1 /*
2 * Aura 2 decoder
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * Aura 2 decoder
24 */
25
29
31 {
32 /* width needs to be divisible by 4 for this codec to work */
33 if (avctx->
width & 0x3)
36
37 return 0;
38 }
39
41 void *
data,
int *got_frame,
43 {
49
50 /* prediction error tables (make it clear that they are signed values) */
51 const int8_t *delta_table = (const int8_t*)buf + 16;
52
57 }
58
59 /* pixel data starts 48 bytes in, after 3x16-byte tables */
60 buf += 48;
61
64
68
69 /* iterate through each line in the height */
70 for (y = 0; y < avctx->
height; y++) {
71 /* reset predictors */
72 val = *buf++;
73 U[0] = val & 0xF0;
74 Y[0] = val << 4;
75 val = *buf++;
76 V[0] = val & 0xF0;
77 Y[1] = Y[0] + delta_table[val & 0xF];
78 Y += 2; U++; V++;
79
80 /* iterate through the remaining pixel groups (4 pixels/group) */
81 for (x = 1; x < (avctx->
width >> 1); x++) {
82 val = *buf++;
83 U[0] = U[-1] + delta_table[val >> 4];
84 Y[0] = Y[-1] + delta_table[val & 0xF];
85 val = *buf++;
86 V[0] = V[-1] + delta_table[val >> 4];
87 Y[1] = Y[ 0] + delta_table[val & 0xF];
88 Y += 2; U++; V++;
89 }
93 }
94
95 *got_frame = 1;
96
98 }
99
108 };