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