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