Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / 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
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 + FF_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, FF_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 init_get_bits(&l->gb, rbuf + 8, (buf_size - 8) * 8);
92
93 if (buf[2] >> 4 == 6)
94 l->shift = 2;
95 else {
96 l->shift = 8 - (buf[2] >> 4);
97 if (l->shift > 4) {
98 avpriv_request_sample(avctx,
99 "Unknown WNV1 frame header value %i",
100 buf[2] >> 4);
101 l->shift = 4;
102 }
103 if (l->shift < 1) {
104 avpriv_request_sample(avctx,
105 "Unknown WNV1 frame header value %i",
106 buf[2] >> 4);
107 l->shift = 1;
108 }
109 }
110
111 Y = p->data[0];
112 U = p->data[1];
113 V = p->data[2];
114 for (j = 0; j < avctx->height; j++) {
115 for (i = 0; i < avctx->width / 2; i++) {
116 Y[i * 2] = wnv1_get_code(l, prev_y);
117 prev_u = U[i] = wnv1_get_code(l, prev_u);
118 prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
119 prev_v = V[i] = wnv1_get_code(l, prev_v);
120 }
121 Y += p->linesize[0];
122 U += p->linesize[1];
123 V += p->linesize[2];
124 }
125
126
127 *got_frame = 1;
128 av_free(rbuf);
129
130 return buf_size;
131 }
132
133 static av_cold int decode_init(AVCodecContext *avctx)
134 {
135 static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
136
137 avctx->pix_fmt = AV_PIX_FMT_YUV422P;
138
139 code_vlc.table = code_table;
140 code_vlc.table_allocated = 1 << CODE_VLC_BITS;
141 init_vlc(&code_vlc, CODE_VLC_BITS, 16,
142 &code_tab[0][1], 4, 2,
143 &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
144
145 return 0;
146 }
147
148 AVCodec ff_wnv1_decoder = {
149 .name = "wnv1",
150 .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
151 .type = AVMEDIA_TYPE_VIDEO,
152 .id = AV_CODEC_ID_WNV1,
153 .priv_data_size = sizeof(WNV1Context),
154 .init = decode_init,
155 .decode = decode_frame,
156 .capabilities = CODEC_CAP_DR1,
157 };