d95226678b1e767a79f4e501c95fe756426681b6
[libav.git] / libavcodec / tiertexseqv.c
1 /*
2 * Tiertex Limited SEQ Video Decoder
3 * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 "bitstream.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 BitstreamContext bc;
45 int code_table[64];
46
47 /* get the rle codes */
48 bitstream_init(&bc, src, (src_end - src) * 8);
49 for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
50 if (bitstream_bits_left(&bc) < 4)
51 return NULL;
52 code_table[i] = bitstream_read_signed(&bc, 4);
53 sz += FFABS(code_table[i]);
54 }
55 src += (bitstream_tell(&bc) + 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 BitstreamContext bc;
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 bitstream_init(&bc, src, bits * 8 * 8);
117 src += bits * 8;
118 for (b = 0; b < 8; b++) {
119 for (i = 0; i < 8; i++)
120 dst[i] = color_table[bitstream_read(&bc, bits)];
121 dst += seq->frame->linesize[0];
122 }
123 }
124
125 return src;
126 }
127
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
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
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 BitstreamContext bc;
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] = 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 bitstream_init(&bc, data, 128 * 8);
192 data += 128;
193 for (y = 0; y < 128; y += 8)
194 for (x = 0; x < 256; x += 8) {
195 dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
196 op = bitstream_read(&bc, 2);
197 switch (op) {
198 case 1:
199 data = seq_decode_op1(seq, data, data_end, dst);
200 break;
201 case 2:
202 data = seq_decode_op2(seq, data, data_end, dst);
203 break;
204 case 3:
205 data = seq_decode_op3(seq, data, data_end, dst);
206 break;
207 }
208 if (!data)
209 return AVERROR_INVALIDDATA;
210 }
211 }
212 return 0;
213 }
214
215 static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
216 {
217 SeqVideoContext *seq = avctx->priv_data;
218
219 seq->avctx = avctx;
220 avctx->pix_fmt = AV_PIX_FMT_PAL8;
221
222 seq->frame = av_frame_alloc();
223 if (!seq->frame)
224 return AVERROR(ENOMEM);
225
226 return 0;
227 }
228
229 static int seqvideo_decode_frame(AVCodecContext *avctx,
230 void *data, int *got_frame,
231 AVPacket *avpkt)
232 {
233 const uint8_t *buf = avpkt->data;
234 int buf_size = avpkt->size;
235 int ret;
236
237 SeqVideoContext *seq = avctx->priv_data;
238
239 if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) {
240 av_log(seq->avctx, AV_LOG_ERROR, "tiertexseqvideo: reget_buffer() failed\n");
241 return ret;
242 }
243
244 if (seqvideo_decode(seq, buf, buf_size))
245 return AVERROR_INVALIDDATA;
246
247 if ((ret = av_frame_ref(data, seq->frame)) < 0)
248 return ret;
249 *got_frame = 1;
250
251 return buf_size;
252 }
253
254 static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
255 {
256 SeqVideoContext *seq = avctx->priv_data;
257
258 av_frame_free(&seq->frame);
259
260 return 0;
261 }
262
263 AVCodec ff_tiertexseqvideo_decoder = {
264 .name = "tiertexseqvideo",
265 .long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
266 .type = AVMEDIA_TYPE_VIDEO,
267 .id = AV_CODEC_ID_TIERTEXSEQVIDEO,
268 .priv_data_size = sizeof(SeqVideoContext),
269 .init = seqvideo_decode_init,
270 .close = seqvideo_decode_end,
271 .decode = seqvideo_decode_frame,
272 .capabilities = AV_CODEC_CAP_DR1,
273 };