/src/ffmpeg/libavcodec/kmvc.c

Source
/*
 * KMVC decoder
 * Copyright (c) 2006 Konstantin Shishkov
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * Karl Morton's Video Codec decoder
 */

#include <stdio.h>

#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "libavutil/common.h"

#define KMVC_KEYFRAME 0x80
#define KMVC_PALETTE  0x40
#define KMVC_METHOD   0x0F
#define MAX_PALSIZE   256

/*
 * Decoder context
 */
typedef struct KmvcContext {
    AVCodecContext *avctx;

    GetByteContext g;
    uint8_t *cur, *prev;
    int setpal;
    int palsize;
    uint32_t pal[MAX_PALSIZE];
    uint8_t frm0[320 * 200], frm1[320 * 200];
} KmvcContext;

typedef struct BitBuf {
    int bits;
    int bitbuf;
} BitBuf;

#define BLK(data, x, y)  data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]

#define kmvc_init_getbits(bb, g)  bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);

#define kmvc_getbit(bb, g, res) {\
    res = 0; \
    if (bb.bitbuf & (1 << bb.bits)) res = 1; \
    bb.bits--; \
    if(bb.bits == -1) { \
        bb.bitbuf = bytestream2_get_byte(g); \
        bb.bits = 7; \
    } \
}

static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
{
    BitBuf bb;
    int res, val;
    int i, j;
    int bx, by;
    int l0x, l1x, l0y, l1y;
    int mx, my;

    kmvc_init_getbits(bb, &ctx->g);

    for (by = 0; by < h; by += 8)
        for (bx = 0; bx < w; bx += 8) {
            if (!bytestream2_get_bytes_left(&ctx->g)) {
                av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                return AVERROR_INVALIDDATA;
            }
            kmvc_getbit(bb, &ctx->g, res);
            if (!res) {         // fill whole 8x8 block
                val = bytestream2_get_byte(&ctx->g);
                for (i = 0; i < 64; i++)
                    BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
            } else {            // handle four 4x4 subblocks
                for (i = 0; i < 4; i++) {
                    l0x = bx + (i & 1) * 4;
                    l0y = by + (i & 2) * 2;
                    kmvc_getbit(bb, &ctx->g, res);
                    if (!res) {
                        kmvc_getbit(bb, &ctx->g, res);
                        if (!res) {     // fill whole 4x4 block
                            val = bytestream2_get_byte(&ctx->g);
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
                        } else {        // copy block from already decoded place
                            val = bytestream2_get_byte(&ctx->g);
                            mx = val & 0xF;
                            my = val >> 4;
                            if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 320*197 - 4) {
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                return AVERROR_INVALIDDATA;
                            }
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
                                    BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
                        }
                    } else {    // descend to 2x2 sub-sub-blocks
                        for (j = 0; j < 4; j++) {
                            l1x = l0x + (j & 1) * 2;
                            l1y = l0y + (j & 2);
                            kmvc_getbit(bb, &ctx->g, res);
                            if (!res) {
                                kmvc_getbit(bb, &ctx->g, res);
                                if (!res) {     // fill whole 2x2 block
                                    val = bytestream2_get_byte(&ctx->g);
                                    BLK(ctx->cur, l1x, l1y) = val;
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
                                } else {        // copy block from already decoded place
                                    val = bytestream2_get_byte(&ctx->g);
                                    mx = val & 0xF;
                                    my = val >> 4;
                                    if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 320*199 - 2) {
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                        return AVERROR_INVALIDDATA;
                                    }
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
                                    BLK(ctx->cur, l1x + 1, l1y) =
                                        BLK(ctx->cur, l1x + 1 - mx, l1y - my);
                                    BLK(ctx->cur, l1x, l1y + 1) =
                                        BLK(ctx->cur, l1x - mx, l1y + 1 - my);
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
                                        BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
                                }
                            } else {    // read values for block
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
                            }
                        }
                    }
                }
            }
        }

    return 0;
}

static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
{
    BitBuf bb;
    int res, val;
    int i, j;
    int bx, by;
    int l0x, l1x, l0y, l1y;
    int mx, my;

    kmvc_init_getbits(bb, &ctx->g);

    for (by = 0; by < h; by += 8)
        for (bx = 0; bx < w; bx += 8) {
            kmvc_getbit(bb, &ctx->g, res);
            if (!res) {
                kmvc_getbit(bb, &ctx->g, res);
                if (!res) {     // fill whole 8x8 block
                    if (!bytestream2_get_bytes_left(&ctx->g)) {
                        av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                        return AVERROR_INVALIDDATA;
                    }
                    val = bytestream2_get_byte(&ctx->g);
                    for (i = 0; i < 64; i++)
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
                } else {        // copy block from previous frame
                    for (i = 0; i < 64; i++)
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
                            BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
                }
            } else {            // handle four 4x4 subblocks
                if (!bytestream2_get_bytes_left(&ctx->g)) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                    return AVERROR_INVALIDDATA;
                }
                for (i = 0; i < 4; i++) {
                    l0x = bx + (i & 1) * 4;
                    l0y = by + (i & 2) * 2;
                    kmvc_getbit(bb, &ctx->g, res);
                    if (!res) {
                        kmvc_getbit(bb, &ctx->g, res);
                        if (!res) {     // fill whole 4x4 block
                            val = bytestream2_get_byte(&ctx->g);
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
                        } else {        // copy block
                            val = bytestream2_get_byte(&ctx->g);
                            mx = (val & 0xF) - 8;
                            my = (val >> 4) - 8;
                            if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 320*197 - 4) {
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                return AVERROR_INVALIDDATA;
                            }
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
                                    BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
                        }
                    } else {    // descend to 2x2 sub-sub-blocks
                        for (j = 0; j < 4; j++) {
                            l1x = l0x + (j & 1) * 2;
                            l1y = l0y + (j & 2);
                            kmvc_getbit(bb, &ctx->g, res);
                            if (!res) {
                                kmvc_getbit(bb, &ctx->g, res);
                                if (!res) {     // fill whole 2x2 block
                                    val = bytestream2_get_byte(&ctx->g);
                                    BLK(ctx->cur, l1x, l1y) = val;
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
                                } else {        // copy block
                                    val = bytestream2_get_byte(&ctx->g);
                                    mx = (val & 0xF) - 8;
                                    my = (val >> 4) - 8;
                                    if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 320*199 - 2) {
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                        return AVERROR_INVALIDDATA;
                                    }
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
                                    BLK(ctx->cur, l1x + 1, l1y) =
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + my);
                                    BLK(ctx->cur, l1x, l1y + 1) =
                                        BLK(ctx->prev, l1x + mx, l1y + 1 + my);
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
                                }
                            } else {    // read values for block
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
                            }
                        }
                    }
                }
            }
        }

    return 0;
}

static int decode_frame(AVCodecContext * avctx, AVFrame *frame,
                        int *got_frame, AVPacket *avpkt)
{
    KmvcContext *const ctx = avctx->priv_data;
    uint8_t *out, *src;
    int i, ret;
    int header;
    int blocksize;

    bytestream2_init(&ctx->g, avpkt->data, avpkt->size);

    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;

    ff_copy_palette(ctx->pal, avpkt, avctx);

    header = bytestream2_get_byte(&ctx->g);

    /* blocksize 127 is really palette change event */
    if (bytestream2_peek_byte(&ctx->g) == 127) {
        bytestream2_skip(&ctx->g, 3);
        for (i = 0; i < 127; i++) {
            ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
            bytestream2_skip(&ctx->g, 1);
        }
        bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
    }

    if (header & KMVC_KEYFRAME) {
        frame->flags |= AV_FRAME_FLAG_KEY;
        frame->pict_type = AV_PICTURE_TYPE_I;
    } else {
        frame->flags &= ~AV_FRAME_FLAG_KEY;
        frame->pict_type = AV_PICTURE_TYPE_P;
    }

    if (header & KMVC_PALETTE) {
        // palette starts from index 1 and has 127 entries
        for (i = 1; i <= ctx->palsize; i++) {
            ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
        }
    }

    if (ctx->setpal) {
        ctx->setpal = 0;
    }

    /* make the palette available on the way out */
    memcpy(frame->data[1], ctx->pal, 1024);

    blocksize = bytestream2_get_byte(&ctx->g);

    if (blocksize != 8 && blocksize != 127) {
        av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
        return AVERROR_INVALIDDATA;
    }
    memset(ctx->cur, 0, 320 * 200);
    switch (header & KMVC_METHOD) {
    case 0:
    case 1: // used in palette changed event
        memcpy(ctx->cur, ctx->prev, 320 * 200);
        break;
    case 3:
        kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
        break;
    case 4:
        kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
        return AVERROR_INVALIDDATA;
    }

    out = frame->data[0];
    src = ctx->cur;
    for (i = 0; i < avctx->height; i++) {
        memcpy(out, src, avctx->width);
        src += 320;
        out += frame->linesize[0];
    }

    /* flip buffers */
    FFSWAP(uint8_t *, ctx->cur, ctx->prev);

    *got_frame = 1;

    /* always report that the buffer was completely consumed */
    return avpkt->size;
}



/*
 * Init kmvc decoder
 */
static av_cold int decode_init(AVCodecContext * avctx)
{
    KmvcContext *const c = avctx->priv_data;
    int i;

    c->avctx = avctx;

    if (avctx->width > 320 || avctx->height > 200) {
        av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
        return AVERROR(EINVAL);
    }

    c->cur = c->frm0;
    c->prev = c->frm1;

    for (i = 0; i < 256; i++) {
        c->pal[i] = 0xFFU << 24 | i * 0x10101;
    }

    if (avctx->extradata_size < 12) {
        av_log(avctx, AV_LOG_WARNING,
               "Extradata missing, decoding may not work properly...\n");
        c->palsize = 127;
    } else {
        c->palsize = AV_RL16(avctx->extradata + 10);
        if (c->palsize >= (unsigned)MAX_PALSIZE) {
            c->palsize = 127;
            av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
            return AVERROR_INVALIDDATA;
        }
    }

    if (avctx->extradata_size == 1036) {        // palette in extradata
        uint8_t *src = avctx->extradata + 12;
        for (i = 0; i < 256; i++) {
            c->pal[i] = AV_RL32(src);
            src += 4;
        }
        c->setpal = 1;
    }

    avctx->pix_fmt = AV_PIX_FMT_PAL8;

    return 0;
}

const FFCodec ff_kmvc_decoder = {
    .p.name         = "kmvc",
    CODEC_LONG_NAME("Karl Morton's video codec"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_KMVC,
    .priv_data_size = sizeof(KmvcContext),
    .init           = decode_init,
    FF_CODEC_DECODE_CB(decode_frame),
    .p.capabilities = AV_CODEC_CAP_DR1,
};

Coverage Report

Created: 2025-12-31 07:57

Line	Count	Source
1		/*
2		* KMVC decoder
3		* Copyright (c) 2006 Konstantin Shishkov
4		*
5		* This file is part of FFmpeg.
6		*
7		* FFmpeg 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.
11		*
12		* FFmpeg 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.
16		*
17		* You should have received a copy of the GNU Lesser General Public
18		* License along with FFmpeg; if not, write to the Free Software
19		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20		*/
21
22		/**
23		* @file
24		* Karl Morton's Video Codec decoder
25		*/
26
27		#include <stdio.h>
28
29		#include "avcodec.h"
30		#include "bytestream.h"
31		#include "codec_internal.h"
32		#include "decode.h"
33		#include "libavutil/common.h"
34
35	884k	#define KMVC_KEYFRAME 0x80
36	884k	#define KMVC_PALETTE 0x40
37	112k	#define KMVC_METHOD 0x0F
38	81	#define MAX_PALSIZE 256
39
40		/*
41		* Decoder context
42		*/
43		typedef struct KmvcContext {
44		AVCodecContext *avctx;
45
46		GetByteContext g;
47		uint8_t cur, prev;
48		int setpal;
49		int palsize;
50		uint32_t pal[MAX_PALSIZE];
51		uint8_t frm0[320 * 200], frm1[320 * 200];
52		} KmvcContext;
53
54		typedef struct BitBuf {
55		int bits;
56		int bitbuf;
57		} BitBuf;
58
59	23.6M	#define BLK(data, x, y) data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]
60
61	110k	#define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
62
63	1.74M	#define kmvc_getbit(bb, g, res) {\
64	1.74M	res = 0; \
65	1.74M	if (bb.bitbuf & (1 << bb.bits)) res = 1; \
66	1.74M	bb.bits--; \
67	1.74M	if(bb.bits == -1) { \
68	212k	bb.bitbuf = bytestream2_get_byte(g); \
69	212k	bb.bits = 7; \
70	212k	} \
71	1.74M	}
72
73		static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
74	100k	{
75	100k	BitBuf bb;
76	100k	int res, val;
77	100k	int i, j;
78	100k	int bx, by;
79	100k	int l0x, l1x, l0y, l1y;
80	100k	int mx, my;
81
82	100k	kmvc_init_getbits(bb, &ctx->g);
83
84	126k	for (by = 0; by < h; by += 8)
85	276k	for (bx = 0; bx < w; bx += 8) {
86	250k	if (!bytestream2_get_bytes_left(&ctx->g)) {
87	99.1k	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
88	99.1k	return AVERROR_INVALIDDATA;
89	99.1k	}
90	151k	kmvc_getbit(bb, &ctx->g, res);
91	151k	if (!res) { // fill whole 8x8 block
92	113k	val = bytestream2_get_byte(&ctx->g);
93	7.37M	for (i = 0; i < 64; i++)
94	7.26M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
95	113k	} else { // handle four 4x4 subblocks
96	184k	for (i = 0; i < 4; i++) {
97	148k	l0x = bx + (i & 1) * 4;
98	148k	l0y = by + (i & 2) * 2;
99	148k	kmvc_getbit(bb, &ctx->g, res);
100	148k	if (!res) {
101	69.0k	kmvc_getbit(bb, &ctx->g, res);
102	69.0k	if (!res) { // fill whole 4x4 block
103	30.5k	val = bytestream2_get_byte(&ctx->g);
104	519k	for (j = 0; j < 16; j++)
105	489k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
106	38.5k	} else { // copy block from already decoded place
107	38.5k	val = bytestream2_get_byte(&ctx->g);
108	38.5k	mx = val & 0xF;
109	38.5k	my = val >> 4;
110	38.5k	if ((l0x-mx) + 320(l0y-my) < 0 \|\| (l0x-mx) + 320(l0y-my) > 320*197 - 4) {
111	829	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
112	829	return AVERROR_INVALIDDATA;
113	829	}
114	640k	for (j = 0; j < 16; j++)
115	602k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
116	602k	BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
117	37.6k	}
118	78.9k	} else { // descend to 2x2 sub-sub-blocks
119	393k	for (j = 0; j < 4; j++) {
120	315k	l1x = l0x + (j & 1) * 2;
121	315k	l1y = l0y + (j & 2);
122	315k	kmvc_getbit(bb, &ctx->g, res);
123	315k	if (!res) {
124	208k	kmvc_getbit(bb, &ctx->g, res);
125	208k	if (!res) { // fill whole 2x2 block
126	92.9k	val = bytestream2_get_byte(&ctx->g);
127	92.9k	BLK(ctx->cur, l1x, l1y) = val;
128	92.9k	BLK(ctx->cur, l1x + 1, l1y) = val;
129	92.9k	BLK(ctx->cur, l1x, l1y + 1) = val;
130	92.9k	BLK(ctx->cur, l1x + 1, l1y + 1) = val;
131	115k	} else { // copy block from already decoded place
132	115k	val = bytestream2_get_byte(&ctx->g);
133	115k	mx = val & 0xF;
134	115k	my = val >> 4;
135	115k	if ((l1x-mx) + 320(l1y-my) < 0 \|\| (l1x-mx) + 320(l1y-my) > 320*199 - 2) {
136	348	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
137	348	return AVERROR_INVALIDDATA;
138	348	}
139	114k	BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
140	114k	BLK(ctx->cur, l1x + 1, l1y) =
141	114k	BLK(ctx->cur, l1x + 1 - mx, l1y - my);
142	114k	BLK(ctx->cur, l1x, l1y + 1) =
143	114k	BLK(ctx->cur, l1x - mx, l1y + 1 - my);
144	114k	BLK(ctx->cur, l1x + 1, l1y + 1) =
145	114k	BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
146	114k	}
147	208k	} else { // read values for block
148	106k	BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
149	106k	BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
150	106k	BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
151	106k	BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
152	106k	}
153	315k	}
154	78.9k	}
155	148k	}
156	37.6k	}
157	151k	}
158
159	381	return 0;
160	100k	}
161
162		static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
163	9.97k	{
164	9.97k	BitBuf bb;
165	9.97k	int res, val;
166	9.97k	int i, j;
167	9.97k	int bx, by;
168	9.97k	int l0x, l1x, l0y, l1y;
169	9.97k	int mx, my;
170
171	9.97k	kmvc_init_getbits(bb, &ctx->g);
172
173	33.0k	for (by = 0; by < h; by += 8)
174	189k	for (bx = 0; bx < w; bx += 8) {
175	166k	kmvc_getbit(bb, &ctx->g, res);
176	166k	if (!res) {
177	137k	kmvc_getbit(bb, &ctx->g, res);
178	137k	if (!res) { // fill whole 8x8 block
179	103k	if (!bytestream2_get_bytes_left(&ctx->g)) {
180	7.82k	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
181	7.82k	return AVERROR_INVALIDDATA;
182	7.82k	}
183	95.6k	val = bytestream2_get_byte(&ctx->g);
184	6.21M	for (i = 0; i < 64; i++)
185	6.12M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
186	95.6k	} else { // copy block from previous frame
187	2.22M	for (i = 0; i < 64; i++)
188	2.19M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
189	2.19M	BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
190	34.2k	}
191	137k	} else { // handle four 4x4 subblocks
192	28.9k	if (!bytestream2_get_bytes_left(&ctx->g)) {
193	513	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
194	513	return AVERROR_INVALIDDATA;
195	513	}
196	138k	for (i = 0; i < 4; i++) {
197	111k	l0x = bx + (i & 1) * 4;
198	111k	l0y = by + (i & 2) * 2;
199	111k	kmvc_getbit(bb, &ctx->g, res);
200	111k	if (!res) {
201	50.3k	kmvc_getbit(bb, &ctx->g, res);
202	50.3k	if (!res) { // fill whole 4x4 block
203	28.6k	val = bytestream2_get_byte(&ctx->g);
204	486k	for (j = 0; j < 16; j++)
205	457k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
206	28.6k	} else { // copy block
207	21.7k	val = bytestream2_get_byte(&ctx->g);
208	21.7k	mx = (val & 0xF) - 8;
209	21.7k	my = (val >> 4) - 8;
210	21.7k	if ((l0x+mx) + 320(l0y+my) < 0 \|\| (l0x+mx) + 320(l0y+my) > 320*197 - 4) {
211	595	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
212	595	return AVERROR_INVALIDDATA;
213	595	}
214	359k	for (j = 0; j < 16; j++)
215	338k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
216	338k	BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
217	21.1k	}
218	61.0k	} else { // descend to 2x2 sub-sub-blocks
219	303k	for (j = 0; j < 4; j++) {
220	243k	l1x = l0x + (j & 1) * 2;
221	243k	l1y = l0y + (j & 2);
222	243k	kmvc_getbit(bb, &ctx->g, res);
223	243k	if (!res) {
224	143k	kmvc_getbit(bb, &ctx->g, res);
225	143k	if (!res) { // fill whole 2x2 block
226	64.9k	val = bytestream2_get_byte(&ctx->g);
227	64.9k	BLK(ctx->cur, l1x, l1y) = val;
228	64.9k	BLK(ctx->cur, l1x + 1, l1y) = val;
229	64.9k	BLK(ctx->cur, l1x, l1y + 1) = val;
230	64.9k	BLK(ctx->cur, l1x + 1, l1y + 1) = val;
231	78.0k	} else { // copy block
232	78.0k	val = bytestream2_get_byte(&ctx->g);
233	78.0k	mx = (val & 0xF) - 8;
234	78.0k	my = (val >> 4) - 8;
235	78.0k	if ((l1x+mx) + 320(l1y+my) < 0 \|\| (l1x+mx) + 320(l1y+my) > 320*199 - 2) {
236	599	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
237	599	return AVERROR_INVALIDDATA;
238	599	}
239	77.4k	BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
240	77.4k	BLK(ctx->cur, l1x + 1, l1y) =
241	77.4k	BLK(ctx->prev, l1x + 1 + mx, l1y + my);
242	77.4k	BLK(ctx->cur, l1x, l1y + 1) =
243	77.4k	BLK(ctx->prev, l1x + mx, l1y + 1 + my);
244	77.4k	BLK(ctx->cur, l1x + 1, l1y + 1) =
245	77.4k	BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
246	77.4k	}
247	143k	} else { // read values for block
248	100k	BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
249	100k	BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
250	100k	BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
251	100k	BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
252	100k	}
253	243k	}
254	61.0k	}
255	111k	}
256	28.4k	}
257	166k	}
258
259	440	return 0;
260	9.97k	}
261
262		static int decode_frame(AVCodecContext * avctx, AVFrame *frame,
263		int got_frame, AVPacket avpkt)
264	921k	{
265	921k	KmvcContext *const ctx = avctx->priv_data;
266	921k	uint8_t out, src;
267	921k	int i, ret;
268	921k	int header;
269	921k	int blocksize;
270
271	921k	bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
272
273	921k	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
274	37.3k	return ret;
275
276	884k	ff_copy_palette(ctx->pal, avpkt, avctx);
277
278	884k	header = bytestream2_get_byte(&ctx->g);
279
280		/* blocksize 127 is really palette change event */
281	884k	if (bytestream2_peek_byte(&ctx->g) == 127) {
282	1.76k	bytestream2_skip(&ctx->g, 3);
283	225k	for (i = 0; i < 127; i++) {
284	223k	ctx->pal[i + (header & 0x81)] = 0xFFU << 24 \| bytestream2_get_be24(&ctx->g);
285	223k	bytestream2_skip(&ctx->g, 1);
286	223k	}
287	1.76k	bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
288	1.76k	}
289
290	884k	if (header & KMVC_KEYFRAME) {
291	719k	frame->flags \|= AV_FRAME_FLAG_KEY;
292	719k	frame->pict_type = AV_PICTURE_TYPE_I;
293	719k	} else {
294	165k	frame->flags &= ~AV_FRAME_FLAG_KEY;
295	165k	frame->pict_type = AV_PICTURE_TYPE_P;
296	165k	}
297
298	884k	if (header & KMVC_PALETTE) {
299		// palette starts from index 1 and has 127 entries
300	86.2M	for (i = 1; i <= ctx->palsize; i++) {
301	85.5M	ctx->pal[i] = 0xFFU << 24 \| bytestream2_get_be24(&ctx->g);
302	85.5M	}
303	749k	}
304
305	884k	if (ctx->setpal) {
306	1	ctx->setpal = 0;
307	1	}
308
309		/* make the palette available on the way out */
310	884k	memcpy(frame->data[1], ctx->pal, 1024);
311
312	884k	blocksize = bytestream2_get_byte(&ctx->g);
313
314	884k	if (blocksize != 8 && blocksize != 127) {
315	772k	av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
316	772k	return AVERROR_INVALIDDATA;
317	772k	}
318	111k	memset(ctx->cur, 0, 320 * 200);
319	111k	switch (header & KMVC_METHOD) {
320	465	case 0:
321	724	case 1: // used in palette changed event
322	724	memcpy(ctx->cur, ctx->prev, 320 * 200);
323	724	break;
324	100k	case 3:
325	100k	kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
326	100k	break;
327	9.97k	case 4:
328	9.97k	kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
329	9.97k	break;
330	371	default:
331	371	av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
332	371	return AVERROR_INVALIDDATA;
333	111k	}
334
335	111k	out = frame->data[0];
336	111k	src = ctx->cur;
337	16.3M	for (i = 0; i < avctx->height; i++) {
338	16.2M	memcpy(out, src, avctx->width);
339	16.2M	src += 320;
340	16.2M	out += frame->linesize[0];
341	16.2M	}
342
343		/* flip buffers */
344	111k	FFSWAP(uint8_t *, ctx->cur, ctx->prev);
345
346	111k	*got_frame = 1;
347
348		/* always report that the buffer was completely consumed */
349	111k	return avpkt->size;
350	111k	}
351
352
353
354		/*
355		* Init kmvc decoder
356		*/
357		static av_cold int decode_init(AVCodecContext * avctx)
358	1.19k	{
359	1.19k	KmvcContext *const c = avctx->priv_data;
360	1.19k	int i;
361
362	1.19k	c->avctx = avctx;
363
364	1.19k	if (avctx->width > 320 \|\| avctx->height > 200) {
365	33	av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
366	33	return AVERROR(EINVAL);
367	33	}
368
369	1.15k	c->cur = c->frm0;
370	1.15k	c->prev = c->frm1;
371
372	297k	for (i = 0; i < 256; i++) {
373	296k	c->pal[i] = 0xFFU << 24 \| i * 0x10101;
374	296k	}
375
376	1.15k	if (avctx->extradata_size < 12) {
377	1.07k	av_log(avctx, AV_LOG_WARNING,
378	1.07k	"Extradata missing, decoding may not work properly...\n");
379	1.07k	c->palsize = 127;
380	1.07k	} else {
381	81	c->palsize = AV_RL16(avctx->extradata + 10);
382	81	if (c->palsize >= (unsigned)MAX_PALSIZE) {
383	17	c->palsize = 127;
384	17	av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
385	17	return AVERROR_INVALIDDATA;
386	17	}
387	81	}
388
389	1.14k	if (avctx->extradata_size == 1036) { // palette in extradata
390	1	uint8_t *src = avctx->extradata + 12;
391	257	for (i = 0; i < 256; i++) {
392	256	c->pal[i] = AV_RL32(src);
393	256	src += 4;
394	256	}
395	1	c->setpal = 1;
396	1	}
397
398	1.14k	avctx->pix_fmt = AV_PIX_FMT_PAL8;
399
400	1.14k	return 0;
401	1.15k	}
402
403		const FFCodec ff_kmvc_decoder = {
404		.p.name = "kmvc",
405		CODEC_LONG_NAME("Karl Morton's video codec"),
406		.p.type = AVMEDIA_TYPE_VIDEO,
407		.p.id = AV_CODEC_ID_KMVC,
408		.priv_data_size = sizeof(KmvcContext),
409		.init = decode_init,
410		FF_CODEC_DECODE_CB(decode_frame),
411		.p.capabilities = AV_CODEC_CAP_DR1,
412		};