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 "get_bits.h"
31 #include "internal.h"
32
33
34 typedef struct SeqVideoContext {
35 AVCodecContext *avctx;
36 AVFrame *frame;
37 } SeqVideoContext;
38
39
seq_unpack_rle_block(const unsigned char * src,const unsigned char * src_end,unsigned char * dst,int dst_size)40 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 init_get_bits(&gb, src, (src_end - src) * 8);
50 for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
51 if (get_bits_left(&gb) < 4)
52 return NULL;
53 code_table[i] = get_sbits(&gb, 4);
54 sz += FFABS(code_table[i]);
55 }
56 src += (get_bits_count(&gb) + 7) / 8;
57
58 /* do the rle unpacking */
59 for (i = 0; i < 64 && dst_size > 0; i++) {
60 len = code_table[i];
61 if (len < 0) {
62 len = -len;
63 if (src_end - src < 1)
64 return NULL;
65 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 dst += len;
73 dst_size -= len;
74 }
75 return src;
76 }
77
seq_decode_op1(SeqVideoContext * seq,const unsigned char * src,const unsigned char * src_end,unsigned char * dst)78 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 if (src_end - src < 1)
89 return NULL;
90 len = *src++;
91 if (len & 0x80) {
92 switch (len & 3) {
93 case 1:
94 src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
95 for (b = 0; b < 8; b++) {
96 memcpy(dst, &block[b * 8], 8);
97 dst += seq->frame->linesize[0];
98 }
99 break;
100 case 2:
101 src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
102 for (i = 0; i < 8; i++) {
103 for (b = 0; b < 8; b++)
104 dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
105 ++dst;
106 }
107 break;
108 }
109 } else {
110 if (len <= 0)
111 return NULL;
112 bits = ff_log2_tab[len - 1] + 1;
113 if (src_end - src < len + 8 * bits)
114 return NULL;
115 color_table = src;
116 src += len;
117 init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
118 for (b = 0; b < 8; b++) {
119 for (i = 0; i < 8; i++)
120 dst[i] = color_table[get_bits(&gb, bits)];
121 dst += seq->frame->linesize[0];
122 }
123 }
124
125 return src;
126 }
127
seq_decode_op2(SeqVideoContext * seq,const unsigned char * src,const unsigned char * src_end,unsigned char * dst)128 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 if (src_end - src < 8 * 8)
136 return NULL;
137
138 for (i = 0; i < 8; i++) {
139 memcpy(dst, src, 8);
140 src += 8;
141 dst += seq->frame->linesize[0];
142 }
143
144 return src;
145 }
146
seq_decode_op3(SeqVideoContext * seq,const unsigned char * src,const unsigned char * src_end,unsigned char * dst)147 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 if (src_end - src < 2)
156 return NULL;
157 pos = *src++;
158 offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
159 dst[offset] = *src++;
160 } while (!(pos & 0x80));
161
162 return src;
163 }
164
seqvideo_decode(SeqVideoContext * seq,const unsigned char * data,int data_size)165 static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
166 {
167 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 flags = *data++;
175
176 if (flags & 1) {
177 palette = (uint32_t *)seq->frame->data[1];
178 if (data_end - data < 256 * 3)
179 return AVERROR_INVALIDDATA;
180 for (i = 0; i < 256; i++) {
181 for (j = 0; j < 3; j++, data++)
182 c[j] = (*data << 2) | (*data >> 4);
183 palette[i] = 0xFFU << 24 | AV_RB24(c);
184 }
185 seq->frame->palette_has_changed = 1;
186 }
187
188 if (flags & 2) {
189 if (data_end - data < 128)
190 return AVERROR_INVALIDDATA;
191 init_get_bits(&gb, data, 128 * 8); data += 128;
192 for (y = 0; y < 128; y += 8)
193 for (x = 0; x < 256; x += 8) {
194 dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
195 op = get_bits(&gb, 2);
196 switch (op) {
197 case 1:
198 data = seq_decode_op1(seq, data, data_end, dst);
199 break;
200 case 2:
201 data = seq_decode_op2(seq, data, data_end, dst);
202 break;
203 case 3:
204 data = seq_decode_op3(seq, data, data_end, dst);
205 break;
206 }
207 if (!data)
208 return AVERROR_INVALIDDATA;
209 }
210 }
211 return 0;
212 }
213
seqvideo_decode_init(AVCodecContext * avctx)214 static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
215 {
216 SeqVideoContext *seq = avctx->priv_data;
217 int ret;
218
219 seq->avctx = avctx;
220 avctx->pix_fmt = AV_PIX_FMT_PAL8;
221
222 ret = ff_set_dimensions(avctx, 256, 128);
223 if (ret < 0)
224 return ret;
225
226 seq->frame = av_frame_alloc();
227 if (!seq->frame)
228 return AVERROR(ENOMEM);
229
230 return 0;
231 }
232
seqvideo_decode_frame(AVCodecContext * avctx,AVFrame * rframe,int * got_frame,AVPacket * avpkt)233 static int seqvideo_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
234 int *got_frame, AVPacket *avpkt)
235 {
236 const uint8_t *buf = avpkt->data;
237 int buf_size = avpkt->size;
238 int ret;
239
240 SeqVideoContext *seq = avctx->priv_data;
241
242 if ((ret = ff_reget_buffer(avctx, seq->frame, 0)) < 0)
243 return ret;
244
245 if (seqvideo_decode(seq, buf, buf_size))
246 return AVERROR_INVALIDDATA;
247
248 if ((ret = av_frame_ref(rframe, seq->frame)) < 0)
249 return ret;
250 *got_frame = 1;
251
252 return buf_size;
253 }
254
seqvideo_decode_end(AVCodecContext * avctx)255 static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
256 {
257 SeqVideoContext *seq = avctx->priv_data;
258
259 av_frame_free(&seq->frame);
260
261 return 0;
262 }
263
264 const FFCodec ff_tiertexseqvideo_decoder = {
265 .p.name = "tiertexseqvideo",
266 .p.long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
267 .p.type = AVMEDIA_TYPE_VIDEO,
268 .p.id = AV_CODEC_ID_TIERTEXSEQVIDEO,
269 .priv_data_size = sizeof(SeqVideoContext),
270 .init = seqvideo_decode_init,
271 .close = seqvideo_decode_end,
272 FF_CODEC_DECODE_CB(seqvideo_decode_frame),
273 .p.capabilities = AV_CODEC_CAP_DR1,
274 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
275 };
276