yading@10: /*
yading@10:  * Beam Software VB decoder
yading@10:  * Copyright (c) 2007 Konstantin Shishkov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * VB Video decoder
yading@10:  */
yading@10: 
yading@10: #include <stdio.h>
yading@10: #include <stdlib.h>
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: enum VBFlags {
yading@10:     VB_HAS_GMC     = 0x01,
yading@10:     VB_HAS_AUDIO   = 0x04,
yading@10:     VB_HAS_VIDEO   = 0x08,
yading@10:     VB_HAS_PALETTE = 0x10,
yading@10:     VB_HAS_LENGTH  = 0x20
yading@10: };
yading@10: 
yading@10: typedef struct VBDecContext {
yading@10:     AVCodecContext *avctx;
yading@10: 
yading@10:     uint8_t *frame, *prev_frame;
yading@10:     uint32_t pal[AVPALETTE_COUNT];
yading@10:     GetByteContext stream;
yading@10: } VBDecContext;
yading@10: 
yading@10: static const uint16_t vb_patterns[64] = {
yading@10:     0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
yading@10:     0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
yading@10:     0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
yading@10:     0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
yading@10:     0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
yading@10:     0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
yading@10:     0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
yading@10:     0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
yading@10: };
yading@10: 
yading@10: static void vb_decode_palette(VBDecContext *c, int data_size)
yading@10: {
yading@10:     int start, size, i;
yading@10: 
yading@10:     start = bytestream2_get_byte(&c->stream);
yading@10:     size  = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
yading@10:     if (start + size > 255) {
yading@10:         av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
yading@10:         return;
yading@10:     }
yading@10:     if (size*3+2 > data_size) {
yading@10:         av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
yading@10:         return;
yading@10:     }
yading@10:     for (i = start; i <= start + size; i++)
yading@10:         c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&c->stream);
yading@10: }
yading@10: 
yading@10: static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
yading@10: {
yading@10:     return buf >= start && buf < end;
yading@10: }
yading@10: 
yading@10: static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
yading@10: {
yading@10:     return buf >= start && (buf + 4) <= end;
yading@10: }
yading@10: 
yading@10: static int vb_decode_framedata(VBDecContext *c, int offset)
yading@10: {
yading@10:     GetByteContext g;
yading@10:     uint8_t *prev, *cur;
yading@10:     int blk, blocks, t, blk2;
yading@10:     int blocktypes = 0;
yading@10:     int x, y, a, b;
yading@10:     int pattype, pattern;
yading@10:     const int width = c->avctx->width;
yading@10:     uint8_t *pstart = c->prev_frame;
yading@10:     uint8_t *pend   = c->prev_frame + width*c->avctx->height;
yading@10: 
yading@10:     g = c->stream;
yading@10: 
yading@10:     prev = c->prev_frame + offset;
yading@10:     cur  = c->frame;
yading@10: 
yading@10:     blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
yading@10:     blk2   = 0;
yading@10:     for (blk = 0; blk < blocks; blk++) {
yading@10:         if (!(blk & 3)) {
yading@10:             blocktypes = bytestream2_get_byte(&g);
yading@10:         }
yading@10:         switch (blocktypes & 0xC0) {
yading@10:         case 0x00: //skip
yading@10:             for (y = 0; y < 4; y++)
yading@10:                 if (check_line(prev + y*width, pstart, pend))
yading@10:                     memcpy(cur + y*width, prev + y*width, 4);
yading@10:                 else
yading@10:                     memset(cur + y*width, 0, 4);
yading@10:             break;
yading@10:         case 0x40:
yading@10:             t = bytestream2_get_byte(&g);
yading@10:             if (!t) { //raw block
yading@10:                 if (bytestream2_get_bytes_left(&g) < 16) {
yading@10:                     av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
yading@10:                     return AVERROR_INVALIDDATA;
yading@10:                 }
yading@10:                 for (y = 0; y < 4; y++)
yading@10:                     bytestream2_get_buffer(&g, cur + y * width, 4);
yading@10:             } else { // motion compensation
yading@10:                 x = ((t & 0xF)^8) - 8;
yading@10:                 y = ((t >> 4) ^8) - 8;
yading@10:                 t = x + y*width;
yading@10:                 for (y = 0; y < 4; y++)
yading@10:                     if (check_line(prev + t + y*width, pstart, pend))
yading@10:                         memcpy(cur + y*width, prev + t + y*width, 4);
yading@10:                     else
yading@10:                         memset(cur + y*width, 0, 4);
yading@10:             }
yading@10:             break;
yading@10:         case 0x80: // fill
yading@10:             t = bytestream2_get_byte(&g);
yading@10:             for (y = 0; y < 4; y++)
yading@10:                 memset(cur + y*width, t, 4);
yading@10:             break;
yading@10:         case 0xC0: // pattern fill
yading@10:             t       = bytestream2_get_byte(&g);
yading@10:             pattype = t >> 6;
yading@10:             pattern = vb_patterns[t & 0x3F];
yading@10:             switch (pattype) {
yading@10:             case 0:
yading@10:                 a = bytestream2_get_byte(&g);
yading@10:                 b = bytestream2_get_byte(&g);
yading@10:                 for (y = 0; y < 4; y++)
yading@10:                     for (x = 0; x < 4; x++, pattern >>= 1)
yading@10:                         cur[x + y*width] = (pattern & 1) ? b : a;
yading@10:                 break;
yading@10:             case 1:
yading@10:                 pattern = ~pattern;
yading@10:             case 2:
yading@10:                 a = bytestream2_get_byte(&g);
yading@10:                 for (y = 0; y < 4; y++)
yading@10:                     for (x = 0; x < 4; x++, pattern >>= 1)
yading@10:                         if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
yading@10:                             cur[x + y*width] = prev[x + y*width];
yading@10:                         else
yading@10:                             cur[x + y*width] = a;
yading@10:                 break;
yading@10:             case 3:
yading@10:                 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             }
yading@10:             break;
yading@10:         }
yading@10:         blocktypes <<= 2;
yading@10:         cur  += 4;
yading@10:         prev += 4;
yading@10:         blk2++;
yading@10:         if (blk2 == (width >> 2)) {
yading@10:             blk2  = 0;
yading@10:             cur  += width * 3;
yading@10:             prev += width * 3;
yading@10:         }
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
yading@10:                         AVPacket *avpkt)
yading@10: {
yading@10:     VBDecContext * const c = avctx->priv_data;
yading@10:     AVFrame *frame         = data;
yading@10:     uint8_t *outptr, *srcptr;
yading@10:     int i, j, ret;
yading@10:     int flags;
yading@10:     uint32_t size;
yading@10:     int offset = 0;
yading@10: 
yading@10:     bytestream2_init(&c->stream, avpkt->data, avpkt->size);
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     flags = bytestream2_get_le16(&c->stream);
yading@10: 
yading@10:     if (flags & VB_HAS_GMC) {
yading@10:         i = (int16_t)bytestream2_get_le16(&c->stream);
yading@10:         j = (int16_t)bytestream2_get_le16(&c->stream);
yading@10:         offset = i + j * avctx->width;
yading@10:     }
yading@10:     if (flags & VB_HAS_VIDEO) {
yading@10:         size = bytestream2_get_le32(&c->stream);
yading@10:         if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){
yading@10:             av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n");
yading@10:             return -1;
yading@10:         }
yading@10:         vb_decode_framedata(c, offset);
yading@10:         bytestream2_skip(&c->stream, size - 4);
yading@10:     }
yading@10:     if (flags & VB_HAS_PALETTE) {
yading@10:         size = bytestream2_get_le32(&c->stream);
yading@10:         vb_decode_palette(c, size);
yading@10:     }
yading@10: 
yading@10:     memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
yading@10:     frame->palette_has_changed = flags & VB_HAS_PALETTE;
yading@10: 
yading@10:     outptr = frame->data[0];
yading@10:     srcptr = c->frame;
yading@10: 
yading@10:     for (i = 0; i < avctx->height; i++) {
yading@10:         memcpy(outptr, srcptr, avctx->width);
yading@10:         srcptr += avctx->width;
yading@10:         outptr += frame->linesize[0];
yading@10:     }
yading@10: 
yading@10:     FFSWAP(uint8_t*, c->frame, c->prev_frame);
yading@10: 
yading@10:     *got_frame = 1;
yading@10: 
yading@10:     /* always report that the buffer was completely consumed */
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     VBDecContext * const c = avctx->priv_data;
yading@10: 
yading@10:     c->avctx       = avctx;
yading@10:     avctx->pix_fmt = AV_PIX_FMT_PAL8;
yading@10: 
yading@10:     c->frame      = av_mallocz(avctx->width * avctx->height);
yading@10:     c->prev_frame = av_mallocz(avctx->width * avctx->height);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext *avctx)
yading@10: {
yading@10:     VBDecContext *c = avctx->priv_data;
yading@10: 
yading@10:     av_freep(&c->frame);
yading@10:     av_freep(&c->prev_frame);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_vb_decoder = {
yading@10:     .name           = "vb",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_VB,
yading@10:     .priv_data_size = sizeof(VBDecContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Beam Software VB"),
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10: };