1/*
2 * Interplay MVE Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
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 * Interplay MVE Video Decoder by Mike Melanson (melanson@pcisys.net)
25 * For more information about the Interplay MVE format, visit:
26 *   http://www.pcisys.net/~melanson/codecs/interplay-mve.txt
27 * This code is written in such a way that the identifiers match up
28 * with the encoding descriptions in the document.
29 *
30 * This decoder presently only supports a PAL8 output colorspace.
31 *
32 * An Interplay video frame consists of 2 parts: The decoding map and
33 * the video data. A demuxer must load these 2 parts together in a single
34 * buffer before sending it through the stream to this decoder.
35 */
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40
41#include "avcodec.h"
42#include "bytestream.h"
43#include "hpeldsp.h"
44#define BITSTREAM_READER_LE
45#include "get_bits.h"
46#include "internal.h"
47
48#define PALETTE_COUNT 256
49
50typedef struct IpvideoContext {
51
52    AVCodecContext *avctx;
53    HpelDSPContext hdsp;
54    AVFrame *second_last_frame;
55    AVFrame *last_frame;
56    const unsigned char *decoding_map;
57    int decoding_map_size;
58
59    int is_16bpp;
60    GetByteContext stream_ptr, mv_ptr;
61    unsigned char *pixel_ptr;
62    int line_inc;
63    int stride;
64    int upper_motion_limit_offset;
65
66    uint32_t pal[256];
67} IpvideoContext;
68
69static int copy_from(IpvideoContext *s, AVFrame *src, AVFrame *dst, int delta_x, int delta_y)
70{
71    int current_offset = s->pixel_ptr - dst->data[0];
72    int motion_offset = current_offset + delta_y * dst->linesize[0]
73                       + delta_x * (1 + s->is_16bpp);
74    if (motion_offset < 0) {
75        av_log(s->avctx, AV_LOG_ERROR, "motion offset < 0 (%d)\n", motion_offset);
76        return AVERROR_INVALIDDATA;
77    } else if (motion_offset > s->upper_motion_limit_offset) {
78        av_log(s->avctx, AV_LOG_ERROR, "motion offset above limit (%d >= %d)\n",
79            motion_offset, s->upper_motion_limit_offset);
80        return AVERROR_INVALIDDATA;
81    }
82    if (src->data[0] == NULL) {
83        av_log(s->avctx, AV_LOG_ERROR, "Invalid decode type, corrupted header?\n");
84        return AVERROR(EINVAL);
85    }
86    s->hdsp.put_pixels_tab[!s->is_16bpp][0](s->pixel_ptr, src->data[0] + motion_offset,
87                                            dst->linesize[0], 8);
88    return 0;
89}
90
91static int ipvideo_decode_block_opcode_0x0(IpvideoContext *s, AVFrame *frame)
92{
93    return copy_from(s, s->last_frame, frame, 0, 0);
94}
95
96static int ipvideo_decode_block_opcode_0x1(IpvideoContext *s, AVFrame *frame)
97{
98    return copy_from(s, s->second_last_frame, frame, 0, 0);
99}
100
101static int ipvideo_decode_block_opcode_0x2(IpvideoContext *s, AVFrame *frame)
102{
103    unsigned char B;
104    int x, y;
105
106    /* copy block from 2 frames ago using a motion vector; need 1 more byte */
107    if (!s->is_16bpp) {
108        B = bytestream2_get_byte(&s->stream_ptr);
109    } else {
110        B = bytestream2_get_byte(&s->mv_ptr);
111    }
112
113    if (B < 56) {
114        x = 8 + (B % 7);
115        y = B / 7;
116    } else {
117        x = -14 + ((B - 56) % 29);
118        y =   8 + ((B - 56) / 29);
119    }
120
121    av_dlog(s->avctx, "motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
122    return copy_from(s, s->second_last_frame, frame, x, y);
123}
124
125static int ipvideo_decode_block_opcode_0x3(IpvideoContext *s, AVFrame *frame)
126{
127    unsigned char B;
128    int x, y;
129
130    /* copy 8x8 block from current frame from an up/left block */
131
132    /* need 1 more byte for motion */
133    if (!s->is_16bpp) {
134        B = bytestream2_get_byte(&s->stream_ptr);
135    } else {
136        B = bytestream2_get_byte(&s->mv_ptr);
137    }
138
139    if (B < 56) {
140        x = -(8 + (B % 7));
141        y = -(B / 7);
142    } else {
143        x = -(-14 + ((B - 56) % 29));
144        y = -(  8 + ((B - 56) / 29));
145    }
146
147    av_dlog(s->avctx, "motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
148    return copy_from(s, frame, frame, x, y);
149}
150
151static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s, AVFrame *frame)
152{
153    int x, y;
154    unsigned char B, BL, BH;
155
156    /* copy a block from the previous frame; need 1 more byte */
157    if (!s->is_16bpp) {
158        B = bytestream2_get_byte(&s->stream_ptr);
159    } else {
160        B = bytestream2_get_byte(&s->mv_ptr);
161    }
162
163    BL = B & 0x0F;
164    BH = (B >> 4) & 0x0F;
165    x = -8 + BL;
166    y = -8 + BH;
167
168    av_dlog(s->avctx, "motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
169    return copy_from(s, s->last_frame, frame, x, y);
170}
171
172static int ipvideo_decode_block_opcode_0x5(IpvideoContext *s, AVFrame *frame)
173{
174    signed char x, y;
175
176    /* copy a block from the previous frame using an expanded range;
177     * need 2 more bytes */
178    x = bytestream2_get_byte(&s->stream_ptr);
179    y = bytestream2_get_byte(&s->stream_ptr);
180
181    av_dlog(s->avctx, "motion bytes = %d, %d\n", x, y);
182    return copy_from(s, s->last_frame, frame, x, y);
183}
184
185static int ipvideo_decode_block_opcode_0x6(IpvideoContext *s, AVFrame *frame)
186{
187    /* mystery opcode? skip multiple blocks? */
188    av_log(s->avctx, AV_LOG_ERROR, "Help! Mystery opcode 0x6 seen\n");
189
190    /* report success */
191    return 0;
192}
193
194static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s, AVFrame *frame)
195{
196    int x, y;
197    unsigned char P[2];
198    unsigned int flags;
199
200    if (bytestream2_get_bytes_left(&s->stream_ptr) < 4) {
201        av_log(s->avctx, AV_LOG_ERROR, "too little data for opcode 0x7\n");
202        return AVERROR_INVALIDDATA;
203    }
204
205    /* 2-color encoding */
206    P[0] = bytestream2_get_byte(&s->stream_ptr);
207    P[1] = bytestream2_get_byte(&s->stream_ptr);
208
209    if (P[0] <= P[1]) {
210
211        /* need 8 more bytes from the stream */
212        for (y = 0; y < 8; y++) {
213            flags = bytestream2_get_byte(&s->stream_ptr) | 0x100;
214            for (; flags != 1; flags >>= 1)
215                *s->pixel_ptr++ = P[flags & 1];
216            s->pixel_ptr += s->line_inc;
217        }
218
219    } else {
220
221        /* need 2 more bytes from the stream */
222        flags = bytestream2_get_le16(&s->stream_ptr);
223        for (y = 0; y < 8; y += 2) {
224            for (x = 0; x < 8; x += 2, flags >>= 1) {
225                s->pixel_ptr[x                ] =
226                s->pixel_ptr[x + 1            ] =
227                s->pixel_ptr[x +     s->stride] =
228                s->pixel_ptr[x + 1 + s->stride] = P[flags & 1];
229            }
230            s->pixel_ptr += s->stride * 2;
231        }
232    }
233
234    /* report success */
235    return 0;
236}
237
238static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s, AVFrame *frame)
239{
240    int x, y;
241    unsigned char P[4];
242    unsigned int flags = 0;
243
244    if (bytestream2_get_bytes_left(&s->stream_ptr) < 12) {
245        av_log(s->avctx, AV_LOG_ERROR, "too little data for opcode 0x8\n");
246        return AVERROR_INVALIDDATA;
247    }
248
249    /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
250     * either top and bottom or left and right halves */
251    P[0] = bytestream2_get_byte(&s->stream_ptr);
252    P[1] = bytestream2_get_byte(&s->stream_ptr);
253
254    if (P[0] <= P[1]) {
255        for (y = 0; y < 16; y++) {
256            // new values for each 4x4 block
257            if (!(y & 3)) {
258                if (y) {
259                    P[0]  = bytestream2_get_byte(&s->stream_ptr);
260                    P[1]  = bytestream2_get_byte(&s->stream_ptr);
261                }
262                flags = bytestream2_get_le16(&s->stream_ptr);
263            }
264
265            for (x = 0; x < 4; x++, flags >>= 1)
266                *s->pixel_ptr++ = P[flags & 1];
267            s->pixel_ptr += s->stride - 4;
268            // switch to right half
269            if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
270        }
271
272    } else {
273        flags = bytestream2_get_le32(&s->stream_ptr);
274        P[2] = bytestream2_get_byte(&s->stream_ptr);
275        P[3] = bytestream2_get_byte(&s->stream_ptr);
276
277        if (P[2] <= P[3]) {
278
279            /* vertical split; left & right halves are 2-color encoded */
280
281            for (y = 0; y < 16; y++) {
282                for (x = 0; x < 4; x++, flags >>= 1)
283                    *s->pixel_ptr++ = P[flags & 1];
284                s->pixel_ptr += s->stride - 4;
285                // switch to right half
286                if (y == 7) {
287                    s->pixel_ptr -= 8 * s->stride - 4;
288                    P[0]  = P[2];
289                    P[1]  = P[3];
290                    flags = bytestream2_get_le32(&s->stream_ptr);
291                }
292            }
293
294        } else {
295
296            /* horizontal split; top & bottom halves are 2-color encoded */
297
298            for (y = 0; y < 8; y++) {
299                if (y == 4) {
300                    P[0]  = P[2];
301                    P[1]  = P[3];
302                    flags = bytestream2_get_le32(&s->stream_ptr);
303                }
304
305                for (x = 0; x < 8; x++, flags >>= 1)
306                    *s->pixel_ptr++ = P[flags & 1];
307                s->pixel_ptr += s->line_inc;
308            }
309        }
310    }
311
312    /* report success */
313    return 0;
314}
315
316static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s, AVFrame *frame)
317{
318    int x, y;
319    unsigned char P[4];
320
321    if (bytestream2_get_bytes_left(&s->stream_ptr) < 8) {
322        av_log(s->avctx, AV_LOG_ERROR, "too little data for opcode 0x9\n");
323        return AVERROR_INVALIDDATA;
324    }
325
326    /* 4-color encoding */
327    bytestream2_get_buffer(&s->stream_ptr, P, 4);
328
329    if (P[0] <= P[1]) {
330        if (P[2] <= P[3]) {
331
332            /* 1 of 4 colors for each pixel, need 16 more bytes */
333            for (y = 0; y < 8; y++) {
334                /* get the next set of 8 2-bit flags */
335                int flags = bytestream2_get_le16(&s->stream_ptr);
336                for (x = 0; x < 8; x++, flags >>= 2)
337                    *s->pixel_ptr++ = P[flags & 0x03];
338                s->pixel_ptr += s->line_inc;
339            }
340
341        } else {
342            uint32_t flags;
343
344            /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
345            flags = bytestream2_get_le32(&s->stream_ptr);
346
347            for (y = 0; y < 8; y += 2) {
348                for (x = 0; x < 8; x += 2, flags >>= 2) {
349                    s->pixel_ptr[x                ] =
350                    s->pixel_ptr[x + 1            ] =
351                    s->pixel_ptr[x +     s->stride] =
352                    s->pixel_ptr[x + 1 + s->stride] = P[flags & 0x03];
353                }
354                s->pixel_ptr += s->stride * 2;
355            }
356
357        }
358    } else {
359        uint64_t flags;
360
361        /* 1 of 4 colors for each 2x1 or 1x2 block, need 8 more bytes */
362        flags = bytestream2_get_le64(&s->stream_ptr);
363        if (P[2] <= P[3]) {
364            for (y = 0; y < 8; y++) {
365                for (x = 0; x < 8; x += 2, flags >>= 2) {
366                    s->pixel_ptr[x    ] =
367                    s->pixel_ptr[x + 1] = P[flags & 0x03];
368                }
369                s->pixel_ptr += s->stride;
370            }
371        } else {
372            for (y = 0; y < 8; y += 2) {
373                for (x = 0; x < 8; x++, flags >>= 2) {
374                    s->pixel_ptr[x            ] =
375                    s->pixel_ptr[x + s->stride] = P[flags & 0x03];
376                }
377                s->pixel_ptr += s->stride * 2;
378            }
379        }
380    }
381
382    /* report success */
383    return 0;
384}
385
386static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s, AVFrame *frame)
387{
388    int x, y;
389    unsigned char P[8];
390    int flags = 0;
391
392    if (bytestream2_get_bytes_left(&s->stream_ptr) < 16) {
393        av_log(s->avctx, AV_LOG_ERROR, "too little data for opcode 0xA\n");
394        return AVERROR_INVALIDDATA;
395    }
396
397    bytestream2_get_buffer(&s->stream_ptr, P, 4);
398
399    /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
400     * either top and bottom or left and right halves */
401    if (P[0] <= P[1]) {
402
403        /* 4-color encoding for each quadrant; need 32 bytes */
404        for (y = 0; y < 16; y++) {
405            // new values for each 4x4 block
406            if (!(y & 3)) {
407                if (y) bytestream2_get_buffer(&s->stream_ptr, P, 4);
408                flags = bytestream2_get_le32(&s->stream_ptr);
409            }
410
411            for (x = 0; x < 4; x++, flags >>= 2)
412                *s->pixel_ptr++ = P[flags & 0x03];
413
414            s->pixel_ptr += s->stride - 4;
415            // switch to right half
416            if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
417        }
418
419    } else {
420        // vertical split?
421        int vert;
422        uint64_t flags = bytestream2_get_le64(&s->stream_ptr);
423
424        bytestream2_get_buffer(&s->stream_ptr, P + 4, 4);
425        vert = P[4] <= P[5];
426
427        /* 4-color encoding for either left and right or top and bottom
428         * halves */
429
430        for (y = 0; y < 16; y++) {
431            for (x = 0; x < 4; x++, flags >>= 2)
432                *s->pixel_ptr++ = P[flags & 0x03];
433
434            if (vert) {
435                s->pixel_ptr += s->stride - 4;
436                // switch to right half
437                if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
438            } else if (y & 1) s->pixel_ptr += s->line_inc;
439
440            // load values for second half
441            if (y == 7) {
442                memcpy(P, P + 4, 4);
443                flags = bytestream2_get_le64(&s->stream_ptr);
444            }
445        }
446    }
447
448    /* report success */
449    return 0;
450}
451
452static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s, AVFrame *frame)
453{
454    int y;
455
456    /* 64-color encoding (each pixel in block is a different color) */
457    for (y = 0; y < 8; y++) {
458        bytestream2_get_buffer(&s->stream_ptr, s->pixel_ptr, 8);
459        s->pixel_ptr  += s->stride;
460    }
461
462    /* report success */
463    return 0;
464}
465
466static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s, AVFrame *frame)
467{
468    int x, y;
469
470    /* 16-color block encoding: each 2x2 block is a different color */
471    for (y = 0; y < 8; y += 2) {
472        for (x = 0; x < 8; x += 2) {
473            s->pixel_ptr[x                ] =
474            s->pixel_ptr[x + 1            ] =
475            s->pixel_ptr[x +     s->stride] =
476            s->pixel_ptr[x + 1 + s->stride] = bytestream2_get_byte(&s->stream_ptr);
477        }
478        s->pixel_ptr += s->stride * 2;
479    }
480
481    /* report success */
482    return 0;
483}
484
485static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s, AVFrame *frame)
486{
487    int y;
488    unsigned char P[2];
489
490    if (bytestream2_get_bytes_left(&s->stream_ptr) < 4) {
491        av_log(s->avctx, AV_LOG_ERROR, "too little data for opcode 0xD\n");
492        return AVERROR_INVALIDDATA;
493    }
494
495    /* 4-color block encoding: each 4x4 block is a different color */
496    for (y = 0; y < 8; y++) {
497        if (!(y & 3)) {
498            P[0] = bytestream2_get_byte(&s->stream_ptr);
499            P[1] = bytestream2_get_byte(&s->stream_ptr);
500        }
501        memset(s->pixel_ptr,     P[0], 4);
502        memset(s->pixel_ptr + 4, P[1], 4);
503        s->pixel_ptr += s->stride;
504    }
505
506    /* report success */
507    return 0;
508}
509
510static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s, AVFrame *frame)
511{
512    int y;
513    unsigned char pix;
514
515    /* 1-color encoding: the whole block is 1 solid color */
516    pix = bytestream2_get_byte(&s->stream_ptr);
517
518    for (y = 0; y < 8; y++) {
519        memset(s->pixel_ptr, pix, 8);
520        s->pixel_ptr += s->stride;
521    }
522
523    /* report success */
524    return 0;
525}
526
527static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s, AVFrame *frame)
528{
529    int x, y;
530    unsigned char sample[2];
531
532    /* dithered encoding */
533    sample[0] = bytestream2_get_byte(&s->stream_ptr);
534    sample[1] = bytestream2_get_byte(&s->stream_ptr);
535
536    for (y = 0; y < 8; y++) {
537        for (x = 0; x < 8; x += 2) {
538            *s->pixel_ptr++ = sample[  y & 1 ];
539            *s->pixel_ptr++ = sample[!(y & 1)];
540        }
541        s->pixel_ptr += s->line_inc;
542    }
543
544    /* report success */
545    return 0;
546}
547
548static int ipvideo_decode_block_opcode_0x6_16(IpvideoContext *s, AVFrame *frame)
549{
550    signed char x, y;
551
552    /* copy a block from the second last frame using an expanded range */
553    x = bytestream2_get_byte(&s->stream_ptr);
554    y = bytestream2_get_byte(&s->stream_ptr);
555
556    av_dlog(s->avctx, "motion bytes = %d, %d\n", x, y);
557    return copy_from(s, s->second_last_frame, frame, x, y);
558}
559
560static int ipvideo_decode_block_opcode_0x7_16(IpvideoContext *s, AVFrame *frame)
561{
562    int x, y;
563    uint16_t P[2];
564    unsigned int flags;
565    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
566
567    /* 2-color encoding */
568    P[0] = bytestream2_get_le16(&s->stream_ptr);
569    P[1] = bytestream2_get_le16(&s->stream_ptr);
570
571    if (!(P[0] & 0x8000)) {
572
573        for (y = 0; y < 8; y++) {
574            flags = bytestream2_get_byte(&s->stream_ptr) | 0x100;
575            for (; flags != 1; flags >>= 1)
576                *pixel_ptr++ = P[flags & 1];
577            pixel_ptr += s->line_inc;
578        }
579
580    } else {
581
582        flags = bytestream2_get_le16(&s->stream_ptr);
583        for (y = 0; y < 8; y += 2) {
584            for (x = 0; x < 8; x += 2, flags >>= 1) {
585                pixel_ptr[x                ] =
586                pixel_ptr[x + 1            ] =
587                pixel_ptr[x +     s->stride] =
588                pixel_ptr[x + 1 + s->stride] = P[flags & 1];
589            }
590            pixel_ptr += s->stride * 2;
591        }
592    }
593
594    return 0;
595}
596
597static int ipvideo_decode_block_opcode_0x8_16(IpvideoContext *s, AVFrame *frame)
598{
599    int x, y;
600    uint16_t P[4];
601    unsigned int flags = 0;
602    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
603
604    /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
605     * either top and bottom or left and right halves */
606    P[0] = bytestream2_get_le16(&s->stream_ptr);
607    P[1] = bytestream2_get_le16(&s->stream_ptr);
608
609    if (!(P[0] & 0x8000)) {
610
611        for (y = 0; y < 16; y++) {
612            // new values for each 4x4 block
613            if (!(y & 3)) {
614                if (y) {
615                    P[0] = bytestream2_get_le16(&s->stream_ptr);
616                    P[1] = bytestream2_get_le16(&s->stream_ptr);
617                }
618                flags = bytestream2_get_le16(&s->stream_ptr);
619            }
620
621            for (x = 0; x < 4; x++, flags >>= 1)
622                *pixel_ptr++ = P[flags & 1];
623            pixel_ptr += s->stride - 4;
624            // switch to right half
625            if (y == 7) pixel_ptr -= 8 * s->stride - 4;
626        }
627
628    } else {
629
630        flags = bytestream2_get_le32(&s->stream_ptr);
631        P[2]  = bytestream2_get_le16(&s->stream_ptr);
632        P[3]  = bytestream2_get_le16(&s->stream_ptr);
633
634        if (!(P[2] & 0x8000)) {
635
636            /* vertical split; left & right halves are 2-color encoded */
637
638            for (y = 0; y < 16; y++) {
639                for (x = 0; x < 4; x++, flags >>= 1)
640                    *pixel_ptr++ = P[flags & 1];
641                pixel_ptr += s->stride - 4;
642                // switch to right half
643                if (y == 7) {
644                    pixel_ptr -= 8 * s->stride - 4;
645                    P[0]  = P[2];
646                    P[1]  = P[3];
647                    flags = bytestream2_get_le32(&s->stream_ptr);
648                }
649            }
650
651        } else {
652
653            /* horizontal split; top & bottom halves are 2-color encoded */
654
655            for (y = 0; y < 8; y++) {
656                if (y == 4) {
657                    P[0]  = P[2];
658                    P[1]  = P[3];
659                    flags = bytestream2_get_le32(&s->stream_ptr);
660                }
661
662                for (x = 0; x < 8; x++, flags >>= 1)
663                    *pixel_ptr++ = P[flags & 1];
664                pixel_ptr += s->line_inc;
665            }
666        }
667    }
668
669    /* report success */
670    return 0;
671}
672
673static int ipvideo_decode_block_opcode_0x9_16(IpvideoContext *s, AVFrame *frame)
674{
675    int x, y;
676    uint16_t P[4];
677    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
678
679    /* 4-color encoding */
680    for (x = 0; x < 4; x++)
681        P[x] = bytestream2_get_le16(&s->stream_ptr);
682
683    if (!(P[0] & 0x8000)) {
684        if (!(P[2] & 0x8000)) {
685
686            /* 1 of 4 colors for each pixel */
687            for (y = 0; y < 8; y++) {
688                /* get the next set of 8 2-bit flags */
689                int flags = bytestream2_get_le16(&s->stream_ptr);
690                for (x = 0; x < 8; x++, flags >>= 2)
691                    *pixel_ptr++ = P[flags & 0x03];
692                pixel_ptr += s->line_inc;
693            }
694
695        } else {
696            uint32_t flags;
697
698            /* 1 of 4 colors for each 2x2 block */
699            flags = bytestream2_get_le32(&s->stream_ptr);
700
701            for (y = 0; y < 8; y += 2) {
702                for (x = 0; x < 8; x += 2, flags >>= 2) {
703                    pixel_ptr[x                ] =
704                    pixel_ptr[x + 1            ] =
705                    pixel_ptr[x +     s->stride] =
706                    pixel_ptr[x + 1 + s->stride] = P[flags & 0x03];
707                }
708                pixel_ptr += s->stride * 2;
709            }
710
711        }
712    } else {
713        uint64_t flags;
714
715        /* 1 of 4 colors for each 2x1 or 1x2 block */
716        flags = bytestream2_get_le64(&s->stream_ptr);
717        if (!(P[2] & 0x8000)) {
718            for (y = 0; y < 8; y++) {
719                for (x = 0; x < 8; x += 2, flags >>= 2) {
720                    pixel_ptr[x    ] =
721                    pixel_ptr[x + 1] = P[flags & 0x03];
722                }
723                pixel_ptr += s->stride;
724            }
725        } else {
726            for (y = 0; y < 8; y += 2) {
727                for (x = 0; x < 8; x++, flags >>= 2) {
728                    pixel_ptr[x            ] =
729                    pixel_ptr[x + s->stride] = P[flags & 0x03];
730                }
731                pixel_ptr += s->stride * 2;
732            }
733        }
734    }
735
736    /* report success */
737    return 0;
738}
739
740static int ipvideo_decode_block_opcode_0xA_16(IpvideoContext *s, AVFrame *frame)
741{
742    int x, y;
743    uint16_t P[8];
744    int flags = 0;
745    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
746
747    for (x = 0; x < 4; x++)
748        P[x] = bytestream2_get_le16(&s->stream_ptr);
749
750    /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
751     * either top and bottom or left and right halves */
752    if (!(P[0] & 0x8000)) {
753
754        /* 4-color encoding for each quadrant */
755        for (y = 0; y < 16; y++) {
756            // new values for each 4x4 block
757            if (!(y & 3)) {
758                if (y)
759                    for (x = 0; x < 4; x++)
760                        P[x] = bytestream2_get_le16(&s->stream_ptr);
761                flags = bytestream2_get_le32(&s->stream_ptr);
762            }
763
764            for (x = 0; x < 4; x++, flags >>= 2)
765                *pixel_ptr++ = P[flags & 0x03];
766
767            pixel_ptr += s->stride - 4;
768            // switch to right half
769            if (y == 7) pixel_ptr -= 8 * s->stride - 4;
770        }
771
772    } else {
773        // vertical split?
774        int vert;
775        uint64_t flags = bytestream2_get_le64(&s->stream_ptr);
776
777        for (x = 4; x < 8; x++)
778            P[x] = bytestream2_get_le16(&s->stream_ptr);
779        vert = !(P[4] & 0x8000);
780
781        /* 4-color encoding for either left and right or top and bottom
782         * halves */
783
784        for (y = 0; y < 16; y++) {
785            for (x = 0; x < 4; x++, flags >>= 2)
786                *pixel_ptr++ = P[flags & 0x03];
787
788            if (vert) {
789                pixel_ptr += s->stride - 4;
790                // switch to right half
791                if (y == 7) pixel_ptr -= 8 * s->stride - 4;
792            } else if (y & 1) pixel_ptr += s->line_inc;
793
794            // load values for second half
795            if (y == 7) {
796                memcpy(P, P + 4, 8);
797                flags = bytestream2_get_le64(&s->stream_ptr);
798            }
799        }
800    }
801
802    /* report success */
803    return 0;
804}
805
806static int ipvideo_decode_block_opcode_0xB_16(IpvideoContext *s, AVFrame *frame)
807{
808    int x, y;
809    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
810
811    /* 64-color encoding (each pixel in block is a different color) */
812    for (y = 0; y < 8; y++) {
813        for (x = 0; x < 8; x++)
814            pixel_ptr[x] = bytestream2_get_le16(&s->stream_ptr);
815        pixel_ptr  += s->stride;
816    }
817
818    /* report success */
819    return 0;
820}
821
822static int ipvideo_decode_block_opcode_0xC_16(IpvideoContext *s, AVFrame *frame)
823{
824    int x, y;
825    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
826
827    /* 16-color block encoding: each 2x2 block is a different color */
828    for (y = 0; y < 8; y += 2) {
829        for (x = 0; x < 8; x += 2) {
830            pixel_ptr[x                ] =
831            pixel_ptr[x + 1            ] =
832            pixel_ptr[x +     s->stride] =
833            pixel_ptr[x + 1 + s->stride] = bytestream2_get_le16(&s->stream_ptr);
834        }
835        pixel_ptr += s->stride * 2;
836    }
837
838    /* report success */
839    return 0;
840}
841
842static int ipvideo_decode_block_opcode_0xD_16(IpvideoContext *s, AVFrame *frame)
843{
844    int x, y;
845    uint16_t P[2];
846    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
847
848    /* 4-color block encoding: each 4x4 block is a different color */
849    for (y = 0; y < 8; y++) {
850        if (!(y & 3)) {
851            P[0] = bytestream2_get_le16(&s->stream_ptr);
852            P[1] = bytestream2_get_le16(&s->stream_ptr);
853        }
854        for (x = 0; x < 8; x++)
855            pixel_ptr[x] = P[x >> 2];
856        pixel_ptr += s->stride;
857    }
858
859    /* report success */
860    return 0;
861}
862
863static int ipvideo_decode_block_opcode_0xE_16(IpvideoContext *s, AVFrame *frame)
864{
865    int x, y;
866    uint16_t pix;
867    uint16_t *pixel_ptr = (uint16_t*)s->pixel_ptr;
868
869    /* 1-color encoding: the whole block is 1 solid color */
870    pix = bytestream2_get_le16(&s->stream_ptr);
871
872    for (y = 0; y < 8; y++) {
873        for (x = 0; x < 8; x++)
874            pixel_ptr[x] = pix;
875        pixel_ptr += s->stride;
876    }
877
878    /* report success */
879    return 0;
880}
881
882static int (* const ipvideo_decode_block[])(IpvideoContext *s, AVFrame *frame) = {
883    ipvideo_decode_block_opcode_0x0, ipvideo_decode_block_opcode_0x1,
884    ipvideo_decode_block_opcode_0x2, ipvideo_decode_block_opcode_0x3,
885    ipvideo_decode_block_opcode_0x4, ipvideo_decode_block_opcode_0x5,
886    ipvideo_decode_block_opcode_0x6, ipvideo_decode_block_opcode_0x7,
887    ipvideo_decode_block_opcode_0x8, ipvideo_decode_block_opcode_0x9,
888    ipvideo_decode_block_opcode_0xA, ipvideo_decode_block_opcode_0xB,
889    ipvideo_decode_block_opcode_0xC, ipvideo_decode_block_opcode_0xD,
890    ipvideo_decode_block_opcode_0xE, ipvideo_decode_block_opcode_0xF,
891};
892
893static int (* const ipvideo_decode_block16[])(IpvideoContext *s, AVFrame *frame) = {
894    ipvideo_decode_block_opcode_0x0,    ipvideo_decode_block_opcode_0x1,
895    ipvideo_decode_block_opcode_0x2,    ipvideo_decode_block_opcode_0x3,
896    ipvideo_decode_block_opcode_0x4,    ipvideo_decode_block_opcode_0x5,
897    ipvideo_decode_block_opcode_0x6_16, ipvideo_decode_block_opcode_0x7_16,
898    ipvideo_decode_block_opcode_0x8_16, ipvideo_decode_block_opcode_0x9_16,
899    ipvideo_decode_block_opcode_0xA_16, ipvideo_decode_block_opcode_0xB_16,
900    ipvideo_decode_block_opcode_0xC_16, ipvideo_decode_block_opcode_0xD_16,
901    ipvideo_decode_block_opcode_0xE_16, ipvideo_decode_block_opcode_0x1,
902};
903
904static void ipvideo_decode_opcodes(IpvideoContext *s, AVFrame *frame)
905{
906    int x, y;
907    unsigned char opcode;
908    int ret;
909    GetBitContext gb;
910
911    bytestream2_skip(&s->stream_ptr, 14); /* data starts 14 bytes in */
912    if (!s->is_16bpp) {
913        /* this is PAL8, so make the palette available */
914        memcpy(frame->data[1], s->pal, AVPALETTE_SIZE);
915
916        s->stride = frame->linesize[0];
917    } else {
918        s->stride = frame->linesize[0] >> 1;
919        s->mv_ptr = s->stream_ptr;
920        bytestream2_skip(&s->mv_ptr, bytestream2_get_le16(&s->stream_ptr));
921    }
922    s->line_inc = s->stride - 8;
923    s->upper_motion_limit_offset = (s->avctx->height - 8) * frame->linesize[0]
924                                  + (s->avctx->width - 8) * (1 + s->is_16bpp);
925
926    init_get_bits(&gb, s->decoding_map, s->decoding_map_size * 8);
927    for (y = 0; y < s->avctx->height; y += 8) {
928        for (x = 0; x < s->avctx->width; x += 8) {
929            opcode = get_bits(&gb, 4);
930
931            av_dlog(s->avctx,
932                    "  block @ (%3d, %3d): encoding 0x%X, data ptr offset %d\n",
933                    x, y, opcode, bytestream2_tell(&s->stream_ptr));
934
935            if (!s->is_16bpp) {
936                s->pixel_ptr = frame->data[0] + x
937                              + y*frame->linesize[0];
938                ret = ipvideo_decode_block[opcode](s, frame);
939            } else {
940                s->pixel_ptr = frame->data[0] + x*2
941                              + y*frame->linesize[0];
942                ret = ipvideo_decode_block16[opcode](s, frame);
943            }
944            if (ret != 0) {
945                av_log(s->avctx, AV_LOG_ERROR, "decode problem on frame %d, @ block (%d, %d)\n",
946                       s->avctx->frame_number, x, y);
947                return;
948            }
949        }
950    }
951    if (bytestream2_get_bytes_left(&s->stream_ptr) > 1) {
952        av_log(s->avctx, AV_LOG_ERROR,
953               "decode finished with %d bytes left over\n",
954               bytestream2_get_bytes_left(&s->stream_ptr));
955    }
956}
957
958static av_cold int ipvideo_decode_init(AVCodecContext *avctx)
959{
960    IpvideoContext *s = avctx->priv_data;
961
962    s->avctx = avctx;
963
964    s->is_16bpp = avctx->bits_per_coded_sample == 16;
965    avctx->pix_fmt = s->is_16bpp ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_PAL8;
966
967    ff_hpeldsp_init(&s->hdsp, avctx->flags);
968
969    s->last_frame        = av_frame_alloc();
970    s->second_last_frame = av_frame_alloc();
971    if (!s->last_frame || !s->second_last_frame) {
972        av_frame_free(&s->last_frame);
973        av_frame_free(&s->second_last_frame);
974        return AVERROR(ENOMEM);
975    }
976
977    return 0;
978}
979
980static int ipvideo_decode_frame(AVCodecContext *avctx,
981                                void *data, int *got_frame,
982                                AVPacket *avpkt)
983{
984    const uint8_t *buf = avpkt->data;
985    int buf_size = avpkt->size;
986    IpvideoContext *s = avctx->priv_data;
987    AVFrame *frame = data;
988    int ret;
989
990    /* decoding map contains 4 bits of information per 8x8 block */
991    s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
992
993    /* compressed buffer needs to be large enough to at least hold an entire
994     * decoding map */
995    if (buf_size < s->decoding_map_size)
996        return buf_size;
997
998    if (av_packet_get_side_data(avpkt, AV_PKT_DATA_PARAM_CHANGE, NULL)) {
999        av_frame_unref(s->last_frame);
1000        av_frame_unref(s->second_last_frame);
1001    }
1002
1003    s->decoding_map = buf;
1004    bytestream2_init(&s->stream_ptr, buf + s->decoding_map_size,
1005                     buf_size - s->decoding_map_size);
1006
1007    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
1008        return ret;
1009
1010    if (!s->is_16bpp) {
1011        const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
1012        if (pal) {
1013            frame->palette_has_changed = 1;
1014            memcpy(s->pal, pal, AVPALETTE_SIZE);
1015        }
1016    }
1017
1018    ipvideo_decode_opcodes(s, frame);
1019
1020    *got_frame = 1;
1021
1022    /* shuffle frames */
1023    av_frame_unref(s->second_last_frame);
1024    FFSWAP(AVFrame*, s->second_last_frame, s->last_frame);
1025    if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
1026        return ret;
1027
1028    /* report that the buffer was completely consumed */
1029    return buf_size;
1030}
1031
1032static av_cold int ipvideo_decode_end(AVCodecContext *avctx)
1033{
1034    IpvideoContext *s = avctx->priv_data;
1035
1036    av_frame_free(&s->last_frame);
1037    av_frame_free(&s->second_last_frame);
1038
1039    return 0;
1040}
1041
1042AVCodec ff_interplay_video_decoder = {
1043    .name           = "interplayvideo",
1044    .long_name      = NULL_IF_CONFIG_SMALL("Interplay MVE video"),
1045    .type           = AVMEDIA_TYPE_VIDEO,
1046    .id             = AV_CODEC_ID_INTERPLAY_VIDEO,
1047    .priv_data_size = sizeof(IpvideoContext),
1048    .init           = ipvideo_decode_init,
1049    .close          = ipvideo_decode_end,
1050    .decode         = ipvideo_decode_frame,
1051    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
1052};
1053