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
24 * DXA Video decoder
25 */
26
27#include <stdio.h>
28#include <stdlib.h>
29
30#include "libavutil/common.h"
31#include "libavutil/intreadwrite.h"
32#include "bytestream.h"
33#include "avcodec.h"
34#include "internal.h"
35
36#include <zlib.h>
37
38/*
39 * Decoder context
40 */
41typedef struct DxaDecContext {
42    AVFrame *prev;
43
44    int dsize;
45#define DECOMP_BUF_PADDING 16
46    uint8_t *decomp_buf;
47    uint32_t pal[256];
48} DxaDecContext;
49
50static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
51static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
52
53static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst,
54                     int stride, uint8_t *src, int srcsize, uint8_t *ref)
55{
56    uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
57    uint8_t *src_end = src + srcsize;
58    int i, j, k;
59    int type, x, y, d, d2;
60    uint32_t mask;
61
62    if (12ULL  + ((avctx->width * avctx->height) >> 4) + AV_RB32(src + 0) + AV_RB32(src + 4) > srcsize)
63        return AVERROR_INVALIDDATA;
64
65    code = src  + 12;
66    data = code + ((avctx->width * avctx->height) >> 4);
67    mv   = data + AV_RB32(src + 0);
68    msk  = mv   + AV_RB32(src + 4);
69
70    for(j = 0; j < avctx->height; j += 4){
71        for(i = 0; i < avctx->width; i += 4){
72            if (data > src_end || mv > src_end || msk > src_end)
73                return AVERROR_INVALIDDATA;
74            tmp  = dst + i;
75            tmp2 = ref + i;
76            type = *code++;
77            switch(type){
78            case 4: // motion compensation
79                x = (*mv) >> 4;    if(x & 8) x = 8 - x;
80                y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
81                if (i < -x || avctx->width  - i - 4 < x ||
82                    j < -y || avctx->height - j - 4 < y) {
83                    av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
84                    return AVERROR_INVALIDDATA;
85                }
86                tmp2 += x + y*stride;
87            case 0: // skip
88            case 5: // skip in method 12
89                for(y = 0; y < 4; y++){
90                    memcpy(tmp, tmp2, 4);
91                    tmp  += stride;
92                    tmp2 += stride;
93                }
94                break;
95            case 1:  // masked change
96            case 10: // masked change with only half of pixels changed
97            case 11: // cases 10-15 are for method 12 only
98            case 12:
99            case 13:
100            case 14:
101            case 15:
102                if(type == 1){
103                    mask = AV_RB16(msk);
104                    msk += 2;
105                }else{
106                    type -= 10;
107                    mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
108                    msk++;
109                }
110                for(y = 0; y < 4; y++){
111                    for(x = 0; x < 4; x++){
112                        tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
113                        mask <<= 1;
114                    }
115                    tmp  += stride;
116                    tmp2 += stride;
117                }
118                break;
119            case 2: // fill block
120                for(y = 0; y < 4; y++){
121                    memset(tmp, data[0], 4);
122                    tmp += stride;
123                }
124                data++;
125                break;
126            case 3: // raw block
127                for(y = 0; y < 4; y++){
128                    memcpy(tmp, data, 4);
129                    data += 4;
130                    tmp  += stride;
131                }
132                break;
133            case 8: // subblocks - method 13 only
134                mask = *msk++;
135                for(k = 0; k < 4; k++){
136                    d  = ((k & 1) << 1) + ((k & 2) * stride);
137                    d2 = ((k & 1) << 1) + ((k & 2) * stride);
138                    tmp2 = ref + i + d2;
139                    switch(mask & 0xC0){
140                    case 0x80: // motion compensation
141                        x = (*mv) >> 4;    if(x & 8) x = 8 - x;
142                        y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
143                        if (i + 2*(k & 1) < -x || avctx->width  - i - 2*(k & 1) - 2 < x ||
144                            j +   (k & 2) < -y || avctx->height - j -   (k & 2) - 2 < y) {
145                            av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
146                            return AVERROR_INVALIDDATA;
147                        }
148                        tmp2 += x + y*stride;
149                    case 0x00: // skip
150                        tmp[d + 0         ] = tmp2[0];
151                        tmp[d + 1         ] = tmp2[1];
152                        tmp[d + 0 + stride] = tmp2[0 + stride];
153                        tmp[d + 1 + stride] = tmp2[1 + stride];
154                        break;
155                    case 0x40: // fill
156                        tmp[d + 0         ] = data[0];
157                        tmp[d + 1         ] = data[0];
158                        tmp[d + 0 + stride] = data[0];
159                        tmp[d + 1 + stride] = data[0];
160                        data++;
161                        break;
162                    case 0xC0: // raw
163                        tmp[d + 0         ] = *data++;
164                        tmp[d + 1         ] = *data++;
165                        tmp[d + 0 + stride] = *data++;
166                        tmp[d + 1 + stride] = *data++;
167                        break;
168                    }
169                    mask <<= 2;
170                }
171                break;
172            case 32: // vector quantization - 2 colors
173                mask = AV_RB16(msk);
174                msk += 2;
175                for(y = 0; y < 4; y++){
176                    for(x = 0; x < 4; x++){
177                        tmp[x] = data[mask & 1];
178                        mask >>= 1;
179                    }
180                    tmp  += stride;
181                    tmp2 += stride;
182                }
183                data += 2;
184                break;
185            case 33: // vector quantization - 3 or 4 colors
186            case 34:
187                mask = AV_RB32(msk);
188                msk += 4;
189                for(y = 0; y < 4; y++){
190                    for(x = 0; x < 4; x++){
191                        tmp[x] = data[mask & 3];
192                        mask >>= 2;
193                    }
194                    tmp  += stride;
195                    tmp2 += stride;
196                }
197                data += type - 30;
198                break;
199            default:
200                av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
201                return AVERROR_INVALIDDATA;
202            }
203        }
204        dst += stride * 4;
205        ref += stride * 4;
206    }
207    return 0;
208}
209
210static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
211{
212    AVFrame *frame = data;
213    DxaDecContext * const c = avctx->priv_data;
214    uint8_t *outptr, *srcptr, *tmpptr;
215    unsigned long dsize;
216    int i, j, compr, ret;
217    int stride;
218    int pc = 0;
219    GetByteContext gb;
220
221    bytestream2_init(&gb, avpkt->data, avpkt->size);
222
223    /* make the palette available on the way out */
224    if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {
225        bytestream2_skip(&gb, 4);
226        for(i = 0; i < 256; i++){
227            c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
228        }
229        pc = 1;
230    }
231
232    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
233        return ret;
234    memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
235    frame->palette_has_changed = pc;
236
237    outptr = frame->data[0];
238    srcptr = c->decomp_buf;
239    tmpptr = c->prev->data[0];
240    stride = frame->linesize[0];
241
242    if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
243        compr = -1;
244    else
245        compr = bytestream2_get_byte(&gb);
246
247    dsize = c->dsize;
248    if (compr != 4 && compr != -1) {
249        bytestream2_skip(&gb, 4);
250        if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),
251                       bytestream2_get_bytes_left(&gb)) != Z_OK) {
252            av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
253            return AVERROR_UNKNOWN;
254        }
255        memset(c->decomp_buf + dsize, 0, DECOMP_BUF_PADDING);
256    }
257
258    if (avctx->debug & FF_DEBUG_PICT_INFO)
259        av_log(avctx, AV_LOG_DEBUG, "compr:%2d, dsize:%d\n", compr, (int)dsize);
260
261    switch(compr){
262    case -1:
263        frame->key_frame = 0;
264        frame->pict_type = AV_PICTURE_TYPE_P;
265        if (c->prev->data[0])
266            memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);
267        else{ // Should happen only when first frame is 'NULL'
268            memset(frame->data[0], 0, frame->linesize[0] * avctx->height);
269            frame->key_frame = 1;
270            frame->pict_type = AV_PICTURE_TYPE_I;
271        }
272        break;
273    case 2:
274    case 4:
275        frame->key_frame = 1;
276        frame->pict_type = AV_PICTURE_TYPE_I;
277        for (j = 0; j < avctx->height; j++) {
278                memcpy(outptr, srcptr, avctx->width);
279            outptr += stride;
280            srcptr += avctx->width;
281        }
282        break;
283    case 3:
284    case 5:
285        if (!tmpptr) {
286            av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
287            if (!(avctx->flags2 & CODEC_FLAG2_SHOW_ALL))
288                return AVERROR_INVALIDDATA;
289        }
290        frame->key_frame = 0;
291        frame->pict_type = AV_PICTURE_TYPE_P;
292        for (j = 0; j < avctx->height; j++) {
293            if(tmpptr){
294                for(i = 0; i < avctx->width; i++)
295                    outptr[i] = srcptr[i] ^ tmpptr[i];
296                tmpptr += stride;
297            }else
298                memcpy(outptr, srcptr, avctx->width);
299            outptr += stride;
300            srcptr += avctx->width;
301        }
302        break;
303    case 12: // ScummVM coding
304    case 13:
305        frame->key_frame = 0;
306        frame->pict_type = AV_PICTURE_TYPE_P;
307        if (!c->prev->data[0]) {
308            av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
309            return AVERROR_INVALIDDATA;
310        }
311        decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, dsize, c->prev->data[0]);
312        break;
313    default:
314        av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
315        return AVERROR_INVALIDDATA;
316    }
317
318    av_frame_unref(c->prev);
319    if ((ret = av_frame_ref(c->prev, frame)) < 0)
320        return ret;
321
322    *got_frame = 1;
323
324    /* always report that the buffer was completely consumed */
325    return avpkt->size;
326}
327
328static av_cold int decode_init(AVCodecContext *avctx)
329{
330    DxaDecContext * const c = avctx->priv_data;
331
332    c->prev = av_frame_alloc();
333    if (!c->prev)
334        return AVERROR(ENOMEM);
335
336    avctx->pix_fmt = AV_PIX_FMT_PAL8;
337
338    c->dsize = avctx->width * avctx->height * 2;
339    c->decomp_buf = av_malloc(c->dsize + DECOMP_BUF_PADDING);
340    if (!c->decomp_buf) {
341        av_frame_free(&c->prev);
342        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
343        return AVERROR(ENOMEM);
344    }
345
346    return 0;
347}
348
349static av_cold int decode_end(AVCodecContext *avctx)
350{
351    DxaDecContext * const c = avctx->priv_data;
352
353    av_freep(&c->decomp_buf);
354    av_frame_free(&c->prev);
355
356    return 0;
357}
358
359AVCodec ff_dxa_decoder = {
360    .name           = "dxa",
361    .long_name      = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
362    .type           = AVMEDIA_TYPE_VIDEO,
363    .id             = AV_CODEC_ID_DXA,
364    .priv_data_size = sizeof(DxaDecContext),
365    .init           = decode_init,
366    .close          = decode_end,
367    .decode         = decode_frame,
368    .capabilities   = CODEC_CAP_DR1,
369};
370