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/*
2
 * Interplay MVE Video Decoder
3
 * Copyright (C) 2003 the ffmpeg project
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
20

    
21
/**
22
 * @file interplayvideo.c
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 * Interplay MVE Video Decoder by Mike Melanson (melanson@pcisys.net)
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 * For more information about the Interplay MVE format, visit:
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 *   http://www.pcisys.net/~melanson/codecs/interplay-mve.txt
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 * This code is written in such a way that the identifiers match up
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 * with the encoding descriptions in the document.
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 *
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 * This decoder presently only supports a PAL8 output colorspace.
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 *
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 * An Interplay video frame consists of 2 parts: The decoding map and
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 * the video data. A demuxer must load these 2 parts together in a single
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 * buffer before sending it through the stream to this decoder.
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 */
35

    
36
#include <stdio.h>
37
#include <stdlib.h>
38
#include <string.h>
39
#include <unistd.h>
40

    
41
#include "common.h"
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#include "avcodec.h"
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#include "dsputil.h"
44

    
45
#define PALETTE_COUNT 256
46

    
47
/* debugging support */
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#define DEBUG_INTERPLAY 0
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#if DEBUG_INTERPLAY
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#define debug_interplay printf
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#else
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static inline void debug_interplay(const char *format, ...) { }
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#endif
54

    
55
typedef struct IpvideoContext {
56

    
57
    AVCodecContext *avctx;
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    DSPContext dsp;
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    AVFrame second_last_frame;
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    AVFrame last_frame;
61
    AVFrame current_frame;
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    unsigned char *decoding_map;
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    int decoding_map_size;
64

    
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    unsigned char *buf;
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    int size;
67

    
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    unsigned char *stream_ptr;
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    unsigned char *stream_end;
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    unsigned char *pixel_ptr;
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    int line_inc;
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    int stride;
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    int upper_motion_limit_offset;
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75
} IpvideoContext;
76

    
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#define CHECK_STREAM_PTR(n) \
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  if ((s->stream_ptr + n) > s->stream_end) { \
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    av_log(s->avctx, AV_LOG_ERROR, "Interplay video warning: stream_ptr out of bounds (%p >= %p)\n", \
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      s->stream_ptr + n, s->stream_end); \
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    return -1; \
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  }
83

    
84
#define COPY_FROM_CURRENT() \
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    motion_offset = current_offset; \
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    motion_offset += y * s->stride; \
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    motion_offset += x; \
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    if (motion_offset < 0) { \
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        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
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        return -1; \
91
    } else if (motion_offset > s->upper_motion_limit_offset) { \
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        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
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            motion_offset, s->upper_motion_limit_offset); \
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        return -1; \
95
    } \
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    s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
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        s->current_frame.data[0] + motion_offset, s->stride, 8);
98

    
99
#define COPY_FROM_PREVIOUS() \
100
    motion_offset = current_offset; \
101
    motion_offset += y * s->stride; \
102
    motion_offset += x; \
103
    if (motion_offset < 0) { \
104
        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
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        return -1; \
106
    } else if (motion_offset > s->upper_motion_limit_offset) { \
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        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
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            motion_offset, s->upper_motion_limit_offset); \
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        return -1; \
110
    } \
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    s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
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        s->last_frame.data[0] + motion_offset, s->stride, 8);
113

    
114
#define COPY_FROM_SECOND_LAST() \
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    motion_offset = current_offset; \
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    motion_offset += y * s->stride; \
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    motion_offset += x; \
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    if (motion_offset < 0) { \
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        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
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        return -1; \
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    } else if (motion_offset > s->upper_motion_limit_offset) { \
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        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
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            motion_offset, s->upper_motion_limit_offset); \
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        return -1; \
125
    } \
126
    s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
127
        s->second_last_frame.data[0] + motion_offset, s->stride, 8);
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129
static int ipvideo_decode_block_opcode_0x0(IpvideoContext *s)
130
{
131
    int x, y;
132
    int motion_offset;
133
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
134

    
135
    /* copy a block from the previous frame */
136
    x = y = 0;
137
    COPY_FROM_PREVIOUS();
138

    
139
    /* report success */
140
    return 0;
141
}
142

    
143
static int ipvideo_decode_block_opcode_0x1(IpvideoContext *s)
144
{
145
    int x, y;
146
    int motion_offset;
147
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
148

    
149
    /* copy block from 2 frames ago */
150
    x = y = 0;
151
    COPY_FROM_SECOND_LAST();
152

    
153
    /* report success */
154
    return 0;
155
}
156

    
157
static int ipvideo_decode_block_opcode_0x2(IpvideoContext *s)
158
{
159
    unsigned char B;
160
    int x, y;
161
    int motion_offset;
162
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
163

    
164
    /* copy block from 2 frames ago using a motion vector; need 1 more byte */
165
    CHECK_STREAM_PTR(1);
166
    B = *s->stream_ptr++;
167

    
168
    if (B < 56) {
169
        x = 8 + (B % 7);
170
        y = B / 7;
171
    } else {
172
        x = -14 + ((B - 56) % 29);
173
        y =   8 + ((B - 56) / 29);
174
    }
175

    
176
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
177
    COPY_FROM_SECOND_LAST();
178

    
179
    /* report success */
180
    return 0;
181
}
182

    
183
static int ipvideo_decode_block_opcode_0x3(IpvideoContext *s)
184
{
185
    unsigned char B;
186
    int x, y;
187
    int motion_offset;
188
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
189

    
190
    /* copy 8x8 block from current frame from an up/left block */
191

    
192
    /* need 1 more byte for motion */
193
    CHECK_STREAM_PTR(1);
194
    B = *s->stream_ptr++;
195

    
196
    if (B < 56) {
197
        x = -(8 + (B % 7));
198
        y = -(B / 7);
199
    } else {
200
        x = -(-14 + ((B - 56) % 29));
201
        y = -(  8 + ((B - 56) / 29));
202
    }
203

    
204
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
205
    COPY_FROM_CURRENT();
206

    
207
    /* report success */
208
    return 0;
209
}
210

    
211
static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s)
212
{
213
    int x, y;
214
    unsigned char B, BL, BH;
215
    int motion_offset;
216
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
217

    
218
    /* copy a block from the previous frame; need 1 more byte */
219
    CHECK_STREAM_PTR(1);
220

    
221
    B = *s->stream_ptr++;
222
    BL = B & 0x0F;
223
    BH = (B >> 4) & 0x0F;
224
    x = -8 + BL;
225
    y = -8 + BH;
226

    
227
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
228
    COPY_FROM_PREVIOUS();
229

    
230
    /* report success */
231
    return 0;
232
}
233

    
234
static int ipvideo_decode_block_opcode_0x5(IpvideoContext *s)
235
{
236
    signed char x, y;
237
    int motion_offset;
238
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
239

    
240
    /* copy a block from the previous frame using an expanded range;
241
     * need 2 more bytes */
242
    CHECK_STREAM_PTR(2);
243

    
244
    x = *s->stream_ptr++;
245
    y = *s->stream_ptr++;
246

    
247
    debug_interplay ("    motion bytes = %d, %d\n", x, y);
248
    COPY_FROM_PREVIOUS();
249

    
250
    /* report success */
251
    return 0;
252
}
253

    
254
static int ipvideo_decode_block_opcode_0x6(IpvideoContext *s)
255
{
256
    /* mystery opcode? skip multiple blocks? */
257
    av_log(s->avctx, AV_LOG_ERROR, "  Interplay video: Help! Mystery opcode 0x6 seen\n");
258

    
259
    /* report success */
260
    return 0;
261
}
262

    
263
static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s)
264
{
265
    int x, y;
266
    unsigned char P0, P1;
267
    unsigned char B[8];
268
    unsigned int flags;
269
    int bitmask;
270

    
271
    /* 2-color encoding */
272
    CHECK_STREAM_PTR(2);
273

    
274
    P0 = *s->stream_ptr++;
275
    P1 = *s->stream_ptr++;
276

    
277
    if (P0 <= P1) {
278

    
279
        /* need 8 more bytes from the stream */
280
        CHECK_STREAM_PTR(8);
281
        for (y = 0; y < 8; y++)
282
            B[y] = *s->stream_ptr++;
283

    
284
        for (y = 0; y < 8; y++) {
285
            flags = B[y];
286
            for (x = 0x01; x <= 0x80; x <<= 1) {
287
                if (flags & x)
288
                    *s->pixel_ptr++ = P1;
289
                else
290
                    *s->pixel_ptr++ = P0;
291
            }
292
            s->pixel_ptr += s->line_inc;
293
        }
294

    
295
    } else {
296

    
297
        /* need 2 more bytes from the stream */
298
        CHECK_STREAM_PTR(2);
299
        B[0] = *s->stream_ptr++;
300
        B[1] = *s->stream_ptr++;
301

    
302
        flags = (B[1] << 8) | B[0];
303
        bitmask = 0x0001;
304
        for (y = 0; y < 8; y += 2) {
305
            for (x = 0; x < 8; x += 2, bitmask <<= 1) {
306
                if (flags & bitmask) {
307
                    *(s->pixel_ptr + x) = P1;
308
                    *(s->pixel_ptr + x + 1) = P1;
309
                    *(s->pixel_ptr + s->stride + x) = P1;
310
                    *(s->pixel_ptr + s->stride + x + 1) = P1;
311
                } else {
312
                    *(s->pixel_ptr + x) = P0;
313
                    *(s->pixel_ptr + x + 1) = P0;
314
                    *(s->pixel_ptr + s->stride + x) = P0;
315
                    *(s->pixel_ptr + s->stride + x + 1) = P0;
316
                }
317
            }
318
            s->pixel_ptr += s->stride * 2;
319
        }
320
    }
321

    
322
    /* report success */
323
    return 0;
324
}
325

    
326
static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
327
{
328
    int x, y;
329
    unsigned char P[8];
330
    unsigned char B[8];
331
    unsigned int flags = 0;
332
    unsigned int bitmask = 0;
333
    unsigned char P0 = 0, P1 = 0;
334
    int lower_half = 0;
335

    
336
    /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
337
     * either top and bottom or left and right halves */
338
    CHECK_STREAM_PTR(2);
339

    
340
    P[0] = *s->stream_ptr++;
341
    P[1] = *s->stream_ptr++;
342

    
343
    if (P[0] <= P[1]) {
344

    
345
        /* need 12 more bytes */
346
        CHECK_STREAM_PTR(12);
347
        B[0] = *s->stream_ptr++;  B[1] = *s->stream_ptr++;
348
        P[2] = *s->stream_ptr++;  P[3] = *s->stream_ptr++;
349
        B[2] = *s->stream_ptr++;  B[3] = *s->stream_ptr++;
350
        P[4] = *s->stream_ptr++;  P[5] = *s->stream_ptr++;
351
        B[4] = *s->stream_ptr++;  B[5] = *s->stream_ptr++;
352
        P[6] = *s->stream_ptr++;  P[7] = *s->stream_ptr++;
353
        B[6] = *s->stream_ptr++;  B[7] = *s->stream_ptr++;
354

    
355
        for (y = 0; y < 8; y++) {
356

    
357
            /* time to reload flags? */
358
            if (y == 0) {
359
                flags =
360
                    ((B[0] & 0xF0) <<  4) | ((B[4] & 0xF0) <<  8) |
361
                    ((B[0] & 0x0F)      ) | ((B[4] & 0x0F) <<  4) |
362
                    ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
363
                    ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
364
                bitmask = 0x00000001;
365
                lower_half = 0;  /* still on top half */
366
            } else if (y == 4) {
367
                flags =
368
                    ((B[2] & 0xF0) <<  4) | ((B[6] & 0xF0) <<  8) |
369
                    ((B[2] & 0x0F)      ) | ((B[6] & 0x0F) <<  4) |
370
                    ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
371
                    ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
372
                bitmask = 0x00000001;
373
                lower_half = 2;
374
            }
375

    
376
            for (x = 0; x < 8; x++, bitmask <<= 1) {
377
                /* get the pixel values ready for this quadrant */
378
                if (x == 0) {
379
                    P0 = P[lower_half + 0];
380
                    P1 = P[lower_half + 1];
381
                } else if (x == 4) {
382
                    P0 = P[lower_half + 4];
383
                    P1 = P[lower_half + 5];
384
                }
385

    
386
                if (flags & bitmask)
387
                    *s->pixel_ptr++ = P1;
388
                else
389
                    *s->pixel_ptr++ = P0;
390
            }
391
            s->pixel_ptr += s->line_inc;
392
        }
393

    
394
    } else {
395

    
396
        /* need 10 more bytes */
397
        CHECK_STREAM_PTR(10);
398
        B[0] = *s->stream_ptr++;  B[1] = *s->stream_ptr++;
399
        B[2] = *s->stream_ptr++;  B[3] = *s->stream_ptr++;
400
        P[2] = *s->stream_ptr++;  P[3] = *s->stream_ptr++;
401
        B[4] = *s->stream_ptr++;  B[5] = *s->stream_ptr++;
402
        B[6] = *s->stream_ptr++;  B[7] = *s->stream_ptr++;
403

    
404
        if (P[2] <= P[3]) {
405

    
406
            /* vertical split; left & right halves are 2-color encoded */
407

    
408
            for (y = 0; y < 8; y++) {
409

    
410
                /* time to reload flags? */
411
                if (y == 0) {
412
                    flags =
413
                        ((B[0] & 0xF0) <<  4) | ((B[4] & 0xF0) <<  8) |
414
                        ((B[0] & 0x0F)      ) | ((B[4] & 0x0F) <<  4) |
415
                        ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
416
                        ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
417
                    bitmask = 0x00000001;
418
                } else if (y == 4) {
419
                    flags =
420
                        ((B[2] & 0xF0) <<  4) | ((B[6] & 0xF0) <<  8) |
421
                        ((B[2] & 0x0F)      ) | ((B[6] & 0x0F) <<  4) |
422
                        ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
423
                        ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
424
                    bitmask = 0x00000001;
425
                }
426

    
427
                for (x = 0; x < 8; x++, bitmask <<= 1) {
428
                    /* get the pixel values ready for this half */
429
                    if (x == 0) {
430
                        P0 = P[0];
431
                        P1 = P[1];
432
                    } else if (x == 4) {
433
                        P0 = P[2];
434
                        P1 = P[3];
435
                    }
436

    
437
                    if (flags & bitmask)
438
                        *s->pixel_ptr++ = P1;
439
                    else
440
                        *s->pixel_ptr++ = P0;
441
                }
442
                s->pixel_ptr += s->line_inc;
443
            }
444

    
445
        } else {
446

    
447
            /* horizontal split; top & bottom halves are 2-color encoded */
448

    
449
            for (y = 0; y < 8; y++) {
450

    
451
                flags = B[y];
452
                if (y == 0) {
453
                    P0 = P[0];
454
                    P1 = P[1];
455
                } else if (y == 4) {
456
                    P0 = P[2];
457
                    P1 = P[3];
458
                }
459

    
460
                for (bitmask = 0x01; bitmask <= 0x80; bitmask <<= 1) {
461

    
462
                    if (flags & bitmask)
463
                        *s->pixel_ptr++ = P1;
464
                    else
465
                        *s->pixel_ptr++ = P0;
466
                }
467
                s->pixel_ptr += s->line_inc;
468
            }
469
        }
470
    }
471

    
472
    /* report success */
473
    return 0;
474
}
475

    
476
static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
477
{
478
    int x, y;
479
    unsigned char P[4];
480
    unsigned char B[4];
481
    unsigned int flags = 0;
482
    int shifter = 0;
483
    unsigned char pix;
484

    
485
    /* 4-color encoding */
486
    CHECK_STREAM_PTR(4);
487

    
488
    for (y = 0; y < 4; y++)
489
        P[y] = *s->stream_ptr++;
490

    
491
    if ((P[0] <= P[1]) && (P[2] <= P[3])) {
492

    
493
        /* 1 of 4 colors for each pixel, need 16 more bytes */
494
        CHECK_STREAM_PTR(16);
495

    
496
        for (y = 0; y < 8; y++) {
497
            /* get the next set of 8 2-bit flags */
498
            flags = (s->stream_ptr[1] << 8) | s->stream_ptr[0];
499
            s->stream_ptr += 2;
500
            for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
501
                *s->pixel_ptr++ = P[(flags >> shifter) & 0x03];
502
            }
503
            s->pixel_ptr += s->line_inc;
504
        }
505

    
506
    } else if ((P[0] <= P[1]) && (P[2] > P[3])) {
507

    
508
        /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
509
        CHECK_STREAM_PTR(4);
510

    
511
        B[0] = *s->stream_ptr++;
512
        B[1] = *s->stream_ptr++;
513
        B[2] = *s->stream_ptr++;
514
        B[3] = *s->stream_ptr++;
515
        flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
516
        shifter = 0;
517

    
518
        for (y = 0; y < 8; y += 2) {
519
            for (x = 0; x < 8; x += 2, shifter += 2) {
520
                pix = P[(flags >> shifter) & 0x03];
521
                *(s->pixel_ptr + x) = pix;
522
                *(s->pixel_ptr + x + 1) = pix;
523
                *(s->pixel_ptr + s->stride + x) = pix;
524
                *(s->pixel_ptr + s->stride + x + 1) = pix;
525
            }
526
            s->pixel_ptr += s->stride * 2;
527
        }
528

    
529
    } else if ((P[0] > P[1]) && (P[2] <= P[3])) {
530

    
531
        /* 1 of 4 colors for each 2x1 block, need 8 more bytes */
532
        CHECK_STREAM_PTR(8);
533

    
534
        for (y = 0; y < 8; y++) {
535
            /* time to reload flags? */
536
            if ((y == 0) || (y == 4)) {
537
                B[0] = *s->stream_ptr++;
538
                B[1] = *s->stream_ptr++;
539
                B[2] = *s->stream_ptr++;
540
                B[3] = *s->stream_ptr++;
541
                flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
542
                shifter = 0;
543
            }
544
            for (x = 0; x < 8; x += 2, shifter += 2) {
545
                pix = P[(flags >> shifter) & 0x03];
546
                *(s->pixel_ptr + x) = pix;
547
                *(s->pixel_ptr + x + 1) = pix;
548
            }
549
            s->pixel_ptr += s->stride;
550
        }
551

    
552
    } else {
553

    
554
        /* 1 of 4 colors for each 1x2 block, need 8 more bytes */
555
        CHECK_STREAM_PTR(8);
556

    
557
        for (y = 0; y < 8; y += 2) {
558
            /* time to reload flags? */
559
            if ((y == 0) || (y == 4)) {
560
                B[0] = *s->stream_ptr++;
561
                B[1] = *s->stream_ptr++;
562
                B[2] = *s->stream_ptr++;
563
                B[3] = *s->stream_ptr++;
564
                flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
565
                shifter = 0;
566
            }
567
            for (x = 0; x < 8; x++, shifter += 2) {
568
                pix = P[(flags >> shifter) & 0x03];
569
                *(s->pixel_ptr + x) = pix;
570
                *(s->pixel_ptr + s->stride + x) = pix;
571
            }
572
            s->pixel_ptr += s->stride * 2;
573
        }
574
    }
575

    
576
    /* report success */
577
    return 0;
578
}
579

    
580
static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
581
{
582
    int x, y;
583
    unsigned char P[16];
584
    unsigned char B[16];
585
    int flags = 0;
586
    int shifter = 0;
587
    int index;
588
    int split;
589
    int lower_half;
590

    
591
    /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
592
     * either top and bottom or left and right halves */
593
    CHECK_STREAM_PTR(4);
594

    
595
    for (y = 0; y < 4; y++)
596
        P[y] = *s->stream_ptr++;
597

    
598
    if (P[0] <= P[1]) {
599

    
600
        /* 4-color encoding for each quadrant; need 28 more bytes */
601
        CHECK_STREAM_PTR(28);
602

    
603
        for (y = 0; y < 4; y++)
604
            B[y] = *s->stream_ptr++;
605
        for (y = 4; y < 16; y += 4) {
606
            for (x = y; x < y + 4; x++)
607
                P[x] = *s->stream_ptr++;
608
            for (x = y; x < y + 4; x++)
609
                B[x] = *s->stream_ptr++;
610
        }
611

    
612
        for (y = 0; y < 8; y++) {
613

    
614
            lower_half = (y >= 4) ? 4 : 0;
615
            flags = (B[y + 8] << 8) | B[y];
616

    
617
            for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
618
                split = (x >= 4) ? 8 : 0;
619
                index = split + lower_half + ((flags >> shifter) & 0x03);
620
                *s->pixel_ptr++ = P[index];
621
            }
622

    
623
            s->pixel_ptr += s->line_inc;
624
        }
625

    
626
    } else {
627

    
628
        /* 4-color encoding for either left and right or top and bottom
629
         * halves; need 20 more bytes */
630
        CHECK_STREAM_PTR(20);
631

    
632
        for (y = 0; y < 8; y++)
633
            B[y] = *s->stream_ptr++;
634
        for (y = 4; y < 8; y++)
635
            P[y] = *s->stream_ptr++;
636
        for (y = 8; y < 16; y++)
637
            B[y] = *s->stream_ptr++;
638

    
639
        if (P[4] <= P[5]) {
640

    
641
            /* block is divided into left and right halves */
642
            for (y = 0; y < 8; y++) {
643

    
644
                flags = (B[y + 8] << 8) | B[y];
645
                split = 0;
646

    
647
                for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
648
                    if (x == 4)
649
                        split = 4;
650
                    *s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
651
                }
652

    
653
                s->pixel_ptr += s->line_inc;
654
            }
655

    
656
        } else {
657

    
658
            /* block is divided into top and bottom halves */
659
            split = 0;
660
            for (y = 0; y < 8; y++) {
661

    
662
                flags = (B[y * 2 + 1] << 8) | B[y * 2];
663
                if (y == 4)
664
                    split = 4;
665

    
666
                for (x = 0, shifter = 0; x < 8; x++, shifter += 2)
667
                    *s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
668

    
669
                s->pixel_ptr += s->line_inc;
670
            }
671
        }
672
    }
673

    
674
    /* report success */
675
    return 0;
676
}
677

    
678
static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s)
679
{
680
    int x, y;
681

    
682
    /* 64-color encoding (each pixel in block is a different color) */
683
    CHECK_STREAM_PTR(64);
684

    
685
    for (y = 0; y < 8; y++) {
686
        for (x = 0; x < 8; x++) {
687
            *s->pixel_ptr++ = *s->stream_ptr++;
688
        }
689
        s->pixel_ptr += s->line_inc;
690
    }
691

    
692
    /* report success */
693
    return 0;
694
}
695

    
696
static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
697
{
698
    int x, y;
699
    unsigned char pix;
700

    
701
    /* 16-color block encoding: each 2x2 block is a different color */
702
    CHECK_STREAM_PTR(16);
703

    
704
    for (y = 0; y < 8; y += 2) {
705
        for (x = 0; x < 8; x += 2) {
706
            pix = *s->stream_ptr++;
707
            *(s->pixel_ptr + x) = pix;
708
            *(s->pixel_ptr + x + 1) = pix;
709
            *(s->pixel_ptr + s->stride + x) = pix;
710
            *(s->pixel_ptr + s->stride + x + 1) = pix;
711
        }
712
        s->pixel_ptr += s->stride * 2;
713
    }
714

    
715
    /* report success */
716
    return 0;
717
}
718

    
719
static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
720
{
721
    int x, y;
722
    unsigned char P[4];
723
    unsigned char index = 0;
724

    
725
    /* 4-color block encoding: each 4x4 block is a different color */
726
    CHECK_STREAM_PTR(4);
727

    
728
    for (y = 0; y < 4; y++)
729
        P[y] = *s->stream_ptr++;
730

    
731
    for (y = 0; y < 8; y++) {
732
        if (y < 4)
733
            index = 0;
734
        else
735
            index = 2;
736

    
737
        for (x = 0; x < 8; x++) {
738
            if (x == 4)
739
                index++;
740
            *s->pixel_ptr++ = P[index];
741
        }
742
        s->pixel_ptr += s->line_inc;
743
    }
744

    
745
    /* report success */
746
    return 0;
747
}
748

    
749
static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s)
750
{
751
    int x, y;
752
    unsigned char pix;
753

    
754
    /* 1-color encoding: the whole block is 1 solid color */
755
    CHECK_STREAM_PTR(1);
756
    pix = *s->stream_ptr++;
757

    
758
    for (y = 0; y < 8; y++) {
759
        for (x = 0; x < 8; x++) {
760
            *s->pixel_ptr++ = pix;
761
        }
762
        s->pixel_ptr += s->line_inc;
763
    }
764

    
765
    /* report success */
766
    return 0;
767
}
768

    
769
static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s)
770
{
771
    int x, y;
772
    unsigned char sample0, sample1;
773

    
774
    /* dithered encoding */
775
    CHECK_STREAM_PTR(2);
776
    sample0 = *s->stream_ptr++;
777
    sample1 = *s->stream_ptr++;
778

    
779
    for (y = 0; y < 8; y++) {
780
        for (x = 0; x < 8; x += 2) {
781
            if (y & 1) {
782
                *s->pixel_ptr++ = sample1;
783
                *s->pixel_ptr++ = sample0;
784
            } else {
785
                *s->pixel_ptr++ = sample0;
786
                *s->pixel_ptr++ = sample1;
787
            }
788
        }
789
        s->pixel_ptr += s->line_inc;
790
    }
791

    
792
    /* report success */
793
    return 0;
794
}
795

    
796
static int (*ipvideo_decode_block[16])(IpvideoContext *s);
797

    
798
static void ipvideo_decode_opcodes(IpvideoContext *s)
799
{
800
    int x, y;
801
    int index = 0;
802
    unsigned char opcode;
803
    int ret;
804
    int code_counts[16];
805
    static int frame = 0;
806

    
807
    debug_interplay("------------------ frame %d\n", frame);
808
    frame++;
809

    
810
    for (x = 0; x < 16; x++)
811
        code_counts[x] = 0;
812

    
813
    /* this is PAL8, so make the palette available */
814
    memcpy(s->current_frame.data[1], s->avctx->palctrl->palette, PALETTE_COUNT * 4);
815

    
816
    s->stride = s->current_frame.linesize[0];
817
    s->stream_ptr = s->buf + 14;  /* data starts 14 bytes in */
818
    s->stream_end = s->buf + s->size;
819
    s->line_inc = s->stride - 8;
820
    s->upper_motion_limit_offset = (s->avctx->height - 8) * s->stride
821
        + s->avctx->width - 8;
822
    s->dsp = s->dsp;
823

    
824
    for (y = 0; y < (s->stride * s->avctx->height); y += s->stride * 8) {
825
        for (x = y; x < y + s->avctx->width; x += 8) {
826
            /* bottom nibble first, then top nibble (which makes it
827
             * hard to use a GetBitcontext) */
828
            if (index & 1)
829
                opcode = s->decoding_map[index >> 1] >> 4;
830
            else
831
                opcode = s->decoding_map[index >> 1] & 0xF;
832
            index++;
833

    
834
            debug_interplay("  block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
835
                x - y, y / s->stride, opcode, s->stream_ptr);
836
            code_counts[opcode]++;
837

    
838
            s->pixel_ptr = s->current_frame.data[0] + x;
839
            ret = ipvideo_decode_block[opcode](s);
840
            if (ret != 0) {
841
                av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
842
                    frame, x - y, y / s->stride);
843
                return;
844
            }
845
        }
846
    }
847
    if ((s->stream_ptr != s->stream_end) &&
848
        (s->stream_ptr + 1 != s->stream_end)) {
849
        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %d bytes left over\n",
850
            s->stream_end - s->stream_ptr);
851
    }
852
}
853

    
854
static int ipvideo_decode_init(AVCodecContext *avctx)
855
{
856
    IpvideoContext *s = avctx->priv_data;
857

    
858
    s->avctx = avctx;
859

    
860
    if (s->avctx->palctrl == NULL) {
861
        av_log(avctx, AV_LOG_ERROR, " Interplay video: palette expected.\n");
862
        return -1;
863
    }
864

    
865
    avctx->pix_fmt = PIX_FMT_PAL8;
866
    avctx->has_b_frames = 0;
867
    dsputil_init(&s->dsp, avctx);
868

    
869
    /* decoding map contains 4 bits of information per 8x8 block */
870
    s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
871

    
872
    /* assign block decode functions */
873
    ipvideo_decode_block[0x0] = ipvideo_decode_block_opcode_0x0;
874
    ipvideo_decode_block[0x1] = ipvideo_decode_block_opcode_0x1;
875
    ipvideo_decode_block[0x2] = ipvideo_decode_block_opcode_0x2;
876
    ipvideo_decode_block[0x3] = ipvideo_decode_block_opcode_0x3;
877
    ipvideo_decode_block[0x4] = ipvideo_decode_block_opcode_0x4;
878
    ipvideo_decode_block[0x5] = ipvideo_decode_block_opcode_0x5;
879
    ipvideo_decode_block[0x6] = ipvideo_decode_block_opcode_0x6;
880
    ipvideo_decode_block[0x7] = ipvideo_decode_block_opcode_0x7;
881
    ipvideo_decode_block[0x8] = ipvideo_decode_block_opcode_0x8;
882
    ipvideo_decode_block[0x9] = ipvideo_decode_block_opcode_0x9;
883
    ipvideo_decode_block[0xA] = ipvideo_decode_block_opcode_0xA;
884
    ipvideo_decode_block[0xB] = ipvideo_decode_block_opcode_0xB;
885
    ipvideo_decode_block[0xC] = ipvideo_decode_block_opcode_0xC;
886
    ipvideo_decode_block[0xD] = ipvideo_decode_block_opcode_0xD;
887
    ipvideo_decode_block[0xE] = ipvideo_decode_block_opcode_0xE;
888
    ipvideo_decode_block[0xF] = ipvideo_decode_block_opcode_0xF;
889

    
890
    s->current_frame.data[0] = s->last_frame.data[0] =
891
    s->second_last_frame.data[0] = NULL;
892

    
893
    return 0;
894
}
895

    
896
static int ipvideo_decode_frame(AVCodecContext *avctx,
897
                                void *data, int *data_size,
898
                                uint8_t *buf, int buf_size)
899
{
900
    IpvideoContext *s = avctx->priv_data;
901
    AVPaletteControl *palette_control = avctx->palctrl;
902

    
903
    /* compressed buffer needs to be large enough to at least hold an entire
904
     * decoding map */
905
    if (buf_size < s->decoding_map_size)
906
        return buf_size;
907

    
908
    s->decoding_map = buf;
909
    s->buf = buf + s->decoding_map_size;
910
    s->size = buf_size - s->decoding_map_size;
911

    
912
    s->current_frame.reference = 3;
913
    if (avctx->get_buffer(avctx, &s->current_frame)) {
914
        av_log(avctx, AV_LOG_ERROR, "  Interplay Video: get_buffer() failed\n");
915
        return -1;
916
    }
917

    
918
    ipvideo_decode_opcodes(s);
919

    
920
    if (palette_control->palette_changed) {
921
        palette_control->palette_changed = 0;
922
        s->current_frame.palette_has_changed = 1;
923
    }
924

    
925
    *data_size = sizeof(AVFrame);
926
    *(AVFrame*)data = s->current_frame;
927

    
928
    /* shuffle frames */
929
    if (s->second_last_frame.data[0])
930
        avctx->release_buffer(avctx, &s->second_last_frame);
931
    s->second_last_frame = s->last_frame;
932
    s->last_frame = s->current_frame;
933
    s->current_frame.data[0] = NULL;  /* catch any access attempts */
934

    
935
    /* report that the buffer was completely consumed */
936
    return buf_size;
937
}
938

    
939
static int ipvideo_decode_end(AVCodecContext *avctx)
940
{
941
    IpvideoContext *s = avctx->priv_data;
942

    
943
    /* release the last frame */
944
    if (s->last_frame.data[0])
945
        avctx->release_buffer(avctx, &s->last_frame);
946
    if (s->second_last_frame.data[0])
947
        avctx->release_buffer(avctx, &s->second_last_frame);
948

    
949
    return 0;
950
}
951

    
952
AVCodec interplay_video_decoder = {
953
    "interplayvideo",
954
    CODEC_TYPE_VIDEO,
955
    CODEC_ID_INTERPLAY_VIDEO,
956
    sizeof(IpvideoContext),
957
    ipvideo_decode_init,
958
    NULL,
959
    ipvideo_decode_end,
960
    ipvideo_decode_frame,
961
    CODEC_CAP_DR1,
962
};