FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/xxan.c	Lines:	228	269	84.8 %
Date:	2020-10-23 17:01:47	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) {
        xan_decode_end(avctx);
        return AVERROR(ENOMEM);
    }

    s->pic = av_frame_alloc();
    if (!s->pic) {
        xan_decode_end(avctx);
        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,
};


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			xan_decode_end(avctx);
76			return AVERROR(ENOMEM);
77			}
78
79		3	s->pic = av_frame_alloc();
80	✗✓	3	if (!s->pic) {
81			xan_decode_end(avctx);
82			return AVERROR(ENOMEM);
83			}
84
85		3	return 0;
86			}
87
88		21	static int xan_unpack_luma(XanContext *s,
89			uint8_t *dst, const int dst_size)
90			{
91			int tree_size, eof;
92			int bits, mask;
93			int tree_root, node;
94		21	const uint8_t *dst_end = dst + dst_size;
95		21	GetByteContext tree = s->gb;
96		21	int start_off = bytestream2_tell(&tree);
97
98		21	tree_size = bytestream2_get_byte(&s->gb);
99		21	eof = bytestream2_get_byte(&s->gb);
100		21	tree_root = eof + tree_size;
101		21	bytestream2_skip(&s->gb, tree_size * 2);
102
103		21	node = tree_root;
104		21	bits = bytestream2_get_byte(&s->gb);
105		21	mask = 0x80;
106		691350	for (;;) {
107		691371	int bit = !!(bits & mask);
108		691371	mask >>= 1;
109		691371	bytestream2_seek(&tree, start_off + node2 + bit - eof 2, SEEK_SET);
110		691371	node = bytestream2_get_byte(&tree);
111	✓✓	691371	if (node == eof)
112		21	break;
113	✓✓	691350	if (node < eof) {
114		554400	*dst++ = node;
115	✗✓	554400	if (dst > dst_end)
116			break;
117		554400	node = tree_root;
118			}
119	✓✓	691350	if (!mask) {
120	✗✓	86409	if (bytestream2_get_bytes_left(&s->gb) <= 0)
121			break;
122		86409	bits = bytestream2_get_byteu(&s->gb);
123		86409	mask = 0x80;
124			}
125			}
126	✗✓	21	return dst != dst_end ? AVERROR_INVALIDDATA : 0;
127			}
128
129			/* almost the same as in xan_wc3 decoder */
130		26	static int xan_unpack(XanContext *s,
131			uint8_t *dest, const int dest_len)
132			{
133			uint8_t opcode;
134			int size;
135		26	uint8_t *orig_dest = dest;
136		26	const uint8_t *dest_end = dest + dest_len;
137
138	✓✓	11861	while (dest < dest_end) {
139	✗✓	11856	if (bytestream2_get_bytes_left(&s->gb) <= 0)
140			return AVERROR_INVALIDDATA;
141
142		11856	opcode = bytestream2_get_byteu(&s->gb);
143
144	✓✓	11856	if (opcode < 0xe0) {
145			int size2, back;
146	✓✓	11348	if ((opcode & 0x80) == 0) {
147		7882	size = opcode & 3;
148		7882	back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
149		7882	size2 = ((opcode & 0x1c) >> 2) + 3;
150	✓✓	3466	} else if ((opcode & 0x40) == 0) {
151		3066	size = bytestream2_peek_byte(&s->gb) >> 6;
152		3066	back = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
153		3066	size2 = (opcode & 0x3f) + 4;
154			} else {
155		400	size = opcode & 3;
156		400	back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
157		400	size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&s->gb) + 5;
158	✗✓	400	if (size + size2 > dest_end - dest)
159			break;
160			}
161	✓✗	11348	if (dest + size + size2 > dest_end \|\|
162	✗✓	11348	dest - orig_dest + size < back)
163			return AVERROR_INVALIDDATA;
164		11348	bytestream2_get_buffer(&s->gb, dest, size);
165		11348	dest += size;
166		11348	av_memcpy_backptr(dest, back, size2);
167		11348	dest += size2;
168			} else {
169		508	int finish = opcode >= 0xfc;
170
171	✓✓	508	size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
172	✗✓	508	if (dest_end - dest < size)
173			return AVERROR_INVALIDDATA;
174		508	bytestream2_get_buffer(&s->gb, dest, size);
175		508	dest += size;
176	✓✓	508	if (finish)
177		21	break;
178			}
179			}
180		26	return dest - orig_dest;
181			}
182
183		21	static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
184			{
185		21	XanContext *s = avctx->priv_data;
186			uint8_t U, V;
187			int val, uval, vval;
188			int i, j;
189			const uint8_t src, src_end;
190			const uint8_t *table;
191			int mode, offset, dec_size, table_size;
192
193	✗✓	21	if (!chroma_off)
194			return 0;
195	✗✓	21	if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
196			av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
197			return AVERROR_INVALIDDATA;
198			}
199		21	bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
200		21	mode = bytestream2_get_le16(&s->gb);
201		21	table = s->gb.buffer;
202		21	table_size = bytestream2_get_le16(&s->gb);
203		21	offset = table_size * 2;
204		21	table_size += 1;
205
206	✗✓	21	if (offset >= bytestream2_get_bytes_left(&s->gb)) {
207			av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
208			return AVERROR_INVALIDDATA;
209			}
210
211		21	bytestream2_skip(&s->gb, offset);
212		21	memset(s->scratch_buffer, 0, s->buffer_size);
213		21	dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
214	✗✓	21	if (dec_size < 0) {
215			av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
216			return dec_size;
217			}
218
219		21	U = s->pic->data[1];
220		21	V = s->pic->data[2];
221		21	src = s->scratch_buffer;
222		21	src_end = src + dec_size;
223	✓✓	21	if (mode) {
224	✓✓	332	for (j = 0; j < avctx->height >> 1; j++) {
225	✓✓	52808	for (i = 0; i < avctx->width >> 1; i++) {
226	✗✓	52480	if (src_end - src < 1)
227			return 0;
228		52480	val = *src++;
229	✓✗	52480	if (val) {
230	✗✓	52480	if (val >= table_size)
231			return AVERROR_INVALIDDATA;
232		52480	val = AV_RL16(table + (val << 1));
233		52480	uval = (val >> 3) & 0xF8;
234		52480	vval = (val >> 8) & 0xF8;
235		52480	U[i] = uval \| (uval >> 5);
236		52480	V[i] = vval \| (vval >> 5);
237			}
238			}
239		328	U += s->pic->linesize[1];
240		328	V += s->pic->linesize[2];
241			}
242	✓✗	4	if (avctx->height & 1) {
243		4	memcpy(U, U - s->pic->linesize[1], avctx->width >> 1);
244		4	memcpy(V, V - s->pic->linesize[2], avctx->width >> 1);
245			}
246			} else {
247		17	uint8_t *U2 = U + s->pic->linesize[1];
248		17	uint8_t *V2 = V + s->pic->linesize[2];
249
250	✓✓	714	for (j = 0; j < avctx->height >> 2; j++) {
251	✓✓	56457	for (i = 0; i < avctx->width >> 1; i += 2) {
252	✗✓	55760	if (src_end - src < 1)
253			return 0;
254		55760	val = *src++;
255	✓✓	55760	if (val) {
256	✗✓	17613	if (val >= table_size)
257			return AVERROR_INVALIDDATA;
258		17613	val = AV_RL16(table + (val << 1));
259		17613	uval = (val >> 3) & 0xF8;
260		17613	vval = (val >> 8) & 0xF8;
261		17613	U[i] = U[i+1] = U2[i] = U2[i+1] = uval \| (uval >> 5);
262		17613	V[i] = V[i+1] = V2[i] = V2[i+1] = vval \| (vval >> 5);
263			}
264			}
265		697	U += s->pic->linesize[1] * 2;
266		697	V += s->pic->linesize[2] * 2;
267		697	U2 += s->pic->linesize[1] * 2;
268		697	V2 += s->pic->linesize[2] * 2;
269			}
270	✓✗	17	if (avctx->height & 3) {
271		17	int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;
272
273		17	memcpy(U, U - lines * s->pic->linesize[1], lines * s->pic->linesize[1]);
274		17	memcpy(V, V - lines * s->pic->linesize[2], lines * s->pic->linesize[2]);
275			}
276			}
277
278		21	return 0;
279			}
280
281		5	static int xan_decode_frame_type0(AVCodecContext *avctx)
282			{
283		5	XanContext *s = avctx->priv_data;
284		5	uint8_t ybuf, prev_buf, *src = s->scratch_buffer;
285			unsigned chroma_off, corr_off;
286			int cur, last;
287			int i, j;
288			int ret;
289
290		5	chroma_off = bytestream2_get_le32(&s->gb);
291		5	corr_off = bytestream2_get_le32(&s->gb);
292
293	✗✓	5	if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
294			return ret;
295
296	✗✓	5	if (corr_off >= bytestream2_size(&s->gb)) {
297			av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
298			corr_off = 0;
299			}
300		5	bytestream2_seek(&s->gb, 12, SEEK_SET);
301		5	ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
302	✗✓	5	if (ret) {
303			av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
304			return ret;
305			}
306
307		5	ybuf = s->y_buffer;
308		5	last = *src++;
309		5	ybuf[0] = last << 1;
310	✓✓	800	for (j = 1; j < avctx->width - 1; j += 2) {
311		795	cur = (last + *src++) & 0x1F;
312		795	ybuf[j] = last + cur;
313		795	ybuf[j+1] = cur << 1;
314		795	last = cur;
315			}
316		5	ybuf[j] = last << 1;
317		5	prev_buf = ybuf;
318		5	ybuf += avctx->width;
319
320	✓✓	825	for (i = 1; i < avctx->height; i++) {
321		820	last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
322		820	ybuf[0] = last << 1;
323	✓✓	131200	for (j = 1; j < avctx->width - 1; j += 2) {
324		130380	cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
325		130380	ybuf[j] = last + cur;
326		130380	ybuf[j+1] = cur << 1;
327		130380	last = cur;
328			}
329		820	ybuf[j] = last << 1;
330		820	prev_buf = ybuf;
331		820	ybuf += avctx->width;
332			}
333
334	✓✗	5	if (corr_off) {
335			int dec_size;
336
337		5	bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
338		5	dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
339	✗✓	5	if (dec_size < 0)
340			dec_size = 0;
341			else
342	✓✗	5	dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
343
344	✓✓	132000	for (i = 0; i < dec_size; i++)
345		131995	s->y_buffer[i2+1] = (s->y_buffer[i2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
346			}
347
348		5	src = s->y_buffer;
349		5	ybuf = s->pic->data[0];
350	✓✓	830	for (j = 0; j < avctx->height; j++) {
351	✓✓	264825	for (i = 0; i < avctx->width; i++)
352		264000	ybuf[i] = (src[i] << 2) \| (src[i] >> 3);
353		825	src += avctx->width;
354		825	ybuf += s->pic->linesize[0];
355			}
356
357		5	return 0;
358			}
359
360		16	static int xan_decode_frame_type1(AVCodecContext *avctx)
361			{
362		16	XanContext *s = avctx->priv_data;
363		16	uint8_t ybuf, src = s->scratch_buffer;
364			int cur, last;
365			int i, j;
366			int ret;
367
368	✗✓	16	if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
369			return ret;
370
371		16	bytestream2_seek(&s->gb, 16, SEEK_SET);
372		16	ret = xan_unpack_luma(s, src,
373		16	s->buffer_size >> 1);
374	✗✓	16	if (ret) {
375			av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
376			return ret;
377			}
378
379		16	ybuf = s->y_buffer;
380	✓✓	2656	for (i = 0; i < avctx->height; i++) {
381		2640	last = (ybuf[0] + (*src++ << 1)) & 0x3F;
382		2640	ybuf[0] = last;
383	✓✓	422400	for (j = 1; j < avctx->width - 1; j += 2) {
384		419760	cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
385		419760	ybuf[j] = (last + cur) >> 1;
386		419760	ybuf[j+1] = cur;
387		419760	last = cur;
388			}
389		2640	ybuf[j] = last;
390		2640	ybuf += avctx->width;
391			}
392
393		16	src = s->y_buffer;
394		16	ybuf = s->pic->data[0];
395	✓✓	2656	for (j = 0; j < avctx->height; j++) {
396	✓✓	847440	for (i = 0; i < avctx->width; i++)
397		844800	ybuf[i] = (src[i] << 2) \| (src[i] >> 3);
398		2640	src += avctx->width;
399		2640	ybuf += s->pic->linesize[0];
400			}
401
402		16	return 0;
403			}
404
405		21	static int xan_decode_frame(AVCodecContext *avctx,
406			void data, int got_frame,
407			AVPacket *avpkt)
408			{
409		21	XanContext *s = avctx->priv_data;
410			int ftype;
411			int ret;
412
413	✗✓	21	if ((ret = ff_reget_buffer(avctx, s->pic, 0)) < 0)
414			return ret;
415
416		21	bytestream2_init(&s->gb, avpkt->data, avpkt->size);
417		21	ftype = bytestream2_get_le32(&s->gb);
418	✓✓✗	21	switch (ftype) {
419		5	case 0:
420		5	ret = xan_decode_frame_type0(avctx);
421		5	break;
422		16	case 1:
423		16	ret = xan_decode_frame_type1(avctx);
424		16	break;
425			default:
426			av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
427			return AVERROR_INVALIDDATA;
428			}
429	✗✓	21	if (ret)
430			return ret;
431
432	✗✓	21	if ((ret = av_frame_ref(data, s->pic)) < 0)
433			return ret;
434
435		21	*got_frame = 1;
436
437		21	return avpkt->size;
438			}
439
440			AVCodec ff_xan_wc4_decoder = {
441			.name = "xan_wc4",
442			.long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
443			.type = AVMEDIA_TYPE_VIDEO,
444			.id = AV_CODEC_ID_XAN_WC4,
445			.priv_data_size = sizeof(XanContext),
446			.init = xan_decode_init,
447			.close = xan_decode_end,
448			.decode = xan_decode_frame,
449			.capabilities = AV_CODEC_CAP_DR1,
450			};