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412 lines
13 KiB
C
412 lines
13 KiB
C
/*
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* KMVC decoder
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* Copyright (c) 2006 Konstantin Shishkov
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Karl Morton's Video Codec decoder
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "avcodec.h"
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#include "bytestream.h"
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#define KMVC_KEYFRAME 0x80
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#define KMVC_PALETTE 0x40
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#define KMVC_METHOD 0x0F
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/*
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* Decoder context
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*/
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typedef struct KmvcContext {
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AVCodecContext *avctx;
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AVFrame pic;
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int setpal;
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int palsize;
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uint32_t pal[256];
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uint8_t *cur, *prev;
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uint8_t *frm0, *frm1;
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} KmvcContext;
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typedef struct BitBuf {
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int bits;
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int bitbuf;
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} BitBuf;
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#define BLK(data, x, y) data[(x) + (y) * 320]
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#define kmvc_init_getbits(bb, src) bb.bits = 7; bb.bitbuf = *src++;
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#define kmvc_getbit(bb, src, res) {\
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res = 0; \
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if (bb.bitbuf & (1 << bb.bits)) res = 1; \
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bb.bits--; \
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if(bb.bits == -1) { \
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bb.bitbuf = *src++; \
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bb.bits = 7; \
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} \
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}
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static void kmvc_decode_intra_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h)
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{
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BitBuf bb;
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int res, val;
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int i, j;
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int bx, by;
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int l0x, l1x, l0y, l1y;
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int mx, my;
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kmvc_init_getbits(bb, src);
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for (by = 0; by < h; by += 8)
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for (bx = 0; bx < w; bx += 8) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 8x8 block
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val = *src++;
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for (i = 0; i < 64; i++)
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BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
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} else { // handle four 4x4 subblocks
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for (i = 0; i < 4; i++) {
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l0x = bx + (i & 1) * 4;
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l0y = by + (i & 2) * 2;
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kmvc_getbit(bb, src, res);
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if (!res) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 4x4 block
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val = *src++;
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for (j = 0; j < 16; j++)
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BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
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} else { // copy block from already decoded place
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val = *src++;
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mx = val & 0xF;
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my = val >> 4;
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for (j = 0; j < 16; j++)
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BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
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BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
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}
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} else { // descend to 2x2 sub-sub-blocks
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for (j = 0; j < 4; j++) {
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l1x = l0x + (j & 1) * 2;
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l1y = l0y + (j & 2);
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kmvc_getbit(bb, src, res);
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if (!res) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 2x2 block
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val = *src++;
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BLK(ctx->cur, l1x, l1y) = val;
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BLK(ctx->cur, l1x + 1, l1y) = val;
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BLK(ctx->cur, l1x, l1y + 1) = val;
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BLK(ctx->cur, l1x + 1, l1y + 1) = val;
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} else { // copy block from already decoded place
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val = *src++;
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mx = val & 0xF;
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my = val >> 4;
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BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
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BLK(ctx->cur, l1x + 1, l1y) =
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BLK(ctx->cur, l1x + 1 - mx, l1y - my);
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BLK(ctx->cur, l1x, l1y + 1) =
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BLK(ctx->cur, l1x - mx, l1y + 1 - my);
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BLK(ctx->cur, l1x + 1, l1y + 1) =
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BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
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}
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} else { // read values for block
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BLK(ctx->cur, l1x, l1y) = *src++;
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BLK(ctx->cur, l1x + 1, l1y) = *src++;
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BLK(ctx->cur, l1x, l1y + 1) = *src++;
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BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
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}
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}
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}
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}
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}
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}
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}
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static void kmvc_decode_inter_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h)
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{
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BitBuf bb;
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int res, val;
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int i, j;
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int bx, by;
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int l0x, l1x, l0y, l1y;
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int mx, my;
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kmvc_init_getbits(bb, src);
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for (by = 0; by < h; by += 8)
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for (bx = 0; bx < w; bx += 8) {
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kmvc_getbit(bb, src, res);
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if (!res) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 8x8 block
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val = *src++;
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for (i = 0; i < 64; i++)
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BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
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} else { // copy block from previous frame
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for (i = 0; i < 64; i++)
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BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
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BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
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}
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} else { // handle four 4x4 subblocks
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for (i = 0; i < 4; i++) {
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l0x = bx + (i & 1) * 4;
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l0y = by + (i & 2) * 2;
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kmvc_getbit(bb, src, res);
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if (!res) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 4x4 block
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val = *src++;
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for (j = 0; j < 16; j++)
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BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
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} else { // copy block
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val = *src++;
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mx = (val & 0xF) - 8;
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my = (val >> 4) - 8;
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for (j = 0; j < 16; j++)
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BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
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BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
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}
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} else { // descend to 2x2 sub-sub-blocks
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for (j = 0; j < 4; j++) {
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l1x = l0x + (j & 1) * 2;
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l1y = l0y + (j & 2);
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kmvc_getbit(bb, src, res);
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if (!res) {
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kmvc_getbit(bb, src, res);
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if (!res) { // fill whole 2x2 block
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val = *src++;
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BLK(ctx->cur, l1x, l1y) = val;
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BLK(ctx->cur, l1x + 1, l1y) = val;
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BLK(ctx->cur, l1x, l1y + 1) = val;
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BLK(ctx->cur, l1x + 1, l1y + 1) = val;
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} else { // copy block
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val = *src++;
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mx = (val & 0xF) - 8;
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my = (val >> 4) - 8;
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BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
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BLK(ctx->cur, l1x + 1, l1y) =
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BLK(ctx->prev, l1x + 1 + mx, l1y + my);
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BLK(ctx->cur, l1x, l1y + 1) =
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BLK(ctx->prev, l1x + mx, l1y + 1 + my);
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BLK(ctx->cur, l1x + 1, l1y + 1) =
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BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
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}
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} else { // read values for block
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BLK(ctx->cur, l1x, l1y) = *src++;
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BLK(ctx->cur, l1x + 1, l1y) = *src++;
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BLK(ctx->cur, l1x, l1y + 1) = *src++;
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BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
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}
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}
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}
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}
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}
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}
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}
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static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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int buf_size = avpkt->size;
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KmvcContext *const ctx = avctx->priv_data;
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uint8_t *out, *src;
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int i;
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int header;
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int blocksize;
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const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
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if (ctx->pic.data[0])
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avctx->release_buffer(avctx, &ctx->pic);
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ctx->pic.reference = 1;
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ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
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if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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return -1;
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}
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header = *buf++;
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/* blocksize 127 is really palette change event */
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if (buf[0] == 127) {
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buf += 3;
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for (i = 0; i < 127; i++) {
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ctx->pal[i + (header & 0x81)] = AV_RB24(buf);
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buf += 4;
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}
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buf -= 127 * 4 + 3;
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}
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if (header & KMVC_KEYFRAME) {
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ctx->pic.key_frame = 1;
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ctx->pic.pict_type = AV_PICTURE_TYPE_I;
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} else {
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ctx->pic.key_frame = 0;
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ctx->pic.pict_type = AV_PICTURE_TYPE_P;
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}
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if (header & KMVC_PALETTE) {
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ctx->pic.palette_has_changed = 1;
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// palette starts from index 1 and has 127 entries
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for (i = 1; i <= ctx->palsize; i++) {
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ctx->pal[i] = bytestream_get_be24(&buf);
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}
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}
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if (pal) {
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ctx->pic.palette_has_changed = 1;
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memcpy(ctx->pal, pal, AVPALETTE_SIZE);
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}
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if (ctx->setpal) {
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ctx->setpal = 0;
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ctx->pic.palette_has_changed = 1;
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}
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/* make the palette available on the way out */
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memcpy(ctx->pic.data[1], ctx->pal, 1024);
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blocksize = *buf++;
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if (blocksize != 8 && blocksize != 127) {
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av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
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return -1;
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}
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memset(ctx->cur, 0, 320 * 200);
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switch (header & KMVC_METHOD) {
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case 0:
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case 1: // used in palette changed event
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memcpy(ctx->cur, ctx->prev, 320 * 200);
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break;
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case 3:
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kmvc_decode_intra_8x8(ctx, buf, avctx->width, avctx->height);
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break;
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case 4:
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kmvc_decode_inter_8x8(ctx, buf, avctx->width, avctx->height);
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break;
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default:
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av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
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return -1;
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}
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out = ctx->pic.data[0];
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src = ctx->cur;
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for (i = 0; i < avctx->height; i++) {
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memcpy(out, src, avctx->width);
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src += 320;
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out += ctx->pic.linesize[0];
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}
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/* flip buffers */
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if (ctx->cur == ctx->frm0) {
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ctx->cur = ctx->frm1;
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ctx->prev = ctx->frm0;
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} else {
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ctx->cur = ctx->frm0;
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ctx->prev = ctx->frm1;
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}
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*data_size = sizeof(AVFrame);
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*(AVFrame *) data = ctx->pic;
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/* always report that the buffer was completely consumed */
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return buf_size;
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}
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/*
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* Init kmvc decoder
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*/
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static av_cold int decode_init(AVCodecContext * avctx)
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{
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KmvcContext *const c = avctx->priv_data;
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int i;
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c->avctx = avctx;
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if (avctx->width > 320 || avctx->height > 200) {
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av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
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return -1;
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}
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c->frm0 = av_mallocz(320 * 200);
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c->frm1 = av_mallocz(320 * 200);
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c->cur = c->frm0;
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c->prev = c->frm1;
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for (i = 0; i < 256; i++) {
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c->pal[i] = i * 0x10101;
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}
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if (avctx->extradata_size < 12) {
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av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
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c->palsize = 127;
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} else {
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c->palsize = AV_RL16(avctx->extradata + 10);
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}
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if (avctx->extradata_size == 1036) { // palette in extradata
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uint8_t *src = avctx->extradata + 12;
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for (i = 0; i < 256; i++) {
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c->pal[i] = AV_RL32(src);
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src += 4;
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}
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c->setpal = 1;
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}
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avctx->pix_fmt = PIX_FMT_PAL8;
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return 0;
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}
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/*
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* Uninit kmvc decoder
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*/
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static av_cold int decode_end(AVCodecContext * avctx)
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{
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KmvcContext *const c = avctx->priv_data;
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av_freep(&c->frm0);
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av_freep(&c->frm1);
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if (c->pic.data[0])
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avctx->release_buffer(avctx, &c->pic);
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return 0;
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}
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AVCodec ff_kmvc_decoder = {
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"kmvc",
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AVMEDIA_TYPE_VIDEO,
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CODEC_ID_KMVC,
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sizeof(KmvcContext),
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decode_init,
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NULL,
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decode_end,
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decode_frame,
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CODEC_CAP_DR1,
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.long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
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};
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