1/*
2 * Motion Pixels Video Decoder
3 * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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#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
56    motionpixels_tableinit();
57    mp->avctx = avctx;
58    dsputil_init(&mp->dsp, avctx);
59    mp->changes_map = av_mallocz(avctx->width * avctx->height);
60    mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
61    mp->vpt = av_mallocz(avctx->height * sizeof(YuvPixel));
62    mp->hpt = av_mallocz(avctx->height * avctx->width / 16 * sizeof(YuvPixel));
63    avctx->pix_fmt = PIX_FMT_RGB555;
64    return 0;
65}
66
67static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
68{
69    uint16_t *pixels;
70    int offset, w, h, color = 0, x, y, i;
71
72    while (count--) {
73        offset = get_bits_long(gb, mp->offset_bits_len);
74        w      = get_bits(gb, bits_len) + 1;
75        h      = get_bits(gb, bits_len) + 1;
76        if (read_color)
77            color = get_bits(gb, 15);
78        x = offset % mp->avctx->width;
79        y = offset / mp->avctx->width;
80        if (y >= mp->avctx->height)
81            continue;
82        w = FFMIN(w, mp->avctx->width  - x);
83        h = FFMIN(h, mp->avctx->height - y);
84        pixels = (uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
85        while (h--) {
86            mp->changes_map[offset] = w;
87            if (read_color)
88                for (i = 0; i < w; ++i)
89                    pixels[i] = color;
90            offset += mp->avctx->width;
91            pixels += mp->frame.linesize[0] / 2;
92        }
93    }
94}
95
96static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
97{
98    while (get_bits1(gb)) {
99        ++size;
100        if (size > mp->max_codes_bits) {
101            av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
102            return;
103        }
104        code <<= 1;
105        mp_get_code(mp, gb, size, code + 1);
106    }
107    if (mp->current_codes_count >= MAX_HUFF_CODES) {
108        av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
109        return;
110    }
111    mp->codes[mp->current_codes_count  ].code = code;
112    mp->codes[mp->current_codes_count++].size = size;
113}
114
115static void mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
116{
117    if (mp->codes_count == 1) {
118        mp->codes[0].delta = get_bits(gb, 4);
119    } else {
120        int i;
121
122        mp->max_codes_bits = get_bits(gb, 4);
123        for (i = 0; i < mp->codes_count; ++i)
124            mp->codes[i].delta = get_bits(gb, 4);
125        mp->current_codes_count = 0;
126        mp_get_code(mp, gb, 0, 0);
127   }
128}
129
130static int mp_gradient(MotionPixelsContext *mp, int component, int v)
131{
132    int delta;
133
134    delta = (v - 7) * mp->gradient_scale[component];
135    mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
136    return delta;
137}
138
139static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
140{
141    int color;
142
143    color = *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2];
144    return mp_rgb_yuv_table[color];
145}
146
147static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
148{
149    int color;
150
151    color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
152    *(uint16_t *)&mp->frame.data[0][y * mp->frame.linesize[0] + x * 2] = color;
153}
154
155static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
156{
157    int i;
158
159    i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
160    return mp->codes[i].delta;
161}
162
163static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
164{
165    YuvPixel p;
166    const int y0 = y * mp->avctx->width;
167    int w, i, x = 0;
168
169    p = mp->vpt[y];
170    if (mp->changes_map[y0 + x] == 0) {
171        memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
172        ++x;
173    }
174    while (x < mp->avctx->width) {
175        w = mp->changes_map[y0 + x];
176        if (w != 0) {
177            if ((y & 3) == 0) {
178                if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
179                    mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
180                    mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
181                    for (i = (x + 3) & ~3; i < x + w; i += 4) {
182                        mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
183                    }
184                }
185            }
186            x += w;
187            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
188            p = mp_get_yuv_from_rgb(mp, x - 1, y);
189        } else {
190            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
191            if ((x & 3) == 0) {
192                if ((y & 3) == 0) {
193                    p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
194                    p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
195                    mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
196                } else {
197                    p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
198                    p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
199                }
200            }
201            mp_set_rgb_from_yuv(mp, x, y, &p);
202            ++x;
203        }
204    }
205}
206
207static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
208{
209    YuvPixel p;
210    int y, y0;
211
212    for (y = 0; y < mp->avctx->height; ++y) {
213        if (mp->changes_map[y * mp->avctx->width] != 0) {
214            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
215            p = mp_get_yuv_from_rgb(mp, 0, y);
216        } else {
217            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
218            if ((y & 3) == 0) {
219                p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
220                p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
221            }
222            mp->vpt[y] = p;
223            mp_set_rgb_from_yuv(mp, 0, y, &p);
224        }
225    }
226    for (y0 = 0; y0 < 2; ++y0)
227        for (y = y0; y < mp->avctx->height; y += 2)
228            mp_decode_line(mp, gb, y);
229}
230
231static int mp_decode_frame(AVCodecContext *avctx,
232                                 void *data, int *data_size,
233                                 AVPacket *avpkt)
234{
235    const uint8_t *buf = avpkt->data;
236    int buf_size = avpkt->size;
237    MotionPixelsContext *mp = avctx->priv_data;
238    GetBitContext gb;
239    int i, count1, count2, sz;
240
241    mp->frame.reference = 1;
242    mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
243    if (avctx->reget_buffer(avctx, &mp->frame)) {
244        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
245        return -1;
246    }
247
248    /* le32 bitstream msb first */
249    av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
250    if (!mp->bswapbuf)
251        return AVERROR(ENOMEM);
252    mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
253    if (buf_size & 3)
254        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
255    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
256
257    memset(mp->changes_map, 0, avctx->width * avctx->height);
258    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
259        count1 = get_bits(&gb, 12);
260        count2 = get_bits(&gb, 12);
261        mp_read_changes_map(mp, &gb, count1, 8, i);
262        mp_read_changes_map(mp, &gb, count2, 4, i);
263    }
264
265    mp->codes_count = get_bits(&gb, 4);
266    if (mp->codes_count == 0)
267        goto end;
268
269    if (mp->changes_map[0] == 0) {
270        *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
271        mp->changes_map[0] = 1;
272    }
273    mp_read_codes_table(mp, &gb);
274
275    sz = get_bits(&gb, 18);
276    if (avctx->extradata[0] != 5)
277        sz += get_bits(&gb, 18);
278    if (sz == 0)
279        goto end;
280
281    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);
282    mp_decode_frame_helper(mp, &gb);
283    free_vlc(&mp->vlc);
284
285end:
286    *data_size = sizeof(AVFrame);
287    *(AVFrame *)data = mp->frame;
288    return buf_size;
289}
290
291static av_cold int mp_decode_end(AVCodecContext *avctx)
292{
293    MotionPixelsContext *mp = avctx->priv_data;
294
295    av_freep(&mp->changes_map);
296    av_freep(&mp->vpt);
297    av_freep(&mp->hpt);
298    av_freep(&mp->bswapbuf);
299    if (mp->frame.data[0])
300        avctx->release_buffer(avctx, &mp->frame);
301
302    return 0;
303}
304
305AVCodec motionpixels_decoder = {
306    "motionpixels",
307    AVMEDIA_TYPE_VIDEO,
308    CODEC_ID_MOTIONPIXELS,
309    sizeof(MotionPixelsContext),
310    mp_decode_init,
311    NULL,
312    mp_decode_end,
313    mp_decode_frame,
314    CODEC_CAP_DR1,
315    .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
316};
317