1 /*
2 * Beam Software VB decoder
3 * Copyright (c) 2007 Konstantin Shishkov
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 * VB Video decoder
25 */
26
27 #include <stdio.h>
28 #include <stdlib.h>
29
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33
34 enum VBFlags {
35 VB_HAS_GMC = 0x01,
36 VB_HAS_AUDIO = 0x04,
37 VB_HAS_VIDEO = 0x08,
38 VB_HAS_PALETTE = 0x10,
39 VB_HAS_LENGTH = 0x20
40 };
41
42 typedef struct VBDecContext {
43 AVCodecContext *avctx;
44
45 uint8_t *frame, *prev_frame;
46 uint32_t pal[AVPALETTE_COUNT];
47 GetByteContext stream;
48 } VBDecContext;
49
50 static const uint16_t vb_patterns[64] = {
51 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
52 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
53 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
54 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
55 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
56 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
57 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
58 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
59 };
60
vb_decode_palette(VBDecContext * c,int data_size)61 static void vb_decode_palette(VBDecContext *c, int data_size)
62 {
63 int start, size, i;
64
65 start = bytestream2_get_byte(&c->stream);
66 size = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
67 if (start + size > 255) {
68 av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
69 return;
70 }
71 if (size*3+2 > data_size) {
72 av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
73 return;
74 }
75 for (i = start; i <= start + size; i++)
76 c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
77 }
78
check_pixel(uint8_t * buf,uint8_t * start,uint8_t * end)79 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
80 {
81 return buf >= start && buf < end;
82 }
83
check_line(uint8_t * buf,uint8_t * start,uint8_t * end)84 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
85 {
86 return buf >= start && (buf + 4) <= end;
87 }
88
vb_decode_framedata(VBDecContext * c,int offset)89 static int vb_decode_framedata(VBDecContext *c, int offset)
90 {
91 GetByteContext g;
92 uint8_t *prev, *cur;
93 int blk, blocks, t, blk2;
94 int blocktypes = 0;
95 int x, y, a, b;
96 int pattype, pattern;
97 const int width = c->avctx->width;
98 uint8_t *pstart = c->prev_frame;
99 uint8_t *pend = c->prev_frame + width*c->avctx->height;
100
101 g = c->stream;
102
103 prev = c->prev_frame + offset;
104 cur = c->frame;
105
106 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
107 blk2 = 0;
108 for (blk = 0; blk < blocks; blk++) {
109 if (!(blk & 3)) {
110 if (bytestream2_get_bytes_left(&g) < 1) {
111 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
112 return AVERROR_INVALIDDATA;
113 }
114 blocktypes = bytestream2_get_byte(&g);
115 }
116 switch (blocktypes & 0xC0) {
117 case 0x00: //skip
118 for (y = 0; y < 4; y++)
119 if (check_line(prev + y*width, pstart, pend))
120 memcpy(cur + y*width, prev + y*width, 4);
121 else
122 memset(cur + y*width, 0, 4);
123 break;
124 case 0x40:
125 t = bytestream2_get_byte(&g);
126 if (!t) { //raw block
127 if (bytestream2_get_bytes_left(&g) < 16) {
128 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
129 return AVERROR_INVALIDDATA;
130 }
131 for (y = 0; y < 4; y++)
132 bytestream2_get_buffer(&g, cur + y * width, 4);
133 } else { // motion compensation
134 x = ((t & 0xF)^8) - 8;
135 y = ((t >> 4) ^8) - 8;
136 t = x + y*width;
137 for (y = 0; y < 4; y++)
138 if (check_line(prev + t + y*width, pstart, pend))
139 memcpy(cur + y*width, prev + t + y*width, 4);
140 else
141 memset(cur + y*width, 0, 4);
142 }
143 break;
144 case 0x80: // fill
145 t = bytestream2_get_byte(&g);
146 for (y = 0; y < 4; y++)
147 memset(cur + y*width, t, 4);
148 break;
149 case 0xC0: // pattern fill
150 t = bytestream2_get_byte(&g);
151 pattype = t >> 6;
152 pattern = vb_patterns[t & 0x3F];
153 switch (pattype) {
154 case 0:
155 a = bytestream2_get_byte(&g);
156 b = bytestream2_get_byte(&g);
157 for (y = 0; y < 4; y++)
158 for (x = 0; x < 4; x++, pattern >>= 1)
159 cur[x + y*width] = (pattern & 1) ? b : a;
160 break;
161 case 1:
162 pattern = ~pattern;
163 case 2:
164 a = bytestream2_get_byte(&g);
165 for (y = 0; y < 4; y++)
166 for (x = 0; x < 4; x++, pattern >>= 1)
167 if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
168 cur[x + y*width] = prev[x + y*width];
169 else
170 cur[x + y*width] = a;
171 break;
172 case 3:
173 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
174 return AVERROR_INVALIDDATA;
175 }
176 break;
177 }
178 blocktypes <<= 2;
179 cur += 4;
180 prev += 4;
181 blk2++;
182 if (blk2 == (width >> 2)) {
183 blk2 = 0;
184 cur += width * 3;
185 prev += width * 3;
186 }
187 }
188 return 0;
189 }
190
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)191 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
192 AVPacket *avpkt)
193 {
194 VBDecContext * const c = avctx->priv_data;
195 AVFrame *frame = data;
196 uint8_t *outptr, *srcptr;
197 int i, j, ret;
198 int flags;
199 uint32_t size;
200 int offset = 0;
201
202 if (avpkt->size < 2)
203 return AVERROR_INVALIDDATA;
204
205 bytestream2_init(&c->stream, avpkt->data, avpkt->size);
206
207 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
208 return ret;
209
210 flags = bytestream2_get_le16(&c->stream);
211
212 if (flags & VB_HAS_GMC) {
213 i = (int16_t)bytestream2_get_le16(&c->stream);
214 j = (int16_t)bytestream2_get_le16(&c->stream);
215 if (FFABS(j) > avctx->height) {
216 av_log(avctx, AV_LOG_ERROR, "GMV out of range\n");
217 return AVERROR_INVALIDDATA;
218 }
219 offset = i + j * avctx->width;
220 }
221 if (flags & VB_HAS_VIDEO) {
222 size = bytestream2_get_le32(&c->stream);
223 if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
224 av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
225 return -1;
226 }
227 vb_decode_framedata(c, offset);
228 bytestream2_skip(&c->stream, size - 4);
229 }
230 if (flags & VB_HAS_PALETTE) {
231 size = bytestream2_get_le32(&c->stream);
232 vb_decode_palette(c, size);
233 }
234
235 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
236 frame->palette_has_changed = flags & VB_HAS_PALETTE;
237
238 outptr = frame->data[0];
239 srcptr = c->frame;
240
241 for (i = 0; i < avctx->height; i++) {
242 memcpy(outptr, srcptr, avctx->width);
243 srcptr += avctx->width;
244 outptr += frame->linesize[0];
245 }
246
247 FFSWAP(uint8_t*, c->frame, c->prev_frame);
248
249 *got_frame = 1;
250
251 /* always report that the buffer was completely consumed */
252 return avpkt->size;
253 }
254
decode_init(AVCodecContext * avctx)255 static av_cold int decode_init(AVCodecContext *avctx)
256 {
257 VBDecContext * const c = avctx->priv_data;
258
259 c->avctx = avctx;
260 avctx->pix_fmt = AV_PIX_FMT_PAL8;
261
262 c->frame = av_mallocz(avctx->width * avctx->height);
263 c->prev_frame = av_mallocz(avctx->width * avctx->height);
264
265 if (!c->frame || !c->prev_frame)
266 return AVERROR(ENOMEM);
267
268 return 0;
269 }
270
decode_end(AVCodecContext * avctx)271 static av_cold int decode_end(AVCodecContext *avctx)
272 {
273 VBDecContext *c = avctx->priv_data;
274
275 av_freep(&c->frame);
276 av_freep(&c->prev_frame);
277
278 return 0;
279 }
280
281 AVCodec ff_vb_decoder = {
282 .name = "vb",
283 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
284 .type = AVMEDIA_TYPE_VIDEO,
285 .id = AV_CODEC_ID_VB,
286 .priv_data_size = sizeof(VBDecContext),
287 .init = decode_init,
288 .close = decode_end,
289 .decode = decode_frame,
290 .capabilities = AV_CODEC_CAP_DR1,
291 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
292 };
293