FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/mwsc.c
Date: 2024-04-26 14:42:52
Exec Total Coverage
Lines: 0 80 0.0%
Functions: 0 4 0.0%
Branches: 0 36 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 for (int j = 0; j < run; j++, w++) {
55 if (w == width) {
56 w = 0;
57 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
58 }
59 bytestream2_put_le24(pb, fill);
60 }
61 } else if (run == 255) {
62 int pos = bytestream2_tell_p(pb);
63
64 bytestream2_seek(gbp, pos, SEEK_SET);
65 for (int j = 0; j < fill; j++, w++) {
66 if (w == width) {
67 w = 0;
68 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
69 bytestream2_seek(gbp, -(gbp_linesize + stride), SEEK_CUR);
70 }
71 bytestream2_put_le24(pb, bytestream2_get_le24(gbp));
72 }
73
74 intra = 0;
75 } else {
76 for (int j = 0; j < run; j++, w++) {
77 if (w == width) {
78 w = 0;
79 bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR);
80 }
81 bytestream2_put_le24(pb, fill);
82 }
83 }
84 }
85
86 return intra;
87 }
88
89 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
90 int *got_frame, AVPacket *avpkt)
91 {
92 MWSCContext *s = avctx->priv_data;
93 z_stream *const zstream = &s->zstream.zstream;
94 const uint8_t *buf = avpkt->data;
95 int buf_size = avpkt->size;
96 GetByteContext gb;
97 GetByteContext gbp;
98 PutByteContext pb;
99 int ret;
100
101 ret = inflateReset(zstream);
102 if (ret != Z_OK) {
103 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
104 return AVERROR_EXTERNAL;
105 }
106 zstream->next_in = buf;
107 zstream->avail_in = buf_size;
108 zstream->next_out = s->decomp_buf;
109 zstream->avail_out = s->decomp_size;
110 ret = inflate(zstream, Z_FINISH);
111 if (ret != Z_STREAM_END) {
112 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
113 return AVERROR_EXTERNAL;
114 }
115
116 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
117 return ret;
118
119 bytestream2_init(&gb, s->decomp_buf, zstream->total_out);
120 bytestream2_init(&gbp, s->prev_frame->data[0], avctx->height * s->prev_frame->linesize[0]);
121 bytestream2_init_writer(&pb, frame->data[0], avctx->height * frame->linesize[0]);
122
123 if (rle_uncompress(&gb, &pb, &gbp, avctx->width, avctx->height, avctx->width * 3,
124 frame->linesize[0], s->prev_frame->linesize[0]))
125 frame->flags |= AV_FRAME_FLAG_KEY;
126 else
127 frame->flags &= ~AV_FRAME_FLAG_KEY;
128
129 frame->pict_type = (frame->flags & AV_FRAME_FLAG_KEY) ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
130
131 if ((ret = av_frame_replace(s->prev_frame, frame)) < 0)
132 return ret;
133
134 *got_frame = 1;
135
136 return avpkt->size;
137 }
138
139 static av_cold int decode_init(AVCodecContext *avctx)
140 {
141 MWSCContext *s = avctx->priv_data;
142 int64_t size;
143
144 avctx->pix_fmt = AV_PIX_FMT_BGR24;
145
146 size = 32LL * avctx->height * avctx->width;
147 if (size >= INT32_MAX)
148 return AVERROR_INVALIDDATA;
149 s->decomp_size = size;
150 if (!(s->decomp_buf = av_malloc(s->decomp_size)))
151 return AVERROR(ENOMEM);
152
153 s->prev_frame = av_frame_alloc();
154 if (!s->prev_frame)
155 return AVERROR(ENOMEM);
156
157 return ff_inflate_init(&s->zstream, avctx);
158 }
159
160 static av_cold int decode_close(AVCodecContext *avctx)
161 {
162 MWSCContext *s = avctx->priv_data;
163
164 av_frame_free(&s->prev_frame);
165 av_freep(&s->decomp_buf);
166 s->decomp_size = 0;
167 ff_inflate_end(&s->zstream);
168
169 return 0;
170 }
171
172 const FFCodec ff_mwsc_decoder = {
173 .p.name = "mwsc",
174 CODEC_LONG_NAME("MatchWare Screen Capture Codec"),
175 .p.type = AVMEDIA_TYPE_VIDEO,
176 .p.id = AV_CODEC_ID_MWSC,
177 .priv_data_size = sizeof(MWSCContext),
178 .init = decode_init,
179 .close = decode_close,
180 FF_CODEC_DECODE_CB(decode_frame),
181 .p.capabilities = AV_CODEC_CAP_DR1,
182 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
183 };
184