summaryrefslogtreecommitdiff
path: root/libavcodec/lcldec.c
blob: d2482138abedb8b6937defb5590faae06633385a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
/*
 * LCL (LossLess Codec Library) Codec
 * Copyright (c) 2002-2004 Roberto Togni
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * LCL (LossLess Codec Library) Video Codec
 * Decoder for MSZH and ZLIB codecs
 * Experimental encoder for ZLIB RGB24
 *
 * Fourcc: MSZH, ZLIB
 *
 * Original Win32 dll:
 * Ver2.23 By Kenji Oshima 2000.09.20
 * avimszh.dll, avizlib.dll
 *
 * A description of the decoding algorithm can be found here:
 *   http://www.pcisys.net/~melanson/codecs
 *
 * Supports: BGR24 (RGB 24bpp)
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include "avcodec.h"
#include "bytestream.h"
#include "lcl.h"
#include "libavutil/lzo.h"

#if CONFIG_ZLIB_DECODER
#include <zlib.h>
#endif

/*
 * Decoder context
 */
typedef struct LclDecContext {
    AVFrame pic;

    // Image type
    int imgtype;
    // Compression type
    int compression;
    // Flags
    int flags;
    // Decompressed data size
    unsigned int decomp_size;
    // Decompression buffer
    unsigned char* decomp_buf;
#if CONFIG_ZLIB_DECODER
    z_stream zstream;
#endif
} LclDecContext;


/**
 * @param srcptr compressed source buffer, must be padded with at least 5 extra bytes
 * @param destptr must be padded sufficiently for av_memcpy_backptr
 */
static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsigned char * destptr, unsigned int destsize)
{
    unsigned char *destptr_bak = destptr;
    unsigned char *destptr_end = destptr + destsize;
    const unsigned char *srcptr_end = srcptr + srclen;
    unsigned mask = *srcptr++;
    unsigned maskbit = 0x80;

    while (srcptr < srcptr_end && destptr < destptr_end) {
        if (!(mask & maskbit)) {
            memcpy(destptr, srcptr, 4);
            destptr += 4;
            srcptr += 4;
        } else {
            unsigned ofs = bytestream_get_le16(&srcptr);
            unsigned cnt = (ofs >> 11) + 1;
            ofs &= 0x7ff;
            ofs = FFMIN(ofs, destptr - destptr_bak);
            cnt *= 4;
            cnt = FFMIN(cnt, destptr_end - destptr);
            av_memcpy_backptr(destptr, ofs, cnt);
            destptr += cnt;
        }
        maskbit >>= 1;
        if (!maskbit) {
            mask = *srcptr++;
            while (!mask) {
                if (destptr_end - destptr < 32 || srcptr_end - srcptr < 32) break;
                memcpy(destptr, srcptr, 32);
                destptr += 32;
                srcptr += 32;
                mask = *srcptr++;
            }
            maskbit = 0x80;
        }
    }

    return destptr - destptr_bak;
}


#if CONFIG_ZLIB_DECODER
/**
 * @brief decompress a zlib-compressed data block into decomp_buf
 * @param src compressed input buffer
 * @param src_len data length in input buffer
 * @param offset offset in decomp_buf
 * @param expected expected decompressed length
 */
static int zlib_decomp(AVCodecContext *avctx, const uint8_t *src, int src_len, int offset, int expected)
{
    LclDecContext *c = avctx->priv_data;
    int zret = inflateReset(&c->zstream);
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
        return -1;
    }
    c->zstream.next_in = src;
    c->zstream.avail_in = src_len;
    c->zstream.next_out = c->decomp_buf + offset;
    c->zstream.avail_out = c->decomp_size - offset;
    zret = inflate(&c->zstream, Z_FINISH);
    if (zret != Z_OK && zret != Z_STREAM_END) {
        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
        return -1;
    }
    if (expected != (unsigned int)c->zstream.total_out) {
        av_log(avctx, AV_LOG_ERROR, "Decoded size differs (%d != %lu)\n",
               expected, c->zstream.total_out);
        return -1;
    }
    return c->zstream.total_out;
}
#endif


/*
 *
 * Decode a frame
 *
 */
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    LclDecContext * const c = avctx->priv_data;
    unsigned char *encoded = (unsigned char *)buf;
    unsigned int pixel_ptr;
    int row, col;
    unsigned char *outptr;
    uint8_t *y_out, *u_out, *v_out;
    unsigned int width = avctx->width; // Real image width
    unsigned int height = avctx->height; // Real image height
    unsigned int mszh_dlen;
    unsigned char yq, y1q, uq, vq;
    int uqvq;
    unsigned int mthread_inlen, mthread_outlen;
    unsigned int len = buf_size;

    if(c->pic.data[0])
        avctx->release_buffer(avctx, &c->pic);

    c->pic.reference = 0;
    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
    if(avctx->get_buffer(avctx, &c->pic) < 0){
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    outptr = c->pic.data[0]; // Output image pointer

    /* Decompress frame */
    switch (avctx->codec_id) {
    case AV_CODEC_ID_MSZH:
        switch (c->compression) {
        case COMP_MSZH:
            if (c->flags & FLAG_MULTITHREAD) {
                mthread_inlen = AV_RL32(encoded);
                mthread_inlen = FFMIN(mthread_inlen, len - 8);
                mthread_outlen = AV_RL32(encoded+4);
                mthread_outlen = FFMIN(mthread_outlen, c->decomp_size);
                mszh_dlen = mszh_decomp(encoded + 8, mthread_inlen, c->decomp_buf, c->decomp_size);
                if (mthread_outlen != mszh_dlen) {
                    av_log(avctx, AV_LOG_ERROR, "Mthread1 decoded size differs (%d != %d)\n",
                           mthread_outlen, mszh_dlen);
                    return -1;
                }
                mszh_dlen = mszh_decomp(encoded + 8 + mthread_inlen, len - 8 - mthread_inlen,
                                        c->decomp_buf + mthread_outlen, c->decomp_size - mthread_outlen);
                if (mthread_outlen != mszh_dlen) {
                    av_log(avctx, AV_LOG_ERROR, "Mthread2 decoded size differs (%d != %d)\n",
                           mthread_outlen, mszh_dlen);
                    return -1;
                }
                encoded = c->decomp_buf;
                len = c->decomp_size;
            } else {
                mszh_dlen = mszh_decomp(encoded, len, c->decomp_buf, c->decomp_size);
                if (c->decomp_size != mszh_dlen) {
                    av_log(avctx, AV_LOG_ERROR, "Decoded size differs (%d != %d)\n",
                           c->decomp_size, mszh_dlen);
                    return -1;
                }
                encoded = c->decomp_buf;
                len = mszh_dlen;
            }
            break;
        case COMP_MSZH_NOCOMP: {
            int bppx2;
            switch (c->imgtype) {
            case IMGTYPE_YUV111:
            case IMGTYPE_RGB24:
                bppx2 = 6;
                break;
            case IMGTYPE_YUV422:
            case IMGTYPE_YUV211:
                bppx2 = 4;
                break;
            case IMGTYPE_YUV411:
            case IMGTYPE_YUV420:
                bppx2 = 3;
                break;
            default:
                bppx2 = 0; // will error out below
                break;
            }
            if (len < ((width * height * bppx2) >> 1))
                return AVERROR_INVALIDDATA;
            break;
        }
        default:
            av_log(avctx, AV_LOG_ERROR, "BUG! Unknown MSZH compression in frame decoder.\n");
            return -1;
        }
        break;
#if CONFIG_ZLIB_DECODER
    case AV_CODEC_ID_ZLIB:
        /* Using the original dll with normal compression (-1) and RGB format
         * gives a file with ZLIB fourcc, but frame is really uncompressed.
         * To be sure that's true check also frame size */
        if (c->compression == COMP_ZLIB_NORMAL && c->imgtype == IMGTYPE_RGB24 &&
            len == width * height * 3) {
            if (c->flags & FLAG_PNGFILTER) {
                memcpy(c->decomp_buf, encoded, len);
                encoded = c->decomp_buf;
            } else {
                break;
            }
        } else if (c->flags & FLAG_MULTITHREAD) {
            int ret;
            mthread_inlen = AV_RL32(encoded);
            mthread_inlen = FFMIN(mthread_inlen, len - 8);
            mthread_outlen = AV_RL32(encoded+4);
            mthread_outlen = FFMIN(mthread_outlen, c->decomp_size);
            ret = zlib_decomp(avctx, encoded + 8, mthread_inlen, 0, mthread_outlen);
            if (ret < 0) return ret;
            ret = zlib_decomp(avctx, encoded + 8 + mthread_inlen, len - 8 - mthread_inlen,
                              mthread_outlen, mthread_outlen);
            if (ret < 0) return ret;
        } else {
            int ret = zlib_decomp(avctx, encoded, len, 0, c->decomp_size);
            if (ret < 0) return ret;
        }
        encoded = c->decomp_buf;
        len = c->decomp_size;
        break;
#endif
    default:
        av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in frame decoder compression switch.\n");
        return -1;
    }


    /* Apply PNG filter */
    if (avctx->codec_id == AV_CODEC_ID_ZLIB && (c->flags & FLAG_PNGFILTER)) {
        switch (c->imgtype) {
        case IMGTYPE_YUV111:
        case IMGTYPE_RGB24:
            for (row = 0; row < height; row++) {
                pixel_ptr = row * width * 3;
                yq = encoded[pixel_ptr++];
                uqvq = AV_RL16(encoded+pixel_ptr);
                pixel_ptr += 2;
                for (col = 1; col < width; col++) {
                    encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                    uqvq -= AV_RL16(encoded+pixel_ptr+1);
                    AV_WL16(encoded+pixel_ptr+1, uqvq);
                    pixel_ptr += 3;
                }
            }
            break;
        case IMGTYPE_YUV422:
            for (row = 0; row < height; row++) {
                pixel_ptr = row * width * 2;
                yq = uq = vq =0;
                for (col = 0; col < width/4; col++) {
                    encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                    encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                    encoded[pixel_ptr+2] = yq -= encoded[pixel_ptr+2];
                    encoded[pixel_ptr+3] = yq -= encoded[pixel_ptr+3];
                    encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                    encoded[pixel_ptr+5] = uq -= encoded[pixel_ptr+5];
                    encoded[pixel_ptr+6] = vq -= encoded[pixel_ptr+6];
                    encoded[pixel_ptr+7] = vq -= encoded[pixel_ptr+7];
                    pixel_ptr += 8;
                }
            }
            break;
        case IMGTYPE_YUV411:
            for (row = 0; row < height; row++) {
                pixel_ptr = row * width / 2 * 3;
                yq = uq = vq =0;
                for (col = 0; col < width/4; col++) {
                    encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                    encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                    encoded[pixel_ptr+2] = yq -= encoded[pixel_ptr+2];
                    encoded[pixel_ptr+3] = yq -= encoded[pixel_ptr+3];
                    encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                    encoded[pixel_ptr+5] = vq -= encoded[pixel_ptr+5];
                    pixel_ptr += 6;
                }
            }
            break;
        case IMGTYPE_YUV211:
            for (row = 0; row < height; row++) {
                pixel_ptr = row * width * 2;
                yq = uq = vq =0;
                for (col = 0; col < width/2; col++) {
                    encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                    encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                    encoded[pixel_ptr+2] = uq -= encoded[pixel_ptr+2];
                    encoded[pixel_ptr+3] = vq -= encoded[pixel_ptr+3];
                    pixel_ptr += 4;
                }
            }
            break;
        case IMGTYPE_YUV420:
            for (row = 0; row < height/2; row++) {
                pixel_ptr = row * width * 3;
                yq = y1q = uq = vq =0;
                for (col = 0; col < width/2; col++) {
                    encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                    encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                    encoded[pixel_ptr+2] = y1q -= encoded[pixel_ptr+2];
                    encoded[pixel_ptr+3] = y1q -= encoded[pixel_ptr+3];
                    encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                    encoded[pixel_ptr+5] = vq -= encoded[pixel_ptr+5];
                    pixel_ptr += 6;
                }
            }
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "BUG! Unknown imagetype in pngfilter switch.\n");
            return -1;
        }
    }

    /* Convert colorspace */
    y_out = c->pic.data[0] + (height - 1) * c->pic.linesize[0];
    u_out = c->pic.data[1] + (height - 1) * c->pic.linesize[1];
    v_out = c->pic.data[2] + (height - 1) * c->pic.linesize[2];
    switch (c->imgtype) {
    case IMGTYPE_YUV111:
        for (row = 0; row < height; row++) {
            for (col = 0; col < width; col++) {
                y_out[col] = *encoded++;
                u_out[col] = *encoded++ + 128;
                v_out[col] = *encoded++ + 128;
            }
            y_out -= c->pic.linesize[0];
            u_out -= c->pic.linesize[1];
            v_out -= c->pic.linesize[2];
        }
        break;
    case IMGTYPE_YUV422:
        for (row = 0; row < height; row++) {
            for (col = 0; col < width - 3; col += 4) {
                memcpy(y_out + col, encoded, 4);
                encoded += 4;
                u_out[ col >> 1     ] = *encoded++ + 128;
                u_out[(col >> 1) + 1] = *encoded++ + 128;
                v_out[ col >> 1     ] = *encoded++ + 128;
                v_out[(col >> 1) + 1] = *encoded++ + 128;
            }
            y_out -= c->pic.linesize[0];
            u_out -= c->pic.linesize[1];
            v_out -= c->pic.linesize[2];
        }
        break;
    case IMGTYPE_RGB24:
        for (row = height - 1; row >= 0; row--) {
            pixel_ptr = row * c->pic.linesize[0];
            memcpy(outptr + pixel_ptr, encoded, 3 * width);
            encoded += 3 * width;
        }
        break;
    case IMGTYPE_YUV411:
        for (row = 0; row < height; row++) {
            for (col = 0; col < width - 3; col += 4) {
                memcpy(y_out + col, encoded, 4);
                encoded += 4;
                u_out[col >> 2] = *encoded++ + 128;
                v_out[col >> 2] = *encoded++ + 128;
            }
            y_out -= c->pic.linesize[0];
            u_out -= c->pic.linesize[1];
            v_out -= c->pic.linesize[2];
        }
        break;
    case IMGTYPE_YUV211:
        for (row = 0; row < height; row++) {
            for (col = 0; col < width - 1; col += 2) {
                memcpy(y_out + col, encoded, 2);
                encoded += 2;
                u_out[col >> 1] = *encoded++ + 128;
                v_out[col >> 1] = *encoded++ + 128;
            }
            y_out -= c->pic.linesize[0];
            u_out -= c->pic.linesize[1];
            v_out -= c->pic.linesize[2];
        }
        break;
    case IMGTYPE_YUV420:
        u_out = c->pic.data[1] + ((height >> 1) - 1) * c->pic.linesize[1];
        v_out = c->pic.data[2] + ((height >> 1) - 1) * c->pic.linesize[2];
        for (row = 0; row < height - 1; row += 2) {
            for (col = 0; col < width - 1; col += 2) {
                memcpy(y_out + col, encoded, 2);
                encoded += 2;
                memcpy(y_out + col - c->pic.linesize[0], encoded, 2);
                encoded += 2;
                u_out[col >> 1] = *encoded++ + 128;
                v_out[col >> 1] = *encoded++ + 128;
            }
            y_out -= c->pic.linesize[0] << 1;
            u_out -= c->pic.linesize[1];
            v_out -= c->pic.linesize[2];
        }
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "BUG! Unknown imagetype in image decoder.\n");
        return -1;
    }

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = c->pic;

    /* always report that the buffer was completely consumed */
    return buf_size;
}

/*
 *
 * Init lcl decoder
 *
 */
static av_cold int decode_init(AVCodecContext *avctx)
{
    LclDecContext * const c = avctx->priv_data;
    unsigned int basesize = avctx->width * avctx->height;
    unsigned int max_basesize = FFALIGN(avctx->width, 4) * FFALIGN(avctx->height, 4) + AV_LZO_OUTPUT_PADDING;
    unsigned int max_decomp_size;

    if (avctx->extradata_size < 8) {
        av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
        return AVERROR_INVALIDDATA;
    }

    /* Check codec type */
    if ((avctx->codec_id == AV_CODEC_ID_MSZH  && avctx->extradata[7] != CODEC_MSZH) ||
        (avctx->codec_id == AV_CODEC_ID_ZLIB  && avctx->extradata[7] != CODEC_ZLIB)) {
        av_log(avctx, AV_LOG_ERROR, "Codec id and codec type mismatch. This should not happen.\n");
    }

    /* Detect image type */
    switch (c->imgtype = avctx->extradata[4]) {
    case IMGTYPE_YUV111:
        c->decomp_size = basesize * 3;
        max_decomp_size = max_basesize * 3;
        avctx->pix_fmt = PIX_FMT_YUV444P;
        av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 1:1:1.\n");
        break;
    case IMGTYPE_YUV422:
        c->decomp_size = basesize * 2;
        max_decomp_size = max_basesize * 2;
        avctx->pix_fmt = PIX_FMT_YUV422P;
        av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:2:2.\n");
        break;
    case IMGTYPE_RGB24:
        c->decomp_size = basesize * 3;
        max_decomp_size = max_basesize * 3;
        avctx->pix_fmt = PIX_FMT_BGR24;
        av_log(avctx, AV_LOG_DEBUG, "Image type is RGB 24.\n");
        break;
    case IMGTYPE_YUV411:
        c->decomp_size = basesize / 2 * 3;
        max_decomp_size = max_basesize / 2 * 3;
        avctx->pix_fmt = PIX_FMT_YUV411P;
        av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:1:1.\n");
        break;
    case IMGTYPE_YUV211:
        c->decomp_size = basesize * 2;
        max_decomp_size = max_basesize * 2;
        avctx->pix_fmt = PIX_FMT_YUV422P;
        av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 2:1:1.\n");
        break;
    case IMGTYPE_YUV420:
        c->decomp_size = basesize / 2 * 3;
        max_decomp_size = max_basesize / 2 * 3;
        avctx->pix_fmt = PIX_FMT_YUV420P;
        av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:2:0.\n");
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Unsupported image format %d.\n", c->imgtype);
        return AVERROR_INVALIDDATA;
    }

    /* Detect compression method */
    c->compression = (int8_t)avctx->extradata[5];
    switch (avctx->codec_id) {
    case AV_CODEC_ID_MSZH:
        switch (c->compression) {
        case COMP_MSZH:
            av_log(avctx, AV_LOG_DEBUG, "Compression enabled.\n");
            break;
        case COMP_MSZH_NOCOMP:
            c->decomp_size = 0;
            av_log(avctx, AV_LOG_DEBUG, "No compression.\n");
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unsupported compression format for MSZH (%d).\n", c->compression);
            return AVERROR_INVALIDDATA;
        }
        break;
#if CONFIG_ZLIB_DECODER
    case AV_CODEC_ID_ZLIB:
        switch (c->compression) {
        case COMP_ZLIB_HISPEED:
            av_log(avctx, AV_LOG_DEBUG, "High speed compression.\n");
            break;
        case COMP_ZLIB_HICOMP:
            av_log(avctx, AV_LOG_DEBUG, "High compression.\n");
            break;
        case COMP_ZLIB_NORMAL:
            av_log(avctx, AV_LOG_DEBUG, "Normal compression.\n");
            break;
        default:
            if (c->compression < Z_NO_COMPRESSION || c->compression > Z_BEST_COMPRESSION) {
                av_log(avctx, AV_LOG_ERROR, "Unsupported compression level for ZLIB: (%d).\n", c->compression);
                return AVERROR_INVALIDDATA;
            }
            av_log(avctx, AV_LOG_DEBUG, "Compression level for ZLIB: (%d).\n", c->compression);
        }
        break;
#endif
    default:
        av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in compression switch.\n");
        return AVERROR_INVALIDDATA;
    }

    /* Allocate decompression buffer */
    if (c->decomp_size) {
        if ((c->decomp_buf = av_malloc(max_decomp_size)) == NULL) {
            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
            return AVERROR(ENOMEM);
        }
    }

    /* Detect flags */
    c->flags = avctx->extradata[6];
    if (c->flags & FLAG_MULTITHREAD)
        av_log(avctx, AV_LOG_DEBUG, "Multithread encoder flag set.\n");
    if (c->flags & FLAG_NULLFRAME)
        av_log(avctx, AV_LOG_DEBUG, "Nullframe insertion flag set.\n");
    if (avctx->codec_id == AV_CODEC_ID_ZLIB && (c->flags & FLAG_PNGFILTER))
        av_log(avctx, AV_LOG_DEBUG, "PNG filter flag set.\n");
    if (c->flags & FLAGMASK_UNUSED)
        av_log(avctx, AV_LOG_ERROR, "Unknown flag set (%d).\n", c->flags);

    /* If needed init zlib */
#if CONFIG_ZLIB_DECODER
    if (avctx->codec_id == AV_CODEC_ID_ZLIB) {
        int zret;
        c->zstream.zalloc = Z_NULL;
        c->zstream.zfree = Z_NULL;
        c->zstream.opaque = Z_NULL;
        zret = inflateInit(&c->zstream);
        if (zret != Z_OK) {
            av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
            av_freep(&c->decomp_buf);
            return AVERROR_UNKNOWN;
        }
    }
#endif

    return 0;
}

/*
 *
 * Uninit lcl decoder
 *
 */
static av_cold int decode_end(AVCodecContext *avctx)
{
    LclDecContext * const c = avctx->priv_data;

    av_freep(&c->decomp_buf);
    if (c->pic.data[0])
        avctx->release_buffer(avctx, &c->pic);
#if CONFIG_ZLIB_DECODER
    if (avctx->codec_id == AV_CODEC_ID_ZLIB)
        inflateEnd(&c->zstream);
#endif

    return 0;
}

#if CONFIG_MSZH_DECODER
AVCodec ff_mszh_decoder = {
    .name           = "mszh",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_MSZH,
    .priv_data_size = sizeof(LclDecContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) MSZH"),
};
#endif

#if CONFIG_ZLIB_DECODER
AVCodec ff_zlib_decoder = {
    .name           = "zlib",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_ZLIB,
    .priv_data_size = sizeof(LclDecContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
};
#endif