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 "bswapdsp.h"
25#include "internal.h"
26
27#define MAX_HUFF_CODES 16
28
29#include "motionpixels_tablegen.h"
30
31typedef struct HuffCode {
32    int code;
33    uint8_t size;
34    uint8_t delta;
35} HuffCode;
36
37typedef struct MotionPixelsContext {
38    AVCodecContext *avctx;
39    AVFrame *frame;
40    BswapDSPContext bdsp;
41    uint8_t *changes_map;
42    int offset_bits_len;
43    int codes_count, current_codes_count;
44    int max_codes_bits;
45    HuffCode codes[MAX_HUFF_CODES];
46    VLC vlc;
47    YuvPixel *vpt, *hpt;
48    uint8_t gradient_scale[3];
49    uint8_t *bswapbuf;
50    int bswapbuf_size;
51} MotionPixelsContext;
52
53static av_cold int mp_decode_end(AVCodecContext *avctx)
54{
55    MotionPixelsContext *mp = avctx->priv_data;
56
57    av_freep(&mp->changes_map);
58    av_freep(&mp->vpt);
59    av_freep(&mp->hpt);
60    av_freep(&mp->bswapbuf);
61    av_frame_free(&mp->frame);
62
63    return 0;
64}
65
66static av_cold int mp_decode_init(AVCodecContext *avctx)
67{
68    MotionPixelsContext *mp = avctx->priv_data;
69    int w4 = (avctx->width  + 3) & ~3;
70    int h4 = (avctx->height + 3) & ~3;
71
72    if(avctx->extradata_size < 2){
73        av_log(avctx, AV_LOG_ERROR, "extradata too small\n");
74        return AVERROR_INVALIDDATA;
75    }
76
77    motionpixels_tableinit();
78    mp->avctx = avctx;
79    ff_bswapdsp_init(&mp->bdsp);
80    mp->changes_map = av_mallocz_array(avctx->width, h4);
81    mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
82    mp->vpt = av_mallocz_array(avctx->height, sizeof(YuvPixel));
83    mp->hpt = av_mallocz_array(h4 / 4, w4 / 4 * sizeof(YuvPixel));
84    if (!mp->changes_map || !mp->vpt || !mp->hpt) {
85        av_freep(&mp->changes_map);
86        av_freep(&mp->vpt);
87        av_freep(&mp->hpt);
88        return AVERROR(ENOMEM);
89    }
90    avctx->pix_fmt = AV_PIX_FMT_RGB555;
91
92    mp->frame = av_frame_alloc();
93    if (!mp->frame) {
94        mp_decode_end(avctx);
95        return AVERROR(ENOMEM);
96    }
97
98    return 0;
99}
100
101static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
102{
103    uint16_t *pixels;
104    int offset, w, h, color = 0, x, y, i;
105
106    while (count--) {
107        offset = get_bits_long(gb, mp->offset_bits_len);
108        w      = get_bits(gb, bits_len) + 1;
109        h      = get_bits(gb, bits_len) + 1;
110        if (read_color)
111            color = get_bits(gb, 15);
112        x = offset % mp->avctx->width;
113        y = offset / mp->avctx->width;
114        if (y >= mp->avctx->height)
115            continue;
116        w = FFMIN(w, mp->avctx->width  - x);
117        h = FFMIN(h, mp->avctx->height - y);
118        pixels = (uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
119        while (h--) {
120            mp->changes_map[offset] = w;
121            if (read_color)
122                for (i = 0; i < w; ++i)
123                    pixels[i] = color;
124            offset += mp->avctx->width;
125            pixels += mp->frame->linesize[0] / 2;
126        }
127    }
128}
129
130static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
131{
132    while (get_bits1(gb)) {
133        ++size;
134        if (size > mp->max_codes_bits) {
135            av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
136            return AVERROR_INVALIDDATA;
137        }
138        code <<= 1;
139        if (mp_get_code(mp, gb, size, code + 1) < 0)
140            return AVERROR_INVALIDDATA;
141    }
142    if (mp->current_codes_count >= MAX_HUFF_CODES) {
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  ].code = code;
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)) < 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 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];
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 int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
200{
201    int i;
202
203    i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
204    return mp->codes[i].delta;
205}
206
207static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
208{
209    YuvPixel p;
210    const int y0 = y * mp->avctx->width;
211    int w, i, x = 0;
212
213    p = mp->vpt[y];
214    if (mp->changes_map[y0 + x] == 0) {
215        memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
216        ++x;
217    }
218    while (x < mp->avctx->width) {
219        w = mp->changes_map[y0 + x];
220        if (w != 0) {
221            if ((y & 3) == 0) {
222                if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
223                    mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
224                    mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
225                    for (i = (x + 3) & ~3; i < x + w; i += 4) {
226                        mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
227                    }
228                }
229            }
230            x += w;
231            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
232            p = mp_get_yuv_from_rgb(mp, x - 1, y);
233        } else {
234            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
235            p.y = av_clip(p.y, 0, 31);
236            if ((x & 3) == 0) {
237                if ((y & 3) == 0) {
238                    p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
239                    p.v = av_clip(p.v, -32, 31);
240                    p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
241                    p.u = av_clip(p.u, -32, 31);
242                    mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
243                } else {
244                    p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
245                    p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
246                }
247            }
248            mp_set_rgb_from_yuv(mp, x, y, &p);
249            ++x;
250        }
251    }
252}
253
254static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
255{
256    YuvPixel p;
257    int y, y0;
258
259    av_assert1(mp->changes_map[0]);
260
261    for (y = 0; y < mp->avctx->height; ++y) {
262        if (mp->changes_map[y * mp->avctx->width] != 0) {
263            memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
264            p = mp_get_yuv_from_rgb(mp, 0, y);
265        } else {
266            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
267            p.y = av_clip(p.y, 0, 31);
268            if ((y & 3) == 0) {
269                p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
270                p.v = av_clip(p.v, -32, 31);
271                p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
272                p.u = av_clip(p.u, -32, 31);
273            }
274            mp->vpt[y] = p;
275            mp_set_rgb_from_yuv(mp, 0, y, &p);
276        }
277    }
278    for (y0 = 0; y0 < 2; ++y0)
279        for (y = y0; y < mp->avctx->height; y += 2)
280            mp_decode_line(mp, gb, y);
281}
282
283static int mp_decode_frame(AVCodecContext *avctx,
284                                 void *data, int *got_frame,
285                                 AVPacket *avpkt)
286{
287    const uint8_t *buf = avpkt->data;
288    int buf_size = avpkt->size;
289    MotionPixelsContext *mp = avctx->priv_data;
290    GetBitContext gb;
291    int i, count1, count2, sz, ret;
292
293    if ((ret = ff_reget_buffer(avctx, mp->frame)) < 0)
294        return ret;
295
296    /* le32 bitstream msb first */
297    av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);
298    if (!mp->bswapbuf)
299        return AVERROR(ENOMEM);
300    mp->bdsp.bswap_buf((uint32_t *) mp->bswapbuf, (const uint32_t *) buf,
301                       buf_size / 4);
302    if (buf_size & 3)
303        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
304    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
305
306    memset(mp->changes_map, 0, avctx->width * avctx->height);
307    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
308        count1 = get_bits(&gb, 12);
309        count2 = get_bits(&gb, 12);
310        mp_read_changes_map(mp, &gb, count1, 8, i);
311        mp_read_changes_map(mp, &gb, count2, 4, i);
312    }
313
314    mp->codes_count = get_bits(&gb, 4);
315    if (mp->codes_count == 0)
316        goto end;
317
318    if (mp->changes_map[0] == 0) {
319        *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);
320        mp->changes_map[0] = 1;
321    }
322    if (mp_read_codes_table(mp, &gb) < 0)
323        goto end;
324
325    sz = get_bits(&gb, 18);
326    if (avctx->extradata[0] != 5)
327        sz += get_bits(&gb, 18);
328    if (sz == 0)
329        goto end;
330
331    if (mp->max_codes_bits <= 0)
332        goto end;
333    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))
334        goto end;
335    mp_decode_frame_helper(mp, &gb);
336    ff_free_vlc(&mp->vlc);
337
338end:
339    if ((ret = av_frame_ref(data, mp->frame)) < 0)
340        return ret;
341    *got_frame       = 1;
342    return buf_size;
343}
344
345AVCodec ff_motionpixels_decoder = {
346    .name           = "motionpixels",
347    .long_name      = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
348    .type           = AVMEDIA_TYPE_VIDEO,
349    .id             = AV_CODEC_ID_MOTIONPIXELS,
350    .priv_data_size = sizeof(MotionPixelsContext),
351    .init           = mp_decode_init,
352    .close          = mp_decode_end,
353    .decode         = mp_decode_frame,
354    .capabilities   = CODEC_CAP_DR1,
355};
356