3 * Copyright (c) 2005 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
33 typedef struct WNV1Context
{
38 static const uint16_t code_tab
[16][2] = {
39 { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 },
41 { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 }
44 #define CODE_VLC_BITS 9
47 /* returns modified base_value */
48 static inline int wnv1_get_code(WNV1Context
*w
, int base_value
)
50 int v
= get_vlc2(&w
->gb
, code_vlc
.table
, CODE_VLC_BITS
, 1);
53 return ff_reverse
[get_bits(&w
->gb
, 8 - w
->shift
)];
55 return base_value
+ ((v
- 7) << w
->shift
);
58 static int decode_frame(AVCodecContext
*avctx
,
59 void *data
, int *got_frame
,
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
;
68 int prev_y
= 0, prev_u
= 0, prev_v
= 0;
72 av_log(avctx
, AV_LOG_ERROR
, "Packet size %d is too small\n", buf_size
);
73 return AVERROR_INVALIDDATA
;
76 rbuf
= av_malloc(buf_size
+ FF_INPUT_BUFFER_PADDING_SIZE
);
78 av_log(avctx
, AV_LOG_ERROR
, "Cannot allocate temporary buffer\n");
79 return AVERROR(ENOMEM
);
81 memset(rbuf
+ buf_size
, 0, FF_INPUT_BUFFER_PADDING_SIZE
);
83 if ((ret
= ff_get_buffer(avctx
, p
, 0)) < 0) {
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);
96 l
->shift
= 8 - (buf
[2] >> 4);
98 avpriv_request_sample(avctx
,
99 "Unknown WNV1 frame header value %i",
104 avpriv_request_sample(avctx
,
105 "Unknown WNV1 frame header value %i",
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
);
133 static av_cold
int decode_init(AVCodecContext
*avctx
)
135 static VLC_TYPE code_table
[1 << CODE_VLC_BITS
][2];
137 avctx
->pix_fmt
= AV_PIX_FMT_YUV422P
;
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
);
148 AVCodec ff_wnv1_decoder
= {
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
),
155 .decode
= decode_frame
,
156 .capabilities
= CODEC_CAP_DR1
,