Move ff_reverse in libavcodec to av_reverse in libavutil.
[libav.git] / libavcodec / wnv1.c
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 libavcodec/wnv1.c
24 * Winnov WNV1 codec.
25 */
26
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "libavutil/common.h"
30
31
32 typedef struct WNV1Context{
33 AVCodecContext *avctx;
34 AVFrame pic;
35
36 int shift;
37 GetBitContext gb;
38 } WNV1Context;
39
40 static const uint16_t code_tab[16][2]={
41 {0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3},
42 {0x000,1},
43 {0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8}
44 };
45
46 #define CODE_VLC_BITS 9
47 static VLC code_vlc;
48
49 /* returns modified base_value */
50 static inline int wnv1_get_code(WNV1Context *w, int base_value)
51 {
52 int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
53
54 if(v==15)
55 return av_reverse[ get_bits(&w->gb, 8 - w->shift) ];
56 else
57 return base_value + ((v - 7)<<w->shift);
58 }
59
60 static int decode_frame(AVCodecContext *avctx,
61 void *data, int *data_size,
62 AVPacket *avpkt)
63 {
64 const uint8_t *buf = avpkt->data;
65 int buf_size = avpkt->size;
66 WNV1Context * const l = avctx->priv_data;
67 AVFrame * const p= (AVFrame*)&l->pic;
68 unsigned char *Y,*U,*V;
69 int i, j;
70 int prev_y = 0, prev_u = 0, prev_v = 0;
71 uint8_t *rbuf;
72
73 rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
74 if(!rbuf){
75 av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
76 return -1;
77 }
78
79 if(p->data[0])
80 avctx->release_buffer(avctx, p);
81
82 p->reference = 0;
83 if(avctx->get_buffer(avctx, p) < 0){
84 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
85 av_free(rbuf);
86 return -1;
87 }
88 p->key_frame = 1;
89
90 for(i=8; i<buf_size; i++)
91 rbuf[i]= av_reverse[ buf[i] ];
92 init_get_bits(&l->gb, rbuf+8, (buf_size-8)*8);
93
94 if (buf[2] >> 4 == 6)
95 l->shift = 2;
96 else {
97 l->shift = 8 - (buf[2] >> 4);
98 if (l->shift > 4) {
99 av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4);
100 l->shift = 4;
101 }
102 if (l->shift < 1) {
103 av_log(avctx, AV_LOG_ERROR, "Unknown WNV1 frame header value %i, please upload file for study\n", buf[2] >> 4);
104 l->shift = 1;
105 }
106 }
107
108 Y = p->data[0];
109 U = p->data[1];
110 V = p->data[2];
111 for (j = 0; j < avctx->height; j++) {
112 for (i = 0; i < avctx->width / 2; i++) {
113 Y[i * 2] = wnv1_get_code(l, prev_y);
114 prev_u = U[i] = wnv1_get_code(l, prev_u);
115 prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
116 prev_v = V[i] = wnv1_get_code(l, prev_v);
117 }
118 Y += p->linesize[0];
119 U += p->linesize[1];
120 V += p->linesize[2];
121 }
122
123
124 *data_size = sizeof(AVFrame);
125 *(AVFrame*)data = l->pic;
126 av_free(rbuf);
127
128 return buf_size;
129 }
130
131 static av_cold int decode_init(AVCodecContext *avctx){
132 WNV1Context * const l = avctx->priv_data;
133 static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
134
135 l->avctx = avctx;
136 avctx->pix_fmt = PIX_FMT_YUV422P;
137
138 code_vlc.table = code_table;
139 code_vlc.table_allocated = 1 << CODE_VLC_BITS;
140 init_vlc(&code_vlc, CODE_VLC_BITS, 16,
141 &code_tab[0][1], 4, 2,
142 &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
143
144 return 0;
145 }
146
147 static av_cold int decode_end(AVCodecContext *avctx){
148 WNV1Context * const l = avctx->priv_data;
149 AVFrame *pic = &l->pic;
150
151 if (pic->data[0])
152 avctx->release_buffer(avctx, pic);
153
154 return 0;
155 }
156
157 AVCodec wnv1_decoder = {
158 "wnv1",
159 CODEC_TYPE_VIDEO,
160 CODEC_ID_WNV1,
161 sizeof(WNV1Context),
162 decode_init,
163 NULL,
164 decode_end,
165 decode_frame,
166 CODEC_CAP_DR1,
167 .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
168 };