blob: 9ff99b2f98da98848fa65f7348aad0ee6c41d975
1 | /* |
2 | * Winnov WNV1 codec |
3 | * Copyright (c) 2005 Konstantin Shishkov |
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 | * Winnov WNV1 codec. |
25 | */ |
26 | |
27 | #include "avcodec.h" |
28 | #include "get_bits.h" |
29 | #include "internal.h" |
30 | #include "mathops.h" |
31 | |
32 | |
33 | typedef struct WNV1Context { |
34 | int shift; |
35 | GetBitContext gb; |
36 | } WNV1Context; |
37 | |
38 | static const uint16_t code_tab[16][2] = { |
39 | { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 }, |
40 | { 0x000, 1 }, |
41 | { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 } |
42 | }; |
43 | |
44 | #define CODE_VLC_BITS 9 |
45 | static VLC code_vlc; |
46 | |
47 | /* returns modified base_value */ |
48 | static inline int wnv1_get_code(WNV1Context *w, int base_value) |
49 | { |
50 | int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1); |
51 | |
52 | if (v == 15) |
53 | return ff_reverse[get_bits(&w->gb, 8 - w->shift)]; |
54 | else |
55 | return base_value + ((v - 7) << w->shift); |
56 | } |
57 | |
58 | static int decode_frame(AVCodecContext *avctx, |
59 | void *data, int *got_frame, |
60 | AVPacket *avpkt) |
61 | { |
62 | WNV1Context * const l = avctx->priv_data; |
63 | const uint8_t *buf = avpkt->data; |
64 | int buf_size = avpkt->size; |
65 | AVFrame * const p = data; |
66 | unsigned char *Y,*U,*V; |
67 | int i, j, ret; |
68 | int prev_y = 0, prev_u = 0, prev_v = 0; |
69 | uint8_t *rbuf; |
70 | |
71 | if (buf_size <= 8) { |
72 | av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size); |
73 | return AVERROR_INVALIDDATA; |
74 | } |
75 | |
76 | rbuf = av_malloc(buf_size + AV_INPUT_BUFFER_PADDING_SIZE); |
77 | if (!rbuf) { |
78 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n"); |
79 | return AVERROR(ENOMEM); |
80 | } |
81 | memset(rbuf + buf_size, 0, AV_INPUT_BUFFER_PADDING_SIZE); |
82 | |
83 | if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { |
84 | av_free(rbuf); |
85 | return ret; |
86 | } |
87 | p->key_frame = 1; |
88 | |
89 | for (i = 8; i < buf_size; i++) |
90 | rbuf[i] = ff_reverse[buf[i]]; |
91 | |
92 | if ((ret = init_get_bits8(&l->gb, rbuf + 8, buf_size - 8)) < 0) |
93 | return ret; |
94 | |
95 | if (buf[2] >> 4 == 6) |
96 | l->shift = 2; |
97 | else { |
98 | l->shift = 8 - (buf[2] >> 4); |
99 | if (l->shift > 4) { |
100 | avpriv_request_sample(avctx, |
101 | "Unknown WNV1 frame header value %i", |
102 | buf[2] >> 4); |
103 | l->shift = 4; |
104 | } |
105 | if (l->shift < 1) { |
106 | avpriv_request_sample(avctx, |
107 | "Unknown WNV1 frame header value %i", |
108 | buf[2] >> 4); |
109 | l->shift = 1; |
110 | } |
111 | } |
112 | |
113 | Y = p->data[0]; |
114 | U = p->data[1]; |
115 | V = p->data[2]; |
116 | for (j = 0; j < avctx->height; j++) { |
117 | for (i = 0; i < avctx->width / 2; i++) { |
118 | Y[i * 2] = wnv1_get_code(l, prev_y); |
119 | prev_u = U[i] = wnv1_get_code(l, prev_u); |
120 | prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]); |
121 | prev_v = V[i] = wnv1_get_code(l, prev_v); |
122 | } |
123 | Y += p->linesize[0]; |
124 | U += p->linesize[1]; |
125 | V += p->linesize[2]; |
126 | } |
127 | |
128 | |
129 | *got_frame = 1; |
130 | av_free(rbuf); |
131 | |
132 | return buf_size; |
133 | } |
134 | |
135 | static av_cold int decode_init(AVCodecContext *avctx) |
136 | { |
137 | static VLC_TYPE code_table[1 << CODE_VLC_BITS][2]; |
138 | |
139 | avctx->pix_fmt = AV_PIX_FMT_YUV422P; |
140 | |
141 | code_vlc.table = code_table; |
142 | code_vlc.table_allocated = 1 << CODE_VLC_BITS; |
143 | init_vlc(&code_vlc, CODE_VLC_BITS, 16, |
144 | &code_tab[0][1], 4, 2, |
145 | &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC); |
146 | |
147 | return 0; |
148 | } |
149 | |
150 | AVCodec ff_wnv1_decoder = { |
151 | .name = "wnv1", |
152 | .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"), |
153 | .type = AVMEDIA_TYPE_VIDEO, |
154 | .id = AV_CODEC_ID_WNV1, |
155 | .priv_data_size = sizeof(WNV1Context), |
156 | .init = decode_init, |
157 | .decode = decode_frame, |
158 | .capabilities = AV_CODEC_CAP_DR1, |
159 | }; |
160 |