3 * Copyright (c) 2005 Konstantin Shishkov
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * Intel Indeo 2 decoder.
25 #define ALT_BITSTREAM_READER_LE
27 #include "bitstream.h"
28 #include "indeo2data.h"
30 typedef struct Ir2Context
{
31 AVCodecContext
*avctx
;
37 #define CODE_VLC_BITS 14
40 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
41 static inline int ir2_get_code(GetBitContext
*gb
)
43 return get_vlc2(gb
, ir2_vlc
.table
, CODE_VLC_BITS
, 1) + 1;
46 static int ir2_decode_plane(Ir2Context
*ctx
, int width
, int height
, uint8_t *dst
, int stride
,
58 /* first line contain absolute values, other lines contain deltas */
60 c
= ir2_get_code(&ctx
->gb
);
61 if(c
>= 0x80) { /* we have a run */
65 for (i
= 0; i
< c
* 2; i
++)
67 } else { /* copy two values from table */
68 dst
[out
++] = table
[c
* 2];
69 dst
[out
++] = table
[(c
* 2) + 1];
74 for (j
= 1; j
< height
; j
++){
77 c
= ir2_get_code(&ctx
->gb
);
78 if(c
>= 0x80) { /* we have a skip */
82 for (i
= 0; i
< c
* 2; i
++) {
83 dst
[out
] = dst
[out
- stride
];
86 } else { /* add two deltas from table */
87 t
= dst
[out
- stride
] + (table
[c
* 2] - 128);
91 t
= dst
[out
- stride
] + (table
[(c
* 2) + 1] - 128);
102 static int ir2_decode_plane_inter(Ir2Context
*ctx
, int width
, int height
, uint8_t *dst
, int stride
,
103 const uint8_t *table
)
113 for (j
= 0; j
< height
; j
++){
116 c
= ir2_get_code(&ctx
->gb
);
117 if(c
>= 0x80) { /* we have a skip */
120 } else { /* add two deltas from table */
121 t
= dst
[out
] + (((table
[c
* 2] - 128)*3) >> 2);
125 t
= dst
[out
] + (((table
[(c
* 2) + 1] - 128)*3) >> 2);
136 static int ir2_decode_frame(AVCodecContext
*avctx
,
137 void *data
, int *data_size
,
138 uint8_t *buf
, int buf_size
)
140 Ir2Context
* const s
= avctx
->priv_data
;
141 AVFrame
*picture
= data
;
142 AVFrame
* const p
= (AVFrame
*)&s
->picture
;
147 avctx
->release_buffer(avctx
, p
);
150 p
->buffer_hints
= FF_BUFFER_HINTS_VALID
| FF_BUFFER_HINTS_PRESERVE
| FF_BUFFER_HINTS_REUSABLE
;
151 if (avctx
->reget_buffer(avctx
, p
)) {
152 av_log(s
->avctx
, AV_LOG_ERROR
, "reget_buffer() failed\n");
156 s
->decode_delta
= buf
[18];
158 /* decide whether frame uses deltas or not */
159 #ifndef ALT_BITSTREAM_READER_LE
160 for (i
= 0; i
< buf_size
; i
++)
161 buf
[i
] = ff_reverse
[buf
[i
]];
163 start
= 48; /* hardcoded for now */
165 init_get_bits(&s
->gb
, buf
+ start
, buf_size
- start
);
167 if (s
->decode_delta
) { /* intraframe */
168 ir2_decode_plane(s
, avctx
->width
, avctx
->height
,
169 s
->picture
.data
[0], s
->picture
.linesize
[0], ir2_luma_table
);
170 /* swapped U and V */
171 ir2_decode_plane(s
, avctx
->width
>> 2, avctx
->height
>> 2,
172 s
->picture
.data
[2], s
->picture
.linesize
[2], ir2_luma_table
);
173 ir2_decode_plane(s
, avctx
->width
>> 2, avctx
->height
>> 2,
174 s
->picture
.data
[1], s
->picture
.linesize
[1], ir2_luma_table
);
175 } else { /* interframe */
176 ir2_decode_plane_inter(s
, avctx
->width
, avctx
->height
,
177 s
->picture
.data
[0], s
->picture
.linesize
[0], ir2_luma_table
);
178 /* swapped U and V */
179 ir2_decode_plane_inter(s
, avctx
->width
>> 2, avctx
->height
>> 2,
180 s
->picture
.data
[2], s
->picture
.linesize
[2], ir2_luma_table
);
181 ir2_decode_plane_inter(s
, avctx
->width
>> 2, avctx
->height
>> 2,
182 s
->picture
.data
[1], s
->picture
.linesize
[1], ir2_luma_table
);
185 *picture
= *(AVFrame
*)&s
->picture
;
186 *data_size
= sizeof(AVPicture
);
191 static int ir2_decode_init(AVCodecContext
*avctx
){
192 Ir2Context
* const ic
= avctx
->priv_data
;
196 avctx
->pix_fmt
= PIX_FMT_YUV410P
;
199 init_vlc(&ir2_vlc
, CODE_VLC_BITS
, IR2_CODES
,
200 &ir2_codes
[0][1], 4, 2,
201 #ifdef ALT_BITSTREAM_READER_LE
202 &ir2_codes
[0][0], 4, 2, INIT_VLC_USE_STATIC
| INIT_VLC_LE
);
204 &ir2_codes
[0][0], 4, 2, INIT_VLC_USE_STATIC
);
210 AVCodec indeo2_decoder
= {