lavc: add a wrapper for AVCodecContext.get_buffer().
[libav.git] / libavcodec / vb.c
1 /*
2 * Beam Software VB decoder
3 * Copyright (c) 2007 Konstantin Shishkov
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 * 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 AVFrame pic;
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
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] = bytestream2_get_be24(&c->stream);
78 }
79
80 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
81 {
82 return buf >= start && buf < end;
83 }
84
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
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 blocktypes = bytestream2_get_byte(&g);
112 }
113 switch(blocktypes & 0xC0){
114 case 0x00: //skip
115 for(y = 0; y < 4; y++)
116 if(check_line(prev + y*width, pstart, pend))
117 memcpy(cur + y*width, prev + y*width, 4);
118 else
119 memset(cur + y*width, 0, 4);
120 break;
121 case 0x40:
122 t = bytestream2_get_byte(&g);
123 if(!t){ //raw block
124 if (bytestream2_get_bytes_left(&g) < 16) {
125 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
126 return -1;
127 }
128 for(y = 0; y < 4; y++)
129 bytestream2_get_buffer(&g, cur + y * width, 4);
130 }else{ // motion compensation
131 x = ((t & 0xF)^8) - 8;
132 y = ((t >> 4) ^8) - 8;
133 t = x + y*width;
134 for(y = 0; y < 4; y++)
135 if(check_line(prev + t + y*width, pstart, pend))
136 memcpy(cur + y*width, prev + t + y*width, 4);
137 else
138 memset(cur + y*width, 0, 4);
139 }
140 break;
141 case 0x80: // fill
142 t = bytestream2_get_byte(&g);
143 for(y = 0; y < 4; y++)
144 memset(cur + y*width, t, 4);
145 break;
146 case 0xC0: // pattern fill
147 t = bytestream2_get_byte(&g);
148 pattype = t >> 6;
149 pattern = vb_patterns[t & 0x3F];
150 switch(pattype){
151 case 0:
152 a = bytestream2_get_byte(&g);
153 b = bytestream2_get_byte(&g);
154 for(y = 0; y < 4; y++)
155 for(x = 0; x < 4; x++, pattern >>= 1)
156 cur[x + y*width] = (pattern & 1) ? b : a;
157 break;
158 case 1:
159 pattern = ~pattern;
160 case 2:
161 a = bytestream2_get_byte(&g);
162 for(y = 0; y < 4; y++)
163 for(x = 0; x < 4; x++, pattern >>= 1)
164 if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
165 cur[x + y*width] = prev[x + y*width];
166 else
167 cur[x + y*width] = a;
168 break;
169 case 3:
170 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
171 return -1;
172 }
173 break;
174 }
175 blocktypes <<= 2;
176 cur += 4;
177 prev += 4;
178 blk2++;
179 if(blk2 == (width >> 2)){
180 blk2 = 0;
181 cur += width * 3;
182 prev += width * 3;
183 }
184 }
185 return 0;
186 }
187
188 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
189 {
190 VBDecContext * const c = avctx->priv_data;
191 uint8_t *outptr, *srcptr;
192 int i, j;
193 int flags;
194 uint32_t size;
195 int offset = 0;
196
197 bytestream2_init(&c->stream, avpkt->data, avpkt->size);
198
199 if(c->pic.data[0])
200 avctx->release_buffer(avctx, &c->pic);
201 c->pic.reference = 1;
202 if(ff_get_buffer(avctx, &c->pic) < 0){
203 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
204 return -1;
205 }
206
207 flags = bytestream2_get_le16(&c->stream);
208
209 if(flags & VB_HAS_GMC){
210 i = (int16_t)bytestream2_get_le16(&c->stream);
211 j = (int16_t)bytestream2_get_le16(&c->stream);
212 offset = i + j * avctx->width;
213 }
214 if(flags & VB_HAS_VIDEO){
215 size = bytestream2_get_le32(&c->stream);
216 vb_decode_framedata(c, offset);
217 bytestream2_skip(&c->stream, size - 4);
218 }
219 if(flags & VB_HAS_PALETTE){
220 size = bytestream2_get_le32(&c->stream);
221 vb_decode_palette(c, size);
222 }
223
224 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
225 c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
226
227 outptr = c->pic.data[0];
228 srcptr = c->frame;
229
230 for(i = 0; i < avctx->height; i++){
231 memcpy(outptr, srcptr, avctx->width);
232 srcptr += avctx->width;
233 outptr += c->pic.linesize[0];
234 }
235
236 FFSWAP(uint8_t*, c->frame, c->prev_frame);
237
238 *data_size = sizeof(AVFrame);
239 *(AVFrame*)data = c->pic;
240
241 /* always report that the buffer was completely consumed */
242 return avpkt->size;
243 }
244
245 static av_cold int decode_init(AVCodecContext *avctx)
246 {
247 VBDecContext * const c = avctx->priv_data;
248
249 c->avctx = avctx;
250 avctx->pix_fmt = AV_PIX_FMT_PAL8;
251
252 c->frame = av_mallocz(avctx->width * avctx->height);
253 c->prev_frame = av_mallocz(avctx->width * avctx->height);
254
255 return 0;
256 }
257
258 static av_cold int decode_end(AVCodecContext *avctx)
259 {
260 VBDecContext *c = avctx->priv_data;
261
262 av_freep(&c->frame);
263 av_freep(&c->prev_frame);
264 if(c->pic.data[0])
265 avctx->release_buffer(avctx, &c->pic);
266
267 return 0;
268 }
269
270 AVCodec ff_vb_decoder = {
271 .name = "vb",
272 .type = AVMEDIA_TYPE_VIDEO,
273 .id = AV_CODEC_ID_VB,
274 .priv_data_size = sizeof(VBDecContext),
275 .init = decode_init,
276 .close = decode_end,
277 .decode = decode_frame,
278 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
279 .capabilities = CODEC_CAP_DR1,
280 };