xref: /third_party/ffmpeg/libavcodec/loco.c (revision cabdff1a)
1/*
2 * LOCO codec
3 * Copyright (c) 2005 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/**
23 * @file
24 * LOCO codec.
25 */
26
27#include "avcodec.h"
28#include "codec_internal.h"
29#include "get_bits.h"
30#include "golomb.h"
31#include "internal.h"
32#include "mathops.h"
33
34enum LOCO_MODE {
35    LOCO_UNKN  =  0,
36    LOCO_CYUY2 = -1,
37    LOCO_CRGB  = -2,
38    LOCO_CRGBA = -3,
39    LOCO_CYV12 = -4,
40    LOCO_YUY2  =  1,
41    LOCO_UYVY  =  2,
42    LOCO_RGB   =  3,
43    LOCO_RGBA  =  4,
44    LOCO_YV12  =  5,
45};
46
47typedef struct LOCOContext {
48    AVCodecContext *avctx;
49    int lossy;
50    enum LOCO_MODE mode;
51} LOCOContext;
52
53typedef struct RICEContext {
54    GetBitContext gb;
55    int save, run, run2; /* internal rice decoder state */
56    int sum, count; /* sum and count for getting rice parameter */
57    int lossy;
58} RICEContext;
59
60static int loco_get_rice_param(RICEContext *r)
61{
62    int cnt = 0;
63    int val = r->count;
64
65    while (r->sum > val && cnt < 9) {
66        val <<= 1;
67        cnt++;
68    }
69
70    return cnt;
71}
72
73static inline void loco_update_rice_param(RICEContext *r, int val)
74{
75    r->sum += val;
76    r->count++;
77
78    if (r->count == 16) {
79        r->sum   >>= 1;
80        r->count >>= 1;
81    }
82}
83
84static inline int loco_get_rice(RICEContext *r)
85{
86    unsigned v;
87    if (r->run > 0) { /* we have zero run */
88        r->run--;
89        loco_update_rice_param(r, 0);
90        return 0;
91    }
92    if (get_bits_left(&r->gb) < 1)
93        return INT_MIN;
94    v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
95    loco_update_rice_param(r, (v + 1) >> 1);
96    if (!v) {
97        if (r->save >= 0) {
98            r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
99            if (r->run > 1)
100                r->save += r->run + 1;
101            else
102                r->save -= 3;
103        } else
104            r->run2++;
105    } else {
106        v = ((v >> 1) + r->lossy) ^ -(v & 1);
107        if (r->run2 > 0) {
108            if (r->run2 > 2)
109                r->save += r->run2;
110            else
111                r->save -= 3;
112            r->run2 = 0;
113        }
114    }
115
116    return v;
117}
118
119/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
120static inline int loco_predict(uint8_t* data, int stride)
121{
122    int a, b, c;
123
124    a = data[-stride];
125    b = data[-1];
126    c = data[-stride - 1];
127
128    return mid_pred(a, a + b - c, b);
129}
130
131static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
132                             int stride, const uint8_t *buf, int buf_size)
133{
134    RICEContext rc;
135    unsigned val;
136    int ret;
137    int i, j;
138
139    if(buf_size<=0)
140        return -1;
141
142    if ((ret = init_get_bits8(&rc.gb, buf, buf_size)) < 0)
143        return ret;
144
145    rc.save  = 0;
146    rc.run   = 0;
147    rc.run2  = 0;
148    rc.lossy = l->lossy;
149
150    rc.sum   = 8;
151    rc.count = 1;
152
153    /* restore top left pixel */
154    val     = loco_get_rice(&rc);
155    data[0] = 128 + val;
156    /* restore top line */
157    for (i = 1; i < width; i++) {
158        val = loco_get_rice(&rc);
159        if (val == INT_MIN)
160           return AVERROR_INVALIDDATA;
161        data[i] = data[i - 1] + val;
162    }
163    data += stride;
164    for (j = 1; j < height; j++) {
165        /* restore left column */
166        val = loco_get_rice(&rc);
167        if (val == INT_MIN)
168           return AVERROR_INVALIDDATA;
169        data[0] = data[-stride] + val;
170        /* restore all other pixels */
171        for (i = 1; i < width; i++) {
172            val = loco_get_rice(&rc);
173            if (val == INT_MIN)
174                return -1;
175            data[i] = loco_predict(&data[i], stride) + val;
176        }
177        data += stride;
178    }
179
180    return (get_bits_count(&rc.gb) + 7) >> 3;
181}
182
183static void rotate_faulty_loco(uint8_t *data, int width, int height, int stride)
184{
185    int y;
186
187    for (y=1; y<height; y++) {
188        if (width>=y) {
189            memmove(data + y*stride,
190                    data + y*(stride + 1),
191                    (width-y));
192            if (y+1 < height)
193                memmove(data + y*stride + (width-y),
194                        data + (y+1)*stride, y);
195        }
196    }
197}
198
199static int decode_frame(AVCodecContext *avctx, AVFrame *p,
200                        int *got_frame, AVPacket *avpkt)
201{
202    LOCOContext * const l = avctx->priv_data;
203    const uint8_t *buf    = avpkt->data;
204    int buf_size          = avpkt->size;
205    int decoded, ret;
206
207    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
208        return ret;
209    p->key_frame = 1;
210
211#define ADVANCE_BY_DECODED do { \
212    if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \
213    buf += decoded; buf_size -= decoded; \
214} while(0)
215    switch(l->mode) {
216    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
217        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
218                                    p->linesize[0], buf, buf_size);
219        ADVANCE_BY_DECODED;
220        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
221                                    p->linesize[1], buf, buf_size);
222        ADVANCE_BY_DECODED;
223        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
224                                    p->linesize[2], buf, buf_size);
225        break;
226    case LOCO_CYV12: case LOCO_YV12:
227        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
228                                    p->linesize[0], buf, buf_size);
229        ADVANCE_BY_DECODED;
230        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
231                                    p->linesize[2], buf, buf_size);
232        ADVANCE_BY_DECODED;
233        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
234                                    p->linesize[1], buf, buf_size);
235        break;
236    case LOCO_CRGB: case LOCO_RGB:
237        decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
238                                    -p->linesize[1], buf, buf_size);
239        ADVANCE_BY_DECODED;
240        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
241                                    -p->linesize[0], buf, buf_size);
242        ADVANCE_BY_DECODED;
243        decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
244                                    -p->linesize[2], buf, buf_size);
245        if (avctx->width & 1) {
246            rotate_faulty_loco(p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[0]);
247            rotate_faulty_loco(p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[1]);
248            rotate_faulty_loco(p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[2]);
249        }
250        break;
251    case LOCO_CRGBA:
252    case LOCO_RGBA:
253        decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
254                                    -p->linesize[1], buf, buf_size);
255        ADVANCE_BY_DECODED;
256        decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
257                                    -p->linesize[0], buf, buf_size);
258        ADVANCE_BY_DECODED;
259        decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
260                                    -p->linesize[2], buf, buf_size);
261        ADVANCE_BY_DECODED;
262        decoded = loco_decode_plane(l, p->data[3] + p->linesize[3]*(avctx->height-1), avctx->width, avctx->height,
263                                    -p->linesize[3], buf, buf_size);
264        break;
265    default:
266        av_assert0(0);
267    }
268
269    if (decoded < 0 || decoded > buf_size)
270        goto buf_too_small;
271    buf_size -= decoded;
272
273    *got_frame      = 1;
274
275    return avpkt->size - buf_size;
276buf_too_small:
277    av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
278    return AVERROR(EINVAL);
279}
280
281static av_cold int decode_init(AVCodecContext *avctx)
282{
283    LOCOContext * const l = avctx->priv_data;
284    int version;
285
286    l->avctx = avctx;
287    if (avctx->extradata_size < 12) {
288        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
289               avctx->extradata_size);
290        return AVERROR_INVALIDDATA;
291    }
292    version = AV_RL32(avctx->extradata);
293    switch (version) {
294    case 1:
295        l->lossy = 0;
296        break;
297    case 2:
298        l->lossy = AV_RL32(avctx->extradata + 8);
299        break;
300    default:
301        l->lossy = AV_RL32(avctx->extradata + 8);
302        avpriv_request_sample(avctx, "LOCO codec version %i", version);
303    }
304
305    if (l->lossy > 65536U) {
306        av_log(avctx, AV_LOG_ERROR, "lossy %i is too large\n", l->lossy);
307        return AVERROR_INVALIDDATA;
308    }
309
310    l->mode = AV_RL32(avctx->extradata + 4);
311    switch (l->mode) {
312    case LOCO_CYUY2:
313    case LOCO_YUY2:
314    case LOCO_UYVY:
315        avctx->pix_fmt = AV_PIX_FMT_YUV422P;
316        break;
317    case LOCO_CRGB:
318    case LOCO_RGB:
319        avctx->pix_fmt = AV_PIX_FMT_GBRP;
320        break;
321    case LOCO_CYV12:
322    case LOCO_YV12:
323        avctx->pix_fmt = AV_PIX_FMT_YUV420P;
324        break;
325    case LOCO_CRGBA:
326    case LOCO_RGBA:
327        avctx->pix_fmt = AV_PIX_FMT_GBRAP;
328        break;
329    default:
330        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
331        return AVERROR_INVALIDDATA;
332    }
333    if (avctx->debug & FF_DEBUG_PICT_INFO)
334        av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
335
336    return 0;
337}
338
339const FFCodec ff_loco_decoder = {
340    .p.name         = "loco",
341    .p.long_name    = NULL_IF_CONFIG_SMALL("LOCO"),
342    .p.type         = AVMEDIA_TYPE_VIDEO,
343    .p.id           = AV_CODEC_ID_LOCO,
344    .priv_data_size = sizeof(LOCOContext),
345    .init           = decode_init,
346    FF_CODEC_DECODE_CB(decode_frame),
347    .p.capabilities = AV_CODEC_CAP_DR1,
348    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
349};
350