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a8a15e9d MM |
1 | /* |
2 | * Winnov WNV1 codec | |
3 | * Copyright (c) 2005 Konstantin Shishkov | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; either | |
8 | * version 2 of the License, or (at your option) any later version. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | * | |
19 | */ | |
20 | ||
21 | /** | |
22 | * @file wnv1.c | |
23 | * Winnov WNV1 codec. | |
24 | */ | |
25 | ||
26 | #include "avcodec.h" | |
27 | #include "common.h" | |
083b80b5 | 28 | #include "bitstream.h" |
a8a15e9d MM |
29 | |
30 | ||
31 | typedef struct WNV1Context{ | |
32 | AVCodecContext *avctx; | |
33 | AVFrame pic; | |
34 | ||
35 | int shift; | |
083b80b5 | 36 | GetBitContext gb; |
a8a15e9d MM |
37 | } WNV1Context; |
38 | ||
083b80b5 MN |
39 | static uint16_t code_tab[16][2]={ |
40 | {0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3}, | |
41 | {0x000,1}, | |
42 | {0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8} | |
43 | }; | |
44 | ||
45 | #define CODE_VLC_BITS 9 | |
46 | static VLC code_vlc; | |
47 | ||
a8a15e9d MM |
48 | /* returns modified base_value */ |
49 | static inline int wnv1_get_code(WNV1Context *w, int base_value) | |
50 | { | |
083b80b5 | 51 | int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1); |
a8a15e9d | 52 | |
083b80b5 MN |
53 | if(v==15) |
54 | return ff_reverse[ get_bits(&w->gb, 8 - w->shift) ]; | |
55 | else | |
56 | return base_value + ((v - 7)<<w->shift); | |
a8a15e9d MM |
57 | } |
58 | ||
59 | static int decode_frame(AVCodecContext *avctx, | |
60 | void *data, int *data_size, | |
61 | uint8_t *buf, int buf_size) | |
62 | { | |
63 | WNV1Context * const l = avctx->priv_data; | |
64 | AVFrame * const p= (AVFrame*)&l->pic; | |
65 | unsigned char *Y,*U,*V; | |
66 | int i, j; | |
67 | int prev_y = 0, prev_u = 0, prev_v = 0; | |
68 | ||
69 | if(p->data[0]) | |
70 | avctx->release_buffer(avctx, p); | |
71 | ||
72 | p->reference = 0; | |
73 | if(avctx->get_buffer(avctx, p) < 0){ | |
74 | av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); | |
75 | return -1; | |
76 | } | |
77 | p->key_frame = 1; | |
083b80b5 MN |
78 | |
79 | for(i=8; i<buf_size; i++) | |
80 | buf[i]= ff_reverse[ buf[i] ]; //FIXME ensure that the buffer is modifyable or use a temp one | |
81 | init_get_bits(&l->gb, buf+8, (buf_size-8)*8); | |
82 | ||
a8a15e9d MM |
83 | if (buf[2] >> 4 == 6) |
84 | l->shift = 2; | |
85 | else { | |
86 | l->shift = 8 - (buf[2] >> 4); | |
87 | if (l->shift > 4) { | |
88 | av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4); | |
89 | l->shift = 4; | |
90 | } | |
91 | if (l->shift < 1) { | |
92 | av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4); | |
93 | l->shift = 1; | |
94 | } | |
95 | } | |
96 | ||
97 | Y = p->data[0]; | |
98 | U = p->data[1]; | |
99 | V = p->data[2]; | |
100 | for (j = 0; j < avctx->height; j++) { | |
101 | for (i = 0; i < avctx->width / 2; i++) { | |
102 | Y[i * 2] = wnv1_get_code(l, prev_y); | |
103 | prev_u = U[i] = wnv1_get_code(l, prev_u); | |
104 | prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]); | |
105 | prev_v = V[i] = wnv1_get_code(l, prev_v); | |
106 | } | |
107 | Y += p->linesize[0]; | |
108 | U += p->linesize[1]; | |
109 | V += p->linesize[2]; | |
110 | } | |
111 | ||
112 | ||
113 | *data_size = sizeof(AVFrame); | |
114 | *(AVFrame*)data = l->pic; | |
115 | ||
116 | return buf_size; | |
117 | } | |
118 | ||
119 | static int decode_init(AVCodecContext *avctx){ | |
120 | WNV1Context * const l = avctx->priv_data; | |
121 | ||
122 | l->avctx = avctx; | |
123 | avctx->pix_fmt = PIX_FMT_YUV422P; | |
124 | ||
083b80b5 MN |
125 | if(!code_vlc.table){ |
126 | init_vlc(&code_vlc, CODE_VLC_BITS, 16, | |
127 | &code_tab[0][1], 4, 2, | |
128 | &code_tab[0][0], 4, 2, 1); | |
129 | } | |
130 | ||
a8a15e9d MM |
131 | return 0; |
132 | } | |
133 | ||
134 | AVCodec wnv1_decoder = { | |
135 | "wnv1", | |
136 | CODEC_TYPE_VIDEO, | |
137 | CODEC_ID_WNV1, | |
138 | sizeof(WNV1Context), | |
139 | decode_init, | |
140 | NULL, | |
141 | NULL, | |
142 | decode_frame, | |
143 | CODEC_CAP_DR1, | |
144 | }; |