FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/xxan.c	Lines:	228	267	85.4 %
Date:	2021-04-22 14:24:15	Branches:	87	123	70.7 %


/*
 * Wing Commander/Xan Video Decoder
 * Copyright (C) 2011 Konstantin Shishkov
 * based on work by Mike Melanson
 *
 * 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
 */

#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"

#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"

typedef struct XanContext {
    AVCodecContext *avctx;
    AVFrame *pic;

    uint8_t *y_buffer;
    uint8_t *scratch_buffer;
    int     buffer_size;
    GetByteContext gb;
} XanContext;

static av_cold int xan_decode_end(AVCodecContext *avctx)
{
    XanContext *s = avctx->priv_data;

    av_frame_free(&s->pic);

    av_freep(&s->y_buffer);
    av_freep(&s->scratch_buffer);

    return 0;
}

static av_cold int xan_decode_init(AVCodecContext *avctx)
{
    XanContext *s = avctx->priv_data;

    s->avctx = avctx;

    avctx->pix_fmt = AV_PIX_FMT_YUV420P;

    if (avctx->height < 8) {
        av_log(avctx, AV_LOG_ERROR, "Invalid frame height: %d.\n", avctx->height);
        return AVERROR(EINVAL);
    }
    if (avctx->width & 1) {
        av_log(avctx, AV_LOG_ERROR, "Invalid frame width: %d.\n", avctx->width);
        return AVERROR(EINVAL);
    }

    s->buffer_size = avctx->width * avctx->height;
    s->y_buffer = av_malloc(s->buffer_size);
    if (!s->y_buffer)
        return AVERROR(ENOMEM);
    s->scratch_buffer = av_malloc(s->buffer_size + 130);
    if (!s->scratch_buffer)
        return AVERROR(ENOMEM);

    s->pic = av_frame_alloc();
    if (!s->pic)
        return AVERROR(ENOMEM);

    return 0;
}

static int xan_unpack_luma(XanContext *s,
                           uint8_t *dst, const int dst_size)
{
    int tree_size, eof;
    int bits, mask;
    int tree_root, node;
    const uint8_t *dst_end = dst + dst_size;
    GetByteContext tree = s->gb;
    int start_off = bytestream2_tell(&tree);

    tree_size = bytestream2_get_byte(&s->gb);
    eof       = bytestream2_get_byte(&s->gb);
    tree_root = eof + tree_size;
    bytestream2_skip(&s->gb, tree_size * 2);

    node = tree_root;
    bits = bytestream2_get_byte(&s->gb);
    mask = 0x80;
    for (;;) {
        int bit = !!(bits & mask);
        mask >>= 1;
        bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
        node = bytestream2_get_byte(&tree);
        if (node == eof)
            break;
        if (node < eof) {
            *dst++ = node;
            if (dst > dst_end)
                break;
            node = tree_root;
        }
        if (!mask) {
            if (bytestream2_get_bytes_left(&s->gb) <= 0)
                break;
            bits = bytestream2_get_byteu(&s->gb);
            mask = 0x80;
        }
    }
    return dst != dst_end ? AVERROR_INVALIDDATA : 0;
}

/* almost the same as in xan_wc3 decoder */
static int xan_unpack(XanContext *s,
                      uint8_t *dest, const int dest_len)
{
    uint8_t opcode;
    int size;
    uint8_t *orig_dest = dest;
    const uint8_t *dest_end = dest + dest_len;

    while (dest < dest_end) {
        if (bytestream2_get_bytes_left(&s->gb) <= 0)
            return AVERROR_INVALIDDATA;

        opcode = bytestream2_get_byteu(&s->gb);

        if (opcode < 0xe0) {
            int size2, back;
            if ((opcode & 0x80) == 0) {
                size  = opcode & 3;
                back  = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
                size2 = ((opcode & 0x1c) >> 2) + 3;
            } else if ((opcode & 0x40) == 0) {
                size  = bytestream2_peek_byte(&s->gb) >> 6;
                back  = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
                size2 = (opcode & 0x3f) + 4;
            } else {
                size  = opcode & 3;
                back  = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
                size2 = ((opcode & 0x0c) <<  6) + bytestream2_get_byte(&s->gb) + 5;
                if (size + size2 > dest_end - dest)
                    break;
            }
            if (dest + size + size2 > dest_end ||
                dest - orig_dest + size < back)
                return AVERROR_INVALIDDATA;
            bytestream2_get_buffer(&s->gb, dest, size);
            dest += size;
            av_memcpy_backptr(dest, back, size2);
            dest += size2;
        } else {
            int finish = opcode >= 0xfc;

            size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
            if (dest_end - dest < size)
                return AVERROR_INVALIDDATA;
            bytestream2_get_buffer(&s->gb, dest, size);
            dest += size;
            if (finish)
                break;
        }
    }
    return dest - orig_dest;
}

static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
{
    XanContext *s = avctx->priv_data;
    uint8_t *U, *V;
    int val, uval, vval;
    int i, j;
    const uint8_t *src, *src_end;
    const uint8_t *table;
    int mode, offset, dec_size, table_size;

    if (!chroma_off)
        return 0;
    if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
        return AVERROR_INVALIDDATA;
    }
    bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
    mode        = bytestream2_get_le16(&s->gb);
    table       = s->gb.buffer;
    table_size  = bytestream2_get_le16(&s->gb);
    offset      = table_size * 2;
    table_size += 1;

    if (offset >= bytestream2_get_bytes_left(&s->gb)) {
        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
        return AVERROR_INVALIDDATA;
    }

    bytestream2_skip(&s->gb, offset);
    memset(s->scratch_buffer, 0, s->buffer_size);
    dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
    if (dec_size < 0) {
        av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
        return dec_size;
    }

    U = s->pic->data[1];
    V = s->pic->data[2];
    src     = s->scratch_buffer;
    src_end = src + dec_size;
    if (mode) {
        for (j = 0; j < avctx->height >> 1; j++) {
            for (i = 0; i < avctx->width >> 1; i++) {
                if (src_end - src < 1)
                    return 0;
                val = *src++;
                if (val) {
                    if (val >= table_size)
                        return AVERROR_INVALIDDATA;
                    val  = AV_RL16(table + (val << 1));
                    uval = (val >> 3) & 0xF8;
                    vval = (val >> 8) & 0xF8;
                    U[i] = uval | (uval >> 5);
                    V[i] = vval | (vval >> 5);
                }
            }
            U += s->pic->linesize[1];
            V += s->pic->linesize[2];
        }
        if (avctx->height & 1) {
            memcpy(U, U - s->pic->linesize[1], avctx->width >> 1);
            memcpy(V, V - s->pic->linesize[2], avctx->width >> 1);
        }
    } else {
        uint8_t *U2 = U + s->pic->linesize[1];
        uint8_t *V2 = V + s->pic->linesize[2];

        for (j = 0; j < avctx->height >> 2; j++) {
            for (i = 0; i < avctx->width >> 1; i += 2) {
                if (src_end - src < 1)
                    return 0;
                val = *src++;
                if (val) {
                    if (val >= table_size)
                        return AVERROR_INVALIDDATA;
                    val  = AV_RL16(table + (val << 1));
                    uval = (val >> 3) & 0xF8;
                    vval = (val >> 8) & 0xF8;
                    U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
                    V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
                }
            }
            U  += s->pic->linesize[1] * 2;
            V  += s->pic->linesize[2] * 2;
            U2 += s->pic->linesize[1] * 2;
            V2 += s->pic->linesize[2] * 2;
        }
        if (avctx->height & 3) {
            int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;

            memcpy(U, U - lines * s->pic->linesize[1], lines * s->pic->linesize[1]);
            memcpy(V, V - lines * s->pic->linesize[2], lines * s->pic->linesize[2]);
        }
    }

    return 0;
}

static int xan_decode_frame_type0(AVCodecContext *avctx)
{
    XanContext *s = avctx->priv_data;
    uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
    unsigned  chroma_off, corr_off;
    int cur, last;
    int i, j;
    int ret;

    chroma_off = bytestream2_get_le32(&s->gb);
    corr_off   = bytestream2_get_le32(&s->gb);

    if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
        return ret;

    if (corr_off >= bytestream2_size(&s->gb)) {
        av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
        corr_off = 0;
    }
    bytestream2_seek(&s->gb, 12, SEEK_SET);
    ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
    if (ret) {
        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
        return ret;
    }

    ybuf = s->y_buffer;
    last = *src++;
    ybuf[0] = last << 1;
    for (j = 1; j < avctx->width - 1; j += 2) {
        cur = (last + *src++) & 0x1F;
        ybuf[j]   = last + cur;
        ybuf[j+1] = cur << 1;
        last = cur;
    }
    ybuf[j]  = last << 1;
    prev_buf = ybuf;
    ybuf += avctx->width;

    for (i = 1; i < avctx->height; i++) {
        last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
        ybuf[0] = last << 1;
        for (j = 1; j < avctx->width - 1; j += 2) {
            cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
            ybuf[j]   = last + cur;
            ybuf[j+1] = cur << 1;
            last = cur;
        }
        ybuf[j] = last << 1;
        prev_buf = ybuf;
        ybuf += avctx->width;
    }

    if (corr_off) {
        int dec_size;

        bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
        dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
        if (dec_size < 0)
            dec_size = 0;
        else
            dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);

        for (i = 0; i < dec_size; i++)
            s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
    }

    src  = s->y_buffer;
    ybuf = s->pic->data[0];
    for (j = 0; j < avctx->height; j++) {
        for (i = 0; i < avctx->width; i++)
            ybuf[i] = (src[i] << 2) | (src[i] >> 3);
        src  += avctx->width;
        ybuf += s->pic->linesize[0];
    }

    return 0;
}

static int xan_decode_frame_type1(AVCodecContext *avctx)
{
    XanContext *s = avctx->priv_data;
    uint8_t *ybuf, *src = s->scratch_buffer;
    int cur, last;
    int i, j;
    int ret;

    if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
        return ret;

    bytestream2_seek(&s->gb, 16, SEEK_SET);
    ret = xan_unpack_luma(s, src,
                          s->buffer_size >> 1);
    if (ret) {
        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
        return ret;
    }

    ybuf = s->y_buffer;
    for (i = 0; i < avctx->height; i++) {
        last = (ybuf[0] + (*src++ << 1)) & 0x3F;
        ybuf[0] = last;
        for (j = 1; j < avctx->width - 1; j += 2) {
            cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
            ybuf[j]   = (last + cur) >> 1;
            ybuf[j+1] = cur;
            last = cur;
        }
        ybuf[j] = last;
        ybuf += avctx->width;
    }

    src = s->y_buffer;
    ybuf = s->pic->data[0];
    for (j = 0; j < avctx->height; j++) {
        for (i = 0; i < avctx->width; i++)
            ybuf[i] = (src[i] << 2) | (src[i] >> 3);
        src  += avctx->width;
        ybuf += s->pic->linesize[0];
    }

    return 0;
}

static int xan_decode_frame(AVCodecContext *avctx,
                            void *data, int *got_frame,
                            AVPacket *avpkt)
{
    XanContext *s = avctx->priv_data;
    int ftype;
    int ret;

    if ((ret = ff_reget_buffer(avctx, s->pic, 0)) < 0)
        return ret;

    bytestream2_init(&s->gb, avpkt->data, avpkt->size);
    ftype = bytestream2_get_le32(&s->gb);
    switch (ftype) {
    case 0:
        ret = xan_decode_frame_type0(avctx);
        break;
    case 1:
        ret = xan_decode_frame_type1(avctx);
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
        return AVERROR_INVALIDDATA;
    }
    if (ret)
        return ret;

    if ((ret = av_frame_ref(data, s->pic)) < 0)
        return ret;

    *got_frame = 1;

    return avpkt->size;
}

AVCodec ff_xan_wc4_decoder = {
    .name           = "xan_wc4",
    .long_name      = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_XAN_WC4,
    .priv_data_size = sizeof(XanContext),
    .init           = xan_decode_init,
    .close          = xan_decode_end,
    .decode         = xan_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
};


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* Wing Commander/Xan Video Decoder
3			* Copyright (C) 2011 Konstantin Shishkov
4			* based on work by Mike Melanson
5			*
6			* This file is part of FFmpeg.
7			*
8			* FFmpeg is free software; you can redistribute it and/or
9			* modify it under the terms of the GNU Lesser General Public
10			* License as published by the Free Software Foundation; either
11			* version 2.1 of the License, or (at your option) any later version.
12			*
13			* FFmpeg is distributed in the hope that it will be useful,
14			* but WITHOUT ANY WARRANTY; without even the implied warranty of
15			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16			* Lesser General Public License for more details.
17			*
18			* You should have received a copy of the GNU Lesser General Public
19			* License along with FFmpeg; if not, write to the Free Software
20			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21			*/
22
23			#include "libavutil/intreadwrite.h"
24			#include "libavutil/mem.h"
25
26			#include "avcodec.h"
27			#include "bytestream.h"
28			#include "internal.h"
29
30			typedef struct XanContext {
31			AVCodecContext *avctx;
32			AVFrame *pic;
33
34			uint8_t *y_buffer;
35			uint8_t *scratch_buffer;
36			int buffer_size;
37			GetByteContext gb;
38			} XanContext;
39
40		3	static av_cold int xan_decode_end(AVCodecContext *avctx)
41			{
42		3	XanContext *s = avctx->priv_data;
43
44		3	av_frame_free(&s->pic);
45
46		3	av_freep(&s->y_buffer);
47		3	av_freep(&s->scratch_buffer);
48
49		3	return 0;
50			}
51
52		3	static av_cold int xan_decode_init(AVCodecContext *avctx)
53			{
54		3	XanContext *s = avctx->priv_data;
55
56		3	s->avctx = avctx;
57
58		3	avctx->pix_fmt = AV_PIX_FMT_YUV420P;
59
60	✗✓	3	if (avctx->height < 8) {
61			av_log(avctx, AV_LOG_ERROR, "Invalid frame height: %d.\n", avctx->height);
62			return AVERROR(EINVAL);
63			}
64	✗✓	3	if (avctx->width & 1) {
65			av_log(avctx, AV_LOG_ERROR, "Invalid frame width: %d.\n", avctx->width);
66			return AVERROR(EINVAL);
67			}
68
69		3	s->buffer_size = avctx->width * avctx->height;
70		3	s->y_buffer = av_malloc(s->buffer_size);
71	✗✓	3	if (!s->y_buffer)
72			return AVERROR(ENOMEM);
73		3	s->scratch_buffer = av_malloc(s->buffer_size + 130);
74	✗✓	3	if (!s->scratch_buffer)
75			return AVERROR(ENOMEM);
76
77		3	s->pic = av_frame_alloc();
78	✗✓	3	if (!s->pic)
79			return AVERROR(ENOMEM);
80
81		3	return 0;
82			}
83
84		21	static int xan_unpack_luma(XanContext *s,
85			uint8_t *dst, const int dst_size)
86			{
87			int tree_size, eof;
88			int bits, mask;
89			int tree_root, node;
90		21	const uint8_t *dst_end = dst + dst_size;
91		21	GetByteContext tree = s->gb;
92		21	int start_off = bytestream2_tell(&tree);
93
94		21	tree_size = bytestream2_get_byte(&s->gb);
95		21	eof = bytestream2_get_byte(&s->gb);
96		21	tree_root = eof + tree_size;
97		21	bytestream2_skip(&s->gb, tree_size * 2);
98
99		21	node = tree_root;
100		21	bits = bytestream2_get_byte(&s->gb);
101		21	mask = 0x80;
102		691350	for (;;) {
103		691371	int bit = !!(bits & mask);
104		691371	mask >>= 1;
105		691371	bytestream2_seek(&tree, start_off + node2 + bit - eof 2, SEEK_SET);
106		691371	node = bytestream2_get_byte(&tree);
107	✓✓	691371	if (node == eof)
108		21	break;
109	✓✓	691350	if (node < eof) {
110		554400	*dst++ = node;
111	✗✓	554400	if (dst > dst_end)
112			break;
113		554400	node = tree_root;
114			}
115	✓✓	691350	if (!mask) {
116	✗✓	86409	if (bytestream2_get_bytes_left(&s->gb) <= 0)
117			break;
118		86409	bits = bytestream2_get_byteu(&s->gb);
119		86409	mask = 0x80;
120			}
121			}
122	✗✓	21	return dst != dst_end ? AVERROR_INVALIDDATA : 0;
123			}
124
125			/* almost the same as in xan_wc3 decoder */
126		26	static int xan_unpack(XanContext *s,
127			uint8_t *dest, const int dest_len)
128			{
129			uint8_t opcode;
130			int size;
131		26	uint8_t *orig_dest = dest;
132		26	const uint8_t *dest_end = dest + dest_len;
133
134	✓✓	11861	while (dest < dest_end) {
135	✗✓	11856	if (bytestream2_get_bytes_left(&s->gb) <= 0)
136			return AVERROR_INVALIDDATA;
137
138		11856	opcode = bytestream2_get_byteu(&s->gb);
139
140	✓✓	11856	if (opcode < 0xe0) {
141			int size2, back;
142	✓✓	11348	if ((opcode & 0x80) == 0) {
143		7882	size = opcode & 3;
144		7882	back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
145		7882	size2 = ((opcode & 0x1c) >> 2) + 3;
146	✓✓	3466	} else if ((opcode & 0x40) == 0) {
147		3066	size = bytestream2_peek_byte(&s->gb) >> 6;
148		3066	back = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
149		3066	size2 = (opcode & 0x3f) + 4;
150			} else {
151		400	size = opcode & 3;
152		400	back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
153		400	size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&s->gb) + 5;
154	✗✓	400	if (size + size2 > dest_end - dest)
155			break;
156			}
157	✓✗	11348	if (dest + size + size2 > dest_end \|\|
158	✗✓	11348	dest - orig_dest + size < back)
159			return AVERROR_INVALIDDATA;
160		11348	bytestream2_get_buffer(&s->gb, dest, size);
161		11348	dest += size;
162		11348	av_memcpy_backptr(dest, back, size2);
163		11348	dest += size2;
164			} else {
165		508	int finish = opcode >= 0xfc;
166
167	✓✓	508	size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
168	✗✓	508	if (dest_end - dest < size)
169			return AVERROR_INVALIDDATA;
170		508	bytestream2_get_buffer(&s->gb, dest, size);
171		508	dest += size;
172	✓✓	508	if (finish)
173		21	break;
174			}
175			}
176		26	return dest - orig_dest;
177			}
178
179		21	static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
180			{
181		21	XanContext *s = avctx->priv_data;
182			uint8_t U, V;
183			int val, uval, vval;
184			int i, j;
185			const uint8_t src, src_end;
186			const uint8_t *table;
187			int mode, offset, dec_size, table_size;
188
189	✗✓	21	if (!chroma_off)
190			return 0;
191	✗✓	21	if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
192			av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
193			return AVERROR_INVALIDDATA;
194			}
195		21	bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
196		21	mode = bytestream2_get_le16(&s->gb);
197		21	table = s->gb.buffer;
198		21	table_size = bytestream2_get_le16(&s->gb);
199		21	offset = table_size * 2;
200		21	table_size += 1;
201
202	✗✓	21	if (offset >= bytestream2_get_bytes_left(&s->gb)) {
203			av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
204			return AVERROR_INVALIDDATA;
205			}
206
207		21	bytestream2_skip(&s->gb, offset);
208		21	memset(s->scratch_buffer, 0, s->buffer_size);
209		21	dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
210	✗✓	21	if (dec_size < 0) {
211			av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
212			return dec_size;
213			}
214
215		21	U = s->pic->data[1];
216		21	V = s->pic->data[2];
217		21	src = s->scratch_buffer;
218		21	src_end = src + dec_size;
219	✓✓	21	if (mode) {
220	✓✓	332	for (j = 0; j < avctx->height >> 1; j++) {
221	✓✓	52808	for (i = 0; i < avctx->width >> 1; i++) {
222	✗✓	52480	if (src_end - src < 1)
223			return 0;
224		52480	val = *src++;
225	✓✗	52480	if (val) {
226	✗✓	52480	if (val >= table_size)
227			return AVERROR_INVALIDDATA;
228		52480	val = AV_RL16(table + (val << 1));
229		52480	uval = (val >> 3) & 0xF8;
230		52480	vval = (val >> 8) & 0xF8;
231		52480	U[i] = uval \| (uval >> 5);
232		52480	V[i] = vval \| (vval >> 5);
233			}
234			}
235		328	U += s->pic->linesize[1];
236		328	V += s->pic->linesize[2];
237			}
238	✓✗	4	if (avctx->height & 1) {
239		4	memcpy(U, U - s->pic->linesize[1], avctx->width >> 1);
240		4	memcpy(V, V - s->pic->linesize[2], avctx->width >> 1);
241			}
242			} else {
243		17	uint8_t *U2 = U + s->pic->linesize[1];
244		17	uint8_t *V2 = V + s->pic->linesize[2];
245
246	✓✓	714	for (j = 0; j < avctx->height >> 2; j++) {
247	✓✓	56457	for (i = 0; i < avctx->width >> 1; i += 2) {
248	✗✓	55760	if (src_end - src < 1)
249			return 0;
250		55760	val = *src++;
251	✓✓	55760	if (val) {
252	✗✓	17613	if (val >= table_size)
253			return AVERROR_INVALIDDATA;
254		17613	val = AV_RL16(table + (val << 1));
255		17613	uval = (val >> 3) & 0xF8;
256		17613	vval = (val >> 8) & 0xF8;
257		17613	U[i] = U[i+1] = U2[i] = U2[i+1] = uval \| (uval >> 5);
258		17613	V[i] = V[i+1] = V2[i] = V2[i+1] = vval \| (vval >> 5);
259			}
260			}
261		697	U += s->pic->linesize[1] * 2;
262		697	V += s->pic->linesize[2] * 2;
263		697	U2 += s->pic->linesize[1] * 2;
264		697	V2 += s->pic->linesize[2] * 2;
265			}
266	✓✗	17	if (avctx->height & 3) {
267		17	int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;
268
269		17	memcpy(U, U - lines * s->pic->linesize[1], lines * s->pic->linesize[1]);
270		17	memcpy(V, V - lines * s->pic->linesize[2], lines * s->pic->linesize[2]);
271			}
272			}
273
274		21	return 0;
275			}
276
277		5	static int xan_decode_frame_type0(AVCodecContext *avctx)
278			{
279		5	XanContext *s = avctx->priv_data;
280		5	uint8_t ybuf, prev_buf, *src = s->scratch_buffer;
281			unsigned chroma_off, corr_off;
282			int cur, last;
283			int i, j;
284			int ret;
285
286		5	chroma_off = bytestream2_get_le32(&s->gb);
287		5	corr_off = bytestream2_get_le32(&s->gb);
288
289	✗✓	5	if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
290			return ret;
291
292	✗✓	5	if (corr_off >= bytestream2_size(&s->gb)) {
293			av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
294			corr_off = 0;
295			}
296		5	bytestream2_seek(&s->gb, 12, SEEK_SET);
297		5	ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
298	✗✓	5	if (ret) {
299			av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
300			return ret;
301			}
302
303		5	ybuf = s->y_buffer;
304		5	last = *src++;
305		5	ybuf[0] = last << 1;
306	✓✓	800	for (j = 1; j < avctx->width - 1; j += 2) {
307		795	cur = (last + *src++) & 0x1F;
308		795	ybuf[j] = last + cur;
309		795	ybuf[j+1] = cur << 1;
310		795	last = cur;
311			}
312		5	ybuf[j] = last << 1;
313		5	prev_buf = ybuf;
314		5	ybuf += avctx->width;
315
316	✓✓	825	for (i = 1; i < avctx->height; i++) {
317		820	last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
318		820	ybuf[0] = last << 1;
319	✓✓	131200	for (j = 1; j < avctx->width - 1; j += 2) {
320		130380	cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
321		130380	ybuf[j] = last + cur;
322		130380	ybuf[j+1] = cur << 1;
323		130380	last = cur;
324			}
325		820	ybuf[j] = last << 1;
326		820	prev_buf = ybuf;
327		820	ybuf += avctx->width;
328			}
329
330	✓✗	5	if (corr_off) {
331			int dec_size;
332
333		5	bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
334		5	dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
335	✗✓	5	if (dec_size < 0)
336			dec_size = 0;
337			else
338	✓✗	5	dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
339
340	✓✓	132000	for (i = 0; i < dec_size; i++)
341		131995	s->y_buffer[i2+1] = (s->y_buffer[i2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
342			}
343
344		5	src = s->y_buffer;
345		5	ybuf = s->pic->data[0];
346	✓✓	830	for (j = 0; j < avctx->height; j++) {
347	✓✓	264825	for (i = 0; i < avctx->width; i++)
348		264000	ybuf[i] = (src[i] << 2) \| (src[i] >> 3);
349		825	src += avctx->width;
350		825	ybuf += s->pic->linesize[0];
351			}
352
353		5	return 0;
354			}
355
356		16	static int xan_decode_frame_type1(AVCodecContext *avctx)
357			{
358		16	XanContext *s = avctx->priv_data;
359		16	uint8_t ybuf, src = s->scratch_buffer;
360			int cur, last;
361			int i, j;
362			int ret;
363
364	✗✓	16	if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
365			return ret;
366
367		16	bytestream2_seek(&s->gb, 16, SEEK_SET);
368		16	ret = xan_unpack_luma(s, src,
369		16	s->buffer_size >> 1);
370	✗✓	16	if (ret) {
371			av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
372			return ret;
373			}
374
375		16	ybuf = s->y_buffer;
376	✓✓	2656	for (i = 0; i < avctx->height; i++) {
377		2640	last = (ybuf[0] + (*src++ << 1)) & 0x3F;
378		2640	ybuf[0] = last;
379	✓✓	422400	for (j = 1; j < avctx->width - 1; j += 2) {
380		419760	cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
381		419760	ybuf[j] = (last + cur) >> 1;
382		419760	ybuf[j+1] = cur;
383		419760	last = cur;
384			}
385		2640	ybuf[j] = last;
386		2640	ybuf += avctx->width;
387			}
388
389		16	src = s->y_buffer;
390		16	ybuf = s->pic->data[0];
391	✓✓	2656	for (j = 0; j < avctx->height; j++) {
392	✓✓	847440	for (i = 0; i < avctx->width; i++)
393		844800	ybuf[i] = (src[i] << 2) \| (src[i] >> 3);
394		2640	src += avctx->width;
395		2640	ybuf += s->pic->linesize[0];
396			}
397
398		16	return 0;
399			}
400
401		21	static int xan_decode_frame(AVCodecContext *avctx,
402			void data, int got_frame,
403			AVPacket *avpkt)
404			{
405		21	XanContext *s = avctx->priv_data;
406			int ftype;
407			int ret;
408
409	✗✓	21	if ((ret = ff_reget_buffer(avctx, s->pic, 0)) < 0)
410			return ret;
411
412		21	bytestream2_init(&s->gb, avpkt->data, avpkt->size);
413		21	ftype = bytestream2_get_le32(&s->gb);
414	✓✓✗	21	switch (ftype) {
415		5	case 0:
416		5	ret = xan_decode_frame_type0(avctx);
417		5	break;
418		16	case 1:
419		16	ret = xan_decode_frame_type1(avctx);
420		16	break;
421			default:
422			av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
423			return AVERROR_INVALIDDATA;
424			}
425	✗✓	21	if (ret)
426			return ret;
427
428	✗✓	21	if ((ret = av_frame_ref(data, s->pic)) < 0)
429			return ret;
430
431		21	*got_frame = 1;
432
433		21	return avpkt->size;
434			}
435
436			AVCodec ff_xan_wc4_decoder = {
437			.name = "xan_wc4",
438			.long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
439			.type = AVMEDIA_TYPE_VIDEO,
440			.id = AV_CODEC_ID_XAN_WC4,
441			.priv_data_size = sizeof(XanContext),
442			.init = xan_decode_init,
443			.close = xan_decode_end,
444			.decode = xan_decode_frame,
445			.capabilities = AV_CODEC_CAP_DR1,
446			.caps_internal = FF_CODEC_CAP_INIT_CLEANUP \| FF_CODEC_CAP_INIT_THREADSAFE,
447			};