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 "codec_internal.h"
33 #include "internal.h"
34
35 enum VBFlags {
36 VB_HAS_GMC = 0x01,
37 VB_HAS_AUDIO = 0x04,
38 VB_HAS_VIDEO = 0x08,
39 VB_HAS_PALETTE = 0x10,
40 VB_HAS_LENGTH = 0x20
41 };
42
43 typedef struct VBDecContext {
44 AVCodecContext *avctx;
45
46 uint8_t *frame, *prev_frame;
47 uint32_t pal[AVPALETTE_COUNT];
48 GetByteContext stream;
49 } VBDecContext;
50
51 static const uint16_t vb_patterns[64] = {
52 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
53 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
54 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
55 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
56 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
57 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
58 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
59 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
60 };
61
vb_decode_palette(VBDecContext *c, int data_size)62 static void vb_decode_palette(VBDecContext *c, int data_size)
63 {
64 int start, size, i;
65
66 start = bytestream2_get_byte(&c->stream);
67 size = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
68 if (start + size > 255) {
69 av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
70 return;
71 }
72 if (size*3+2 > data_size) {
73 av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
74 return;
75 }
76 for (i = start; i <= start + size; i++)
77 c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
78 }
79
check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)80 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
81 {
82 return buf >= start && buf < end;
83 }
84
check_line(uint8_t *buf, uint8_t *start, uint8_t *end)85 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
86 {
87 return buf >= start && (buf + 4) <= end;
88 }
89
vb_decode_framedata(VBDecContext *c, int offset)90 static int vb_decode_framedata(VBDecContext *c, int offset)
91 {
92 GetByteContext g;
93 uint8_t *prev, *cur;
94 int blk, blocks, t, blk2;
95 int blocktypes = 0;
96 int x, y, a, b;
97 int pattype, pattern;
98 const int width = c->avctx->width;
99 uint8_t *pstart = c->prev_frame;
100 uint8_t *pend = c->prev_frame + width*c->avctx->height;
101
102 g = c->stream;
103
104 prev = c->prev_frame + offset;
105 cur = c->frame;
106
107 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
108 blk2 = 0;
109 for (blk = 0; blk < blocks; blk++) {
110 if (!(blk & 3)) {
111 if (bytestream2_get_bytes_left(&g) < 1) {
112 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
113 return AVERROR_INVALIDDATA;
114 }
115 blocktypes = bytestream2_get_byte(&g);
116 }
117 switch (blocktypes & 0xC0) {
118 case 0x00: //skip
119 for (y = 0; y < 4; y++)
120 if (check_line(prev + y*width, pstart, pend))
121 memcpy(cur + y*width, prev + y*width, 4);
122 else
123 memset(cur + y*width, 0, 4);
124 break;
125 case 0x40:
126 t = bytestream2_get_byte(&g);
127 if (!t) { //raw block
128 if (bytestream2_get_bytes_left(&g) < 16) {
129 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
130 return AVERROR_INVALIDDATA;
131 }
132 for (y = 0; y < 4; y++)
133 bytestream2_get_buffer(&g, cur + y * width, 4);
134 } else { // motion compensation
135 x = ((t & 0xF)^8) - 8;
136 y = ((t >> 4) ^8) - 8;
137 t = x + y*width;
138 for (y = 0; y < 4; y++)
139 if (check_line(prev + t + y*width, pstart, pend))
140 memcpy(cur + y*width, prev + t + y*width, 4);
141 else
142 memset(cur + y*width, 0, 4);
143 }
144 break;
145 case 0x80: // fill
146 t = bytestream2_get_byte(&g);
147 for (y = 0; y < 4; y++)
148 memset(cur + y*width, t, 4);
149 break;
150 case 0xC0: // pattern fill
151 t = bytestream2_get_byte(&g);
152 pattype = t >> 6;
153 pattern = vb_patterns[t & 0x3F];
154 switch (pattype) {
155 case 0:
156 a = bytestream2_get_byte(&g);
157 b = bytestream2_get_byte(&g);
158 for (y = 0; y < 4; y++)
159 for (x = 0; x < 4; x++, pattern >>= 1)
160 cur[x + y*width] = (pattern & 1) ? b : a;
161 break;
162 case 1:
163 pattern = ~pattern;
164 case 2:
165 a = bytestream2_get_byte(&g);
166 for (y = 0; y < 4; y++)
167 for (x = 0; x < 4; x++, pattern >>= 1)
168 if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
169 cur[x + y*width] = prev[x + y*width];
170 else
171 cur[x + y*width] = a;
172 break;
173 case 3:
174 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
175 return AVERROR_INVALIDDATA;
176 }
177 break;
178 }
179 blocktypes <<= 2;
180 cur += 4;
181 prev += 4;
182 blk2++;
183 if (blk2 == (width >> 2)) {
184 blk2 = 0;
185 cur += width * 3;
186 prev += width * 3;
187 }
188 }
189 return 0;
190 }
191
decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)192 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
193 int *got_frame, AVPacket *avpkt)
194 {
195 VBDecContext * const c = avctx->priv_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 const FFCodec ff_vb_decoder = {
282 .p.name = "vb",
283 .p.long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
284 .p.type = AVMEDIA_TYPE_VIDEO,
285 .p.id = AV_CODEC_ID_VB,
286 .priv_data_size = sizeof(VBDecContext),
287 .init = decode_init,
288 .close = decode_end,
289 FF_CODEC_DECODE_CB(decode_frame),
290 .p.capabilities = AV_CODEC_CAP_DR1,
291 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
292 };
293