/* * Beam Software VB decoder * Copyright (c) 2007 Konstantin Shishkov * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * VB Video decoder */ #include <stdio.h> #include <stdlib.h> #include "avcodec.h" #include "bytestream.h" enum VBFlags{ VB_HAS_GMC = 0x01, VB_HAS_AUDIO = 0x04, VB_HAS_VIDEO = 0x08, VB_HAS_PALETTE = 0x10, VB_HAS_LENGTH = 0x20 }; typedef struct VBDecContext { AVCodecContext *avctx; AVFrame pic; uint8_t *frame, *prev_frame; uint32_t pal[AVPALETTE_COUNT]; const uint8_t *stream; } VBDecContext; static const uint16_t vb_patterns[64] = { 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8, 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00, 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222, 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC, 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113, 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC, 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63, 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C }; static void vb_decode_palette(VBDecContext *c, int data_size) { int start, size, i; start = bytestream_get_byte(&c->stream); size = (bytestream_get_byte(&c->stream) - 1) & 0xFF; if(start + size > 255){ av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n"); return; } if(size*3+2 > data_size){ av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n"); return; } for(i = start; i <= start + size; i++) c->pal[i] = bytestream_get_be24(&c->stream); } static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end) { return buf >= start && buf < end; } static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end) { return buf >= start && (buf + 4) <= end; } static int vb_decode_framedata(VBDecContext *c, const uint8_t *buf, int data_size, int offset) { uint8_t *prev, *cur; const uint8_t* data_end = buf + data_size; int blk, blocks, t, blk2; int blocktypes = 0; int x, y, a, b; int pattype, pattern; const int width = c->avctx->width; uint8_t *pstart = c->prev_frame; uint8_t *pend = c->prev_frame + width*c->avctx->height; prev = c->prev_frame + offset; cur = c->frame; blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2); blk2 = 0; for(blk = 0; blk < blocks; blk++){ if(!(blk & 3)) { if(buf >= data_end){ av_log(c->avctx, AV_LOG_ERROR, "Data pointer out of bounds\n"); return -1; } blocktypes = bytestream_get_byte(&buf); } switch(blocktypes & 0xC0){ case 0x00: //skip for(y = 0; y < 4; y++) if(check_line(prev + y*width, pstart, pend)) memcpy(cur + y*width, prev + y*width, 4); else memset(cur + y*width, 0, 4); break; case 0x40: t = bytestream_get_byte(&buf); if(!t){ //raw block if(buf + 16 > data_end){ av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n"); return -1; } for(y = 0; y < 4; y++) memcpy(cur + y*width, buf + y*4, 4); buf += 16; }else{ // motion compensation x = ((t & 0xF)^8) - 8; y = ((t >> 4) ^8) - 8; t = x + y*width; for(y = 0; y < 4; y++) if(check_line(prev + t + y*width, pstart, pend)) memcpy(cur + y*width, prev + t + y*width, 4); else memset(cur + y*width, 0, 4); } break; case 0x80: // fill t = bytestream_get_byte(&buf); for(y = 0; y < 4; y++) memset(cur + y*width, t, 4); break; case 0xC0: // pattern fill if(buf + 2 > data_end){ av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n"); return -1; } t = bytestream_get_byte(&buf); pattype = t >> 6; pattern = vb_patterns[t & 0x3F]; switch(pattype){ case 0: a = bytestream_get_byte(&buf); b = bytestream_get_byte(&buf); for(y = 0; y < 4; y++) for(x = 0; x < 4; x++, pattern >>= 1) cur[x + y*width] = (pattern & 1) ? b : a; break; case 1: pattern = ~pattern; case 2: a = bytestream_get_byte(&buf); for(y = 0; y < 4; y++) for(x = 0; x < 4; x++, pattern >>= 1) if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend)) cur[x + y*width] = prev[x + y*width]; else cur[x + y*width] = a; break; case 3: av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk); return -1; } break; } blocktypes <<= 2; cur += 4; prev += 4; blk2++; if(blk2 == (width >> 2)){ blk2 = 0; cur += width * 3; prev += width * 3; } } return 0; } static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; VBDecContext * const c = avctx->priv_data; uint8_t *outptr, *srcptr; int i, j; int flags; uint32_t size; int rest = buf_size; int offset = 0; if(c->pic.data[0]) avctx->release_buffer(avctx, &c->pic); c->pic.reference = 1; if(avctx->get_buffer(avctx, &c->pic) < 0){ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } c->stream = buf; flags = bytestream_get_le16(&c->stream); rest -= 2; if(flags & VB_HAS_GMC){ i = (int16_t)bytestream_get_le16(&c->stream); j = (int16_t)bytestream_get_le16(&c->stream); offset = i + j * avctx->width; rest -= 4; } if(flags & VB_HAS_VIDEO){ size = bytestream_get_le32(&c->stream); if(size > rest){ av_log(avctx, AV_LOG_ERROR, "Frame size is too big\n"); return -1; } vb_decode_framedata(c, c->stream, size, offset); c->stream += size - 4; rest -= size; } if(flags & VB_HAS_PALETTE){ size = bytestream_get_le32(&c->stream); if(size > rest){ av_log(avctx, AV_LOG_ERROR, "Palette size is too big\n"); return -1; } vb_decode_palette(c, size); rest -= size; } memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE); c->pic.palette_has_changed = flags & VB_HAS_PALETTE; outptr = c->pic.data[0]; srcptr = c->frame; for(i = 0; i < avctx->height; i++){ memcpy(outptr, srcptr, avctx->width); srcptr += avctx->width; outptr += c->pic.linesize[0]; } FFSWAP(uint8_t*, c->frame, c->prev_frame); *data_size = sizeof(AVFrame); *(AVFrame*)data = c->pic; /* always report that the buffer was completely consumed */ return buf_size; } static av_cold int decode_init(AVCodecContext *avctx) { VBDecContext * const c = avctx->priv_data; c->avctx = avctx; avctx->pix_fmt = PIX_FMT_PAL8; c->frame = av_mallocz(avctx->width * avctx->height); c->prev_frame = av_mallocz(avctx->width * avctx->height); return 0; } static av_cold int decode_end(AVCodecContext *avctx) { VBDecContext *c = avctx->priv_data; av_freep(&c->frame); av_freep(&c->prev_frame); if(c->pic.data[0]) avctx->release_buffer(avctx, &c->pic); return 0; } AVCodec ff_vb_decoder = { .name = "vb", .type = AVMEDIA_TYPE_VIDEO, .id = CODEC_ID_VB, .priv_data_size = sizeof(VBDecContext), .init = decode_init, .close = decode_end, .decode = decode_frame, .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"), };