Statistics
| Branch: | Revision:

ffmpeg / libavcodec / dxa.c @ 72415b2a

History | View | Annotate | Download (10.1 KB)

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
 */
38
typedef 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

    
47
static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
48
static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
49

    
50
static 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

    
191
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
192
{
193
    const uint8_t *buf = avpkt->data;
194
    int buf_size = avpkt->size;
195
    DxaDecContext * const c = avctx->priv_data;
196
    uint8_t *outptr, *srcptr, *tmpptr;
197
    unsigned long dsize;
198
    int i, j, compr;
199
    int stride;
200
    int orig_buf_size = buf_size;
201
    int pc = 0;
202

    
203
    /* make the palette available on the way out */
204
    if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
205
        int r, g, b;
206

    
207
        buf += 4;
208
        for(i = 0; i < 256; i++){
209
            r = *buf++;
210
            g = *buf++;
211
            b = *buf++;
212
            c->pal[i] = (r << 16) | (g << 8) | b;
213
        }
214
        pc = 1;
215
        buf_size -= 768+4;
216
    }
217

    
218
    if(avctx->get_buffer(avctx, &c->pic) < 0){
219
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
220
        return -1;
221
    }
222
    memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
223
    c->pic.palette_has_changed = pc;
224

    
225
    outptr = c->pic.data[0];
226
    srcptr = c->decomp_buf;
227
    tmpptr = c->prev.data[0];
228
    stride = c->pic.linesize[0];
229

    
230
    if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
231
        compr = -1;
232
    else
233
        compr = buf[4];
234

    
235
    dsize = c->dsize;
236
    if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
237
        av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
238
        return -1;
239
    }
240
    switch(compr){
241
    case -1:
242
        c->pic.key_frame = 0;
243
        c->pic.pict_type = FF_P_TYPE;
244
        if(c->prev.data[0])
245
            memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
246
        else{ // Should happen only when first frame is 'NULL'
247
            memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
248
            c->pic.key_frame = 1;
249
            c->pic.pict_type = FF_I_TYPE;
250
        }
251
        break;
252
    case 2:
253
    case 3:
254
    case 4:
255
    case 5:
256
        c->pic.key_frame = !(compr & 1);
257
        c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
258
        for(j = 0; j < avctx->height; j++){
259
            if(compr & 1){
260
                for(i = 0; i < avctx->width; i++)
261
                    outptr[i] = srcptr[i] ^ tmpptr[i];
262
                tmpptr += stride;
263
            }else
264
                memcpy(outptr, srcptr, avctx->width);
265
            outptr += stride;
266
            srcptr += avctx->width;
267
        }
268
        break;
269
    case 12: // ScummVM coding
270
    case 13:
271
        c->pic.key_frame = 0;
272
        c->pic.pict_type = FF_P_TYPE;
273
        decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
274
        break;
275
    default:
276
        av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
277
        return -1;
278
    }
279

    
280
    FFSWAP(AVFrame, c->pic, c->prev);
281
    if(c->pic.data[0])
282
        avctx->release_buffer(avctx, &c->pic);
283

    
284
    *data_size = sizeof(AVFrame);
285
    *(AVFrame*)data = c->prev;
286

    
287
    /* always report that the buffer was completely consumed */
288
    return orig_buf_size;
289
}
290

    
291
static av_cold int decode_init(AVCodecContext *avctx)
292
{
293
    DxaDecContext * const c = avctx->priv_data;
294

    
295
    c->avctx = avctx;
296
    avctx->pix_fmt = PIX_FMT_PAL8;
297

    
298
    c->dsize = avctx->width * avctx->height * 2;
299
    if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
300
        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
301
        return -1;
302
    }
303

    
304
    return 0;
305
}
306

    
307
static av_cold int decode_end(AVCodecContext *avctx)
308
{
309
    DxaDecContext * const c = avctx->priv_data;
310

    
311
    av_freep(&c->decomp_buf);
312
    if(c->prev.data[0])
313
        avctx->release_buffer(avctx, &c->prev);
314
    if(c->pic.data[0])
315
        avctx->release_buffer(avctx, &c->pic);
316

    
317
    return 0;
318
}
319

    
320
AVCodec dxa_decoder = {
321
    "dxa",
322
    AVMEDIA_TYPE_VIDEO,
323
    CODEC_ID_DXA,
324
    sizeof(DxaDecContext),
325
    decode_init,
326
    NULL,
327
    decode_end,
328
    decode_frame,
329
    CODEC_CAP_DR1,
330
    .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
331
};
332