lavc: fix decode_frame() third parameter semantics for video decoders
[libav.git] / libavcodec / wnv1.c
1 /*
2 * Winnov WNV1 codec
3 * Copyright (c) 2005 Konstantin Shishkov
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 AVCodecContext *avctx;
35 AVFrame pic;
36
37 int shift;
38 GetBitContext gb;
39 } WNV1Context;
40
41 static const uint16_t code_tab[16][2]={
42 {0x1FD,9}, {0xFD,8}, {0x7D,7}, {0x3D,6}, {0x1D,5}, {0x0D,4}, {0x005,3},
43 {0x000,1},
44 {0x004,3}, {0x0C,4}, {0x1C,5}, {0x3C,6}, {0x7C,7}, {0xFC,8}, {0x1FC,9}, {0xFF,8}
45 };
46
47 #define CODE_VLC_BITS 9
48 static VLC code_vlc;
49
50 /* returns modified base_value */
51 static inline int wnv1_get_code(WNV1Context *w, int base_value)
52 {
53 int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
54
55 if(v==15)
56 return ff_reverse[ get_bits(&w->gb, 8 - w->shift) ];
57 else
58 return base_value + ((v - 7)<<w->shift);
59 }
60
61 static int decode_frame(AVCodecContext *avctx,
62 void *data, int *got_frame,
63 AVPacket *avpkt)
64 {
65 const uint8_t *buf = avpkt->data;
66 int buf_size = avpkt->size;
67 WNV1Context * const l = avctx->priv_data;
68 AVFrame * const p = &l->pic;
69 unsigned char *Y,*U,*V;
70 int i, j;
71 int prev_y = 0, prev_u = 0, prev_v = 0;
72 uint8_t *rbuf;
73
74 rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
75 if(!rbuf){
76 av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
77 return -1;
78 }
79
80 if(p->data[0])
81 avctx->release_buffer(avctx, p);
82
83 p->reference = 0;
84 if(ff_get_buffer(avctx, p) < 0){
85 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
86 av_free(rbuf);
87 return -1;
88 }
89 p->key_frame = 1;
90
91 for(i=8; i<buf_size; i++)
92 rbuf[i]= ff_reverse[ buf[i] ];
93 init_get_bits(&l->gb, rbuf+8, (buf_size-8)*8);
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 av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
101 buf[2] >> 4);
102 l->shift = 4;
103 }
104 if (l->shift < 1) {
105 av_log_ask_for_sample(avctx, "Unknown WNV1 frame header value %i\n",
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 *(AVFrame*)data = l->pic;
129 av_free(rbuf);
130
131 return buf_size;
132 }
133
134 static av_cold int decode_init(AVCodecContext *avctx){
135 WNV1Context * const l = avctx->priv_data;
136 static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
137
138 l->avctx = avctx;
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 static av_cold int decode_end(AVCodecContext *avctx){
151 WNV1Context * const l = avctx->priv_data;
152 AVFrame *pic = &l->pic;
153
154 if (pic->data[0])
155 avctx->release_buffer(avctx, pic);
156
157 return 0;
158 }
159
160 AVCodec ff_wnv1_decoder = {
161 .name = "wnv1",
162 .type = AVMEDIA_TYPE_VIDEO,
163 .id = AV_CODEC_ID_WNV1,
164 .priv_data_size = sizeof(WNV1Context),
165 .init = decode_init,
166 .close = decode_end,
167 .decode = decode_frame,
168 .capabilities = CODEC_CAP_DR1,
169 .long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
170 };