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1 /*
2  * Smacker decoder
3  * Copyright (c) 2006 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Smacker decoder
25  */
26 
27 /*
28  * Based on http://wiki.multimedia.cx/index.php?title=Smacker
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 
34 #include "libavutil/channel_layout.h"
35 
36 #define BITSTREAM_READER_LE
37 #include "avcodec.h"
38 #include "bytestream.h"
39 #include "get_bits.h"
40 #include "internal.h"
41 #include "mathops.h"
42 
43 #define SMKTREE_BITS 9
44 #define SMK_NODE 0x80000000
45 
46 #define SMKTREE_DECODE_MAX_RECURSION 32
47 #define SMKTREE_DECODE_BIG_MAX_RECURSION 500
48 
49 typedef struct SmackVContext {
50     AVCodecContext *avctx;
51     AVFrame *pic;
52 
53     int *mmap_tbl, *mclr_tbl, *full_tbl, *type_tbl;
54     int mmap_last[3], mclr_last[3], full_last[3], type_last[3];
55 } SmackVContext;
56 
57 /**
58  * Context used for code reconstructing
59  */
60 typedef struct HuffContext {
61     int length;
62     int maxlength;
63     int current;
64     uint32_t *bits;
65     int *lengths;
66     int *values;
67 } HuffContext;
68 
69 /* common parameters used for decode_bigtree */
70 typedef struct DBCtx {
71     VLC *v1, *v2;
72     int *recode1, *recode2;
73     int escapes[3];
74     int *last;
75     int lcur;
76 } DBCtx;
77 
78 /* possible runs of blocks */
79 static const int block_runs[64] = {
80       1,    2,    3,    4,    5,    6,    7,    8,
81       9,   10,   11,   12,   13,   14,   15,   16,
82      17,   18,   19,   20,   21,   22,   23,   24,
83      25,   26,   27,   28,   29,   30,   31,   32,
84      33,   34,   35,   36,   37,   38,   39,   40,
85      41,   42,   43,   44,   45,   46,   47,   48,
86      49,   50,   51,   52,   53,   54,   55,   56,
87      57,   58,   59,  128,  256,  512, 1024, 2048 };
88 
89 enum SmkBlockTypes {
90     SMK_BLK_MONO = 0,
91     SMK_BLK_FULL = 1,
92     SMK_BLK_SKIP = 2,
93     SMK_BLK_FILL = 3 };
94 
95 /**
96  * Decode local frame tree
97  */
smacker_decode_tree(GetBitContext * gb,HuffContext * hc,uint32_t prefix,int length)98 static int smacker_decode_tree(GetBitContext *gb, HuffContext *hc, uint32_t prefix, int length)
99 {
100     if (length > SMKTREE_DECODE_MAX_RECURSION || length > 3 * SMKTREE_BITS) {
101         av_log(NULL, AV_LOG_ERROR, "Maximum tree recursion level exceeded.\n");
102         return AVERROR_INVALIDDATA;
103     }
104 
105     if(!get_bits1(gb)){ //Leaf
106         if(hc->current >= hc->length){
107             av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
108             return AVERROR_INVALIDDATA;
109         }
110         if(length){
111             hc->bits[hc->current] = prefix;
112             hc->lengths[hc->current] = length;
113         } else {
114             hc->bits[hc->current] = 0;
115             hc->lengths[hc->current] = 0;
116         }
117         hc->values[hc->current] = get_bits(gb, 8);
118         hc->current++;
119         if(hc->maxlength < length)
120             hc->maxlength = length;
121         return 0;
122     } else { //Node
123         int r;
124         length++;
125         r = smacker_decode_tree(gb, hc, prefix, length);
126         if(r)
127             return r;
128         return smacker_decode_tree(gb, hc, prefix | (1 << (length - 1)), length);
129     }
130 }
131 
132 /**
133  * Decode header tree
134  */
smacker_decode_bigtree(GetBitContext * gb,HuffContext * hc,DBCtx * ctx,int length)135 static int smacker_decode_bigtree(GetBitContext *gb, HuffContext *hc,
136                                   DBCtx *ctx, int length)
137 {
138     // Larger length can cause segmentation faults due to too deep recursion.
139     if (length > SMKTREE_DECODE_BIG_MAX_RECURSION) {
140         av_log(NULL, AV_LOG_ERROR, "Maximum bigtree recursion level exceeded.\n");
141         return AVERROR_INVALIDDATA;
142     }
143 
144     if (hc->current + 1 >= hc->length) {
145         av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
146         return AVERROR_INVALIDDATA;
147     }
148     if(!get_bits1(gb)){ //Leaf
149         int val, i1, i2;
150         i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3) : 0;
151         i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3) : 0;
152         if (i1 < 0 || i2 < 0)
153             return AVERROR_INVALIDDATA;
154         val = ctx->recode1[i1] | (ctx->recode2[i2] << 8);
155         if(val == ctx->escapes[0]) {
156             ctx->last[0] = hc->current;
157             val = 0;
158         } else if(val == ctx->escapes[1]) {
159             ctx->last[1] = hc->current;
160             val = 0;
161         } else if(val == ctx->escapes[2]) {
162             ctx->last[2] = hc->current;
163             val = 0;
164         }
165 
166         hc->values[hc->current++] = val;
167         return 1;
168     } else { //Node
169         int r = 0, r_new, t;
170 
171         t = hc->current++;
172         r = smacker_decode_bigtree(gb, hc, ctx, length + 1);
173         if(r < 0)
174             return r;
175         hc->values[t] = SMK_NODE | r;
176         r++;
177         r_new = smacker_decode_bigtree(gb, hc, ctx, length + 1);
178         if (r_new < 0)
179             return r_new;
180         return r + r_new;
181     }
182 }
183 
184 /**
185  * Store large tree as FFmpeg's vlc codes
186  */
smacker_decode_header_tree(SmackVContext * smk,GetBitContext * gb,int ** recodes,int * last,int size)187 static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int **recodes, int *last, int size)
188 {
189     int res;
190     HuffContext huff;
191     HuffContext tmp1, tmp2;
192     VLC vlc[2] = { { 0 } };
193     int escapes[3];
194     DBCtx ctx;
195     int err = 0;
196 
197     if(size >= UINT_MAX>>4){ // (((size + 3) >> 2) + 3) << 2 must not overflow
198         av_log(smk->avctx, AV_LOG_ERROR, "size too large\n");
199         return AVERROR_INVALIDDATA;
200     }
201 
202     tmp1.length = 256;
203     tmp1.maxlength = 0;
204     tmp1.current = 0;
205     tmp1.bits = av_mallocz(256 * 4);
206     tmp1.lengths = av_mallocz(256 * sizeof(int));
207     tmp1.values = av_mallocz(256 * sizeof(int));
208 
209     tmp2.length = 256;
210     tmp2.maxlength = 0;
211     tmp2.current = 0;
212     tmp2.bits = av_mallocz(256 * 4);
213     tmp2.lengths = av_mallocz(256 * sizeof(int));
214     tmp2.values = av_mallocz(256 * sizeof(int));
215     if (!tmp1.bits || !tmp1.lengths || !tmp1.values ||
216         !tmp2.bits || !tmp2.lengths || !tmp2.values) {
217         err = AVERROR(ENOMEM);
218         goto error;
219     }
220 
221     if(get_bits1(gb)) {
222         res = smacker_decode_tree(gb, &tmp1, 0, 0);
223         if (res < 0) {
224             err = res;
225             goto error;
226         }
227         skip_bits1(gb);
228         if(tmp1.current > 1) {
229             res = init_vlc(&vlc[0], SMKTREE_BITS, tmp1.length,
230                         tmp1.lengths, sizeof(int), sizeof(int),
231                         tmp1.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
232             if(res < 0) {
233                 av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
234                 err = res;
235                 goto error;
236             }
237         }
238     }
239     if (!vlc[0].table) {
240         av_log(smk->avctx, AV_LOG_ERROR, "Skipping low bytes tree\n");
241     }
242     if(get_bits1(gb)){
243         res = smacker_decode_tree(gb, &tmp2, 0, 0);
244         if (res < 0) {
245             err = res;
246             goto error;
247         }
248         skip_bits1(gb);
249         if(tmp2.current > 1) {
250             res = init_vlc(&vlc[1], SMKTREE_BITS, tmp2.length,
251                         tmp2.lengths, sizeof(int), sizeof(int),
252                         tmp2.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
253             if(res < 0) {
254                 av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
255                 err = res;
256                 goto error;
257             }
258         }
259     }
260     if (!vlc[1].table) {
261         av_log(smk->avctx, AV_LOG_ERROR, "Skipping high bytes tree\n");
262     }
263 
264     escapes[0]  = get_bits(gb, 16);
265     escapes[1]  = get_bits(gb, 16);
266     escapes[2]  = get_bits(gb, 16);
267 
268     last[0] = last[1] = last[2] = -1;
269 
270     ctx.escapes[0] = escapes[0];
271     ctx.escapes[1] = escapes[1];
272     ctx.escapes[2] = escapes[2];
273     ctx.v1 = &vlc[0];
274     ctx.v2 = &vlc[1];
275     ctx.recode1 = tmp1.values;
276     ctx.recode2 = tmp2.values;
277     ctx.last = last;
278 
279     huff.length = ((size + 3) >> 2) + 4;
280     huff.maxlength = 0;
281     huff.current = 0;
282     huff.values = av_mallocz_array(huff.length, sizeof(int));
283     if (!huff.values) {
284         err = AVERROR(ENOMEM);
285         goto error;
286     }
287 
288     res = smacker_decode_bigtree(gb, &huff, &ctx, 0);
289     if (res < 0)
290         err = res;
291     skip_bits1(gb);
292     if(ctx.last[0] == -1) ctx.last[0] = huff.current++;
293     if(ctx.last[1] == -1) ctx.last[1] = huff.current++;
294     if(ctx.last[2] == -1) ctx.last[2] = huff.current++;
295     if (ctx.last[0] >= huff.length ||
296         ctx.last[1] >= huff.length ||
297         ctx.last[2] >= huff.length) {
298         av_log(smk->avctx, AV_LOG_ERROR, "Huffman codes out of range\n");
299         err = AVERROR_INVALIDDATA;
300     }
301 
302     *recodes = huff.values;
303 
304 error:
305     if(vlc[0].table)
306         ff_free_vlc(&vlc[0]);
307     if(vlc[1].table)
308         ff_free_vlc(&vlc[1]);
309     av_free(tmp1.bits);
310     av_free(tmp1.lengths);
311     av_free(tmp1.values);
312     av_free(tmp2.bits);
313     av_free(tmp2.lengths);
314     av_free(tmp2.values);
315 
316     return err;
317 }
318 
decode_header_trees(SmackVContext * smk)319 static int decode_header_trees(SmackVContext *smk) {
320     GetBitContext gb;
321     int mmap_size, mclr_size, full_size, type_size, ret;
322     int skip = 0;
323 
324     mmap_size = AV_RL32(smk->avctx->extradata);
325     mclr_size = AV_RL32(smk->avctx->extradata + 4);
326     full_size = AV_RL32(smk->avctx->extradata + 8);
327     type_size = AV_RL32(smk->avctx->extradata + 12);
328 
329     ret = init_get_bits8(&gb, smk->avctx->extradata + 16, smk->avctx->extradata_size - 16);
330     if (ret < 0)
331         return ret;
332 
333     if(!get_bits1(&gb)) {
334         skip ++;
335         av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");
336         smk->mmap_tbl = av_malloc(sizeof(int) * 2);
337         if (!smk->mmap_tbl)
338             return AVERROR(ENOMEM);
339         smk->mmap_tbl[0] = 0;
340         smk->mmap_last[0] = smk->mmap_last[1] = smk->mmap_last[2] = 1;
341     } else {
342         ret = smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size);
343         if (ret < 0)
344             return ret;
345     }
346     if(!get_bits1(&gb)) {
347         skip ++;
348         av_log(smk->avctx, AV_LOG_INFO, "Skipping MCLR tree\n");
349         smk->mclr_tbl = av_malloc(sizeof(int) * 2);
350         if (!smk->mclr_tbl)
351             return AVERROR(ENOMEM);
352         smk->mclr_tbl[0] = 0;
353         smk->mclr_last[0] = smk->mclr_last[1] = smk->mclr_last[2] = 1;
354     } else {
355         ret = smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size);
356         if (ret < 0)
357             return ret;
358     }
359     if(!get_bits1(&gb)) {
360         skip ++;
361         av_log(smk->avctx, AV_LOG_INFO, "Skipping FULL tree\n");
362         smk->full_tbl = av_malloc(sizeof(int) * 2);
363         if (!smk->full_tbl)
364             return AVERROR(ENOMEM);
365         smk->full_tbl[0] = 0;
366         smk->full_last[0] = smk->full_last[1] = smk->full_last[2] = 1;
367     } else {
368         ret = smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size);
369         if (ret < 0)
370             return ret;
371     }
372     if(!get_bits1(&gb)) {
373         skip ++;
374         av_log(smk->avctx, AV_LOG_INFO, "Skipping TYPE tree\n");
375         smk->type_tbl = av_malloc(sizeof(int) * 2);
376         if (!smk->type_tbl)
377             return AVERROR(ENOMEM);
378         smk->type_tbl[0] = 0;
379         smk->type_last[0] = smk->type_last[1] = smk->type_last[2] = 1;
380     } else {
381         ret = smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size);
382         if (ret < 0)
383             return ret;
384     }
385     if (skip == 4)
386         return AVERROR_INVALIDDATA;
387 
388     return 0;
389 }
390 
last_reset(int * recode,int * last)391 static av_always_inline void last_reset(int *recode, int *last) {
392     recode[last[0]] = recode[last[1]] = recode[last[2]] = 0;
393 }
394 
395 /* get code and update history */
smk_get_code(GetBitContext * gb,int * recode,int * last)396 static av_always_inline int smk_get_code(GetBitContext *gb, int *recode, int *last) {
397     register int *table = recode;
398     int v;
399 
400     while(*table & SMK_NODE) {
401         if (get_bits_left(gb) < 1)
402             return AVERROR_INVALIDDATA;
403         if(get_bits1(gb))
404             table += (*table) & (~SMK_NODE);
405         table++;
406     }
407     v = *table;
408 
409     if(v != recode[last[0]]) {
410         recode[last[2]] = recode[last[1]];
411         recode[last[1]] = recode[last[0]];
412         recode[last[0]] = v;
413     }
414     return v;
415 }
416 
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)417 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
418                         AVPacket *avpkt)
419 {
420     SmackVContext * const smk = avctx->priv_data;
421     uint8_t *out;
422     uint32_t *pal;
423     GetByteContext gb2;
424     GetBitContext gb;
425     int blocks, blk, bw, bh;
426     int i, ret;
427     int stride;
428     int flags;
429 
430     if (avpkt->size <= 769)
431         return AVERROR_INVALIDDATA;
432 
433     if ((ret = ff_reget_buffer(avctx, smk->pic, 0)) < 0)
434         return ret;
435 
436     /* make the palette available on the way out */
437     pal = (uint32_t*)smk->pic->data[1];
438     bytestream2_init(&gb2, avpkt->data, avpkt->size);
439     flags = bytestream2_get_byteu(&gb2);
440     smk->pic->palette_has_changed = flags & 1;
441     smk->pic->key_frame = !!(flags & 2);
442     if (smk->pic->key_frame)
443         smk->pic->pict_type = AV_PICTURE_TYPE_I;
444     else
445         smk->pic->pict_type = AV_PICTURE_TYPE_P;
446 
447     for(i = 0; i < 256; i++)
448         *pal++ = 0xFFU << 24 | bytestream2_get_be24u(&gb2);
449 
450     last_reset(smk->mmap_tbl, smk->mmap_last);
451     last_reset(smk->mclr_tbl, smk->mclr_last);
452     last_reset(smk->full_tbl, smk->full_last);
453     last_reset(smk->type_tbl, smk->type_last);
454     if ((ret = init_get_bits8(&gb, avpkt->data + 769, avpkt->size - 769)) < 0)
455         return ret;
456 
457     blk = 0;
458     bw = avctx->width >> 2;
459     bh = avctx->height >> 2;
460     blocks = bw * bh;
461     stride = smk->pic->linesize[0];
462     while(blk < blocks) {
463         int type, run, mode;
464         uint16_t pix;
465 
466         type = smk_get_code(&gb, smk->type_tbl, smk->type_last);
467         if (type < 0)
468             return type;
469         run = block_runs[(type >> 2) & 0x3F];
470         switch(type & 3){
471         case SMK_BLK_MONO:
472             while(run-- && blk < blocks){
473                 int clr, map;
474                 int hi, lo;
475                 clr = smk_get_code(&gb, smk->mclr_tbl, smk->mclr_last);
476                 map = smk_get_code(&gb, smk->mmap_tbl, smk->mmap_last);
477                 out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
478                 hi = clr >> 8;
479                 lo = clr & 0xFF;
480                 for(i = 0; i < 4; i++) {
481                     if(map & 1) out[0] = hi; else out[0] = lo;
482                     if(map & 2) out[1] = hi; else out[1] = lo;
483                     if(map & 4) out[2] = hi; else out[2] = lo;
484                     if(map & 8) out[3] = hi; else out[3] = lo;
485                     map >>= 4;
486                     out += stride;
487                 }
488                 blk++;
489             }
490             break;
491         case SMK_BLK_FULL:
492             mode = 0;
493             if(avctx->codec_tag == MKTAG('S', 'M', 'K', '4')) { // In case of Smacker v4 we have three modes
494                 if (get_bits_left(&gb) < 1)
495                     return AVERROR_INVALIDDATA;
496                 if(get_bits1(&gb)) mode = 1;
497                 else if(get_bits1(&gb)) mode = 2;
498             }
499             while(run-- && blk < blocks){
500                 out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
501                 switch(mode){
502                 case 0:
503                     for(i = 0; i < 4; i++) {
504                         pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
505                         AV_WL16(out+2,pix);
506                         pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
507                         AV_WL16(out,pix);
508                         out += stride;
509                     }
510                     break;
511                 case 1:
512                     pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
513                     out[0] = out[1] = pix & 0xFF;
514                     out[2] = out[3] = pix >> 8;
515                     out += stride;
516                     out[0] = out[1] = pix & 0xFF;
517                     out[2] = out[3] = pix >> 8;
518                     out += stride;
519                     pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
520                     out[0] = out[1] = pix & 0xFF;
521                     out[2] = out[3] = pix >> 8;
522                     out += stride;
523                     out[0] = out[1] = pix & 0xFF;
524                     out[2] = out[3] = pix >> 8;
525                     break;
526                 case 2:
527                     for(i = 0; i < 2; i++) {
528                         uint16_t pix1, pix2;
529                         pix2 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
530                         pix1 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
531                         AV_WL16(out,pix1);
532                         AV_WL16(out+2,pix2);
533                         out += stride;
534                         AV_WL16(out,pix1);
535                         AV_WL16(out+2,pix2);
536                         out += stride;
537                     }
538                     break;
539                 }
540                 blk++;
541             }
542             break;
543         case SMK_BLK_SKIP:
544             while(run-- && blk < blocks)
545                 blk++;
546             break;
547         case SMK_BLK_FILL:
548             mode = type >> 8;
549             while(run-- && blk < blocks){
550                 uint32_t col;
551                 out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
552                 col = mode * 0x01010101U;
553                 for(i = 0; i < 4; i++) {
554                     *((uint32_t*)out) = col;
555                     out += stride;
556                 }
557                 blk++;
558             }
559             break;
560         }
561 
562     }
563 
564     if ((ret = av_frame_ref(data, smk->pic)) < 0)
565         return ret;
566 
567     *got_frame = 1;
568 
569     /* always report that the buffer was completely consumed */
570     return avpkt->size;
571 }
572 
573 
decode_end(AVCodecContext * avctx)574 static av_cold int decode_end(AVCodecContext *avctx)
575 {
576     SmackVContext * const smk = avctx->priv_data;
577 
578     av_freep(&smk->mmap_tbl);
579     av_freep(&smk->mclr_tbl);
580     av_freep(&smk->full_tbl);
581     av_freep(&smk->type_tbl);
582 
583     av_frame_free(&smk->pic);
584 
585     return 0;
586 }
587 
588 
decode_init(AVCodecContext * avctx)589 static av_cold int decode_init(AVCodecContext *avctx)
590 {
591     SmackVContext * const c = avctx->priv_data;
592     int ret;
593 
594     c->avctx = avctx;
595 
596     avctx->pix_fmt = AV_PIX_FMT_PAL8;
597 
598     c->pic = av_frame_alloc();
599     if (!c->pic)
600         return AVERROR(ENOMEM);
601 
602     /* decode huffman trees from extradata */
603     if(avctx->extradata_size < 16){
604         av_log(avctx, AV_LOG_ERROR, "Extradata missing!\n");
605         decode_end(avctx);
606         return AVERROR(EINVAL);
607     }
608 
609     ret = decode_header_trees(c);
610     if (ret < 0) {
611         decode_end(avctx);
612         return ret;
613     }
614 
615     return 0;
616 }
617 
618 
smka_decode_init(AVCodecContext * avctx)619 static av_cold int smka_decode_init(AVCodecContext *avctx)
620 {
621     if (avctx->channels < 1 || avctx->channels > 2) {
622         av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
623         return AVERROR_INVALIDDATA;
624     }
625     avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
626     avctx->sample_fmt = avctx->bits_per_coded_sample == 8 ? AV_SAMPLE_FMT_U8 : AV_SAMPLE_FMT_S16;
627 
628     return 0;
629 }
630 
631 /**
632  * Decode Smacker audio data
633  */
smka_decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)634 static int smka_decode_frame(AVCodecContext *avctx, void *data,
635                              int *got_frame_ptr, AVPacket *avpkt)
636 {
637     AVFrame *frame     = data;
638     const uint8_t *buf = avpkt->data;
639     int buf_size = avpkt->size;
640     GetBitContext gb;
641     HuffContext h[4] = { { 0 } };
642     VLC vlc[4]       = { { 0 } };
643     int16_t *samples;
644     uint8_t *samples8;
645     int val;
646     int i, res, ret;
647     int unp_size;
648     int bits, stereo;
649     int pred[2] = {0, 0};
650 
651     if (buf_size <= 4) {
652         av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
653         return AVERROR_INVALIDDATA;
654     }
655 
656     unp_size = AV_RL32(buf);
657 
658     if (unp_size > (1U<<24)) {
659         av_log(avctx, AV_LOG_ERROR, "packet is too big\n");
660         return AVERROR_INVALIDDATA;
661     }
662 
663     if ((ret = init_get_bits8(&gb, buf + 4, buf_size - 4)) < 0)
664         return ret;
665 
666     if(!get_bits1(&gb)){
667         av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
668         *got_frame_ptr = 0;
669         return 1;
670     }
671     stereo = get_bits1(&gb);
672     bits = get_bits1(&gb);
673     if (stereo ^ (avctx->channels != 1)) {
674         av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
675         return AVERROR_INVALIDDATA;
676     }
677     if (bits == (avctx->sample_fmt == AV_SAMPLE_FMT_U8)) {
678         av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
679         return AVERROR_INVALIDDATA;
680     }
681 
682     /* get output buffer */
683     frame->nb_samples = unp_size / (avctx->channels * (bits + 1));
684     if (unp_size % (avctx->channels * (bits + 1))) {
685         av_log(avctx, AV_LOG_ERROR,
686                "The buffer does not contain an integer number of samples\n");
687         return AVERROR_INVALIDDATA;
688     }
689     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
690         return ret;
691     samples  = (int16_t *)frame->data[0];
692     samples8 =            frame->data[0];
693 
694     // Initialize
695     for(i = 0; i < (1 << (bits + stereo)); i++) {
696         h[i].length = 256;
697         h[i].maxlength = 0;
698         h[i].current = 0;
699         h[i].bits = av_mallocz(256 * 4);
700         h[i].lengths = av_mallocz(256 * sizeof(int));
701         h[i].values = av_mallocz(256 * sizeof(int));
702         if (!h[i].bits || !h[i].lengths || !h[i].values) {
703             ret = AVERROR(ENOMEM);
704             goto error;
705         }
706         skip_bits1(&gb);
707         if (smacker_decode_tree(&gb, &h[i], 0, 0) < 0) {
708             ret = AVERROR_INVALIDDATA;
709             goto error;
710         }
711         skip_bits1(&gb);
712         if(h[i].current > 1) {
713             res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
714                     h[i].lengths, sizeof(int), sizeof(int),
715                     h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
716             if(res < 0) {
717                 av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
718                 ret = AVERROR_INVALIDDATA;
719                 goto error;
720             }
721         }
722     }
723     /* this codec relies on wraparound instead of clipping audio */
724     if(bits) { //decode 16-bit data
725         for(i = stereo; i >= 0; i--)
726             pred[i] = sign_extend(av_bswap16(get_bits(&gb, 16)), 16);
727         for(i = 0; i <= stereo; i++)
728             *samples++ = pred[i];
729         for(; i < unp_size / 2; i++) {
730             if (get_bits_left(&gb) < 0) {
731                 ret = AVERROR_INVALIDDATA;
732                 goto error;
733             }
734             if(i & stereo) {
735                 if(vlc[2].table)
736                     res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
737                 else
738                     res = 0;
739                 if (res < 0) {
740                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
741                     ret = AVERROR_INVALIDDATA;
742                     goto error;
743                 }
744                 val  = h[2].values[res];
745                 if(vlc[3].table)
746                     res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
747                 else
748                     res = 0;
749                 if (res < 0) {
750                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
751                     ret = AVERROR_INVALIDDATA;
752                     goto error;
753                 }
754                 val |= h[3].values[res] << 8;
755                 pred[1] += (unsigned)sign_extend(val, 16);
756                 *samples++ = pred[1];
757             } else {
758                 if(vlc[0].table)
759                     res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
760                 else
761                     res = 0;
762                 if (res < 0) {
763                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
764                     ret = AVERROR_INVALIDDATA;
765                     goto error;
766                 }
767                 val  = h[0].values[res];
768                 if(vlc[1].table)
769                     res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
770                 else
771                     res = 0;
772                 if (res < 0) {
773                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
774                     ret = AVERROR_INVALIDDATA;
775                     goto error;
776                 }
777                 val |= h[1].values[res] << 8;
778                 pred[0] += (unsigned)sign_extend(val, 16);
779                 *samples++ = pred[0];
780             }
781         }
782     } else { //8-bit data
783         for(i = stereo; i >= 0; i--)
784             pred[i] = get_bits(&gb, 8);
785         for(i = 0; i <= stereo; i++)
786             *samples8++ = pred[i];
787         for(; i < unp_size; i++) {
788             if (get_bits_left(&gb) < 0) {
789                 ret = AVERROR_INVALIDDATA;
790                 goto error;
791             }
792             if(i & stereo){
793                 if(vlc[1].table)
794                     res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
795                 else
796                     res = 0;
797                 if (res < 0) {
798                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
799                     ret = AVERROR_INVALIDDATA;
800                     goto error;
801                 }
802                 pred[1] += sign_extend(h[1].values[res], 8);
803                 *samples8++ = pred[1];
804             } else {
805                 if(vlc[0].table)
806                     res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
807                 else
808                     res = 0;
809                 if (res < 0) {
810                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
811                     ret = AVERROR_INVALIDDATA;
812                     goto error;
813                 }
814                 pred[0] += sign_extend(h[0].values[res], 8);
815                 *samples8++ = pred[0];
816             }
817         }
818     }
819 
820     *got_frame_ptr = 1;
821     ret = buf_size;
822 
823 error:
824     for(i = 0; i < 4; i++) {
825         if(vlc[i].table)
826             ff_free_vlc(&vlc[i]);
827         av_free(h[i].bits);
828         av_free(h[i].lengths);
829         av_free(h[i].values);
830     }
831 
832     return ret;
833 }
834 
835 AVCodec ff_smacker_decoder = {
836     .name           = "smackvid",
837     .long_name      = NULL_IF_CONFIG_SMALL("Smacker video"),
838     .type           = AVMEDIA_TYPE_VIDEO,
839     .id             = AV_CODEC_ID_SMACKVIDEO,
840     .priv_data_size = sizeof(SmackVContext),
841     .init           = decode_init,
842     .close          = decode_end,
843     .decode         = decode_frame,
844     .capabilities   = AV_CODEC_CAP_DR1,
845 };
846 
847 AVCodec ff_smackaud_decoder = {
848     .name           = "smackaud",
849     .long_name      = NULL_IF_CONFIG_SMALL("Smacker audio"),
850     .type           = AVMEDIA_TYPE_AUDIO,
851     .id             = AV_CODEC_ID_SMACKAUDIO,
852     .init           = smka_decode_init,
853     .decode         = smka_decode_frame,
854     .capabilities   = AV_CODEC_CAP_DR1,
855 };
856