path: root/libavcodec/smacker.c (plain)
blob: 2d20be9c10e23e01eede83ae0a3302bca824dd9c

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
47	typedef struct SmackVContext {
48	AVCodecContext *avctx;
49	AVFrame *pic;
50
51	int *mmap_tbl, *mclr_tbl, *full_tbl, *type_tbl;
52	int mmap_last[3], mclr_last[3], full_last[3], type_last[3];
53	} SmackVContext;
54
55	/**
56	* Context used for code reconstructing
57	*/
58	typedef struct HuffContext {
59	int length;
60	int maxlength;
61	int current;
62	uint32_t *bits;
63	int *lengths;
64	int *values;
65	} HuffContext;
66
67	/* common parameters used for decode_bigtree */
68	typedef struct DBCtx {
69	VLC *v1, *v2;
70	int *recode1, *recode2;
71	int escapes[3];
72	int *last;
73	int lcur;
74	} DBCtx;
75
76	/* possible runs of blocks */
77	static const int block_runs[64] = {
78	1, 2, 3, 4, 5, 6, 7, 8,
79	9, 10, 11, 12, 13, 14, 15, 16,
80	17, 18, 19, 20, 21, 22, 23, 24,
81	25, 26, 27, 28, 29, 30, 31, 32,
82	33, 34, 35, 36, 37, 38, 39, 40,
83	41, 42, 43, 44, 45, 46, 47, 48,
84	49, 50, 51, 52, 53, 54, 55, 56,
85	57, 58, 59, 128, 256, 512, 1024, 2048 };
86
87	enum SmkBlockTypes {
88	SMK_BLK_MONO = 0,
89	SMK_BLK_FULL = 1,
90	SMK_BLK_SKIP = 2,
91	SMK_BLK_FILL = 3 };
92
93	/**
94	* Decode local frame tree
95	*/
96	static int smacker_decode_tree(GetBitContext *gb, HuffContext *hc, uint32_t prefix, int length)
97	{
98	if(length > 32 || length > 3*SMKTREE_BITS) {
99	av_log(NULL, AV_LOG_ERROR, "length too long\n");
100	return AVERROR_INVALIDDATA;
101	}
102	if(!get_bits1(gb)){ //Leaf
103	if(hc->current >= hc->length){
104	av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
105	return AVERROR_INVALIDDATA;
106	}
107	if(length){
108	hc->bits[hc->current] = prefix;
109	hc->lengths[hc->current] = length;
110	} else {
111	hc->bits[hc->current] = 0;
112	hc->lengths[hc->current] = 0;
113	}
114	hc->values[hc->current] = get_bits(gb, 8);
115	hc->current++;
116	if(hc->maxlength < length)
117	hc->maxlength = length;
118	return 0;
119	} else { //Node
120	int r;
121	length++;
122	r = smacker_decode_tree(gb, hc, prefix, length);
123	if(r)
124	return r;
125	return smacker_decode_tree(gb, hc, prefix | (1 << (length - 1)), length);
126	}
127	}
128
129	/**
130	* Decode header tree
131	*/
132	static int smacker_decode_bigtree(GetBitContext *gb, HuffContext *hc, DBCtx *ctx, int length)
133	{
134	if(length > 500) { // Larger length can cause segmentation faults due to too deep recursion.
135	av_log(NULL, AV_LOG_ERROR, "length too long\n");
136	return AVERROR_INVALIDDATA;
137	}
138	if (hc->current + 1 >= hc->length) {
139	av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
140	return AVERROR_INVALIDDATA;
141	}
142	if(!get_bits1(gb)){ //Leaf
143	int val, i1, i2;
144	i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3) : 0;
145	i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3) : 0;
146	if (i1 < 0 || i2 < 0)
147	return AVERROR_INVALIDDATA;
148	val = ctx->recode1[i1] | (ctx->recode2[i2] << 8);
149	if(val == ctx->escapes[0]) {
150	ctx->last[0] = hc->current;
151	val = 0;
152	} else if(val == ctx->escapes[1]) {
153	ctx->last[1] = hc->current;
154	val = 0;
155	} else if(val == ctx->escapes[2]) {
156	ctx->last[2] = hc->current;
157	val = 0;
158	}
159
160	hc->values[hc->current++] = val;
161	return 1;
162	} else { //Node
163	int r = 0, r_new, t;
164
165	t = hc->current++;
166	r = smacker_decode_bigtree(gb, hc, ctx, length + 1);
167	if(r < 0)
168	return r;
169	hc->values[t] = SMK_NODE | r;
170	r++;
171	r_new = smacker_decode_bigtree(gb, hc, ctx, length + 1);
172	if (r_new < 0)
173	return r_new;
174	return r + r_new;
175	}
176	}
177
178	/**
179	* Store large tree as FFmpeg's vlc codes
180	*/
181	static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int **recodes, int *last, int size)
182	{
183	int res;
184	HuffContext huff;
185	HuffContext tmp1, tmp2;
186	VLC vlc[2] = { { 0 } };
187	int escapes[3];
188	DBCtx ctx;
189	int err = 0;
190
191	if(size >= UINT_MAX>>4){ // (((size + 3) >> 2) + 3) << 2 must not overflow
192	av_log(smk->avctx, AV_LOG_ERROR, "size too large\n");
193	return AVERROR_INVALIDDATA;
194	}
195
196	tmp1.length = 256;
197	tmp1.maxlength = 0;
198	tmp1.current = 0;
199	tmp1.bits = av_mallocz(256 * 4);
200	tmp1.lengths = av_mallocz(256 * sizeof(int));
201	tmp1.values = av_mallocz(256 * sizeof(int));
202
203	tmp2.length = 256;
204	tmp2.maxlength = 0;
205	tmp2.current = 0;
206	tmp2.bits = av_mallocz(256 * 4);
207	tmp2.lengths = av_mallocz(256 * sizeof(int));
208	tmp2.values = av_mallocz(256 * sizeof(int));
209	if (!tmp1.bits || !tmp1.lengths || !tmp1.values ||
210	!tmp2.bits || !tmp2.lengths || !tmp2.values) {
211	err = AVERROR(ENOMEM);
212	goto error;
213	}
214
215	if(get_bits1(gb)) {
216	res = smacker_decode_tree(gb, &tmp1, 0, 0);
217	if (res < 0) {
218	err = res;
219	goto error;
220	}
221	skip_bits1(gb);
222	if(tmp1.current > 1) {
223	res = init_vlc(&vlc[0], SMKTREE_BITS, tmp1.length,
224	tmp1.lengths, sizeof(int), sizeof(int),
225	tmp1.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
226	if(res < 0) {
227	av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
228	err = res;
229	goto error;
230	}
231	}
232	}
233	if (!vlc[0].table) {
234	av_log(smk->avctx, AV_LOG_ERROR, "Skipping low bytes tree\n");
235	}
236	if(get_bits1(gb)){
237	res = smacker_decode_tree(gb, &tmp2, 0, 0);
238	if (res < 0) {
239	err = res;
240	goto error;
241	}
242	skip_bits1(gb);
243	if(tmp2.current > 1) {
244	res = init_vlc(&vlc[1], SMKTREE_BITS, tmp2.length,
245	tmp2.lengths, sizeof(int), sizeof(int),
246	tmp2.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
247	if(res < 0) {
248	av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
249	err = res;
250	goto error;
251	}
252	}
253	}
254	if (!vlc[1].table) {
255	av_log(smk->avctx, AV_LOG_ERROR, "Skipping high bytes tree\n");
256	}
257
258	escapes[0] = get_bits(gb, 16);
259	escapes[1] = get_bits(gb, 16);
260	escapes[2] = get_bits(gb, 16);
261
262	last[0] = last[1] = last[2] = -1;
263
264	ctx.escapes[0] = escapes[0];
265	ctx.escapes[1] = escapes[1];
266	ctx.escapes[2] = escapes[2];
267	ctx.v1 = &vlc[0];
268	ctx.v2 = &vlc[1];
269	ctx.recode1 = tmp1.values;
270	ctx.recode2 = tmp2.values;
271	ctx.last = last;
272
273	huff.length = ((size + 3) >> 2) + 4;
274	huff.maxlength = 0;
275	huff.current = 0;
276	huff.values = av_mallocz_array(huff.length, sizeof(int));
277	if (!huff.values) {
278	err = AVERROR(ENOMEM);
279	goto error;
280	}
281
282	if (smacker_decode_bigtree(gb, &huff, &ctx, 0) < 0)
283	err = -1;
284	skip_bits1(gb);
285	if(ctx.last[0] == -1) ctx.last[0] = huff.current++;
286	if(ctx.last[1] == -1) ctx.last[1] = huff.current++;
287	if(ctx.last[2] == -1) ctx.last[2] = huff.current++;
288	if (ctx.last[0] >= huff.length ||
289	ctx.last[1] >= huff.length ||
290	ctx.last[2] >= huff.length) {
291	av_log(smk->avctx, AV_LOG_ERROR, "Huffman codes out of range\n");
292	err = AVERROR_INVALIDDATA;
293	}
294
295	*recodes = huff.values;
296
297	error:
298	if(vlc[0].table)
299	ff_free_vlc(&vlc[0]);
300	if(vlc[1].table)
301	ff_free_vlc(&vlc[1]);
302	av_free(tmp1.bits);
303	av_free(tmp1.lengths);
304	av_free(tmp1.values);
305	av_free(tmp2.bits);
306	av_free(tmp2.lengths);
307	av_free(tmp2.values);
308
309	return err;
310	}
311
312	static int decode_header_trees(SmackVContext *smk) {
313	GetBitContext gb;
314	int mmap_size, mclr_size, full_size, type_size, ret;
315
316	mmap_size = AV_RL32(smk->avctx->extradata);
317	mclr_size = AV_RL32(smk->avctx->extradata + 4);
318	full_size = AV_RL32(smk->avctx->extradata + 8);
319	type_size = AV_RL32(smk->avctx->extradata + 12);
320
321	ret = init_get_bits8(&gb, smk->avctx->extradata + 16, smk->avctx->extradata_size - 16);
322	if (ret < 0)
323	return ret;
324
325	if(!get_bits1(&gb)) {
326	av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");
327	smk->mmap_tbl = av_malloc(sizeof(int) * 2);
328	if (!smk->mmap_tbl)
329	return AVERROR(ENOMEM);
330	smk->mmap_tbl[0] = 0;
331	smk->mmap_last[0] = smk->mmap_last[1] = smk->mmap_last[2] = 1;
332	} else {
333	ret = smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size);
334	if (ret < 0)
335	return ret;
336	}
337	if(!get_bits1(&gb)) {
338	av_log(smk->avctx, AV_LOG_INFO, "Skipping MCLR tree\n");
339	smk->mclr_tbl = av_malloc(sizeof(int) * 2);
340	if (!smk->mclr_tbl)
341	return AVERROR(ENOMEM);
342	smk->mclr_tbl[0] = 0;
343	smk->mclr_last[0] = smk->mclr_last[1] = smk->mclr_last[2] = 1;
344	} else {
345	ret = smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size);
346	if (ret < 0)
347	return ret;
348	}
349	if(!get_bits1(&gb)) {
350	av_log(smk->avctx, AV_LOG_INFO, "Skipping FULL tree\n");
351	smk->full_tbl = av_malloc(sizeof(int) * 2);
352	if (!smk->full_tbl)
353	return AVERROR(ENOMEM);
354	smk->full_tbl[0] = 0;
355	smk->full_last[0] = smk->full_last[1] = smk->full_last[2] = 1;
356	} else {
357	ret = smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size);
358	if (ret < 0)
359	return ret;
360	}
361	if(!get_bits1(&gb)) {
362	av_log(smk->avctx, AV_LOG_INFO, "Skipping TYPE tree\n");
363	smk->type_tbl = av_malloc(sizeof(int) * 2);
364	if (!smk->type_tbl)
365	return AVERROR(ENOMEM);
366	smk->type_tbl[0] = 0;
367	smk->type_last[0] = smk->type_last[1] = smk->type_last[2] = 1;
368	} else {
369	ret = smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size);
370	if (ret < 0)
371	return ret;
372	}
373
374	return 0;
375	}
376
377	static av_always_inline void last_reset(int *recode, int *last) {
378	recode[last[0]] = recode[last[1]] = recode[last[2]] = 0;
379	}
380
381	/* get code and update history */
382	static av_always_inline int smk_get_code(GetBitContext *gb, int *recode, int *last) {
383	register int *table = recode;
384	int v;
385
386	while(*table & SMK_NODE) {
387	if(get_bits1(gb))
388	table += (*table) & (~SMK_NODE);
389	table++;
390	}
391	v = *table;
392
393	if(v != recode[last[0]]) {
394	recode[last[2]] = recode[last[1]];
395	recode[last[1]] = recode[last[0]];
396	recode[last[0]] = v;
397	}
398	return v;
399	}
400
401	static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
402	AVPacket *avpkt)
403	{
404	SmackVContext * const smk = avctx->priv_data;
405	uint8_t *out;
406	uint32_t *pal;
407	GetByteContext gb2;
408	GetBitContext gb;
409	int blocks, blk, bw, bh;
410	int i, ret;
411	int stride;
412	int flags;
413
414	if (avpkt->size <= 769)
415	return AVERROR_INVALIDDATA;
416
417	if ((ret = ff_reget_buffer(avctx, smk->pic)) < 0)
418	return ret;
419
420	/* make the palette available on the way out */
421	pal = (uint32_t*)smk->pic->data[1];
422	bytestream2_init(&gb2, avpkt->data, avpkt->size);
423	flags = bytestream2_get_byteu(&gb2);
424	smk->pic->palette_has_changed = flags & 1;
425	smk->pic->key_frame = !!(flags & 2);
426	if (smk->pic->key_frame)
427	smk->pic->pict_type = AV_PICTURE_TYPE_I;
428	else
429	smk->pic->pict_type = AV_PICTURE_TYPE_P;
430
431	for(i = 0; i < 256; i++)
432	*pal++ = 0xFFU << 24 | bytestream2_get_be24u(&gb2);
433
434	last_reset(smk->mmap_tbl, smk->mmap_last);
435	last_reset(smk->mclr_tbl, smk->mclr_last);
436	last_reset(smk->full_tbl, smk->full_last);
437	last_reset(smk->type_tbl, smk->type_last);
438	if ((ret = init_get_bits8(&gb, avpkt->data + 769, avpkt->size - 769)) < 0)
439	return ret;
440
441	blk = 0;
442	bw = avctx->width >> 2;
443	bh = avctx->height >> 2;
444	blocks = bw * bh;
445	stride = smk->pic->linesize[0];
446	while(blk < blocks) {
447	int type, run, mode;
448	uint16_t pix;
449
450	type = smk_get_code(&gb, smk->type_tbl, smk->type_last);
451	run = block_runs[(type >> 2) & 0x3F];
452	switch(type & 3){
453	case SMK_BLK_MONO:
454	while(run-- && blk < blocks){
455	int clr, map;
456	int hi, lo;
457	clr = smk_get_code(&gb, smk->mclr_tbl, smk->mclr_last);
458	map = smk_get_code(&gb, smk->mmap_tbl, smk->mmap_last);
459	out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
460	hi = clr >> 8;
461	lo = clr & 0xFF;
462	for(i = 0; i < 4; i++) {
463	if(map & 1) out[0] = hi; else out[0] = lo;
464	if(map & 2) out[1] = hi; else out[1] = lo;
465	if(map & 4) out[2] = hi; else out[2] = lo;
466	if(map & 8) out[3] = hi; else out[3] = lo;
467	map >>= 4;
468	out += stride;
469	}
470	blk++;
471	}
472	break;
473	case SMK_BLK_FULL:
474	mode = 0;
475	if(avctx->codec_tag == MKTAG('S', 'M', 'K', '4')) { // In case of Smacker v4 we have three modes
476	if(get_bits1(&gb)) mode = 1;
477	else if(get_bits1(&gb)) mode = 2;
478	}
479	while(run-- && blk < blocks){
480	out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
481	switch(mode){
482	case 0:
483	for(i = 0; i < 4; i++) {
484	pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
485	AV_WL16(out+2,pix);
486	pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
487	AV_WL16(out,pix);
488	out += stride;
489	}
490	break;
491	case 1:
492	pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
493	out[0] = out[1] = pix & 0xFF;
494	out[2] = out[3] = pix >> 8;
495	out += stride;
496	out[0] = out[1] = pix & 0xFF;
497	out[2] = out[3] = pix >> 8;
498	out += stride;
499	pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);
500	out[0] = out[1] = pix & 0xFF;
501	out[2] = out[3] = pix >> 8;
502	out += stride;
503	out[0] = out[1] = pix & 0xFF;
504	out[2] = out[3] = pix >> 8;
505	break;
506	case 2:
507	for(i = 0; i < 2; i++) {
508	uint16_t pix1, pix2;
509	pix2 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
510	pix1 = smk_get_code(&gb, smk->full_tbl, smk->full_last);
511	AV_WL16(out,pix1);
512	AV_WL16(out+2,pix2);
513	out += stride;
514	AV_WL16(out,pix1);
515	AV_WL16(out+2,pix2);
516	out += stride;
517	}
518	break;
519	}
520	blk++;
521	}
522	break;
523	case SMK_BLK_SKIP:
524	while(run-- && blk < blocks)
525	blk++;
526	break;
527	case SMK_BLK_FILL:
528	mode = type >> 8;
529	while(run-- && blk < blocks){
530	uint32_t col;
531	out = smk->pic->data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;
532	col = mode * 0x01010101;
533	for(i = 0; i < 4; i++) {
534	*((uint32_t*)out) = col;
535	out += stride;
536	}
537	blk++;
538	}
539	break;
540	}
541
542	}
543
544	if ((ret = av_frame_ref(data, smk->pic)) < 0)
545	return ret;
546
547	*got_frame = 1;
548
549	/* always report that the buffer was completely consumed */
550	return avpkt->size;
551	}
552
553
554	static av_cold int decode_end(AVCodecContext *avctx)
555	{
556	SmackVContext * const smk = avctx->priv_data;
557
558	av_freep(&smk->mmap_tbl);
559	av_freep(&smk->mclr_tbl);
560	av_freep(&smk->full_tbl);
561	av_freep(&smk->type_tbl);
562
563	av_frame_free(&smk->pic);
564
565	return 0;
566	}
567
568
569	static av_cold int decode_init(AVCodecContext *avctx)
570	{
571	SmackVContext * const c = avctx->priv_data;
572	int ret;
573
574	c->avctx = avctx;
575
576	avctx->pix_fmt = AV_PIX_FMT_PAL8;
577
578	c->pic = av_frame_alloc();
579	if (!c->pic)
580	return AVERROR(ENOMEM);
581
582	/* decode huffman trees from extradata */
583	if(avctx->extradata_size < 16){
584	av_log(avctx, AV_LOG_ERROR, "Extradata missing!\n");
585	decode_end(avctx);
586	return AVERROR(EINVAL);
587	}
588
589	ret = decode_header_trees(c);
590	if (ret < 0) {
591	decode_end(avctx);
592	return ret;
593	}
594
595	return 0;
596	}
597
598
599	static av_cold int smka_decode_init(AVCodecContext *avctx)
600	{
601	if (avctx->channels < 1 || avctx->channels > 2) {
602	av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
603	return AVERROR(EINVAL);
604	}
605	avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
606	avctx->sample_fmt = avctx->bits_per_coded_sample == 8 ? AV_SAMPLE_FMT_U8 : AV_SAMPLE_FMT_S16;
607
608	return 0;
609	}
610
611	/**
612	* Decode Smacker audio data
613	*/
614	static int smka_decode_frame(AVCodecContext *avctx, void *data,
615	int *got_frame_ptr, AVPacket *avpkt)
616	{
617	AVFrame *frame = data;
618	const uint8_t *buf = avpkt->data;
619	int buf_size = avpkt->size;
620	GetBitContext gb;
621	HuffContext h[4] = { { 0 } };
622	VLC vlc[4] = { { 0 } };
623	int16_t *samples;
624	uint8_t *samples8;
625	int val;
626	int i, res, ret;
627	int unp_size;
628	int bits, stereo;
629	int pred[2] = {0, 0};
630
631	if (buf_size <= 4) {
632	av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
633	return AVERROR(EINVAL);
634	}
635
636	unp_size = AV_RL32(buf);
637
638	if (unp_size > (1U<<24)) {
639	av_log(avctx, AV_LOG_ERROR, "packet is too big\n");
640	return AVERROR_INVALIDDATA;
641	}
642
643	if ((ret = init_get_bits8(&gb, buf + 4, buf_size - 4)) < 0)
644	return ret;
645
646	if(!get_bits1(&gb)){
647	av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
648	*got_frame_ptr = 0;
649	return 1;
650	}
651	stereo = get_bits1(&gb);
652	bits = get_bits1(&gb);
653	if (stereo ^ (avctx->channels != 1)) {
654	av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
655	return AVERROR(EINVAL);
656	}
657	if (bits == (avctx->sample_fmt == AV_SAMPLE_FMT_U8)) {
658	av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
659	return AVERROR(EINVAL);
660	}
661
662	/* get output buffer */
663	frame->nb_samples = unp_size / (avctx->channels * (bits + 1));
664	if (unp_size % (avctx->channels * (bits + 1))) {
665	av_log(avctx, AV_LOG_ERROR, "unp_size %d is odd\n", unp_size);
666	return AVERROR(EINVAL);
667	}
668	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
669	return ret;
670	samples = (int16_t *)frame->data[0];
671	samples8 = frame->data[0];
672
673	// Initialize
674	for(i = 0; i < (1 << (bits + stereo)); i++) {
675	h[i].length = 256;
676	h[i].maxlength = 0;
677	h[i].current = 0;
678	h[i].bits = av_mallocz(256 * 4);
679	h[i].lengths = av_mallocz(256 * sizeof(int));
680	h[i].values = av_mallocz(256 * sizeof(int));
681	if (!h[i].bits || !h[i].lengths || !h[i].values) {
682	ret = AVERROR(ENOMEM);
683	goto error;
684	}
685	skip_bits1(&gb);
686	if (smacker_decode_tree(&gb, &h[i], 0, 0) < 0) {
687	ret = AVERROR_INVALIDDATA;
688	goto error;
689	}
690	skip_bits1(&gb);
691	if(h[i].current > 1) {
692	res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
693	h[i].lengths, sizeof(int), sizeof(int),
694	h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
695	if(res < 0) {
696	av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
697	ret = AVERROR_INVALIDDATA;
698	goto error;
699	}
700	}
701	}
702	/* this codec relies on wraparound instead of clipping audio */
703	if(bits) { //decode 16-bit data
704	for(i = stereo; i >= 0; i--)
705	pred[i] = sign_extend(av_bswap16(get_bits(&gb, 16)), 16);
706	for(i = 0; i <= stereo; i++)
707	*samples++ = pred[i];
708	for(; i < unp_size / 2; i++) {
709	if(get_bits_left(&gb)<0)
710	return AVERROR_INVALIDDATA;
711	if(i & stereo) {
712	if(vlc[2].table)
713	res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
714	else
715	res = 0;
716	if (res < 0) {
717	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
718	return AVERROR_INVALIDDATA;
719	}
720	val = h[2].values[res];
721	if(vlc[3].table)
722	res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
723	else
724	res = 0;
725	if (res < 0) {
726	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
727	return AVERROR_INVALIDDATA;
728	}
729	val |= h[3].values[res] << 8;
730	pred[1] += sign_extend(val, 16);
731	*samples++ = pred[1];
732	} else {
733	if(vlc[0].table)
734	res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
735	else
736	res = 0;
737	if (res < 0) {
738	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
739	return AVERROR_INVALIDDATA;
740	}
741	val = h[0].values[res];
742	if(vlc[1].table)
743	res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
744	else
745	res = 0;
746	if (res < 0) {
747	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
748	return AVERROR_INVALIDDATA;
749	}
750	val |= h[1].values[res] << 8;
751	pred[0] += sign_extend(val, 16);
752	*samples++ = pred[0];
753	}
754	}
755	} else { //8-bit data
756	for(i = stereo; i >= 0; i--)
757	pred[i] = get_bits(&gb, 8);
758	for(i = 0; i <= stereo; i++)
759	*samples8++ = pred[i];
760	for(; i < unp_size; i++) {
761	if(get_bits_left(&gb)<0)
762	return AVERROR_INVALIDDATA;
763	if(i & stereo){
764	if(vlc[1].table)
765	res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
766	else
767	res = 0;
768	if (res < 0) {
769	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
770	return AVERROR_INVALIDDATA;
771	}
772	pred[1] += sign_extend(h[1].values[res], 8);
773	*samples8++ = pred[1];
774	} else {
775	if(vlc[0].table)
776	res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
777	else
778	res = 0;
779	if (res < 0) {
780	av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");
781	return AVERROR_INVALIDDATA;
782	}
783	pred[0] += sign_extend(h[0].values[res], 8);
784	*samples8++ = pred[0];
785	}
786	}
787	}
788
789	*got_frame_ptr = 1;
790	ret = buf_size;
791
792	error:
793	for(i = 0; i < 4; i++) {
794	if(vlc[i].table)
795	ff_free_vlc(&vlc[i]);
796	av_free(h[i].bits);
797	av_free(h[i].lengths);
798	av_free(h[i].values);
799	}
800
801	return ret;
802	}
803
804	AVCodec ff_smacker_decoder = {
805	.name = "smackvid",
806	.long_name = NULL_IF_CONFIG_SMALL("Smacker video"),
807	.type = AVMEDIA_TYPE_VIDEO,
808	.id = AV_CODEC_ID_SMACKVIDEO,
809	.priv_data_size = sizeof(SmackVContext),
810	.init = decode_init,
811	.close = decode_end,
812	.decode = decode_frame,
813	.capabilities = AV_CODEC_CAP_DR1,
814	};
815
816	AVCodec ff_smackaud_decoder = {
817	.name = "smackaud",
818	.long_name = NULL_IF_CONFIG_SMALL("Smacker audio"),
819	.type = AVMEDIA_TYPE_AUDIO,
820	.id = AV_CODEC_ID_SMACKAUDIO,
821	.init = smka_decode_init,
822	.decode = smka_decode_frame,
823	.capabilities = AV_CODEC_CAP_DR1,
824	};
825