aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/wcmv.c
blob: 04c597e7674616bd70eb6fa00d68604d22f2f5bb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
/*
 * WinCAM Motion Video decoder
 *
 * Copyright (c) 2018 Paul B Mahol
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libavutil/imgutils.h"

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

#include <zlib.h>

typedef struct WCMVContext {
    int         bpp;
    z_stream    zstream;
    AVFrame    *prev_frame;
    uint8_t     block_data[65536*8];
} WCMVContext;

static int decode_frame(AVCodecContext *avctx,
                        void *data, int *got_frame,
                        AVPacket *avpkt)
{
    WCMVContext *s = avctx->priv_data;
    AVFrame *frame = data;
    int skip, blocks, zret, ret, intra = 0, flags = 0, bpp = s->bpp;
    GetByteContext gb;
    uint8_t *dst;

    ret = inflateReset(&s->zstream);
    if (ret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
        return AVERROR_EXTERNAL;
    }

    bytestream2_init(&gb, avpkt->data, avpkt->size);
    blocks = bytestream2_get_le16(&gb);
    if (!blocks)
        flags |= FF_REGET_BUFFER_FLAG_READONLY;

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

    if (blocks > 5) {
        GetByteContext bgb;
        int x = 0, size;

        if (blocks * 8 >= 0xFFFF)
            size = bytestream2_get_le24(&gb);
        else if (blocks * 8 >= 0xFF)
            size = bytestream2_get_le16(&gb);
        else
            size = bytestream2_get_byte(&gb);

        skip = bytestream2_tell(&gb);
        if (size > avpkt->size - skip)
            return AVERROR_INVALIDDATA;

        s->zstream.next_in  = avpkt->data + skip;
        s->zstream.avail_in = size;
        s->zstream.next_out  = s->block_data;
        s->zstream.avail_out = sizeof(s->block_data);

        zret = inflate(&s->zstream, Z_FINISH);
        if (zret != Z_STREAM_END) {
            av_log(avctx, AV_LOG_ERROR,
                   "Inflate failed with return code: %d.\n", zret);
            return AVERROR_INVALIDDATA;
        }

        ret = inflateReset(&s->zstream);
        if (ret != Z_OK) {
            av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
            return AVERROR_EXTERNAL;
        }

        bytestream2_skip(&gb, size);
        bytestream2_init(&bgb, s->block_data, blocks * 8);

        for (int i = 0; i < blocks; i++) {
            int w, h;

            bytestream2_skip(&bgb, 4);
            w = bytestream2_get_le16(&bgb);
            h = bytestream2_get_le16(&bgb);
            if (x + bpp * (int64_t)w * h > INT_MAX)
                return AVERROR_INVALIDDATA;
            x += bpp * w * h;
        }

        if (x >= 0xFFFF)
            bytestream2_skip(&gb, 3);
        else if (x >= 0xFF)
            bytestream2_skip(&gb, 2);
        else
            bytestream2_skip(&gb, 1);

        skip = bytestream2_tell(&gb);

        s->zstream.next_in  = avpkt->data + skip;
        s->zstream.avail_in = avpkt->size - skip;

        bytestream2_init(&gb, s->block_data, blocks * 8);
    } else if (blocks) {
        int x = 0;

        bytestream2_seek(&gb, 2, SEEK_SET);

        for (int i = 0; i < blocks; i++) {
            int w, h;

            bytestream2_skip(&gb, 4);
            w = bytestream2_get_le16(&gb);
            h = bytestream2_get_le16(&gb);
            if (x + bpp * (int64_t)w * h > INT_MAX)
                return AVERROR_INVALIDDATA;
            x += bpp * w * h;
        }

        if (x >= 0xFFFF)
            bytestream2_skip(&gb, 3);
        else if (x >= 0xFF)
            bytestream2_skip(&gb, 2);
        else
            bytestream2_skip(&gb, 1);

        skip = bytestream2_tell(&gb);

        s->zstream.next_in  = avpkt->data + skip;
        s->zstream.avail_in = avpkt->size - skip;

        bytestream2_seek(&gb, 2, SEEK_SET);
    }

    if (bytestream2_get_bytes_left(&gb) < 8LL * blocks)
        return AVERROR_INVALIDDATA;

    if (!avctx->frame_number) {
        ptrdiff_t linesize[4] = { s->prev_frame->linesize[0], 0, 0, 0 };
        av_image_fill_black(s->prev_frame->data, linesize, avctx->pix_fmt, 0,
                            avctx->width, avctx->height);
    }

    for (int block = 0; block < blocks; block++) {
        int x, y, w, h;

        x = bytestream2_get_le16(&gb);
        y = bytestream2_get_le16(&gb);
        w = bytestream2_get_le16(&gb);
        h = bytestream2_get_le16(&gb);

        if (blocks == 1 && x == 0 && y == 0 && w == avctx->width && h == avctx->height)
            intra = 1;

        if (x + w > avctx->width || y + h > avctx->height)
            return AVERROR_INVALIDDATA;

        if (w > avctx->width || h > avctx->height)
            return AVERROR_INVALIDDATA;

        dst = s->prev_frame->data[0] + (avctx->height - y - 1) * s->prev_frame->linesize[0] + x * bpp;
        for (int i = 0; i < h; i++) {
            s->zstream.next_out  = dst;
            s->zstream.avail_out = w * bpp;

            zret = inflate(&s->zstream, Z_SYNC_FLUSH);
            if (zret != Z_OK && zret != Z_STREAM_END) {
                av_log(avctx, AV_LOG_ERROR,
                       "Inflate failed with return code: %d.\n", zret);
                return AVERROR_INVALIDDATA;
            }

            dst -= s->prev_frame->linesize[0];
        }
    }

    s->prev_frame->key_frame = intra;
    s->prev_frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;

    if ((ret = av_frame_ref(frame, s->prev_frame)) < 0)
        return ret;

    *got_frame = 1;

    return avpkt->size;
}

static av_cold int decode_init(AVCodecContext *avctx)
{
    WCMVContext *s = avctx->priv_data;
    int zret;

    switch (avctx->bits_per_coded_sample) {
    case 16: avctx->pix_fmt = AV_PIX_FMT_RGB565LE; break;
    case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24;  break;
    case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA;   break;
    default: av_log(avctx, AV_LOG_ERROR, "Unsupported bits_per_coded_sample: %d\n",
                    avctx->bits_per_coded_sample);
             return AVERROR_PATCHWELCOME;
    }

    s->bpp = avctx->bits_per_coded_sample >> 3;

    s->zstream.zalloc = Z_NULL;
    s->zstream.zfree = Z_NULL;
    s->zstream.opaque = Z_NULL;
    zret = inflateInit(&s->zstream);
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
        return AVERROR_EXTERNAL;
    }

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

    return 0;
}

static av_cold int decode_close(AVCodecContext *avctx)
{
    WCMVContext *s = avctx->priv_data;

    av_frame_free(&s->prev_frame);
    inflateEnd(&s->zstream);

    return 0;
}

const AVCodec ff_wcmv_decoder = {
    .name             = "wcmv",
    .long_name        = NULL_IF_CONFIG_SMALL("WinCAM Motion Video"),
    .type             = AVMEDIA_TYPE_VIDEO,
    .id               = AV_CODEC_ID_WCMV,
    .priv_data_size   = sizeof(WCMVContext),
    .init             = decode_init,
    .close            = decode_close,
    .decode           = decode_frame,
    .capabilities     = AV_CODEC_CAP_DR1,
    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE |
                        FF_CODEC_CAP_INIT_CLEANUP,
};