1 /*
2 * WinCAM Motion Video decoder
3 *
4 * Copyright (c) 2018 Paul B Mahol
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 <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26
27 #include "libavutil/imgutils.h"
28
29 #include "avcodec.h"
30 #include "bytestream.h"
31 #include "internal.h"
32
33 #include <zlib.h>
34
35 typedef struct WCMVContext {
36 int bpp;
37 z_stream zstream;
38 AVFrame *prev_frame;
39 uint8_t block_data[65536*8];
40 } WCMVContext;
41
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)42 static int decode_frame(AVCodecContext *avctx,
43 void *data, int *got_frame,
44 AVPacket *avpkt)
45 {
46 WCMVContext *s = avctx->priv_data;
47 AVFrame *frame = data;
48 int skip, blocks, zret, ret, intra = 0, flags = 0, bpp = s->bpp;
49 GetByteContext gb;
50 uint8_t *dst;
51
52 ret = inflateReset(&s->zstream);
53 if (ret != Z_OK) {
54 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
55 return AVERROR_EXTERNAL;
56 }
57
58 bytestream2_init(&gb, avpkt->data, avpkt->size);
59 blocks = bytestream2_get_le16(&gb);
60 if (!blocks)
61 flags |= FF_REGET_BUFFER_FLAG_READONLY;
62
63 if ((ret = ff_reget_buffer(avctx, s->prev_frame, flags)) < 0)
64 return ret;
65
66 if (blocks > 5) {
67 GetByteContext bgb;
68 int x = 0, size;
69
70 if (blocks * 8 >= 0xFFFF)
71 size = bytestream2_get_le24(&gb);
72 else if (blocks * 8 >= 0xFF)
73 size = bytestream2_get_le16(&gb);
74 else
75 size = bytestream2_get_byte(&gb);
76
77 skip = bytestream2_tell(&gb);
78 if (size > avpkt->size - skip)
79 return AVERROR_INVALIDDATA;
80
81 s->zstream.next_in = avpkt->data + skip;
82 s->zstream.avail_in = size;
83 s->zstream.next_out = s->block_data;
84 s->zstream.avail_out = sizeof(s->block_data);
85
86 zret = inflate(&s->zstream, Z_FINISH);
87 if (zret != Z_STREAM_END) {
88 av_log(avctx, AV_LOG_ERROR,
89 "Inflate failed with return code: %d.\n", zret);
90 return AVERROR_INVALIDDATA;
91 }
92
93 ret = inflateReset(&s->zstream);
94 if (ret != Z_OK) {
95 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
96 return AVERROR_EXTERNAL;
97 }
98
99 bytestream2_skip(&gb, size);
100 bytestream2_init(&bgb, s->block_data, blocks * 8);
101
102 for (int i = 0; i < blocks; i++) {
103 int w, h;
104
105 bytestream2_skip(&bgb, 4);
106 w = bytestream2_get_le16(&bgb);
107 h = bytestream2_get_le16(&bgb);
108 if (x + bpp * (int64_t)w * h > INT_MAX)
109 return AVERROR_INVALIDDATA;
110 x += bpp * w * h;
111 }
112
113 if (x >= 0xFFFF)
114 bytestream2_skip(&gb, 3);
115 else if (x >= 0xFF)
116 bytestream2_skip(&gb, 2);
117 else
118 bytestream2_skip(&gb, 1);
119
120 skip = bytestream2_tell(&gb);
121
122 s->zstream.next_in = avpkt->data + skip;
123 s->zstream.avail_in = avpkt->size - skip;
124
125 bytestream2_init(&gb, s->block_data, blocks * 8);
126 } else if (blocks) {
127 int x = 0;
128
129 bytestream2_seek(&gb, 2, SEEK_SET);
130
131 for (int i = 0; i < blocks; i++) {
132 int w, h;
133
134 bytestream2_skip(&gb, 4);
135 w = bytestream2_get_le16(&gb);
136 h = bytestream2_get_le16(&gb);
137 if (x + bpp * (int64_t)w * h > INT_MAX)
138 return AVERROR_INVALIDDATA;
139 x += bpp * w * h;
140 }
141
142 if (x >= 0xFFFF)
143 bytestream2_skip(&gb, 3);
144 else if (x >= 0xFF)
145 bytestream2_skip(&gb, 2);
146 else
147 bytestream2_skip(&gb, 1);
148
149 skip = bytestream2_tell(&gb);
150
151 s->zstream.next_in = avpkt->data + skip;
152 s->zstream.avail_in = avpkt->size - skip;
153
154 bytestream2_seek(&gb, 2, SEEK_SET);
155 }
156
157 if (bytestream2_get_bytes_left(&gb) < 8LL * blocks)
158 return AVERROR_INVALIDDATA;
159
160 if (!avctx->frame_number) {
161 ptrdiff_t linesize[4] = { s->prev_frame->linesize[0], 0, 0, 0 };
162 av_image_fill_black(s->prev_frame->data, linesize, avctx->pix_fmt, 0,
163 avctx->width, avctx->height);
164 }
165
166 for (int block = 0; block < blocks; block++) {
167 int x, y, w, h;
168
169 x = bytestream2_get_le16(&gb);
170 y = bytestream2_get_le16(&gb);
171 w = bytestream2_get_le16(&gb);
172 h = bytestream2_get_le16(&gb);
173
174 if (blocks == 1 && x == 0 && y == 0 && w == avctx->width && h == avctx->height)
175 intra = 1;
176
177 if (x + w > avctx->width || y + h > avctx->height)
178 return AVERROR_INVALIDDATA;
179
180 if (w > avctx->width || h > avctx->height)
181 return AVERROR_INVALIDDATA;
182
183 dst = s->prev_frame->data[0] + (avctx->height - y - 1) * s->prev_frame->linesize[0] + x * bpp;
184 for (int i = 0; i < h; i++) {
185 s->zstream.next_out = dst;
186 s->zstream.avail_out = w * bpp;
187
188 zret = inflate(&s->zstream, Z_SYNC_FLUSH);
189 if (zret != Z_OK && zret != Z_STREAM_END) {
190 av_log(avctx, AV_LOG_ERROR,
191 "Inflate failed with return code: %d.\n", zret);
192 return AVERROR_INVALIDDATA;
193 }
194
195 dst -= s->prev_frame->linesize[0];
196 }
197 }
198
199 s->prev_frame->key_frame = intra;
200 s->prev_frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
201
202 if ((ret = av_frame_ref(frame, s->prev_frame)) < 0)
203 return ret;
204
205 *got_frame = 1;
206
207 return avpkt->size;
208 }
209
decode_init(AVCodecContext * avctx)210 static av_cold int decode_init(AVCodecContext *avctx)
211 {
212 WCMVContext *s = avctx->priv_data;
213 int zret;
214
215 switch (avctx->bits_per_coded_sample) {
216 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB565LE; break;
217 case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
218 case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break;
219 default: av_log(avctx, AV_LOG_ERROR, "Unsupported bits_per_coded_sample: %d\n",
220 avctx->bits_per_coded_sample);
221 return AVERROR_PATCHWELCOME;
222 }
223
224 s->bpp = avctx->bits_per_coded_sample >> 3;
225
226 s->zstream.zalloc = Z_NULL;
227 s->zstream.zfree = Z_NULL;
228 s->zstream.opaque = Z_NULL;
229 zret = inflateInit(&s->zstream);
230 if (zret != Z_OK) {
231 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
232 return AVERROR_EXTERNAL;
233 }
234
235 s->prev_frame = av_frame_alloc();
236 if (!s->prev_frame)
237 return AVERROR(ENOMEM);
238
239 return 0;
240 }
241
decode_close(AVCodecContext * avctx)242 static av_cold int decode_close(AVCodecContext *avctx)
243 {
244 WCMVContext *s = avctx->priv_data;
245
246 av_frame_free(&s->prev_frame);
247 inflateEnd(&s->zstream);
248
249 return 0;
250 }
251
252 AVCodec ff_wcmv_decoder = {
253 .name = "wcmv",
254 .long_name = NULL_IF_CONFIG_SMALL("WinCAM Motion Video"),
255 .type = AVMEDIA_TYPE_VIDEO,
256 .id = AV_CODEC_ID_WCMV,
257 .priv_data_size = sizeof(WCMVContext),
258 .init = decode_init,
259 .close = decode_close,
260 .decode = decode_frame,
261 .capabilities = AV_CODEC_CAP_DR1,
262 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
263 FF_CODEC_CAP_INIT_CLEANUP,
264 };
265