ffmpeg / libavcodec / kmvc.c @ d36beb3f
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/*
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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 FFmpeg.
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*
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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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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 = FF_I_TYPE; |
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} else {
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ctx->pic.key_frame = 0;
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ctx->pic.pict_type = FF_P_TYPE; |
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} |
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/* if palette has been changed, copy it from palctrl */
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if (ctx->avctx->palctrl && ctx->avctx->palctrl->palette_changed) {
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memcpy(ctx->pal, ctx->avctx->palctrl->palette, AVPALETTE_SIZE); |
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ctx->setpal = 1;
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ctx->avctx->palctrl->palette_changed = 0;
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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 (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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if (c->avctx->palctrl) {
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c->avctx->palctrl->palette_changed = 0;
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} |
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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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}; |