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;
45 uint8_t *frame, *prev_frame;
46 uint32_t pal[AVPALETTE_COUNT];
47 GetByteContext 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 = 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");
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] = bytestream2_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, int offset)
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;
103 prev = c->prev_frame + offset;
106 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
108 for (blk = 0; blk < blocks; blk++) {
110 blocktypes = bytestream2_get_byte(&g);
112 switch (blocktypes & 0xC0) {
114 for (y = 0; y < 4; y++)
115 if (check_line(prev + y*width, pstart, pend))
116 memcpy(cur + y*width, prev + y*width, 4);
118 memset(cur + y*width, 0, 4);
121 t = bytestream2_get_byte(&g);
122 if (!t) { //raw block
123 if (bytestream2_get_bytes_left(&g) < 16) {
124 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
125 return AVERROR_INVALIDDATA;
127 for (y = 0; y < 4; y++)
128 bytestream2_get_buffer(&g, cur + y * width, 4);
129 } else { // motion compensation
130 x = ((t & 0xF)^8) - 8;
131 y = ((t >> 4) ^8) - 8;
133 for (y = 0; y < 4; y++)
134 if (check_line(prev + t + y*width, pstart, pend))
135 memcpy(cur + y*width, prev + t + y*width, 4);
137 memset(cur + y*width, 0, 4);
141 t = bytestream2_get_byte(&g);
142 for (y = 0; y < 4; y++)
143 memset(cur + y*width, t, 4);
145 case 0xC0: // pattern fill
146 t = bytestream2_get_byte(&g);
148 pattern = vb_patterns[t & 0x3F];
151 a = bytestream2_get_byte(&g);
152 b = bytestream2_get_byte(&g);
153 for (y = 0; y < 4; y++)
154 for (x = 0; x < 4; x++, pattern >>= 1)
155 cur[x + y*width] = (pattern & 1) ? b : a;
160 a = bytestream2_get_byte(&g);
161 for (y = 0; y < 4; y++)
162 for (x = 0; x < 4; x++, pattern >>= 1)
163 if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
164 cur[x + y*width] = prev[x + y*width];
166 cur[x + y*width] = a;
169 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
170 return AVERROR_INVALIDDATA;
178 if (blk2 == (width >> 2)) {
187 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
190 VBDecContext * const c = avctx->priv_data;
191 AVFrame *frame = data;
192 uint8_t *outptr, *srcptr;
198 bytestream2_init(&c->stream, avpkt->data, avpkt->size);
200 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
201 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
205 flags = bytestream2_get_le16(&c->stream);
207 if (flags & VB_HAS_GMC) {
208 i = (int16_t)bytestream2_get_le16(&c->stream);
209 j = (int16_t)bytestream2_get_le16(&c->stream);
210 offset = i + j * avctx->width;
212 if (flags & VB_HAS_VIDEO) {
213 size = bytestream2_get_le32(&c->stream);
214 vb_decode_framedata(c, offset);
215 bytestream2_skip(&c->stream, size - 4);
217 if (flags & VB_HAS_PALETTE) {
218 size = bytestream2_get_le32(&c->stream);
219 vb_decode_palette(c, size);
222 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
223 frame->palette_has_changed = flags & VB_HAS_PALETTE;
225 outptr = frame->data[0];
228 for (i = 0; i < avctx->height; i++) {
229 memcpy(outptr, srcptr, avctx->width);
230 srcptr += avctx->width;
231 outptr += frame->linesize[0];
234 FFSWAP(uint8_t*, c->frame, c->prev_frame);
238 /* always report that the buffer was completely consumed */
242 static av_cold int decode_init(AVCodecContext *avctx)
244 VBDecContext * const c = avctx->priv_data;
247 avctx->pix_fmt = AV_PIX_FMT_PAL8;
249 c->frame = av_mallocz(avctx->width * avctx->height);
250 c->prev_frame = av_mallocz(avctx->width * avctx->height);
255 static av_cold int decode_end(AVCodecContext *avctx)
257 VBDecContext *c = avctx->priv_data;
260 av_freep(&c->prev_frame);
265 AVCodec ff_vb_decoder = {
267 .type = AVMEDIA_TYPE_VIDEO,
268 .id = AV_CODEC_ID_VB,
269 .priv_data_size = sizeof(VBDecContext),
272 .decode = decode_frame,
273 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
274 .capabilities = CODEC_CAP_DR1,