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ffmpeg / libavcodec / interplayvideo.c @ 2029f312

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1
/*
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 * Interplay MVE Video Decoder
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 * Copyright (C) 2003 the ffmpeg project
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * 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 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg 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
15
 * 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 FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 *
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 */
22

    
23
/**
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 * @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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 */
37

    
38
#include <stdio.h>
39
#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
42

    
43
#include "avcodec.h"
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#include "dsputil.h"
45

    
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#define PALETTE_COUNT 256
47

    
48
/* debugging support */
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#define DEBUG_INTERPLAY 0
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#if DEBUG_INTERPLAY
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#define debug_interplay(x,...) av_log(NULL, AV_LOG_DEBUG, x, __VA_ARGS__)
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#else
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static inline void debug_interplay(const char *format, ...) { }
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#endif
55

    
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typedef struct IpvideoContext {
57

    
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    AVCodecContext *avctx;
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    DSPContext dsp;
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    AVFrame second_last_frame;
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    AVFrame last_frame;
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    AVFrame current_frame;
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    unsigned char *decoding_map;
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    int decoding_map_size;
65

    
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    unsigned char *buf;
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    int size;
68

    
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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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76
} IpvideoContext;
77

    
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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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  }
84

    
85
#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); \
91
        return -1; \
92
    } 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; \
96
    } \
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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);
99

    
100
#define COPY_FROM_PREVIOUS() \
101
    motion_offset = current_offset; \
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    motion_offset += y * s->stride; \
103
    motion_offset += x; \
104
    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; \
107
    } 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); \
110
        return -1; \
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    } \
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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);
114

    
115
#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); \
121
        return -1; \
122
    } 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; \
126
    } \
127
    s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
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        s->second_last_frame.data[0] + motion_offset, s->stride, 8);
129

    
130
static int ipvideo_decode_block_opcode_0x0(IpvideoContext *s)
131
{
132
    int x, y;
133
    int motion_offset;
134
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
135

    
136
    /* copy a block from the previous frame */
137
    x = y = 0;
138
    COPY_FROM_PREVIOUS();
139

    
140
    /* report success */
141
    return 0;
142
}
143

    
144
static int ipvideo_decode_block_opcode_0x1(IpvideoContext *s)
145
{
146
    int x, y;
147
    int motion_offset;
148
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
149

    
150
    /* copy block from 2 frames ago */
151
    x = y = 0;
152
    COPY_FROM_SECOND_LAST();
153

    
154
    /* report success */
155
    return 0;
156
}
157

    
158
static int ipvideo_decode_block_opcode_0x2(IpvideoContext *s)
159
{
160
    unsigned char B;
161
    int x, y;
162
    int motion_offset;
163
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
164

    
165
    /* copy block from 2 frames ago using a motion vector; need 1 more byte */
166
    CHECK_STREAM_PTR(1);
167
    B = *s->stream_ptr++;
168

    
169
    if (B < 56) {
170
        x = 8 + (B % 7);
171
        y = B / 7;
172
    } else {
173
        x = -14 + ((B - 56) % 29);
174
        y =   8 + ((B - 56) / 29);
175
    }
176

    
177
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
178
    COPY_FROM_SECOND_LAST();
179

    
180
    /* report success */
181
    return 0;
182
}
183

    
184
static int ipvideo_decode_block_opcode_0x3(IpvideoContext *s)
185
{
186
    unsigned char B;
187
    int x, y;
188
    int motion_offset;
189
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
190

    
191
    /* copy 8x8 block from current frame from an up/left block */
192

    
193
    /* need 1 more byte for motion */
194
    CHECK_STREAM_PTR(1);
195
    B = *s->stream_ptr++;
196

    
197
    if (B < 56) {
198
        x = -(8 + (B % 7));
199
        y = -(B / 7);
200
    } else {
201
        x = -(-14 + ((B - 56) % 29));
202
        y = -(  8 + ((B - 56) / 29));
203
    }
204

    
205
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
206
    COPY_FROM_CURRENT();
207

    
208
    /* report success */
209
    return 0;
210
}
211

    
212
static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s)
213
{
214
    int x, y;
215
    unsigned char B, BL, BH;
216
    int motion_offset;
217
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
218

    
219
    /* copy a block from the previous frame; need 1 more byte */
220
    CHECK_STREAM_PTR(1);
221

    
222
    B = *s->stream_ptr++;
223
    BL = B & 0x0F;
224
    BH = (B >> 4) & 0x0F;
225
    x = -8 + BL;
226
    y = -8 + BH;
227

    
228
    debug_interplay ("    motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
229
    COPY_FROM_PREVIOUS();
230

    
231
    /* report success */
232
    return 0;
233
}
234

    
235
static int ipvideo_decode_block_opcode_0x5(IpvideoContext *s)
236
{
237
    signed char x, y;
238
    int motion_offset;
239
    int current_offset = s->pixel_ptr - s->current_frame.data[0];
240

    
241
    /* copy a block from the previous frame using an expanded range;
242
     * need 2 more bytes */
243
    CHECK_STREAM_PTR(2);
244

    
245
    x = *s->stream_ptr++;
246
    y = *s->stream_ptr++;
247

    
248
    debug_interplay ("    motion bytes = %d, %d\n", x, y);
249
    COPY_FROM_PREVIOUS();
250

    
251
    /* report success */
252
    return 0;
253
}
254

    
255
static int ipvideo_decode_block_opcode_0x6(IpvideoContext *s)
256
{
257
    /* mystery opcode? skip multiple blocks? */
258
    av_log(s->avctx, AV_LOG_ERROR, "  Interplay video: Help! Mystery opcode 0x6 seen\n");
259

    
260
    /* report success */
261
    return 0;
262
}
263

    
264
static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s)
265
{
266
    int x, y;
267
    unsigned char P0, P1;
268
    unsigned char B[8];
269
    unsigned int flags;
270
    int bitmask;
271

    
272
    /* 2-color encoding */
273
    CHECK_STREAM_PTR(2);
274

    
275
    P0 = *s->stream_ptr++;
276
    P1 = *s->stream_ptr++;
277

    
278
    if (P0 <= P1) {
279

    
280
        /* need 8 more bytes from the stream */
281
        CHECK_STREAM_PTR(8);
282
        for (y = 0; y < 8; y++)
283
            B[y] = *s->stream_ptr++;
284

    
285
        for (y = 0; y < 8; y++) {
286
            flags = B[y];
287
            for (x = 0x01; x <= 0x80; x <<= 1) {
288
                if (flags & x)
289
                    *s->pixel_ptr++ = P1;
290
                else
291
                    *s->pixel_ptr++ = P0;
292
            }
293
            s->pixel_ptr += s->line_inc;
294
        }
295

    
296
    } else {
297

    
298
        /* need 2 more bytes from the stream */
299
        CHECK_STREAM_PTR(2);
300
        B[0] = *s->stream_ptr++;
301
        B[1] = *s->stream_ptr++;
302

    
303
        flags = (B[1] << 8) | B[0];
304
        bitmask = 0x0001;
305
        for (y = 0; y < 8; y += 2) {
306
            for (x = 0; x < 8; x += 2, bitmask <<= 1) {
307
                if (flags & bitmask) {
308
                    *(s->pixel_ptr + x) = P1;
309
                    *(s->pixel_ptr + x + 1) = P1;
310
                    *(s->pixel_ptr + s->stride + x) = P1;
311
                    *(s->pixel_ptr + s->stride + x + 1) = P1;
312
                } else {
313
                    *(s->pixel_ptr + x) = P0;
314
                    *(s->pixel_ptr + x + 1) = P0;
315
                    *(s->pixel_ptr + s->stride + x) = P0;
316
                    *(s->pixel_ptr + s->stride + x + 1) = P0;
317
                }
318
            }
319
            s->pixel_ptr += s->stride * 2;
320
        }
321
    }
322

    
323
    /* report success */
324
    return 0;
325
}
326

    
327
static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
328
{
329
    int x, y;
330
    unsigned char P[8];
331
    unsigned char B[8];
332
    unsigned int flags = 0;
333
    unsigned int bitmask = 0;
334
    unsigned char P0 = 0, P1 = 0;
335
    int lower_half = 0;
336

    
337
    /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
338
     * either top and bottom or left and right halves */
339
    CHECK_STREAM_PTR(2);
340

    
341
    P[0] = *s->stream_ptr++;
342
    P[1] = *s->stream_ptr++;
343

    
344
    if (P[0] <= P[1]) {
345

    
346
        /* need 12 more bytes */
347
        CHECK_STREAM_PTR(12);
348
        B[0] = *s->stream_ptr++;  B[1] = *s->stream_ptr++;
349
        P[2] = *s->stream_ptr++;  P[3] = *s->stream_ptr++;
350
        B[2] = *s->stream_ptr++;  B[3] = *s->stream_ptr++;
351
        P[4] = *s->stream_ptr++;  P[5] = *s->stream_ptr++;
352
        B[4] = *s->stream_ptr++;  B[5] = *s->stream_ptr++;
353
        P[6] = *s->stream_ptr++;  P[7] = *s->stream_ptr++;
354
        B[6] = *s->stream_ptr++;  B[7] = *s->stream_ptr++;
355

    
356
        for (y = 0; y < 8; y++) {
357

    
358
            /* time to reload flags? */
359
            if (y == 0) {
360
                flags =
361
                    ((B[0] & 0xF0) <<  4) | ((B[4] & 0xF0) <<  8) |
362
                    ((B[0] & 0x0F)      ) | ((B[4] & 0x0F) <<  4) |
363
                    ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
364
                    ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
365
                bitmask = 0x00000001;
366
                lower_half = 0;  /* still on top half */
367
            } else if (y == 4) {
368
                flags =
369
                    ((B[2] & 0xF0) <<  4) | ((B[6] & 0xF0) <<  8) |
370
                    ((B[2] & 0x0F)      ) | ((B[6] & 0x0F) <<  4) |
371
                    ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
372
                    ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
373
                bitmask = 0x00000001;
374
                lower_half = 2;
375
            }
376

    
377
            for (x = 0; x < 8; x++, bitmask <<= 1) {
378
                /* get the pixel values ready for this quadrant */
379
                if (x == 0) {
380
                    P0 = P[lower_half + 0];
381
                    P1 = P[lower_half + 1];
382
                } else if (x == 4) {
383
                    P0 = P[lower_half + 4];
384
                    P1 = P[lower_half + 5];
385
                }
386

    
387
                if (flags & bitmask)
388
                    *s->pixel_ptr++ = P1;
389
                else
390
                    *s->pixel_ptr++ = P0;
391
            }
392
            s->pixel_ptr += s->line_inc;
393
        }
394

    
395
    } else {
396

    
397
        /* need 10 more bytes */
398
        CHECK_STREAM_PTR(10);
399
        B[0] = *s->stream_ptr++;  B[1] = *s->stream_ptr++;
400
        B[2] = *s->stream_ptr++;  B[3] = *s->stream_ptr++;
401
        P[2] = *s->stream_ptr++;  P[3] = *s->stream_ptr++;
402
        B[4] = *s->stream_ptr++;  B[5] = *s->stream_ptr++;
403
        B[6] = *s->stream_ptr++;  B[7] = *s->stream_ptr++;
404

    
405
        if (P[2] <= P[3]) {
406

    
407
            /* vertical split; left & right halves are 2-color encoded */
408

    
409
            for (y = 0; y < 8; y++) {
410

    
411
                /* time to reload flags? */
412
                if (y == 0) {
413
                    flags =
414
                        ((B[0] & 0xF0) <<  4) | ((B[4] & 0xF0) <<  8) |
415
                        ((B[0] & 0x0F)      ) | ((B[4] & 0x0F) <<  4) |
416
                        ((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
417
                        ((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
418
                    bitmask = 0x00000001;
419
                } else if (y == 4) {
420
                    flags =
421
                        ((B[2] & 0xF0) <<  4) | ((B[6] & 0xF0) <<  8) |
422
                        ((B[2] & 0x0F)      ) | ((B[6] & 0x0F) <<  4) |
423
                        ((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
424
                        ((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
425
                    bitmask = 0x00000001;
426
                }
427

    
428
                for (x = 0; x < 8; x++, bitmask <<= 1) {
429
                    /* get the pixel values ready for this half */
430
                    if (x == 0) {
431
                        P0 = P[0];
432
                        P1 = P[1];
433
                    } else if (x == 4) {
434
                        P0 = P[2];
435
                        P1 = P[3];
436
                    }
437

    
438
                    if (flags & bitmask)
439
                        *s->pixel_ptr++ = P1;
440
                    else
441
                        *s->pixel_ptr++ = P0;
442
                }
443
                s->pixel_ptr += s->line_inc;
444
            }
445

    
446
        } else {
447

    
448
            /* horizontal split; top & bottom halves are 2-color encoded */
449

    
450
            for (y = 0; y < 8; y++) {
451

    
452
                flags = B[y];
453
                if (y == 0) {
454
                    P0 = P[0];
455
                    P1 = P[1];
456
                } else if (y == 4) {
457
                    P0 = P[2];
458
                    P1 = P[3];
459
                }
460

    
461
                for (bitmask = 0x01; bitmask <= 0x80; bitmask <<= 1) {
462

    
463
                    if (flags & bitmask)
464
                        *s->pixel_ptr++ = P1;
465
                    else
466
                        *s->pixel_ptr++ = P0;
467
                }
468
                s->pixel_ptr += s->line_inc;
469
            }
470
        }
471
    }
472

    
473
    /* report success */
474
    return 0;
475
}
476

    
477
static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
478
{
479
    int x, y;
480
    unsigned char P[4];
481
    unsigned char B[4];
482
    unsigned int flags = 0;
483
    int shifter = 0;
484
    unsigned char pix;
485

    
486
    /* 4-color encoding */
487
    CHECK_STREAM_PTR(4);
488

    
489
    for (y = 0; y < 4; y++)
490
        P[y] = *s->stream_ptr++;
491

    
492
    if ((P[0] <= P[1]) && (P[2] <= P[3])) {
493

    
494
        /* 1 of 4 colors for each pixel, need 16 more bytes */
495
        CHECK_STREAM_PTR(16);
496

    
497
        for (y = 0; y < 8; y++) {
498
            /* get the next set of 8 2-bit flags */
499
            flags = (s->stream_ptr[1] << 8) | s->stream_ptr[0];
500
            s->stream_ptr += 2;
501
            for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
502
                *s->pixel_ptr++ = P[(flags >> shifter) & 0x03];
503
            }
504
            s->pixel_ptr += s->line_inc;
505
        }
506

    
507
    } else if ((P[0] <= P[1]) && (P[2] > P[3])) {
508

    
509
        /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
510
        CHECK_STREAM_PTR(4);
511

    
512
        B[0] = *s->stream_ptr++;
513
        B[1] = *s->stream_ptr++;
514
        B[2] = *s->stream_ptr++;
515
        B[3] = *s->stream_ptr++;
516
        flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
517
        shifter = 0;
518

    
519
        for (y = 0; y < 8; y += 2) {
520
            for (x = 0; x < 8; x += 2, shifter += 2) {
521
                pix = P[(flags >> shifter) & 0x03];
522
                *(s->pixel_ptr + x) = pix;
523
                *(s->pixel_ptr + x + 1) = pix;
524
                *(s->pixel_ptr + s->stride + x) = pix;
525
                *(s->pixel_ptr + s->stride + x + 1) = pix;
526
            }
527
            s->pixel_ptr += s->stride * 2;
528
        }
529

    
530
    } else if ((P[0] > P[1]) && (P[2] <= P[3])) {
531

    
532
        /* 1 of 4 colors for each 2x1 block, need 8 more bytes */
533
        CHECK_STREAM_PTR(8);
534

    
535
        for (y = 0; y < 8; y++) {
536
            /* time to reload flags? */
537
            if ((y == 0) || (y == 4)) {
538
                B[0] = *s->stream_ptr++;
539
                B[1] = *s->stream_ptr++;
540
                B[2] = *s->stream_ptr++;
541
                B[3] = *s->stream_ptr++;
542
                flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
543
                shifter = 0;
544
            }
545
            for (x = 0; x < 8; x += 2, shifter += 2) {
546
                pix = P[(flags >> shifter) & 0x03];
547
                *(s->pixel_ptr + x) = pix;
548
                *(s->pixel_ptr + x + 1) = pix;
549
            }
550
            s->pixel_ptr += s->stride;
551
        }
552

    
553
    } else {
554

    
555
        /* 1 of 4 colors for each 1x2 block, need 8 more bytes */
556
        CHECK_STREAM_PTR(8);
557

    
558
        for (y = 0; y < 8; y += 2) {
559
            /* time to reload flags? */
560
            if ((y == 0) || (y == 4)) {
561
                B[0] = *s->stream_ptr++;
562
                B[1] = *s->stream_ptr++;
563
                B[2] = *s->stream_ptr++;
564
                B[3] = *s->stream_ptr++;
565
                flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
566
                shifter = 0;
567
            }
568
            for (x = 0; x < 8; x++, shifter += 2) {
569
                pix = P[(flags >> shifter) & 0x03];
570
                *(s->pixel_ptr + x) = pix;
571
                *(s->pixel_ptr + s->stride + x) = pix;
572
            }
573
            s->pixel_ptr += s->stride * 2;
574
        }
575
    }
576

    
577
    /* report success */
578
    return 0;
579
}
580

    
581
static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
582
{
583
    int x, y;
584
    unsigned char P[16];
585
    unsigned char B[16];
586
    int flags = 0;
587
    int shifter = 0;
588
    int index;
589
    int split;
590
    int lower_half;
591

    
592
    /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
593
     * either top and bottom or left and right halves */
594
    CHECK_STREAM_PTR(4);
595

    
596
    for (y = 0; y < 4; y++)
597
        P[y] = *s->stream_ptr++;
598

    
599
    if (P[0] <= P[1]) {
600

    
601
        /* 4-color encoding for each quadrant; need 28 more bytes */
602
        CHECK_STREAM_PTR(28);
603

    
604
        for (y = 0; y < 4; y++)
605
            B[y] = *s->stream_ptr++;
606
        for (y = 4; y < 16; y += 4) {
607
            for (x = y; x < y + 4; x++)
608
                P[x] = *s->stream_ptr++;
609
            for (x = y; x < y + 4; x++)
610
                B[x] = *s->stream_ptr++;
611
        }
612

    
613
        for (y = 0; y < 8; y++) {
614

    
615
            lower_half = (y >= 4) ? 4 : 0;
616
            flags = (B[y + 8] << 8) | B[y];
617

    
618
            for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
619
                split = (x >= 4) ? 8 : 0;
620
                index = split + lower_half + ((flags >> shifter) & 0x03);
621
                *s->pixel_ptr++ = P[index];
622
            }
623

    
624
            s->pixel_ptr += s->line_inc;
625
        }
626

    
627
    } else {
628

    
629
        /* 4-color encoding for either left and right or top and bottom
630
         * halves; need 20 more bytes */
631
        CHECK_STREAM_PTR(20);
632

    
633
        for (y = 0; y < 8; y++)
634
            B[y] = *s->stream_ptr++;
635
        for (y = 4; y < 8; y++)
636
            P[y] = *s->stream_ptr++;
637
        for (y = 8; y < 16; y++)
638
            B[y] = *s->stream_ptr++;
639

    
640
        if (P[4] <= P[5]) {
641

    
642
            /* block is divided into left and right halves */
643
            for (y = 0; y < 8; y++) {
644

    
645
                flags = (B[y + 8] << 8) | B[y];
646
                split = 0;
647

    
648
                for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
649
                    if (x == 4)
650
                        split = 4;
651
                    *s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
652
                }
653

    
654
                s->pixel_ptr += s->line_inc;
655
            }
656

    
657
        } else {
658

    
659
            /* block is divided into top and bottom halves */
660
            split = 0;
661
            for (y = 0; y < 8; y++) {
662

    
663
                flags = (B[y * 2 + 1] << 8) | B[y * 2];
664
                if (y == 4)
665
                    split = 4;
666

    
667
                for (x = 0, shifter = 0; x < 8; x++, shifter += 2)
668
                    *s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
669

    
670
                s->pixel_ptr += s->line_inc;
671
            }
672
        }
673
    }
674

    
675
    /* report success */
676
    return 0;
677
}
678

    
679
static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s)
680
{
681
    int x, y;
682

    
683
    /* 64-color encoding (each pixel in block is a different color) */
684
    CHECK_STREAM_PTR(64);
685

    
686
    for (y = 0; y < 8; y++) {
687
        for (x = 0; x < 8; x++) {
688
            *s->pixel_ptr++ = *s->stream_ptr++;
689
        }
690
        s->pixel_ptr += s->line_inc;
691
    }
692

    
693
    /* report success */
694
    return 0;
695
}
696

    
697
static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
698
{
699
    int x, y;
700
    unsigned char pix;
701

    
702
    /* 16-color block encoding: each 2x2 block is a different color */
703
    CHECK_STREAM_PTR(16);
704

    
705
    for (y = 0; y < 8; y += 2) {
706
        for (x = 0; x < 8; x += 2) {
707
            pix = *s->stream_ptr++;
708
            *(s->pixel_ptr + x) = pix;
709
            *(s->pixel_ptr + x + 1) = pix;
710
            *(s->pixel_ptr + s->stride + x) = pix;
711
            *(s->pixel_ptr + s->stride + x + 1) = pix;
712
        }
713
        s->pixel_ptr += s->stride * 2;
714
    }
715

    
716
    /* report success */
717
    return 0;
718
}
719

    
720
static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
721
{
722
    int x, y;
723
    unsigned char P[4];
724
    unsigned char index = 0;
725

    
726
    /* 4-color block encoding: each 4x4 block is a different color */
727
    CHECK_STREAM_PTR(4);
728

    
729
    for (y = 0; y < 4; y++)
730
        P[y] = *s->stream_ptr++;
731

    
732
    for (y = 0; y < 8; y++) {
733
        if (y < 4)
734
            index = 0;
735
        else
736
            index = 2;
737

    
738
        for (x = 0; x < 8; x++) {
739
            if (x == 4)
740
                index++;
741
            *s->pixel_ptr++ = P[index];
742
        }
743
        s->pixel_ptr += s->line_inc;
744
    }
745

    
746
    /* report success */
747
    return 0;
748
}
749

    
750
static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s)
751
{
752
    int x, y;
753
    unsigned char pix;
754

    
755
    /* 1-color encoding: the whole block is 1 solid color */
756
    CHECK_STREAM_PTR(1);
757
    pix = *s->stream_ptr++;
758

    
759
    for (y = 0; y < 8; y++) {
760
        for (x = 0; x < 8; x++) {
761
            *s->pixel_ptr++ = pix;
762
        }
763
        s->pixel_ptr += s->line_inc;
764
    }
765

    
766
    /* report success */
767
    return 0;
768
}
769

    
770
static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s)
771
{
772
    int x, y;
773
    unsigned char sample0, sample1;
774

    
775
    /* dithered encoding */
776
    CHECK_STREAM_PTR(2);
777
    sample0 = *s->stream_ptr++;
778
    sample1 = *s->stream_ptr++;
779

    
780
    for (y = 0; y < 8; y++) {
781
        for (x = 0; x < 8; x += 2) {
782
            if (y & 1) {
783
                *s->pixel_ptr++ = sample1;
784
                *s->pixel_ptr++ = sample0;
785
            } else {
786
                *s->pixel_ptr++ = sample0;
787
                *s->pixel_ptr++ = sample1;
788
            }
789
        }
790
        s->pixel_ptr += s->line_inc;
791
    }
792

    
793
    /* report success */
794
    return 0;
795
}
796

    
797
static int (*ipvideo_decode_block[16])(IpvideoContext *s);
798

    
799
static void ipvideo_decode_opcodes(IpvideoContext *s)
800
{
801
    int x, y;
802
    int index = 0;
803
    unsigned char opcode;
804
    int ret;
805
    int code_counts[16];
806
    static int frame = 0;
807

    
808
    debug_interplay("------------------ frame %d\n", frame);
809
    frame++;
810

    
811
    for (x = 0; x < 16; x++)
812
        code_counts[x] = 0;
813

    
814
    /* this is PAL8, so make the palette available */
815
    memcpy(s->current_frame.data[1], s->avctx->palctrl->palette, PALETTE_COUNT * 4);
816

    
817
    s->stride = s->current_frame.linesize[0];
818
    s->stream_ptr = s->buf + 14;  /* data starts 14 bytes in */
819
    s->stream_end = s->buf + s->size;
820
    s->line_inc = s->stride - 8;
821
    s->upper_motion_limit_offset = (s->avctx->height - 8) * s->stride
822
        + s->avctx->width - 8;
823
    s->dsp = s->dsp;
824

    
825
    for (y = 0; y < (s->stride * s->avctx->height); y += s->stride * 8) {
826
        for (x = y; x < y + s->avctx->width; x += 8) {
827
            /* bottom nibble first, then top nibble (which makes it
828
             * hard to use a GetBitcontext) */
829
            if (index & 1)
830
                opcode = s->decoding_map[index >> 1] >> 4;
831
            else
832
                opcode = s->decoding_map[index >> 1] & 0xF;
833
            index++;
834

    
835
            debug_interplay("  block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
836
                x - y, y / s->stride, opcode, s->stream_ptr);
837
            code_counts[opcode]++;
838

    
839
            s->pixel_ptr = s->current_frame.data[0] + x;
840
            ret = ipvideo_decode_block[opcode](s);
841
            if (ret != 0) {
842
                av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
843
                    frame, x - y, y / s->stride);
844
                return;
845
            }
846
        }
847
    }
848
    if ((s->stream_ptr != s->stream_end) &&
849
        (s->stream_ptr + 1 != s->stream_end)) {
850
        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %td bytes left over\n",
851
            s->stream_end - s->stream_ptr);
852
    }
853
}
854

    
855
static int ipvideo_decode_init(AVCodecContext *avctx)
856
{
857
    IpvideoContext *s = avctx->priv_data;
858

    
859
    s->avctx = avctx;
860

    
861
    if (s->avctx->palctrl == NULL) {
862
        av_log(avctx, AV_LOG_ERROR, " Interplay video: palette expected.\n");
863
        return -1;
864
    }
865

    
866
    avctx->pix_fmt = PIX_FMT_PAL8;
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
};