FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/kgv1dec.c
Date: 2021-09-22 23:55:11
Exec Total Coverage
Lines: 67 81 82.7%
Branches: 32 50 64.0%

Line Branch Exec Source
1 /*
2 * Kega Game Video (KGV1) decoder
3 * Copyright (c) 2010 Daniel Verkamp
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Kega Game Video decoder
25 */
26
27 #include "libavutil/common.h"
28 #include "libavutil/intreadwrite.h"
29 #include "libavutil/imgutils.h"
30 #include "avcodec.h"
31 #include "internal.h"
32
33 typedef struct KgvContext {
34 uint16_t *frame_buffer;
35 uint16_t *last_frame_buffer;
36 } KgvContext;
37
38 2 static void decode_flush(AVCodecContext *avctx)
39 {
40 2 KgvContext * const c = avctx->priv_data;
41
42 2 av_freep(&c->frame_buffer);
43 2 av_freep(&c->last_frame_buffer);
44 2 }
45
46 313 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
47 AVPacket *avpkt)
48 {
49 313 AVFrame *frame = data;
50 313 const uint8_t *buf = avpkt->data;
51 313 const uint8_t *buf_end = buf + avpkt->size;
52 313 KgvContext * const c = avctx->priv_data;
53 int offsets[8];
54 uint8_t *out, *prev;
55 313 int outcnt = 0, maxcnt;
56 int w, h, i, res;
57
58
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313 if (avpkt->size < 2)
59 return AVERROR_INVALIDDATA;
60
61 313 w = (buf[0] + 1) * 8;
62 313 h = (buf[1] + 1) * 8;
63 313 buf += 2;
64
65
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313 if (avpkt->size < 2 + w*h / 513)
66 return AVERROR_INVALIDDATA;
67
68
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313 if (w != avctx->width || h != avctx->height) {
69 av_freep(&c->frame_buffer);
70 av_freep(&c->last_frame_buffer);
71 if ((res = ff_set_dimensions(avctx, w, h)) < 0)
72 return res;
73 }
74
75
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313 if (!c->frame_buffer) {
76 1 c->frame_buffer = av_mallocz(avctx->width * avctx->height * 2);
77 1 c->last_frame_buffer = av_mallocz(avctx->width * avctx->height * 2);
78
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1 if (!c->frame_buffer || !c->last_frame_buffer) {
79 decode_flush(avctx);
80 return AVERROR(ENOMEM);
81 }
82 }
83
84 313 maxcnt = w * h;
85
86
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313 if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
87 return res;
88 313 out = (uint8_t*)c->frame_buffer;
89 313 prev = (uint8_t*)c->last_frame_buffer;
90
91
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2817 for (i = 0; i < 8; i++)
92 2504 offsets[i] = -1;
93
94
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51104 while (outcnt < maxcnt && buf_end - 2 >= buf) {
95 50791 int code = AV_RL16(buf);
96 50791 buf += 2;
97
98
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50791 if (!(code & 0x8000)) {
99 756 AV_WN16A(&out[2 * outcnt], code); // rgb555 pixel coded directly
100 756 outcnt++;
101 } else {
102 int count;
103
104
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50035 if ((code & 0x6000) == 0x6000) {
105 // copy from previous frame
106 22112 int oidx = (code >> 10) & 7;
107 int start;
108
109 22112 count = (code & 0x3FF) + 3;
110
111
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22112 if (offsets[oidx] < 0) {
112
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304 if (buf_end - 3 < buf)
113 break;
114 304 offsets[oidx] = AV_RL24(buf);
115 304 buf += 3;
116 }
117
118 22112 start = (outcnt + offsets[oidx]) % maxcnt;
119
120
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22112 if (maxcnt - start < count || maxcnt - outcnt < count)
121 break;
122
123
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22112 if (!prev) {
124 av_log(avctx, AV_LOG_ERROR,
125 "Frame reference does not exist\n");
126 break;
127 }
128
129 22112 memcpy(out + 2 * outcnt, prev + 2 * start, 2 * count);
130 } else {
131 // copy from earlier in this frame
132 27923 int offset = (code & 0x1FFF) + 1;
133
134
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27923 if (!(code & 0x6000)) {
135 1091 count = 2;
136
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26832 } else if ((code & 0x6000) == 0x2000) {
137 776 count = 3;
138 } else {
139
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26056 if (buf_end - 1 < buf)
140 break;
141 26056 count = 4 + *buf++;
142 }
143
144
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27923 if (outcnt < offset || maxcnt - outcnt < count)
145 break;
146
147 27923 av_memcpy_backptr(out + 2 * outcnt, 2 * offset, 2 * count);
148 }
149 50035 outcnt += count;
150 }
151 }
152
153
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313 if (outcnt - maxcnt)
154 av_log(avctx, AV_LOG_DEBUG, "frame finished with %d diff\n", outcnt - maxcnt);
155
156 313 av_image_copy_plane(frame->data[0], frame->linesize[0],
157 313 (const uint8_t*)c->frame_buffer, avctx->width * 2,
158 313 avctx->width * 2, avctx->height);
159 313 FFSWAP(uint16_t *, c->frame_buffer, c->last_frame_buffer);
160
161 313 *got_frame = 1;
162
163 313 return avpkt->size;
164 }
165
166 2 static av_cold int decode_init(AVCodecContext *avctx)
167 {
168 2 avctx->pix_fmt = AV_PIX_FMT_RGB555;
169
170 2 return 0;
171 }
172
173 2 static av_cold int decode_end(AVCodecContext *avctx)
174 {
175 2 decode_flush(avctx);
176 2 return 0;
177 }
178
179 const AVCodec ff_kgv1_decoder = {
180 .name = "kgv1",
181 .long_name = NULL_IF_CONFIG_SMALL("Kega Game Video"),
182 .type = AVMEDIA_TYPE_VIDEO,
183 .id = AV_CODEC_ID_KGV1,
184 .priv_data_size = sizeof(KgvContext),
185 .init = decode_init,
186 .close = decode_end,
187 .decode = decode_frame,
188 .flush = decode_flush,
189 .capabilities = AV_CODEC_CAP_DR1,
190 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
191 };
192