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 "libavutil/thread.h"
23
24#include "config.h"
25
26#include "avcodec.h"
27#include "get_bits.h"
28#include "bswapdsp.h"
29#include "codec_internal.h"
30#include "internal.h"
31
32#define MAX_HUFF_CODES 16
33
34#include "motionpixels_tablegen.h"
35
36typedef struct HuffCode {
37    uint8_t size;
38    uint8_t delta;
39} HuffCode;
40
41typedef struct MotionPixelsContext {
42    AVCodecContext *avctx;
43    AVFrame *frame;
44    BswapDSPContext bdsp;
45    uint8_t *changes_map;
46    int offset_bits_len;
47    int codes_count, current_codes_count;
48    int max_codes_bits;
49    HuffCode codes[MAX_HUFF_CODES];
50    VLC vlc;
51    YuvPixel *vpt, *hpt;
52    uint8_t gradient_scale[3];
53    uint8_t *bswapbuf;
54    int bswapbuf_size;
55} MotionPixelsContext;
56
57static av_cold int mp_decode_end(AVCodecContext *avctx)
58{
59    MotionPixelsContext *mp = avctx->priv_data;
60
61    av_freep(&mp->changes_map);
62    av_freep(&mp->vpt);
63    av_freep(&mp->hpt);
64    av_freep(&mp->bswapbuf);
65    av_frame_free(&mp->frame);
66
67    return 0;
68}
69
70static av_cold int mp_decode_init(AVCodecContext *avctx)
71{
72    av_unused static AVOnce init_static_once = AV_ONCE_INIT;
73    MotionPixelsContext *mp = avctx->priv_data;
74    int w4 = (avctx->width  + 3) & ~3;
75    int h4 = (avctx->height + 3) & ~3;
76
77    if(avctx->extradata_size < 2){
78        av_log(avctx, AV_LOG_ERROR, "extradata too small\n");
79        return AVERROR_INVALIDDATA;
80    }
81
82    mp->avctx = avctx;
83    ff_bswapdsp_init(&mp->bdsp);
84    mp->changes_map = av_calloc(avctx->width, h4);
85    mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
86    mp->vpt = av_calloc(avctx->height, sizeof(*mp->vpt));
87    mp->hpt = av_calloc(h4 / 4, w4 / 4 * sizeof(*mp->hpt));
88    if (!mp->changes_map || !mp->vpt || !mp->hpt)
89        return AVERROR(ENOMEM);
90    avctx->pix_fmt = AV_PIX_FMT_RGB555;
91
92    mp->frame = av_frame_alloc();
93    if (!mp->frame)
94        return AVERROR(ENOMEM);
95
96#if !CONFIG_HARDCODED_TABLES
97    ff_thread_once(&init_static_once, motionpixels_tableinit);
98#endif
99
100    return 0;
101}
102
103static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
104{
105    uint16_t *pixels;
106    int offset, w, h, color = 0, x, y, i;
107
108    while (count--) {
109        offset = get_bits_long(gb, mp->offset_bits_len);
110        w      = get_bits(gb, bits_len) + 1;
111        h      = get_bits(gb, bits_len) + 1;
112        if (read_color)
113            color = get_bits(gb, 15);
114        x = offset % mp->avctx->width;
115        y = offset / mp->avctx->width;
116        if (y >= mp->avctx->height)
117            continue;
118        w = FFMIN(w, mp->avctx->width  - x);
119        h = FFMIN(h, mp->avctx->height - y);
120        pixels = (uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
121        while (h--) {
122            mp->changes_map[offset] = w;
123            if (read_color)
124                for (i = 0; i < w; ++i)
125                    pixels[i] = color;
126            offset += mp->avctx->width;
127            pixels += mp->frame->linesize[0] / 2;
128        }
129    }
130}
131
132static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size)
133{
134    while (get_bits1(gb)) {
135        ++size;
136        if (size > mp->max_codes_bits) {
137            av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
138            return AVERROR_INVALIDDATA;
139        }
140        if (mp_get_code(mp, gb, size) < 0)
141            return AVERROR_INVALIDDATA;
142    }
143    if (mp->current_codes_count >= mp->codes_count) {
144        av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
145        return AVERROR_INVALIDDATA;
146    }
147
148    mp->codes[mp->current_codes_count++].size = size;
149    return 0;
150}
151
152static int mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
153{
154    if (mp->codes_count == 1) {
155        mp->codes[0].delta = get_bits(gb, 4);
156    } else {
157        int i;
158        int ret;
159
160        mp->max_codes_bits = get_bits(gb, 4);
161        for (i = 0; i < mp->codes_count; ++i)
162            mp->codes[i].delta = get_bits(gb, 4);
163        mp->current_codes_count = 0;
164        if ((ret = mp_get_code(mp, gb, 0)) < 0)
165            return ret;
166        if (mp->current_codes_count < mp->codes_count) {
167            av_log(mp->avctx, AV_LOG_ERROR, "too few codes\n");
168            return AVERROR_INVALIDDATA;
169        }
170   }
171   return 0;
172}
173
174static av_always_inline int mp_gradient(MotionPixelsContext *mp, int component, int v)
175{
176    int delta;
177
178    delta = (v - 7) * mp->gradient_scale[component];
179    mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
180    return delta;
181}
182
183static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
184{
185    int color;
186
187    color = *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
188    return mp_rgb_yuv_table[color & 0x7FFF];
189}
190
191static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
192{
193    int color;
194
195    color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
196    *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2] = color;
197}
198
199static av_always_inline int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
200{
201    return mp->vlc.table ? get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1)
202                         : mp->codes[0].delta;
203}
204
205static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
206{
207    YuvPixel p;
208    const int y0 = y * mp->avctx->width;
209    int w, i, x = 0;
210
211    p = mp->vpt[y];
212    if (mp->changes_map[y0 + x] == 0) {
213        memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
214        ++x;
215    }
216    while (x < mp->avctx->width) {
217        w = mp->changes_map[y0 + x];
218        if (w != 0) {
219            if ((y & 3) == 0) {
220                if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
221                    mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
222                    mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
223                    for (i = (x + 3) & ~3; i < x + w; i += 4) {
224                        mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
225                    }
226                }
227            }
228            x += w;
229            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
230            p = mp_get_yuv_from_rgb(mp, x - 1, y);
231        } else {
232            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
233            p.y = av_clip_uintp2(p.y, 5);
234            if ((x & 3) == 0) {
235                if ((y & 3) == 0) {
236                    p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
237                    p.v = av_clip_intp2(p.v, 5);
238                    p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
239                    p.u = av_clip_intp2(p.u, 5);
240                    mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
241                } else {
242                    p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
243                    p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
244                }
245            }
246            mp_set_rgb_from_yuv(mp, x, y, &p);
247            ++x;
248        }
249    }
250}
251
252static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
253{
254    YuvPixel p;
255    int y, y0;
256
257    av_assert1(mp->changes_map[0]);
258
259    for (y = 0; y < mp->avctx->height; ++y) {
260        if (mp->changes_map[y * mp->avctx->width] != 0) {
261            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
262            p = mp_get_yuv_from_rgb(mp, 0, y);
263        } else {
264            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
265            p.y = av_clip_uintp2(p.y, 5);
266            if ((y & 3) == 0) {
267                p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
268                p.v = av_clip_intp2(p.v, 5);
269                p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
270                p.u = av_clip_intp2(p.u, 5);
271            }
272            mp->vpt[y] = p;
273            mp_set_rgb_from_yuv(mp, 0, y, &p);
274        }
275    }
276    for (y0 = 0; y0 < 2; ++y0)
277        for (y = y0; y < mp->avctx->height; y += 2)
278            mp_decode_line(mp, gb, y);
279}
280
281static int mp_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
282                           int *got_frame, AVPacket *avpkt)
283{
284    const uint8_t *buf = avpkt->data;
285    int buf_size = avpkt->size;
286    MotionPixelsContext *mp = avctx->priv_data;
287    GetBitContext gb;
288    int i, count1, count2, sz, ret;
289
290    if ((ret = ff_reget_buffer(avctx, mp->frame, 0)) < 0)
291        return ret;
292
293    /* le32 bitstream msb first */
294    av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);
295    if (!mp->bswapbuf)
296        return AVERROR(ENOMEM);
297    mp->bdsp.bswap_buf((uint32_t *) mp->bswapbuf, (const uint32_t *) buf,
298                       buf_size / 4);
299    if (buf_size & 3)
300        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
301    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
302
303    memset(mp->changes_map, 0, avctx->width * avctx->height);
304    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
305        count1 = get_bits(&gb, 12);
306        count2 = get_bits(&gb, 12);
307        mp_read_changes_map(mp, &gb, count1, 8, i);
308        mp_read_changes_map(mp, &gb, count2, 4, i);
309    }
310
311    mp->codes_count = get_bits(&gb, 4);
312    if (mp->codes_count == 0)
313        goto end;
314
315    if (mp->changes_map[0] == 0) {
316        *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);
317        mp->changes_map[0] = 1;
318    }
319    if (mp_read_codes_table(mp, &gb) < 0)
320        goto end;
321
322    sz = get_bits(&gb, 18);
323    if (avctx->extradata[0] != 5)
324        sz += get_bits(&gb, 18);
325    if (sz == 0)
326        goto end;
327
328    if (mp->codes_count > 1) {
329        /* The entries of the mp->codes array are sorted from right to left
330         * in the Huffman tree, hence -(int)sizeof(HuffCode). */
331        ret = ff_init_vlc_from_lengths(&mp->vlc, mp->max_codes_bits, mp->codes_count,
332                                       &mp->codes[mp->codes_count - 1].size,  -(int)sizeof(HuffCode),
333                                       &mp->codes[mp->codes_count - 1].delta, -(int)sizeof(HuffCode), 1,
334                                       0, 0, avctx);
335        if (ret < 0)
336            goto end;
337    }
338    mp_decode_frame_helper(mp, &gb);
339    ff_free_vlc(&mp->vlc);
340
341end:
342    if ((ret = av_frame_ref(rframe, mp->frame)) < 0)
343        return ret;
344    *got_frame       = 1;
345    return buf_size;
346}
347
348const FFCodec ff_motionpixels_decoder = {
349    .p.name         = "motionpixels",
350    .p.long_name    = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
351    .p.type         = AVMEDIA_TYPE_VIDEO,
352    .p.id           = AV_CODEC_ID_MOTIONPIXELS,
353    .priv_data_size = sizeof(MotionPixelsContext),
354    .init           = mp_decode_init,
355    .close          = mp_decode_end,
356    FF_CODEC_DECODE_CB(mp_decode_frame),
357    .p.capabilities = AV_CODEC_CAP_DR1,
358    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
359};
360