FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/mmvideo.c
Date: 2022-07-04 00:18:54
Exec Total Coverage
Lines: 56 108 51.9%
Branches: 25 68 36.8%

Line Branch Exec Source
1 /*
2 * American Laser Games MM Video Decoder
3 * Copyright (c) 2006,2008 Peter Ross
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 * American Laser Games MM Video Decoder
25 * by Peter Ross (pross@xvid.org)
26 *
27 * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
28 * including Mad Dog McCree and Crime Patrol.
29 *
30 * Technical details here:
31 * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
32 */
33
34 #include "libavutil/intreadwrite.h"
35 #include "avcodec.h"
36 #include "bytestream.h"
37 #include "codec_internal.h"
38 #include "internal.h"
39
40 #define MM_PREAMBLE_SIZE 6
41
42 #define MM_TYPE_INTER 0x5
43 #define MM_TYPE_INTRA 0x8
44 #define MM_TYPE_INTRA_HH 0xc
45 #define MM_TYPE_INTER_HH 0xd
46 #define MM_TYPE_INTRA_HHV 0xe
47 #define MM_TYPE_INTER_HHV 0xf
48 #define MM_TYPE_PALETTE 0x31
49
50 typedef struct MmContext {
51 AVCodecContext *avctx;
52 AVFrame *frame;
53 unsigned int palette[AVPALETTE_COUNT];
54 GetByteContext gb;
55 } MmContext;
56
57 2 static av_cold int mm_decode_init(AVCodecContext *avctx)
58 {
59 2 MmContext *s = avctx->priv_data;
60
61 2 s->avctx = avctx;
62
63 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
64
65
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2 if (!avctx->width || !avctx->height ||
66
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2 (avctx->width & 1) || (avctx->height & 1)) {
67 av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
68 avctx->width, avctx->height);
69 return AVERROR(EINVAL);
70 }
71
72 2 s->frame = av_frame_alloc();
73
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2 if (!s->frame)
74 return AVERROR(ENOMEM);
75
76 2 return 0;
77 }
78
79 1 static void mm_decode_pal(MmContext *s)
80 {
81 int i;
82
83 1 bytestream2_skip(&s->gb, 4);
84
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129 for (i = 0; i < 128; i++) {
85 128 s->palette[i] = 0xFFU << 24 | bytestream2_get_be24(&s->gb);
86 128 s->palette[i+128] = s->palette[i]<<2;
87 }
88 1 }
89
90 /**
91 * @param half_horiz Half horizontal resolution (0 or 1)
92 * @param half_vert Half vertical resolution (0 or 1)
93 */
94 31 static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
95 {
96 31 int x = 0, y = 0;
97
98
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168603 while (bytestream2_get_bytes_left(&s->gb) > 0) {
99 int run_length, color;
100
101
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168572 if (y >= s->avctx->height)
102 return 0;
103
104 168572 color = bytestream2_get_byte(&s->gb);
105
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168572 if (color & 0x80) {
106 92018 run_length = 1;
107 }else{
108 76554 run_length = (color & 0x7f) + 2;
109 76554 color = bytestream2_get_byte(&s->gb);
110 }
111
112
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168572 if (half_horiz)
113 run_length *=2;
114
115
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168572 if (run_length > s->avctx->width - x)
116 return AVERROR_INVALIDDATA;
117
118
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168572 if (color) {
119 147172 memset(s->frame->data[0] + y*s->frame->linesize[0] + x, color, run_length);
120
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147172 if (half_vert && y + half_vert < s->avctx->height)
121 memset(s->frame->data[0] + (y+1)*s->frame->linesize[0] + x, color, run_length);
122 }
123 168572 x+= run_length;
124
125
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168572 if (x >= s->avctx->width) {
126 4960 x=0;
127 4960 y += 1 + half_vert;
128 }
129 }
130
131 31 return 0;
132 }
133
134 /**
135 * @param half_horiz Half horizontal resolution (0 or 1)
136 * @param half_vert Half vertical resolution (0 or 1)
137 */
138 static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
139 {
140 int data_off = bytestream2_get_le16(&s->gb);
141 int y = 0;
142 GetByteContext data_ptr;
143
144 if (bytestream2_get_bytes_left(&s->gb) < data_off)
145 return AVERROR_INVALIDDATA;
146
147 bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
148 while (s->gb.buffer < data_ptr.buffer_start) {
149 int i, j;
150 int length = bytestream2_get_byte(&s->gb);
151 int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
152 length &= 0x7F;
153
154 if (length==0) {
155 y += x;
156 continue;
157 }
158
159 if (y + half_vert >= s->avctx->height)
160 return 0;
161
162 for(i=0; i<length; i++) {
163 int replace_array = bytestream2_get_byte(&s->gb);
164 for(j=0; j<8; j++) {
165 int replace = (replace_array >> (7-j)) & 1;
166 if (x + half_horiz >= s->avctx->width)
167 return AVERROR_INVALIDDATA;
168 if (replace) {
169 int color = bytestream2_get_byte(&data_ptr);
170 s->frame->data[0][y*s->frame->linesize[0] + x] = color;
171 if (half_horiz)
172 s->frame->data[0][y*s->frame->linesize[0] + x + 1] = color;
173 if (half_vert) {
174 s->frame->data[0][(y+1)*s->frame->linesize[0] + x] = color;
175 if (half_horiz)
176 s->frame->data[0][(y+1)*s->frame->linesize[0] + x + 1] = color;
177 }
178 }
179 x += 1 + half_horiz;
180 }
181 }
182
183 y += 1 + half_vert;
184 }
185
186 return 0;
187 }
188
189 32 static int mm_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
190 int *got_frame, AVPacket *avpkt)
191 {
192 32 const uint8_t *buf = avpkt->data;
193 32 int buf_size = avpkt->size;
194 32 MmContext *s = avctx->priv_data;
195 int type, res;
196
197
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32 if (buf_size < MM_PREAMBLE_SIZE)
198 return AVERROR_INVALIDDATA;
199 32 type = AV_RL16(&buf[0]);
200 32 buf += MM_PREAMBLE_SIZE;
201 32 buf_size -= MM_PREAMBLE_SIZE;
202 32 bytestream2_init(&s->gb, buf, buf_size);
203
204
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32 if ((res = ff_reget_buffer(avctx, s->frame, 0)) < 0)
205 return res;
206
207
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32 switch(type) {
208 1 case MM_TYPE_PALETTE : mm_decode_pal(s); return avpkt->size;
209 31 case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
210 case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
211 case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
212 case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
213 case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
214 case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
215 default:
216 res = AVERROR_INVALIDDATA;
217 break;
218 }
219
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31 if (res < 0)
220 return res;
221
222 31 memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
223
224
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31 if ((res = av_frame_ref(rframe, s->frame)) < 0)
225 return res;
226
227 31 *got_frame = 1;
228
229 31 return avpkt->size;
230 }
231
232 2 static av_cold int mm_decode_end(AVCodecContext *avctx)
233 {
234 2 MmContext *s = avctx->priv_data;
235
236 2 av_frame_free(&s->frame);
237
238 2 return 0;
239 }
240
241 const FFCodec ff_mmvideo_decoder = {
242 .p.name = "mmvideo",
243 .p.long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
244 .p.type = AVMEDIA_TYPE_VIDEO,
245 .p.id = AV_CODEC_ID_MMVIDEO,
246 .priv_data_size = sizeof(MmContext),
247 .init = mm_decode_init,
248 .close = mm_decode_end,
249 FF_CODEC_DECODE_CB(mm_decode_frame),
250 .p.capabilities = AV_CODEC_CAP_DR1,
251 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
252 };
253