1/*
2 * Feeble Files/ScummVM DXA decoder
3 * Copyright (c) 2007 Konstantin Shishkov
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/**
23 * @file libavcodec/dxa.c
24 * DXA Video decoder
25 */
26
27#include <stdio.h>
28#include <stdlib.h>
29
30#include "libavutil/intreadwrite.h"
31#include "avcodec.h"
32
33#include <zlib.h>
34
35/*
36 * Decoder context
37 */
38typedef struct DxaDecContext {
39    AVCodecContext *avctx;
40    AVFrame pic, prev;
41
42    int dsize;
43    uint8_t *decomp_buf;
44    uint32_t pal[256];
45} DxaDecContext;
46
47static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
48static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
49
50static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
51{
52    uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
53    int i, j, k;
54    int type, x, y, d, d2;
55    int stride = c->pic.linesize[0];
56    uint32_t mask;
57
58    code = src  + 12;
59    data = code + ((avctx->width * avctx->height) >> 4);
60    mv   = data + AV_RB32(src + 0);
61    msk  = mv   + AV_RB32(src + 4);
62
63    for(j = 0; j < avctx->height; j += 4){
64        for(i = 0; i < avctx->width; i += 4){
65            tmp  = dst + i;
66            tmp2 = ref + i;
67            type = *code++;
68            switch(type){
69            case 4: // motion compensation
70                x = (*mv) >> 4;    if(x & 8) x = 8 - x;
71                y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
72                tmp2 += x + y*stride;
73            case 0: // skip
74            case 5: // skip in method 12
75                for(y = 0; y < 4; y++){
76                    memcpy(tmp, tmp2, 4);
77                    tmp  += stride;
78                    tmp2 += stride;
79                }
80                break;
81            case 1:  // masked change
82            case 10: // masked change with only half of pixels changed
83            case 11: // cases 10-15 are for method 12 only
84            case 12:
85            case 13:
86            case 14:
87            case 15:
88                if(type == 1){
89                    mask = AV_RB16(msk);
90                    msk += 2;
91                }else{
92                    type -= 10;
93                    mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
94                    msk++;
95                }
96                for(y = 0; y < 4; y++){
97                    for(x = 0; x < 4; x++){
98                        tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
99                        mask <<= 1;
100                    }
101                    tmp  += stride;
102                    tmp2 += stride;
103                }
104                break;
105            case 2: // fill block
106                for(y = 0; y < 4; y++){
107                    memset(tmp, data[0], 4);
108                    tmp += stride;
109                }
110                data++;
111                break;
112            case 3: // raw block
113                for(y = 0; y < 4; y++){
114                    memcpy(tmp, data, 4);
115                    data += 4;
116                    tmp  += stride;
117                }
118                break;
119            case 8: // subblocks - method 13 only
120                mask = *msk++;
121                for(k = 0; k < 4; k++){
122                    d  = ((k & 1) << 1) + ((k & 2) * stride);
123                    d2 = ((k & 1) << 1) + ((k & 2) * stride);
124                    tmp2 = ref + i + d2;
125                    switch(mask & 0xC0){
126                    case 0x80: // motion compensation
127                        x = (*mv) >> 4;    if(x & 8) x = 8 - x;
128                        y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
129                        tmp2 += x + y*stride;
130                    case 0x00: // skip
131                        tmp[d + 0         ] = tmp2[0];
132                        tmp[d + 1         ] = tmp2[1];
133                        tmp[d + 0 + stride] = tmp2[0 + stride];
134                        tmp[d + 1 + stride] = tmp2[1 + stride];
135                        break;
136                    case 0x40: // fill
137                        tmp[d + 0         ] = data[0];
138                        tmp[d + 1         ] = data[0];
139                        tmp[d + 0 + stride] = data[0];
140                        tmp[d + 1 + stride] = data[0];
141                        data++;
142                        break;
143                    case 0xC0: // raw
144                        tmp[d + 0         ] = *data++;
145                        tmp[d + 1         ] = *data++;
146                        tmp[d + 0 + stride] = *data++;
147                        tmp[d + 1 + stride] = *data++;
148                        break;
149                    }
150                    mask <<= 2;
151                }
152                break;
153            case 32: // vector quantization - 2 colors
154                mask = AV_RB16(msk);
155                msk += 2;
156                for(y = 0; y < 4; y++){
157                    for(x = 0; x < 4; x++){
158                        tmp[x] = data[mask & 1];
159                        mask >>= 1;
160                    }
161                    tmp  += stride;
162                    tmp2 += stride;
163                }
164                data += 2;
165                break;
166            case 33: // vector quantization - 3 or 4 colors
167            case 34:
168                mask = AV_RB32(msk);
169                msk += 4;
170                for(y = 0; y < 4; y++){
171                    for(x = 0; x < 4; x++){
172                        tmp[x] = data[mask & 3];
173                        mask >>= 2;
174                    }
175                    tmp  += stride;
176                    tmp2 += stride;
177                }
178                data += type - 30;
179                break;
180            default:
181                av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
182                return -1;
183            }
184        }
185        dst += stride * 4;
186        ref += stride * 4;
187    }
188    return 0;
189}
190
191static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
192{
193    DxaDecContext * const c = avctx->priv_data;
194    uint8_t *outptr, *srcptr, *tmpptr;
195    unsigned long dsize;
196    int i, j, compr;
197    int stride;
198    int orig_buf_size = buf_size;
199    int pc = 0;
200
201    /* make the palette available on the way out */
202    if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
203        int r, g, b;
204
205        buf += 4;
206        for(i = 0; i < 256; i++){
207            r = *buf++;
208            g = *buf++;
209            b = *buf++;
210            c->pal[i] = (r << 16) | (g << 8) | b;
211        }
212        pc = 1;
213        buf_size -= 768+4;
214    }
215
216    if(avctx->get_buffer(avctx, &c->pic) < 0){
217        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
218        return -1;
219    }
220    memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
221    c->pic.palette_has_changed = pc;
222
223    outptr = c->pic.data[0];
224    srcptr = c->decomp_buf;
225    tmpptr = c->prev.data[0];
226    stride = c->pic.linesize[0];
227
228    if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
229        compr = -1;
230    else
231        compr = buf[4];
232
233    dsize = c->dsize;
234    if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
235        av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
236        return -1;
237    }
238    switch(compr){
239    case -1:
240        c->pic.key_frame = 0;
241        c->pic.pict_type = FF_P_TYPE;
242        if(c->prev.data[0])
243            memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
244        else{ // Should happen only when first frame is 'NULL'
245            memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
246            c->pic.key_frame = 1;
247            c->pic.pict_type = FF_I_TYPE;
248        }
249        break;
250    case 2:
251    case 3:
252    case 4:
253    case 5:
254        c->pic.key_frame = !(compr & 1);
255        c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
256        for(j = 0; j < avctx->height; j++){
257            if(compr & 1){
258                for(i = 0; i < avctx->width; i++)
259                    outptr[i] = srcptr[i] ^ tmpptr[i];
260                tmpptr += stride;
261            }else
262                memcpy(outptr, srcptr, avctx->width);
263            outptr += stride;
264            srcptr += avctx->width;
265        }
266        break;
267    case 12: // ScummVM coding
268    case 13:
269        c->pic.key_frame = 0;
270        c->pic.pict_type = FF_P_TYPE;
271        decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
272        break;
273    default:
274        av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
275        return -1;
276    }
277
278    FFSWAP(AVFrame, c->pic, c->prev);
279    if(c->pic.data[0])
280        avctx->release_buffer(avctx, &c->pic);
281
282    *data_size = sizeof(AVFrame);
283    *(AVFrame*)data = c->prev;
284
285    /* always report that the buffer was completely consumed */
286    return orig_buf_size;
287}
288
289static av_cold int decode_init(AVCodecContext *avctx)
290{
291    DxaDecContext * const c = avctx->priv_data;
292
293    c->avctx = avctx;
294    avctx->pix_fmt = PIX_FMT_PAL8;
295
296    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
297        return -1;
298    }
299
300    c->dsize = avctx->width * avctx->height * 2;
301    if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
302        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
303        return -1;
304    }
305
306    return 0;
307}
308
309static av_cold int decode_end(AVCodecContext *avctx)
310{
311    DxaDecContext * const c = avctx->priv_data;
312
313    av_freep(&c->decomp_buf);
314    if(c->prev.data[0])
315        avctx->release_buffer(avctx, &c->prev);
316    if(c->pic.data[0])
317        avctx->release_buffer(avctx, &c->pic);
318
319    return 0;
320}
321
322AVCodec dxa_decoder = {
323    "dxa",
324    CODEC_TYPE_VIDEO,
325    CODEC_ID_DXA,
326    sizeof(DxaDecContext),
327    decode_init,
328    NULL,
329    decode_end,
330    decode_frame,
331    .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
332};
333
334