summaryrefslogtreecommitdiff
path: root/libavcodec/loco.c
blob: 6be081d8ad3ef4f78b29563d49ab9bac49caa76e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
/*
 * LOCO codec
 * Copyright (c) 2005 Konstantin Shishkov
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * LOCO codec.
 */

#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "internal.h"
#include "mathops.h"

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

typedef struct LOCOContext {
    AVCodecContext *avctx;
    int lossy;
    int mode;
} LOCOContext;

typedef struct RICEContext {
    GetBitContext gb;
    int save, run, run2; /* internal rice decoder state */
    int sum, count; /* sum and count for getting rice parameter */
    int lossy;
} RICEContext;

static int loco_get_rice_param(RICEContext *r)
{
    int cnt = 0;
    int val = r->count;

    while (r->sum > val && cnt < 9) {
        val <<= 1;
        cnt++;
    }

    return cnt;
}

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

    if (r->count == 16) {
        r->sum   >>= 1;
        r->count >>= 1;
    }
}

static inline int loco_get_rice(RICEContext *r)
{
    int v;
    if (r->run > 0) { /* we have zero run */
        r->run--;
        loco_update_rice_param(r, 0);
        return 0;
    }
    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
    loco_update_rice_param(r, (v + 1) >> 1);
    if (!v) {
        if (r->save >= 0) {
            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
            if (r->run > 1)
                r->save += r->run + 1;
            else
                r->save -= 3;
        } else
            r->run2++;
    } else {
        v = ((v >> 1) + r->lossy) ^ -(v & 1);
        if (r->run2 > 0) {
            if (r->run2 > 2)
                r->save += r->run2;
            else
                r->save -= 3;
            r->run2 = 0;
        }
    }

    return v;
}

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

    a = data[-stride];
    b = data[-step];
    c = data[-stride - step];

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

static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
                             int stride, const uint8_t *buf, int buf_size, int step)
{
    RICEContext rc;
    int val;
    int i, j;

    init_get_bits(&rc.gb, buf, buf_size*8);
    rc.save  = 0;
    rc.run   = 0;
    rc.run2  = 0;
    rc.lossy = l->lossy;

    rc.sum   = 8;
    rc.count = 1;

    /* restore top left pixel */
    val     = loco_get_rice(&rc);
    data[0] = 128 + val;
    /* restore top line */
    for (i = 1; i < width; i++) {
        val = loco_get_rice(&rc);
        data[i * step] = data[i * step - step] + val;
    }
    data += stride;
    for (j = 1; j < height; j++) {
        /* restore left column */
        val = loco_get_rice(&rc);
        data[0] = data[-stride] + val;
        /* restore all other pixels */
        for (i = 1; i < width; i++) {
            val = loco_get_rice(&rc);
            data[i * step] = loco_predict(&data[i * step], stride, step) + val;
        }
        data += stride;
    }

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

static int decode_frame(AVCodecContext *avctx,
                        void *data, int *got_frame,
                        AVPacket *avpkt)
{
    LOCOContext * const l = avctx->priv_data;
    const uint8_t *buf    = avpkt->data;
    int buf_size          = avpkt->size;
    AVFrame * const p     = data;
    int decoded, ret;

    if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    p->key_frame = 1;

    switch(l->mode) {
    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 1);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
                                    p->linesize[1], buf, buf_size, 1);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
                                    p->linesize[2], buf, buf_size, 1);
        break;
    case LOCO_CYV12: case LOCO_YV12:
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 1);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
                                    p->linesize[2], buf, buf_size, 1);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
                                    p->linesize[1], buf, buf_size, 1);
        break;
    case LOCO_CRGB: case LOCO_RGB:
        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
                                    -p->linesize[0], buf, buf_size, 3);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
                                    -p->linesize[0], buf, buf_size, 3);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
                                    -p->linesize[0], buf, buf_size, 3);
        break;
    case LOCO_RGBA:
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
        if (decoded >= buf_size)
            goto buf_too_small;
        buf += decoded; buf_size -= decoded;

        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
        break;
    }

    *got_frame      = 1;

    return buf_size;
buf_too_small:
    av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
    return AVERROR(EINVAL);
}

static av_cold int decode_init(AVCodecContext *avctx)
{
    LOCOContext * const l = avctx->priv_data;
    int version;

    l->avctx = avctx;
    if (avctx->extradata_size < 12) {
        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
               avctx->extradata_size);
        return AVERROR_INVALIDDATA;
    }
    version = AV_RL32(avctx->extradata);
    switch (version) {
    case 1:
        l->lossy = 0;
        break;
    case 2:
        l->lossy = AV_RL32(avctx->extradata + 8);
        break;
    default:
        l->lossy = AV_RL32(avctx->extradata + 8);
        avpriv_request_sample(avctx, "LOCO codec version %i", version);
    }

    l->mode = AV_RL32(avctx->extradata + 4);
    switch (l->mode) {
    case LOCO_CYUY2:
    case LOCO_YUY2:
    case LOCO_UYVY:
        avctx->pix_fmt = AV_PIX_FMT_YUV422P;
        break;
    case LOCO_CRGB:
    case LOCO_RGB:
        avctx->pix_fmt = AV_PIX_FMT_BGR24;
        break;
    case LOCO_CYV12:
    case LOCO_YV12:
        avctx->pix_fmt = AV_PIX_FMT_YUV420P;
        break;
    case LOCO_CRGBA:
    case LOCO_RGBA:
        avctx->pix_fmt = AV_PIX_FMT_RGB32;
        break;
    default:
        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
        return AVERROR_INVALIDDATA;
    }
    if (avctx->debug & FF_DEBUG_PICT_INFO)
        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);

    return 0;
}

AVCodec ff_loco_decoder = {
    .name           = "loco",
    .long_name      = NULL_IF_CONFIG_SMALL("LOCO"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_LOCO,
    .priv_data_size = sizeof(LOCOContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};