Statistics
| Branch: | Revision:

ffmpeg / libavcodec / loco.c @ ee7388c9

History | View | Annotate | Download (8.64 KB)

1
/*
2
 * LOCO codec
3
 * Copyright (c) 2005 Konstantin Shishkov
4
 *
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.
9
 *
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.
14
 *
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
 *
19
 */
20

    
21
/**
22
 * @file loco.c
23
 * LOCO codec.
24
 */
25

    
26
#include "avcodec.h"
27
#include "common.h"
28
#include "bitstream.h"
29
#include "golomb.h"
30

    
31
enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CRGBA=-3, LOCO_CYV12=-4,
32
 LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
33

    
34
typedef struct LOCOContext{
35
    AVCodecContext *avctx;
36
    AVFrame pic;
37
    int lossy;
38
    int mode;
39
} LOCOContext;
40

    
41
typedef struct RICEContext{
42
    GetBitContext gb;
43
    int save, run, run2; /* internal rice decoder state */
44
    int sum, count; /* sum and count for getting rice parameter */
45
    int lossy;
46
}RICEContext;
47

    
48
static int loco_get_rice_param(RICEContext *r)
49
{
50
    int cnt = 0;
51
    int val = r->count;
52

    
53
    while(r->sum > val && cnt < 9) {
54
        val <<= 1;
55
        cnt++;
56
    }
57

    
58
    return cnt;
59
}
60

    
61
static inline void loco_update_rice_param(RICEContext *r, int val)
62
{
63
    r->sum += val;
64
    r->count++;
65

    
66
    if(r->count == 16) {
67
        r->sum >>= 1;
68
        r->count >>= 1;
69
    }
70
}
71

    
72
static inline int loco_get_rice(RICEContext *r)
73
{
74
    int v;
75
    if (r->run > 0) { /* we have zero run */
76
        r->run--;
77
        loco_update_rice_param(r, 0);
78
        return 0;
79
    }
80
    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
81
    loco_update_rice_param(r, (v+1)>>1);
82
    if (!v) {
83
        if (r->save >= 0) {
84
            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
85
            if(r->run > 1)
86
                r->save += r->run + 1;
87
            else
88
                r->save -= 3;
89
        }
90
        else
91
            r->run2++;
92
    } else {
93
        v = ((v>>1) + r->lossy) ^ -(v&1);
94
        if (r->run2 > 0) {
95
            if (r->run2 > 2)
96
                r->save += r->run2;
97
            else
98
                r->save -= 3;
99
            r->run2 = 0;
100
        }
101
    }
102

    
103
    return v;
104
}
105

    
106
/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
107
static inline int loco_predict(uint8_t* data, int stride, int step)
108
{
109
    int a, b, c;
110

    
111
    a = data[-stride];
112
    b = data[-step];
113
    c = data[-stride - step];
114

    
115
    return mid_pred(a, a + b - c, b);
116
}
117

    
118
static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
119
                             int stride, uint8_t *buf, int buf_size, int step)
120
{
121
    RICEContext rc;
122
    int val;
123
    int i, j;
124

    
125
    init_get_bits(&rc.gb, buf, buf_size*8);
126
    rc.save = 0;
127
    rc.run = 0;
128
    rc.run2 = 0;
129
    rc.lossy = l->lossy;
130

    
131
    rc.sum = 8;
132
    rc.count = 1;
133

    
134
    /* restore top left pixel */
135
    val = loco_get_rice(&rc);
136
    data[0] = 128 + val;
137
    /* restore top line */
138
    for (i = 1; i < width; i++) {
139
        val = loco_get_rice(&rc);
140
        data[i * step] = data[i * step - step] + val;
141
    }
142
    data += stride;
143
    for (j = 1; j < height; j++) {
144
        /* restore left column */
145
        val = loco_get_rice(&rc);
146
        data[0] = data[-stride] + val;
147
        /* restore all other pixels */
148
        for (i = 1; i < width; i++) {
149
            val = loco_get_rice(&rc);
150
            data[i * step] = loco_predict(&data[i * step], stride, step) + val;
151
        }
152
        data += stride;
153
    }
154

    
155
    return ((get_bits_count(&rc.gb) + 7) >> 3);
156
}
157

    
158
static int decode_frame(AVCodecContext *avctx,
159
                        void *data, int *data_size,
160
                        uint8_t *buf, int buf_size)
161
{
162
    LOCOContext * const l = avctx->priv_data;
163
    AVFrame * const p= (AVFrame*)&l->pic;
164
    int decoded;
165

    
166
    if(p->data[0])
167
        avctx->release_buffer(avctx, p);
168

    
169
    p->reference = 0;
170
    if(avctx->get_buffer(avctx, p) < 0){
171
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
172
        return -1;
173
    }
174
    p->key_frame = 1;
175

    
176
    switch(l->mode) {
177
    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
178
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
179
                                    p->linesize[0], buf, buf_size, 1);
180
        buf += decoded; buf_size -= decoded;
181
        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
182
                                    p->linesize[1], buf, buf_size, 1);
183
        buf += decoded; buf_size -= decoded;
184
        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
185
                                    p->linesize[2], buf, buf_size, 1);
186
        break;
187
    case LOCO_CYV12: case LOCO_YV12:
188
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
189
                                    p->linesize[0], buf, buf_size, 1);
190
        buf += decoded; buf_size -= decoded;
191
        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
192
                                    p->linesize[2], buf, buf_size, 1);
193
        buf += decoded; buf_size -= decoded;
194
        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
195
                                    p->linesize[1], buf, buf_size, 1);
196
        break;
197
    case LOCO_CRGB: case LOCO_RGB:
198
        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
199
                                    -p->linesize[0], buf, buf_size, 3);
200
        buf += decoded; buf_size -= decoded;
201
        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
202
                                    -p->linesize[0], buf, buf_size, 3);
203
        buf += decoded; buf_size -= decoded;
204
        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
205
                                    -p->linesize[0], buf, buf_size, 3);
206
        break;
207
    case LOCO_RGBA:
208
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
209
                                    p->linesize[0], buf, buf_size, 4);
210
        buf += decoded; buf_size -= decoded;
211
        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
212
                                    p->linesize[0], buf, buf_size, 4);
213
        buf += decoded; buf_size -= decoded;
214
        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
215
                                    p->linesize[0], buf, buf_size, 4);
216
        buf += decoded; buf_size -= decoded;
217
        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
218
                                    p->linesize[0], buf, buf_size, 4);
219
        break;
220
    }
221

    
222
    *data_size = sizeof(AVFrame);
223
    *(AVFrame*)data = l->pic;
224

    
225
    return buf_size;
226
}
227

    
228
static int decode_init(AVCodecContext *avctx){
229
    LOCOContext * const l = avctx->priv_data;
230
    int version;
231

    
232
    l->avctx = avctx;
233
    if (avctx->extradata_size < 12) {
234
        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
235
               avctx->extradata_size);
236
        return -1;
237
    }
238
    version = LE_32(avctx->extradata);
239
    switch(version) {
240
    case 1:
241
        l->lossy = 0;
242
        break;
243
    case 2:
244
        l->lossy = LE_32(avctx->extradata + 8);
245
        break;
246
    default:
247
        l->lossy = LE_32(avctx->extradata + 8);
248
        av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
249
    }
250

    
251
    l->mode = LE_32(avctx->extradata + 4);
252
    switch(l->mode) {
253
    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
254
        avctx->pix_fmt = PIX_FMT_YUV422P;
255
        break;
256
    case LOCO_CRGB: case LOCO_RGB:
257
        avctx->pix_fmt = PIX_FMT_BGR24;
258
        break;
259
    case LOCO_CYV12: case LOCO_YV12:
260
        avctx->pix_fmt = PIX_FMT_YUV420P;
261
        break;
262
    case LOCO_CRGBA: case LOCO_RGBA:
263
        avctx->pix_fmt = PIX_FMT_RGBA32;
264
        break;
265
    default:
266
        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
267
        return -1;
268
    }
269
    if(avctx->debug & FF_DEBUG_PICT_INFO)
270
        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
271

    
272
    return 0;
273
}
274

    
275
AVCodec loco_decoder = {
276
    "loco",
277
    CODEC_TYPE_VIDEO,
278
    CODEC_ID_LOCO,
279
    sizeof(LOCOContext),
280
    decode_init,
281
    NULL,
282
    NULL,
283
    decode_frame,
284
    CODEC_CAP_DR1,
285
};