2 * Beam Software VB decoder
3 * Copyright (c) 2007 Konstantin Shishkov
5 * This file is part of Libav.
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.
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.
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
31 #include "bytestream.h"
38 VB_HAS_PALETTE = 0x10,
42 typedef struct VBDecContext {
43 AVCodecContext *avctx;
46 uint8_t *frame, *prev_frame;
47 uint32_t pal[AVPALETTE_COUNT];
48 GetByteContext stream;
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
62 static void vb_decode_palette(VBDecContext *c, int data_size)
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");
72 if(size*3+2 > data_size){
73 av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
76 for(i = start; i <= start + size; i++)
77 c->pal[i] = bytestream2_get_be24(&c->stream);
80 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
82 return buf >= start && buf < end;
85 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
87 return buf >= start && (buf + 4) <= end;
90 static int vb_decode_framedata(VBDecContext *c, int offset)
94 int blk, blocks, t, blk2;
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;
104 prev = c->prev_frame + offset;
107 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
109 for(blk = 0; blk < blocks; blk++){
111 blocktypes = bytestream2_get_byte(&g);
113 switch(blocktypes & 0xC0){
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);
119 memset(cur + y*width, 0, 4);
122 t = bytestream2_get_byte(&g);
124 if (bytestream2_get_bytes_left(&g) < 16) {
125 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
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;
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);
138 memset(cur + y*width, 0, 4);
142 t = bytestream2_get_byte(&g);
143 for(y = 0; y < 4; y++)
144 memset(cur + y*width, t, 4);
146 case 0xC0: // pattern fill
147 t = bytestream2_get_byte(&g);
149 pattern = vb_patterns[t & 0x3F];
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;
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];
167 cur[x + y*width] = a;
170 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
179 if(blk2 == (width >> 2)){
188 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
191 VBDecContext * const c = avctx->priv_data;
192 uint8_t *outptr, *srcptr;
198 bytestream2_init(&c->stream, avpkt->data, avpkt->size);
201 avctx->release_buffer(avctx, &c->pic);
202 c->pic.reference = 1;
203 if(ff_get_buffer(avctx, &c->pic) < 0){
204 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
208 flags = bytestream2_get_le16(&c->stream);
210 if(flags & VB_HAS_GMC){
211 i = (int16_t)bytestream2_get_le16(&c->stream);
212 j = (int16_t)bytestream2_get_le16(&c->stream);
213 offset = i + j * avctx->width;
215 if(flags & VB_HAS_VIDEO){
216 size = bytestream2_get_le32(&c->stream);
217 vb_decode_framedata(c, offset);
218 bytestream2_skip(&c->stream, size - 4);
220 if(flags & VB_HAS_PALETTE){
221 size = bytestream2_get_le32(&c->stream);
222 vb_decode_palette(c, size);
225 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
226 c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
228 outptr = c->pic.data[0];
231 for(i = 0; i < avctx->height; i++){
232 memcpy(outptr, srcptr, avctx->width);
233 srcptr += avctx->width;
234 outptr += c->pic.linesize[0];
237 FFSWAP(uint8_t*, c->frame, c->prev_frame);
240 *(AVFrame*)data = c->pic;
242 /* always report that the buffer was completely consumed */
246 static av_cold int decode_init(AVCodecContext *avctx)
248 VBDecContext * const c = avctx->priv_data;
251 avctx->pix_fmt = AV_PIX_FMT_PAL8;
253 c->frame = av_mallocz(avctx->width * avctx->height);
254 c->prev_frame = av_mallocz(avctx->width * avctx->height);
259 static av_cold int decode_end(AVCodecContext *avctx)
261 VBDecContext *c = avctx->priv_data;
264 av_freep(&c->prev_frame);
266 avctx->release_buffer(avctx, &c->pic);
271 AVCodec ff_vb_decoder = {
273 .type = AVMEDIA_TYPE_VIDEO,
274 .id = AV_CODEC_ID_VB,
275 .priv_data_size = sizeof(VBDecContext),
278 .decode = decode_frame,
279 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
280 .capabilities = CODEC_CAP_DR1,