2 * Beam Software VB decoder
3 * Copyright (c) 2007 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
31 #include "bytestream.h"
37 VB_HAS_PALETTE = 0x10,
41 typedef struct VBDecContext {
42 AVCodecContext *avctx;
45 uint8_t *frame, *prev_frame;
46 uint32_t pal[AVPALETTE_COUNT];
47 const uint8_t *stream;
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
61 static void vb_decode_palette(VBDecContext *c, int data_size)
65 start = bytestream_get_byte(&c->stream);
66 size = (bytestream_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");
71 if(size*3+2 > data_size){
72 av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
75 for(i = start; i <= start + size; i++)
76 c->pal[i] = bytestream_get_be24(&c->stream);
79 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
81 return buf >= start && buf < end;
84 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
86 return buf >= start && (buf + 4) <= end;
89 static int vb_decode_framedata(VBDecContext *c, const uint8_t *buf, int data_size, int offset)
92 const uint8_t* data_end = buf + data_size;
93 int blk, blocks, t, blk2;
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;
101 prev = c->prev_frame + offset;
104 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
106 for(blk = 0; blk < blocks; blk++){
109 av_log(c->avctx, AV_LOG_ERROR, "Data pointer out of bounds\n");
112 blocktypes = bytestream_get_byte(&buf);
114 switch(blocktypes & 0xC0){
116 for(y = 0; y < 4; y++)
117 if(check_line(prev + y*width, pstart, pend))
118 memcpy(cur + y*width, prev + y*width, 4);
120 memset(cur + y*width, 0, 4);
123 t = bytestream_get_byte(&buf);
125 if(buf + 16 > data_end){
126 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
129 for(y = 0; y < 4; y++)
130 memcpy(cur + y*width, buf + y*4, 4);
132 }else{ // motion compensation
133 x = ((t & 0xF)^8) - 8;
134 y = ((t >> 4) ^8) - 8;
136 for(y = 0; y < 4; y++)
137 if(check_line(prev + t + y*width, pstart, pend))
138 memcpy(cur + y*width, prev + t + y*width, 4);
140 memset(cur + y*width, 0, 4);
144 t = bytestream_get_byte(&buf);
145 for(y = 0; y < 4; y++)
146 memset(cur + y*width, t, 4);
148 case 0xC0: // pattern fill
149 if(buf + 2 > data_end){
150 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
153 t = bytestream_get_byte(&buf);
155 pattern = vb_patterns[t & 0x3F];
158 a = bytestream_get_byte(&buf);
159 b = bytestream_get_byte(&buf);
160 for(y = 0; y < 4; y++)
161 for(x = 0; x < 4; x++, pattern >>= 1)
162 cur[x + y*width] = (pattern & 1) ? b : a;
167 a = bytestream_get_byte(&buf);
168 for(y = 0; y < 4; y++)
169 for(x = 0; x < 4; x++, pattern >>= 1)
170 if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
171 cur[x + y*width] = prev[x + y*width];
173 cur[x + y*width] = a;
176 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
185 if(blk2 == (width >> 2)){
194 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
196 const uint8_t *buf = avpkt->data;
197 int buf_size = avpkt->size;
198 VBDecContext * const c = avctx->priv_data;
199 uint8_t *outptr, *srcptr;
207 avctx->release_buffer(avctx, &c->pic);
208 c->pic.reference = 1;
209 if(avctx->get_buffer(avctx, &c->pic) < 0){
210 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
215 flags = bytestream_get_le16(&c->stream);
218 if(flags & VB_HAS_GMC){
219 i = (int16_t)bytestream_get_le16(&c->stream);
220 j = (int16_t)bytestream_get_le16(&c->stream);
221 offset = i + j * avctx->width;
224 if(flags & VB_HAS_VIDEO){
225 size = bytestream_get_le32(&c->stream);
227 av_log(avctx, AV_LOG_ERROR, "Frame size is too big\n");
230 vb_decode_framedata(c, c->stream, size, offset);
231 c->stream += size - 4;
234 if(flags & VB_HAS_PALETTE){
235 size = bytestream_get_le32(&c->stream);
237 av_log(avctx, AV_LOG_ERROR, "Palette size is too big\n");
240 vb_decode_palette(c, size);
244 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
245 c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
247 outptr = c->pic.data[0];
250 for(i = 0; i < avctx->height; i++){
251 memcpy(outptr, srcptr, avctx->width);
252 srcptr += avctx->width;
253 outptr += c->pic.linesize[0];
256 FFSWAP(uint8_t*, c->frame, c->prev_frame);
258 *data_size = sizeof(AVFrame);
259 *(AVFrame*)data = c->pic;
261 /* always report that the buffer was completely consumed */
265 static av_cold int decode_init(AVCodecContext *avctx)
267 VBDecContext * const c = avctx->priv_data;
270 avctx->pix_fmt = PIX_FMT_PAL8;
271 avcodec_get_frame_defaults(&c->pic);
273 c->frame = av_mallocz(avctx->width * avctx->height);
274 c->prev_frame = av_mallocz(avctx->width * avctx->height);
279 static av_cold int decode_end(AVCodecContext *avctx)
281 VBDecContext *c = avctx->priv_data;
284 av_freep(&c->prev_frame);
286 avctx->release_buffer(avctx, &c->pic);
291 AVCodec ff_vb_decoder = {
293 .type = AVMEDIA_TYPE_VIDEO,
295 .priv_data_size = sizeof(VBDecContext),
298 .decode = decode_frame,
299 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),