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
|
/*
* MatchWare Screen Capture Codec 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 "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "zlib_wrapper.h"
#include <zlib.h>
typedef struct MWSCContext {
unsigned int decomp_size;
uint8_t *decomp_buf;
AVFrame *prev_frame;
FFZStream zstream;
} MWSCContext;
static int rle_uncompress(GetByteContext *gb, PutByteContext *pb, GetByteContext *gbp,
int width, int height, int stride, int pb_linesize, int gbp_linesize)
{
int intra = 1, w = 0;
bytestream2_seek_p(pb, (height - 1) * pb_linesize, SEEK_SET);
while (bytestream2_get_bytes_left(gb) > 0) {
uint32_t fill = bytestream2_get_le24(gb);
unsigned run = bytestream2_get_byte(gb);
if (run == 0) {
run = bytestream2_get_le32(gb);
for (int j = 0; j < run; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, fill);
}
} else if (run == 255) {
int pos = bytestream2_tell_p(pb);
bytestream2_seek(gbp, pos, SEEK_SET);
for (int j = 0; j < fill; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
bytestream2_seek(gbp, -(gbp_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, bytestream2_get_le24(gbp));
}
intra = 0;
} else {
for (int j = 0; j < run; j++, w++) {
if (w == width) {
w = 0;
bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
}
bytestream2_put_le24(pb, fill);
}
}
}
return intra;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
MWSCContext *s = avctx->priv_data;
z_stream *const zstream = &s->zstream.zstream;
AVFrame *frame = data;
uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
GetByteContext gb;
GetByteContext gbp;
PutByteContext pb;
int ret;
ret = inflateReset(zstream);
if (ret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
return AVERROR_EXTERNAL;
}
zstream->next_in = buf;
zstream->avail_in = buf_size;
zstream->next_out = s->decomp_buf;
zstream->avail_out = s->decomp_size;
ret = inflate(zstream, Z_FINISH);
if (ret != Z_STREAM_END) {
av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
return AVERROR_EXTERNAL;
}
if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
bytestream2_init(&gb, s->decomp_buf, zstream->total_out);
bytestream2_init(&gbp, s->prev_frame->data[0], avctx->height * s->prev_frame->linesize[0]);
bytestream2_init_writer(&pb, frame->data[0], avctx->height * frame->linesize[0]);
frame->key_frame = rle_uncompress(&gb, &pb, &gbp, avctx->width, avctx->height, avctx->width * 3,
frame->linesize[0], s->prev_frame->linesize[0]);
frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
av_frame_unref(s->prev_frame);
if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
MWSCContext *s = avctx->priv_data;
int64_t size;
avctx->pix_fmt = AV_PIX_FMT_BGR24;
size = 32LL * avctx->height * avctx->width;
if (size >= INT32_MAX)
return AVERROR_INVALIDDATA;
s->decomp_size = size;
if (!(s->decomp_buf = av_malloc(s->decomp_size)))
return AVERROR(ENOMEM);
s->prev_frame = av_frame_alloc();
if (!s->prev_frame)
return AVERROR(ENOMEM);
return ff_inflate_init(&s->zstream, avctx);
}
static av_cold int decode_close(AVCodecContext *avctx)
{
MWSCContext *s = avctx->priv_data;
av_frame_free(&s->prev_frame);
av_freep(&s->decomp_buf);
s->decomp_size = 0;
ff_inflate_end(&s->zstream);
return 0;
}
const AVCodec ff_mwsc_decoder = {
.name = "mwsc",
.long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture Codec"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MWSC,
.priv_data_size = sizeof(MWSCContext),
.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,
};
|
