3101 if (src_end - src < 2)
156 ✗ return NULL;
157 3101 pos = *src++;
158 3101 offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
159 3101 dst[offset] = *src++;
160
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 3101 } while (!(pos & 0x80));
161
162 595 return src;
163 }
164
165 21 static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
166 {
167 21 const unsigned char *data_end = data + data_size;
168 GetBitContext gb;
169 int flags, i, j, x, y, op;
170 unsigned char c[3];
171 unsigned char *dst;
172 uint32_t *palette;
173
174 21 flags = *data++;
175
176
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 21 if (flags & 1) {
177 21 palette = (uint32_t *)seq->frame->data[1];
178
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 21 if (data_end - data < 256 * 3)
179 ✗ return AVERROR_INVALIDDATA;
180
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 5397 for (i = 0; i < 256; i++) {
181
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 21504 for (j = 0; j < 3; j++, data++)
182 16128 c[j] = (*data << 2) | (*data >> 4);
183 5376 palette[i] = 0xFFU << 24 | AV_RB24(c);
184 }
185 }
186
187
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 21 if (flags & 2) {
188
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 21 if (data_end - data < 128)
189 ✗ return AVERROR_INVALIDDATA;
190 21 init_get_bits(&gb, data, 128 * 8); data += 128;
191
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 357 for (y = 0; y < 128; y += 8)
192
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 11088 for (x = 0; x < 256; x += 8) {
193 10752 dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
194 10752 op = get_bits(&gb, 2);
195
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 10752 switch (op) {
196 6758 case 1:
197 6758 data = seq_decode_op1(seq, data, data_end, dst);
198 6758 break;
199 197 case 2:
200 197 data = seq_decode_op2(seq, data, data_end, dst);
201 197 break;
202 595 case 3:
203 595 data = seq_decode_op3(seq, data, data_end, dst);
204 595 break;
205 }
206
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 10752 if (!data)
207 ✗ return AVERROR_INVALIDDATA;
208 }
209 }
210 21 return 0;
211 }
212
213 2 static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
214 {
215 2 SeqVideoContext *seq = avctx->priv_data;
216 int ret;
217
218 2 seq->avctx = avctx;
219 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
220
221 2 ret = ff_set_dimensions(avctx, 256, 128);
222
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 2 if (ret < 0)
223 ✗ return ret;
224
225 2 seq->frame = av_frame_alloc();
226
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 2 if (!seq->frame)
227 ✗ return AVERROR(ENOMEM);
228
229 2 return 0;
230 }
231
232 21 static int seqvideo_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
233 int *got_frame, AVPacket *avpkt)
234 {
235 21 const uint8_t *buf = avpkt->data;
236 21 int buf_size = avpkt->size;
237 int ret;
238
239 21 SeqVideoContext *seq = avctx->priv_data;
240
241
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 21 if ((ret = ff_reget_buffer(avctx, seq->frame, 0)) < 0)
242 ✗ return ret;
243
244
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 21 if (seqvideo_decode(seq, buf, buf_size))
245 ✗ return AVERROR_INVALIDDATA;
246
247
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 21 if ((ret = av_frame_ref(rframe, seq->frame)) < 0)
248 ✗ return ret;
249 21 *got_frame = 1;
250
251 21 return buf_size;
252 }
253
254 2 static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
255 {
256 2 SeqVideoContext *seq = avctx->priv_data;
257
258 2 av_frame_free(&seq->frame);
259
260 2 return 0;
261 }
262
263 const FFCodec ff_tiertexseqvideo_decoder = {
264 .p.name = "tiertexseqvideo",
265 CODEC_LONG_NAME("Tiertex Limited SEQ video"),
266 .p.type = AVMEDIA_TYPE_VIDEO,
267 .p.id = AV_CODEC_ID_TIERTEXSEQVIDEO,
268 .priv_data_size = sizeof(SeqVideoContext),
269 .init = seqvideo_decode_init,
270 .close = seqvideo_decode_end,
271 FF_CODEC_DECODE_CB(seqvideo_decode_frame),
272 .p.capabilities = AV_CODEC_CAP_DR1,
273 };
274