1/*
2 * Motion Pixels Video Decoder
3 * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avcodec.h"
23#include "get_bits.h"
24#include "dsputil.h"
25
26#define MAX_HUFF_CODES 16
27
28#include "motionpixels_tablegen.h"
29
30typedef struct HuffCode {
31    int code;
32    uint8_t size;
33    uint8_t delta;
34} HuffCode;
35
36typedef struct MotionPixelsContext {
37    AVCodecContext *avctx;
38    AVFrame frame;
39    DSPContext dsp;
40    uint8_t *changes_map;
41    int offset_bits_len;
42    int codes_count, current_codes_count;
43    int max_codes_bits;
44    HuffCode codes[MAX_HUFF_CODES];
45    VLC vlc;
46    YuvPixel *vpt, *hpt;
47    uint8_t gradient_scale[3];
48    uint8_t *bswapbuf;
49    int bswapbuf_size;
50} MotionPixelsContext;
51
52static av_cold int mp_decode_init(AVCodecContext *avctx)
53{
54    MotionPixelsContext *mp = avctx->priv_data;
55    int w4 = (avctx->width  + 3) & ~3;
56    int h4 = (avctx->height + 3) & ~3;
57
58    motionpixels_tableinit();
59    mp->avctx = avctx;
60    dsputil_init(&mp->dsp, avctx);
61    mp->changes_map = av_mallocz(avctx->width * h4);
62    mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
63    mp->vpt = av_mallocz(avctx->height * sizeof(YuvPixel));
64    mp->hpt = av_mallocz(h4 * w4 / 16 * sizeof(YuvPixel));
65    avctx->pix_fmt = PIX_FMT_RGB555;
66    return 0;
67}
68
69static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
70{
71    uint16_t *pixels;
72    int offset, w, h, color = 0, x, y, i;
73
74    while (count--) {
75        offset = get_bits_long(gb, mp->offset_bits_len);
76        w      = get_bits(gb, bits_len) + 1;
77        h      = get_bits(gb, bits_len) + 1;
78        if (read_color)
79            color = get_bits(gb, 15);
80        x = offset % mp->avctx->width;
81        y = offset / mp->avctx->width;
82        if (y >= mp->avctx->height)
83            continue;
84        w = FFMIN(w, mp->avctx->width  - x);
85        h = FFMIN(h, mp->avctx->height - y);
86        pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
87        while (h--) {
88            mp->changes_map[offset] = w;
89            if (read_color)
90                for (i = 0; i < w; ++i)
91                    pixels[i] = color;
92            offset += mp->avctx->width;
93            pixels += mp->frame.linesize[0] / 2;
94        }
95    }
96}
97
98static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
99{
100    while (get_bits1(gb)) {
101        ++size;
102        if (size > mp->max_codes_bits) {
103            av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
104            return;
105        }
106        code <<= 1;
107        mp_get_code(mp, gb, size, code + 1);
108    }
109    if (mp->current_codes_count >= MAX_HUFF_CODES) {
110        av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
111        return;
112    }
113    mp->codes[mp->current_codes_count  ].code = code;
114    mp->codes[mp->current_codes_count++].size = size;
115}
116
117static void mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
118{
119    if (mp->codes_count == 1) {
120        mp->codes[0].delta = get_bits(gb, 4);
121    } else {
122        int i;
123
124        mp->max_codes_bits = get_bits(gb, 4);
125        for (i = 0; i < mp->codes_count; ++i)
126            mp->codes[i].delta = get_bits(gb, 4);
127        mp->current_codes_count = 0;
128        mp_get_code(mp, gb, 0, 0);
129   }
130}
131
132static int mp_gradient(MotionPixelsContext *mp, int component, int v)
133{
134    int delta;
135
136    delta = (v - 7) * mp->gradient_scale[component];
137    mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
138    return delta;
139}
140
141static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
142{
143    int color;
144
145    color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
146    return mp_rgb_yuv_table[color];
147}
148
149static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
150{
151    int color;
152
153    color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
154    *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
155}
156
157static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
158{
159    int i;
160
161    i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
162    return mp->codes[i].delta;
163}
164
165static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
166{
167    YuvPixel p;
168    const int y0 = y * mp->avctx->width;
169    int w, i, x = 0;
170
171    p = mp->vpt[y];
172    if (mp->changes_map[y0 + x] == 0) {
173        memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
174        ++x;
175    }
176    while (x < mp->avctx->width) {
177        w = mp->changes_map[y0 + x];
178        if (w != 0) {
179            if ((y & 3) == 0) {
180                if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
181                    mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
182                    mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
183                    for (i = (x + 3) & ~3; i < x + w; i += 4) {
184                        mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
185                    }
186                }
187            }
188            x += w;
189            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
190            p = mp_get_yuv_from_rgb(mp, x - 1, y);
191        } else {
192            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
193            p.y = av_clip(p.y, 0, 31);
194            if ((x & 3) == 0) {
195                if ((y & 3) == 0) {
196                    p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
197                    p.v = av_clip(p.v, -32, 31);
198                    p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
199                    p.u = av_clip(p.u, -32, 31);
200                    mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
201                } else {
202                    p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
203                    p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
204                }
205            }
206            mp_set_rgb_from_yuv(mp, x, y, &p);
207            ++x;
208        }
209    }
210}
211
212static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
213{
214    YuvPixel p;
215    int y, y0;
216
217    for (y = 0; y < mp->avctx->height; ++y) {
218        if (mp->changes_map[y * mp->avctx->width] != 0) {
219            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
220            p = mp_get_yuv_from_rgb(mp, 0, y);
221        } else {
222            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
223            p.y = av_clip(p.y, 0, 31);
224            if ((y & 3) == 0) {
225                p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
226                p.v = av_clip(p.v, -32, 31);
227                p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
228                p.u = av_clip(p.u, -32, 31);
229            }
230            mp->vpt[y] = p;
231            mp_set_rgb_from_yuv(mp, 0, y, &p);
232        }
233    }
234    for (y0 = 0; y0 < 2; ++y0)
235        for (y = y0; y < mp->avctx->height; y += 2)
236            mp_decode_line(mp, gb, y);
237}
238
239static int mp_decode_frame(AVCodecContext *avctx,
240                                 void *data, int *data_size,
241                                 AVPacket *avpkt)
242{
243    const uint8_t *buf = avpkt->data;
244    int buf_size = avpkt->size;
245    MotionPixelsContext *mp = avctx->priv_data;
246    GetBitContext gb;
247    int i, count1, count2, sz;
248
249    mp->frame.reference = 1;
250    mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
251    if (avctx->reget_buffer(avctx, &mp->frame)) {
252        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
253        return -1;
254    }
255
256    /* le32 bitstream msb first */
257    av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
258    if (!mp->bswapbuf)
259        return AVERROR(ENOMEM);
260    mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
261    if (buf_size & 3)
262        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
263    memset(mp->bswapbuf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
264    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
265
266    memset(mp->changes_map, 0, avctx->width * avctx->height);
267    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
268        count1 = get_bits(&gb, 12);
269        count2 = get_bits(&gb, 12);
270        mp_read_changes_map(mp, &gb, count1, 8, i);
271        mp_read_changes_map(mp, &gb, count2, 4, i);
272    }
273
274    mp->codes_count = get_bits(&gb, 4);
275    if (mp->codes_count == 0)
276        goto end;
277
278    if (mp->changes_map[0] == 0) {
279        *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
280        mp->changes_map[0] = 1;
281    }
282    mp_read_codes_table(mp, &gb);
283
284    sz = get_bits(&gb, 18);
285    if (avctx->extradata[0] != 5)
286        sz += get_bits(&gb, 18);
287    if (sz == 0)
288        goto end;
289
290    if (mp->max_codes_bits <= 0)
291        goto end;
292    if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
293        goto end;
294    mp_decode_frame_helper(mp, &gb);
295    ff_free_vlc(&mp->vlc);
296
297end:
298    *data_size = sizeof(AVFrame);
299    *(AVFrame *)data = mp->frame;
300    return buf_size;
301}
302
303static av_cold int mp_decode_end(AVCodecContext *avctx)
304{
305    MotionPixelsContext *mp = avctx->priv_data;
306
307    av_freep(&mp->changes_map);
308    av_freep(&mp->vpt);
309    av_freep(&mp->hpt);
310    av_freep(&mp->bswapbuf);
311    if (mp->frame.data[0])
312        avctx->release_buffer(avctx, &mp->frame);
313
314    return 0;
315}
316
317AVCodec ff_motionpixels_decoder = {
318    .name           = "motionpixels",
319    .type           = AVMEDIA_TYPE_VIDEO,
320    .id             = CODEC_ID_MOTIONPIXELS,
321    .priv_data_size = sizeof(MotionPixelsContext),
322    .init           = mp_decode_init,
323    .close          = mp_decode_end,
324    .decode         = mp_decode_frame,
325    .capabilities   = CODEC_CAP_DR1,
326    .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
327};
328