FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/mwsc.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 0 86 0.0%
Functions: 0 4 0.0%
Branches: 0 42 0.0%

Line Branch Exec Source
1 /*
2 * MatchWare Screen Capture Codec 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
25 #include "libavutil/mem.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "codec_internal.h"
29 #include "decode.h"
30 #include "zlib_wrapper.h"
31
32 #include <zlib.h>
33
34 typedef struct MWSCContext {
35 unsigned int decomp_size;
36 uint8_t *decomp_buf;
37 AVFrame *prev_frame;
38 FFZStream zstream;
39 } MWSCContext;
40
41 static int rle_uncompress(GetByteContext *gb, PutByteContext *pb, GetByteContext *gbp,
42 int width, int height, int stride, int pb_linesize, int gbp_linesize)
43 {
44 int intra = 1, w = 0;
45
46 bytestream2_seek_p(pb, (height - 1) * pb_linesize, SEEK_SET);
47
48 while (bytestream2_get_bytes_left(gb) > 0) {
49 uint32_t fill = bytestream2_get_le24(gb);
50 unsigned run = bytestream2_get_byte(gb);
51
52 if (run == 0) {
53 run = bytestream2_get_le32(gb);
54
55 if (bytestream2_tell_p(pb) + width - w < run)
56 return AVERROR_INVALIDDATA;
57
58 for (int j = 0; j < run; j++, w++) {
59 if (w == width) {
60 w = 0;
61 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
62 }
63 bytestream2_put_le24(pb, fill);
64 }
65 } else if (run == 255) {
66 int pos = bytestream2_tell_p(pb);
67
68 bytestream2_seek(gbp, pos, SEEK_SET);
69
70 if (pos + width - w < fill)
71 return AVERROR_INVALIDDATA;
72
73 for (int j = 0; j < fill; j++, w++) {
74 if (w == width) {
75 w = 0;
76 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
77 bytestream2_seek(gbp, -(gbp_linesize + stride), SEEK_CUR);
78 }
79 bytestream2_put_le24(pb, bytestream2_get_le24(gbp));
80 }
81
82 intra = 0;
83 } else {
84 if (bytestream2_tell_p(pb) + width - w < run)
85 return AVERROR_INVALIDDATA;
86
87 for (int j = 0; j < run; j++, w++) {
88 if (w == width) {
89 w = 0;
90 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
91 }
92 bytestream2_put_le24(pb, fill);
93 }
94 }
95 }
96
97 return intra;
98 }
99
100 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
101 int *got_frame, AVPacket *avpkt)
102 {
103 MWSCContext *s = avctx->priv_data;
104 z_stream *const zstream = &s->zstream.zstream;
105 const uint8_t *buf = avpkt->data;
106 int buf_size = avpkt->size;
107 GetByteContext gb;
108 GetByteContext gbp;
109 PutByteContext pb;
110 int ret;
111
112 ret = inflateReset(zstream);
113 if (ret != Z_OK) {
114 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
115 return AVERROR_EXTERNAL;
116 }
117 zstream->next_in = buf;
118 zstream->avail_in = buf_size;
119 zstream->next_out = s->decomp_buf;
120 zstream->avail_out = s->decomp_size;
121 ret = inflate(zstream, Z_FINISH);
122 if (ret != Z_STREAM_END) {
123 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
124 return AVERROR_EXTERNAL;
125 }
126
127 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
128 return ret;
129
130 bytestream2_init(&gb, s->decomp_buf, zstream->total_out);
131 bytestream2_init(&gbp, s->prev_frame->data[0], avctx->height * s->prev_frame->linesize[0]);
132 bytestream2_init_writer(&pb, frame->data[0], avctx->height * frame->linesize[0]);
133
134 if (rle_uncompress(&gb, &pb, &gbp, avctx->width, avctx->height, avctx->width * 3,
135 frame->linesize[0], s->prev_frame->linesize[0]))
136 frame->flags |= AV_FRAME_FLAG_KEY;
137 else
138 frame->flags &= ~AV_FRAME_FLAG_KEY;
139
140 frame->pict_type = (frame->flags & AV_FRAME_FLAG_KEY) ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
141
142 if ((ret = av_frame_replace(s->prev_frame, frame)) < 0)
143 return ret;
144
145 *got_frame = 1;
146
147 return avpkt->size;
148 }
149
150 static av_cold int decode_init(AVCodecContext *avctx)
151 {
152 MWSCContext *s = avctx->priv_data;
153 int64_t size;
154
155 avctx->pix_fmt = AV_PIX_FMT_BGR24;
156
157 size = 32LL * avctx->height * avctx->width;
158 if (size >= INT32_MAX)
159 return AVERROR_INVALIDDATA;
160 s->decomp_size = size;
161 if (!(s->decomp_buf = av_malloc(s->decomp_size)))
162 return AVERROR(ENOMEM);
163
164 s->prev_frame = av_frame_alloc();
165 if (!s->prev_frame)
166 return AVERROR(ENOMEM);
167
168 return ff_inflate_init(&s->zstream, avctx);
169 }
170
171 static av_cold int decode_close(AVCodecContext *avctx)
172 {
173 MWSCContext *s = avctx->priv_data;
174
175 av_frame_free(&s->prev_frame);
176 av_freep(&s->decomp_buf);
177 s->decomp_size = 0;
178 ff_inflate_end(&s->zstream);
179
180 return 0;
181 }
182
183 const FFCodec ff_mwsc_decoder = {
184 .p.name = "mwsc",
185 CODEC_LONG_NAME("MatchWare Screen Capture Codec"),
186 .p.type = AVMEDIA_TYPE_VIDEO,
187 .p.id = AV_CODEC_ID_MWSC,
188 .priv_data_size = sizeof(MWSCContext),
189 .init = decode_init,
190 .close = decode_close,
191 FF_CODEC_DECODE_CB(decode_frame),
192 .p.capabilities = AV_CODEC_CAP_DR1,
193 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
194 };
195