/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: 2026-09-14 08:00

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	1.49M	#define KMVC_KEYFRAME 0x80
36	1.49M	#define KMVC_PALETTE 0x40
37	116k	#define KMVC_METHOD 0x0F
38	61	#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	21.5M	#define BLK(data, x, y) data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]
60
61	114k	#define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
62
63	1.57M	#define kmvc_getbit(bb, g, res) {\
64	1.57M	res = 0; \
65	1.57M	if (bb.bitbuf & (1 << bb.bits)) res = 1; \
66	1.57M	bb.bits--; \
67	1.57M	if(bb.bits == -1) { \
68	192k	bb.bitbuf = bytestream2_get_byte(g); \
69	192k	bb.bits = 7; \
70	192k	} \
71	1.57M	}
72
73		static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
74	109k	{
75	109k	BitBuf bb;
76	109k	int res, val;
77	109k	int i, j;
78	109k	int bx, by;
79	109k	int l0x, l1x, l0y, l1y;
80	109k	int mx, my;
81
82	109k	kmvc_init_getbits(bb, &ctx->g);
83
84	135k	for (by = 0; by < h; by += 8)
85	279k	for (bx = 0; bx < w; bx += 8) {
86	252k	if (!bytestream2_get_bytes_left(&ctx->g)) {
87	107k	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
88	107k	return AVERROR_INVALIDDATA;
89	107k	}
90	145k	kmvc_getbit(bb, &ctx->g, res);
91	145k	if (!res) { // fill whole 8x8 block
92	109k	val = bytestream2_get_byte(&ctx->g);
93	7.14M	for (i = 0; i < 64; i++)
94	7.03M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
95	109k	} else { // handle four 4x4 subblocks
96	172k	for (i = 0; i < 4; i++) {
97	138k	l0x = bx + (i & 1) * 4;
98	138k	l0y = by + (i & 2) * 2;
99	138k	kmvc_getbit(bb, &ctx->g, res);
100	138k	if (!res) {
101	65.8k	kmvc_getbit(bb, &ctx->g, res);
102	65.8k	if (!res) { // fill whole 4x4 block
103	29.1k	val = bytestream2_get_byte(&ctx->g);
104	495k	for (j = 0; j < 16; j++)
105	466k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
106	36.6k	} else { // copy block from already decoded place
107	36.6k	val = bytestream2_get_byte(&ctx->g);
108	36.6k	mx = val & 0xF;
109	36.6k	my = val >> 4;
110	36.6k	if ((l0x-mx) + 320(l0y-my) < 0 \|\| (l0x-mx) + 320(l0y-my) > 320*197 - 4) {
111	694	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
112	694	return AVERROR_INVALIDDATA;
113	694	}
114	612k	for (j = 0; j < 16; j++)
115	576k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
116	576k	BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
117	36.0k	}
118	72.4k	} else { // descend to 2x2 sub-sub-blocks
119	361k	for (j = 0; j < 4; j++) {
120	289k	l1x = l0x + (j & 1) * 2;
121	289k	l1y = l0y + (j & 2);
122	289k	kmvc_getbit(bb, &ctx->g, res);
123	289k	if (!res) {
124	191k	kmvc_getbit(bb, &ctx->g, res);
125	191k	if (!res) { // fill whole 2x2 block
126	85.7k	val = bytestream2_get_byte(&ctx->g);
127	85.7k	BLK(ctx->cur, l1x, l1y) = val;
128	85.7k	BLK(ctx->cur, l1x + 1, l1y) = val;
129	85.7k	BLK(ctx->cur, l1x, l1y + 1) = val;
130	85.7k	BLK(ctx->cur, l1x + 1, l1y + 1) = val;
131	105k	} else { // copy block from already decoded place
132	105k	val = bytestream2_get_byte(&ctx->g);
133	105k	mx = val & 0xF;
134	105k	my = val >> 4;
135	105k	if ((l1x-mx) + 320(l1y-my) < 0 \|\| (l1x-mx) + 320(l1y-my) > 320*199 - 2) {
136	387	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
137	387	return AVERROR_INVALIDDATA;
138	387	}
139	104k	BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
140	104k	BLK(ctx->cur, l1x + 1, l1y) =
141	104k	BLK(ctx->cur, l1x + 1 - mx, l1y - my);
142	104k	BLK(ctx->cur, l1x, l1y + 1) =
143	104k	BLK(ctx->cur, l1x - mx, l1y + 1 - my);
144	104k	BLK(ctx->cur, l1x + 1, l1y + 1) =
145	104k	BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
146	104k	}
147	191k	} else { // read values for block
148	98.0k	BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
149	98.0k	BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
150	98.0k	BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
151	98.0k	BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
152	98.0k	}
153	289k	}
154	72.4k	}
155	138k	}
156	35.1k	}
157	145k	}
158
159	365	return 0;
160	109k	}
161
162		static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
163	5.68k	{
164	5.68k	BitBuf bb;
165	5.68k	int res, val;
166	5.68k	int i, j;
167	5.68k	int bx, by;
168	5.68k	int l0x, l1x, l0y, l1y;
169	5.68k	int mx, my;
170
171	5.68k	kmvc_init_getbits(bb, &ctx->g);
172
173	26.1k	for (by = 0; by < h; by += 8)
174	161k	for (bx = 0; bx < w; bx += 8) {
175	141k	kmvc_getbit(bb, &ctx->g, res);
176	141k	if (!res) {
177	115k	kmvc_getbit(bb, &ctx->g, res);
178	115k	if (!res) { // fill whole 8x8 block
179	84.4k	if (!bytestream2_get_bytes_left(&ctx->g)) {
180	3.34k	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
181	3.34k	return AVERROR_INVALIDDATA;
182	3.34k	}
183	81.0k	val = bytestream2_get_byte(&ctx->g);
184	5.26M	for (i = 0; i < 64; i++)
185	5.18M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
186	81.0k	} else { // copy block from previous frame
187	2.01M	for (i = 0; i < 64; i++)
188	1.98M	BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
189	1.98M	BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
190	31.0k	}
191	115k	} else { // handle four 4x4 subblocks
192	25.8k	if (!bytestream2_get_bytes_left(&ctx->g)) {
193	402	av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
194	402	return AVERROR_INVALIDDATA;
195	402	}
196	122k	for (i = 0; i < 4; i++) {
197	98.4k	l0x = bx + (i & 1) * 4;
198	98.4k	l0y = by + (i & 2) * 2;
199	98.4k	kmvc_getbit(bb, &ctx->g, res);
200	98.4k	if (!res) {
201	44.5k	kmvc_getbit(bb, &ctx->g, res);
202	44.5k	if (!res) { // fill whole 4x4 block
203	25.0k	val = bytestream2_get_byte(&ctx->g);
204	426k	for (j = 0; j < 16; j++)
205	401k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
206	25.0k	} else { // copy block
207	19.4k	val = bytestream2_get_byte(&ctx->g);
208	19.4k	mx = (val & 0xF) - 8;
209	19.4k	my = (val >> 4) - 8;
210	19.4k	if ((l0x+mx) + 320(l0y+my) < 0 \|\| (l0x+mx) + 320(l0y+my) > 320*197 - 4) {
211	653	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
212	653	return AVERROR_INVALIDDATA;
213	653	}
214	319k	for (j = 0; j < 16; j++)
215	300k	BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
216	300k	BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
217	18.7k	}
218	53.9k	} else { // descend to 2x2 sub-sub-blocks
219	267k	for (j = 0; j < 4; j++) {
220	214k	l1x = l0x + (j & 1) * 2;
221	214k	l1y = l0y + (j & 2);
222	214k	kmvc_getbit(bb, &ctx->g, res);
223	214k	if (!res) {
224	131k	kmvc_getbit(bb, &ctx->g, res);
225	131k	if (!res) { // fill whole 2x2 block
226	59.0k	val = bytestream2_get_byte(&ctx->g);
227	59.0k	BLK(ctx->cur, l1x, l1y) = val;
228	59.0k	BLK(ctx->cur, l1x + 1, l1y) = val;
229	59.0k	BLK(ctx->cur, l1x, l1y + 1) = val;
230	59.0k	BLK(ctx->cur, l1x + 1, l1y + 1) = val;
231	72.0k	} else { // copy block
232	72.0k	val = bytestream2_get_byte(&ctx->g);
233	72.0k	mx = (val & 0xF) - 8;
234	72.0k	my = (val >> 4) - 8;
235	72.0k	if ((l1x+mx) + 320(l1y+my) < 0 \|\| (l1x+mx) + 320(l1y+my) > 320*199 - 2) {
236	886	av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
237	886	return AVERROR_INVALIDDATA;
238	886	}
239	71.1k	BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
240	71.1k	BLK(ctx->cur, l1x + 1, l1y) =
241	71.1k	BLK(ctx->prev, l1x + 1 + mx, l1y + my);
242	71.1k	BLK(ctx->cur, l1x, l1y + 1) =
243	71.1k	BLK(ctx->prev, l1x + mx, l1y + 1 + my);
244	71.1k	BLK(ctx->cur, l1x + 1, l1y + 1) =
245	71.1k	BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
246	71.1k	}
247	131k	} else { // read values for block
248	82.9k	BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
249	82.9k	BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
250	82.9k	BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
251	82.9k	BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
252	82.9k	}
253	214k	}
254	53.9k	}
255	98.4k	}
256	25.4k	}
257	141k	}
258
259	391	return 0;
260	5.68k	}
261
262		static int decode_frame(AVCodecContext * avctx, AVFrame *frame,
263		int got_frame, AVPacket avpkt)
264	1.51M	{
265	1.51M	KmvcContext *const ctx = avctx->priv_data;
266	1.51M	uint8_t out, src;
267	1.51M	int i, ret;
268	1.51M	int header;
269	1.51M	int blocksize;
270
271	1.51M	bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
272
273	1.51M	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
274	20.0k	return ret;
275
276	1.49M	ff_copy_palette(ctx->pal, avpkt, avctx);
277
278	1.49M	header = bytestream2_get_byte(&ctx->g);
279
280		/* blocksize 127 is really palette change event */
281	1.49M	if (bytestream2_peek_byte(&ctx->g) == 127) {
282	2.01k	bytestream2_skip(&ctx->g, 3);
283	258k	for (i = 0; i < 127; i++) {
284	256k	ctx->pal[i + (header & 0x81)] = 0xFFU << 24 \| bytestream2_get_be24(&ctx->g);
285	256k	bytestream2_skip(&ctx->g, 1);
286	256k	}
287	2.01k	bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
288	2.01k	}
289
290	1.49M	if (header & KMVC_KEYFRAME) {
291	1.28M	frame->flags \|= AV_FRAME_FLAG_KEY;
292	1.28M	frame->pict_type = AV_PICTURE_TYPE_I;
293	1.28M	} else {
294	208k	frame->flags &= ~AV_FRAME_FLAG_KEY;
295	208k	frame->pict_type = AV_PICTURE_TYPE_P;
296	208k	}
297
298	1.49M	if (header & KMVC_PALETTE) {
299		// palette starts from index 1 and has 127 entries
300	170M	for (i = 1; i <= ctx->palsize; i++) {
301	169M	ctx->pal[i] = 0xFFU << 24 \| bytestream2_get_be24(&ctx->g);
302	169M	}
303	1.33M	}
304
305	1.49M	if (ctx->setpal) {
306	1	ctx->setpal = 0;
307	1	}
308
309		/* make the palette available on the way out */
310	1.49M	memcpy(frame->data[1], ctx->pal, 1024);
311
312	1.49M	blocksize = bytestream2_get_byte(&ctx->g);
313
314	1.49M	if (blocksize != 8 && blocksize != 127) {
315	1.38M	av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
316	1.38M	return AVERROR_INVALIDDATA;
317	1.38M	}
318	115k	memset(ctx->cur, 0, 320 * 200);
319	115k	switch (header & KMVC_METHOD) {
320	359	case 0:
321	618	case 1: // used in palette changed event
322	618	memcpy(ctx->cur, ctx->prev, 320 * 200);
323	618	break;
324	109k	case 3:
325	109k	kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
326	109k	break;
327	5.68k	case 4:
328	5.68k	kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
329	5.68k	break;
330	329	default:
331	329	av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
332	329	return AVERROR_INVALIDDATA;
333	115k	}
334
335	115k	out = frame->data[0];
336	115k	src = ctx->cur;
337	17.0M	for (i = 0; i < avctx->height; i++) {
338	16.8M	memcpy(out, src, avctx->width);
339	16.8M	src += 320;
340	16.8M	out += frame->linesize[0];
341	16.8M	}
342
343		/* flip buffers */
344	115k	FFSWAP(uint8_t *, ctx->cur, ctx->prev);
345
346	115k	*got_frame = 1;
347
348		/* always report that the buffer was completely consumed */
349	115k	return avpkt->size;
350	115k	}
351
352
353
354		/*
355		* Init kmvc decoder
356		*/
357		static av_cold int decode_init(AVCodecContext * avctx)
358	1.14k	{
359	1.14k	KmvcContext *const c = avctx->priv_data;
360	1.14k	int i;
361
362	1.14k	c->avctx = avctx;
363
364	1.14k	if (avctx->width > 320 \|\| avctx->height > 200) {
365	31	av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
366	31	return AVERROR(EINVAL);
367	31	}
368
369	1.11k	c->cur = c->frm0;
370	1.11k	c->prev = c->frm1;
371
372	285k	for (i = 0; i < 256; i++) {
373	284k	c->pal[i] = 0xFFU << 24 \| i * 0x10101;
374	284k	}
375
376	1.11k	if (avctx->extradata_size < 12) {
377	1.04k	av_log(avctx, AV_LOG_WARNING,
378	1.04k	"Extradata missing, decoding may not work properly...\n");
379	1.04k	c->palsize = 127;
380	1.04k	} else {
381	61	c->palsize = AV_RL16(avctx->extradata + 10);
382	61	if (c->palsize >= (unsigned)MAX_PALSIZE) {
383	12	c->palsize = 127;
384	12	av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
385	12	return AVERROR_INVALIDDATA;
386	12	}
387	61	}
388
389	1.09k	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	1.09k	avctx->pix_fmt = AV_PIX_FMT_PAL8;
399
400	1.09k	return 0;
401	1.11k	}
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		};