loco.c 9.59 KB
Newer Older
1 2 3 4
/*
 * LOCO codec
 * Copyright (c) 2005 Konstantin Shishkov
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav is free software; you can redistribute it and/or
8 9
 * modify it under the terms of the GNU Lesser General Public
 * 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 14 15 16 17
 * 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
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 25
 * LOCO codec.
 */
26

27
#include "avcodec.h"
28
#include "get_bits.h"
29
#include "golomb.h"
30
#include "internal.h"
31
#include "mathops.h"
32

33 34 35 36 37 38 39 40 41 42 43 44
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,
};
45

46
typedef struct LOCOContext {
47 48 49 50 51
    AVCodecContext *avctx;
    int lossy;
    int mode;
} LOCOContext;

52
typedef struct RICEContext {
53 54 55
    GetBitContext gb;
    int save, run, run2; /* internal rice decoder state */
    int sum, count; /* sum and count for getting rice parameter */
56
    int lossy;
57
} RICEContext;
58 59 60 61 62

static int loco_get_rice_param(RICEContext *r)
{
    int cnt = 0;
    int val = r->count;
63

64
    while (r->sum > val && cnt < 9) {
65 66 67
        val <<= 1;
        cnt++;
    }
68

69 70 71 72 73 74 75
    return cnt;
}

static inline void loco_update_rice_param(RICEContext *r, int val)
{
    r->sum += val;
    r->count++;
76

77 78
    if (r->count == 16) {
        r->sum   >>= 1;
79 80 81 82 83 84 85 86 87
        r->count >>= 1;
    }
}

static inline int loco_get_rice(RICEContext *r)
{
    int v;
    if (r->run > 0) { /* we have zero run */
        r->run--;
88
        loco_update_rice_param(r, 0);
89 90
        return 0;
    }
91
    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
92
    loco_update_rice_param(r, (v + 1) >> 1);
93 94
    if (!v) {
        if (r->save >= 0) {
95
            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
96
            if (r->run > 1)
97 98 99
                r->save += r->run + 1;
            else
                r->save -= 3;
100
        } else
101
            r->run2++;
102
    } else {
103
        v = ((v >> 1) + r->lossy) ^ -(v & 1);
104 105 106 107 108 109 110
        if (r->run2 > 0) {
            if (r->run2 > 2)
                r->save += r->run2;
            else
                r->save -= 3;
            r->run2 = 0;
        }
111
    }
112

113 114 115 116 117 118 119
    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;
120

121 122 123
    a = data[-stride];
    b = data[-step];
    c = data[-stride - step];
124

125
    return mid_pred(a, a + b - c, b);
126 127 128
}

static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
Michael Niedermayer's avatar
Michael Niedermayer committed
129
                             int stride, const uint8_t *buf, int buf_size, int step)
130 131 132 133
{
    RICEContext rc;
    int val;
    int i, j;
134

135
    init_get_bits(&rc.gb, buf, buf_size*8);
136 137 138
    rc.save  = 0;
    rc.run   = 0;
    rc.run2  = 0;
139 140
    rc.lossy = l->lossy;

141
    rc.sum   = 8;
142
    rc.count = 1;
143

144
    /* restore top left pixel */
145
    val     = loco_get_rice(&rc);
146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
    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;
    }
164

165
    return (get_bits_count(&rc.gb) + 7) >> 3;
166 167
}

168
static int decode_frame(AVCodecContext *avctx,
169
                        void *data, int *got_frame,
170
                        AVPacket *avpkt)
171 172
{
    LOCOContext * const l = avctx->priv_data;
173 174
    const uint8_t *buf    = avpkt->data;
    int buf_size          = avpkt->size;
175
    AVFrame * const p     = data;
176
    int decoded, ret;
177

178
    if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
179
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
180
        return ret;
181 182 183 184 185 186 187
    }
    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);
188 189
        if (decoded >= buf_size)
            goto buf_too_small;
190
        buf += decoded; buf_size -= decoded;
191

192 193
        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
                                    p->linesize[1], buf, buf_size, 1);
194 195
        if (decoded >= buf_size)
            goto buf_too_small;
196
        buf += decoded; buf_size -= decoded;
197

198 199 200 201 202 203
        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);
204 205
        if (decoded >= buf_size)
            goto buf_too_small;
206
        buf += decoded; buf_size -= decoded;
207

208 209
        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
                                    p->linesize[2], buf, buf_size, 1);
210 211
        if (decoded >= buf_size)
            goto buf_too_small;
212
        buf += decoded; buf_size -= decoded;
213

214 215
        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
                                    p->linesize[1], buf, buf_size, 1);
216 217
        break;
    case LOCO_CRGB: case LOCO_RGB:
218 219
        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);
220 221
        if (decoded >= buf_size)
            goto buf_too_small;
222
        buf += decoded; buf_size -= decoded;
223

224 225
        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);
226 227
        if (decoded >= buf_size)
            goto buf_too_small;
228
        buf += decoded; buf_size -= decoded;
229

230 231
        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);
232 233 234 235
        break;
    case LOCO_RGBA:
        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
236 237
        if (decoded >= buf_size)
            goto buf_too_small;
238
        buf += decoded; buf_size -= decoded;
239

240 241
        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
242 243
        if (decoded >= buf_size)
            goto buf_too_small;
244
        buf += decoded; buf_size -= decoded;
245

246 247
        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
248 249
        if (decoded >= buf_size)
            goto buf_too_small;
250
        buf += decoded; buf_size -= decoded;
251

252 253 254 255 256
        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
                                    p->linesize[0], buf, buf_size, 4);
        break;
    }

257
    *got_frame      = 1;
258

259
    return buf_size;
260 261 262
buf_too_small:
    av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
    return AVERROR(EINVAL);
263 264
}

265 266
static av_cold int decode_init(AVCodecContext *avctx)
{
267 268 269 270 271 272 273
    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);
274
        return AVERROR_INVALIDDATA;
275
    }
276
    version = AV_RL32(avctx->extradata);
277
    switch (version) {
278 279 280 281
    case 1:
        l->lossy = 0;
        break;
    case 2:
282
        l->lossy = AV_RL32(avctx->extradata + 8);
283 284
        break;
    default:
285
        l->lossy = AV_RL32(avctx->extradata + 8);
286
        avpriv_request_sample(avctx, "LOCO codec version %i", version);
287
    }
288

289
    l->mode = AV_RL32(avctx->extradata + 4);
290 291 292 293
    switch (l->mode) {
    case LOCO_CYUY2:
    case LOCO_YUY2:
    case LOCO_UYVY:
294
        avctx->pix_fmt = AV_PIX_FMT_YUV422P;
295
        break;
296 297
    case LOCO_CRGB:
    case LOCO_RGB:
298
        avctx->pix_fmt = AV_PIX_FMT_BGR24;
299
        break;
300 301
    case LOCO_CYV12:
    case LOCO_YV12:
302
        avctx->pix_fmt = AV_PIX_FMT_YUV420P;
303
        break;
304 305
    case LOCO_CRGBA:
    case LOCO_RGBA:
306
        avctx->pix_fmt = AV_PIX_FMT_RGB32;
307 308 309
        break;
    default:
        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
310
        return AVERROR_INVALIDDATA;
311
    }
312
    if (avctx->debug & FF_DEBUG_PICT_INFO)
313
        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
314 315 316 317

    return 0;
}

318
AVCodec ff_loco_decoder = {
319
    .name           = "loco",
320
    .long_name      = NULL_IF_CONFIG_SMALL("LOCO"),
321
    .type           = AVMEDIA_TYPE_VIDEO,
322
    .id             = AV_CODEC_ID_LOCO,
323 324 325 326
    .priv_data_size = sizeof(LOCOContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
327
};