shorten.c@ 7692

Last change on this file since 7692 was 5776, checked in by vboxsync, 17 years ago
ffmpeg: exported to OSE
File size: 16.4 KB

Line
1	/*
2	* Shorten decoder
3	* Copyright (c) 2005 Jeff Muizelaar
4	*
5	* This library is free software; you can redistribute it and/or
6	* modify it under the terms of the GNU Lesser General Public
7	* License as published by the Free Software Foundation; either
8	* version 2 of the License, or (at your option) any later version.
9	*
10	* This library is distributed in the hope that it will be useful,
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13	* Lesser General Public License for more details.
14	*
15	* You should have received a copy of the GNU Lesser General Public
16	* License along with this library; if not, write to the Free Software
17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18	*/
19
20	/**
21	* @file shorten.c
22	* Shorten decoder
23	* @author Jeff Muizelaar
24	*
25	*/
26
27	#define DEBUG
28	#include <limits.h>
29	#include "avcodec.h"
30	#include "bitstream.h"
31	#include "golomb.h"
32
33	#define MAX_CHANNELS 8
34	#define MAX_BLOCKSIZE 65535
35
36	#define OUT_BUFFER_SIZE 16384
37
38	#define ULONGSIZE 2
39
40	#define WAVE_FORMAT_PCM 0x0001
41
42	#define DEFAULT_BLOCK_SIZE 256
43
44	#define TYPESIZE 4
45	#define CHANSIZE 0
46	#define LPCQSIZE 2
47	#define ENERGYSIZE 3
48	#define BITSHIFTSIZE 2
49
50	#define TYPE_S16HL 3
51	#define TYPE_S16LH 5
52
53	#define NWRAP 3
54	#define NSKIPSIZE 1
55
56	#define LPCQUANT 5
57	#define V2LPCQOFFSET (1 << LPCQUANT)
58
59	#define FNSIZE 2
60	#define FN_DIFF0 0
61	#define FN_DIFF1 1
62	#define FN_DIFF2 2
63	#define FN_DIFF3 3
64	#define FN_QUIT 4
65	#define FN_BLOCKSIZE 5
66	#define FN_BITSHIFT 6
67	#define FN_QLPC 7
68	#define FN_ZERO 8
69	#define FN_VERBATIM 9
70
71	#define VERBATIM_CKSIZE_SIZE 5
72	#define VERBATIM_BYTE_SIZE 8
73	#define CANONICAL_HEADER_SIZE 44
74
75	typedef struct ShortenContext {
76	AVCodecContext *avctx;
77	GetBitContext gb;
78
79	int min_framesize, max_framesize;
80	int channels;
81
82	int32_t *decoded[MAX_CHANNELS];
83	int32_t *offset[MAX_CHANNELS];
84	uint8_t *bitstream;
85	int bitstream_size;
86	int bitstream_index;
87	unsigned int allocated_bitstream_size;
88	int header_size;
89	uint8_t header[OUT_BUFFER_SIZE];
90	int version;
91	int cur_chan;
92	int bitshift;
93	int nmean;
94	int internal_ftype;
95	int nwrap;
96	int blocksize;
97	int bitindex;
98	int32_t lpcqoffset;
99	} ShortenContext;
100
101	static int shorten_decode_init(AVCodecContext * avctx)
102	{
103	ShortenContext *s = avctx->priv_data;
104	s->avctx = avctx;
105
106	return 0;
107	}
108
109	static int allocate_buffers(ShortenContext *s)
110	{
111	int i, chan;
112	for (chan=0; chan<s->channels; chan++) {
113	if(FFMAX(1, s->nmean) >= UINT_MAX/sizeof(int32_t)){
114	av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
115	return -1;
116	}
117	if(s->blocksize + s->nwrap >= UINT_MAX/sizeof(int32_t) \|\| s->blocksize + s->nwrap <= (unsigned)s->nwrap){
118	av_log(s->avctx, AV_LOG_ERROR, "s->blocksize + s->nwrap too large\n");
119	return -1;
120	}
121
122	s->offset[chan] = av_realloc(s->offset[chan], sizeof(int32_t)*FFMAX(1, s->nmean));
123
124	s->decoded[chan] = av_realloc(s->decoded[chan], sizeof(int32_t)*(s->blocksize + s->nwrap));
125	for (i=0; i<s->nwrap; i++)
126	s->decoded[chan][i] = 0;
127	s->decoded[chan] += s->nwrap;
128	}
129	return 0;
130	}
131
132
133	static inline unsigned int get_uint(ShortenContext *s, int k)
134	{
135	if (s->version != 0)
136	k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
137	return get_ur_golomb_shorten(&s->gb, k);
138	}
139
140
141	static void fix_bitshift(ShortenContext s, int32_t buffer)
142	{
143	int i;
144
145	if (s->bitshift != 0)
146	for (i = 0; i < s->blocksize; i++)
147	buffer[s->nwrap + i] <<= s->bitshift;
148	}
149
150
151	static void init_offset(ShortenContext *s)
152	{
153	int32_t mean = 0;
154	int chan, i;
155	int nblock = FFMAX(1, s->nmean);
156	/* initialise offset */
157	switch (s->internal_ftype)
158	{
159	case TYPE_S16HL:
160	case TYPE_S16LH:
161	mean = 0;
162	break;
163	default:
164	av_log(s->avctx, AV_LOG_ERROR, "unknown audio type");
165	abort();
166	}
167
168	for (chan = 0; chan < s->channels; chan++)
169	for (i = 0; i < nblock; i++)
170	s->offset[chan][i] = mean;
171	}
172
173	static int inline get_le32(GetBitContext *gb)
174	{
175	return bswap_32(get_bits_long(gb, 32));
176	}
177
178	static short inline get_le16(GetBitContext *gb)
179	{
180	return bswap_16(get_bits_long(gb, 16));
181	}
182
183	static int decode_wave_header(AVCodecContext avctx, uint8_t header, int header_size)
184	{
185	GetBitContext hb;
186	int len;
187	int chunk_size;
188	short wave_format;
189
190	init_get_bits(&hb, header, header_size*8);
191	if (get_le32(&hb) != MKTAG('R','I','F','F')) {
192	av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
193	return -1;
194	}
195
196	chunk_size = get_le32(&hb);
197
198	if (get_le32(&hb) != MKTAG('W','A','V','E')) {
199	av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
200	return -1;
201	}
202
203	while (get_le32(&hb) != MKTAG('f','m','t',' ')) {
204	len = get_le32(&hb);
205	skip_bits(&hb, 8*len);
206	}
207	len = get_le32(&hb);
208
209	if (len < 16) {
210	av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
211	return -1;
212	}
213
214	wave_format = get_le16(&hb);
215
216	switch (wave_format) {
217	case WAVE_FORMAT_PCM:
218	break;
219	default:
220	av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
221	return -1;
222	}
223
224	avctx->channels = get_le16(&hb);
225	avctx->sample_rate = get_le32(&hb);
226	avctx->bit_rate = get_le32(&hb) * 8;
227	avctx->block_align = get_le16(&hb);
228	avctx->bits_per_sample = get_le16(&hb);
229
230	if (avctx->bits_per_sample != 16) {
231	av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample\n");
232	return -1;
233	}
234
235	len -= 16;
236	if (len > 0)
237	av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
238
239	return 0;
240	}
241
242	static int16_t * interleave_buffer(int16_t samples, int nchan, int blocksize, int32_t *buffer) {
243	int i, chan;
244	for (i=0; i<blocksize; i++)
245	for (chan=0; chan < nchan; chan++)
246	*samples++ = FFMIN(buffer[chan][i], 32768);
247	return samples;
248	}
249
250	static void decode_subframe_lpc(ShortenContext *s, int channel, int residual_size, int pred_order)
251	{
252	int sum, i, j;
253	int coeffs[pred_order];
254
255	for (i=0; i<pred_order; i++)
256	coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
257
258	for (i=0; i < s->blocksize; i++) {
259	sum = s->lpcqoffset;
260	for (j=0; j<pred_order; j++)
261	sum += coeffs[j] * s->decoded[channel][i-j-1];
262	s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + (sum >> LPCQUANT);
263	}
264	}
265
266
267	static int shorten_decode_frame(AVCodecContext *avctx,
268	void data, int data_size,
269	uint8_t *buf, int buf_size)
270	{
271	ShortenContext *s = avctx->priv_data;
272	int i, input_buf_size = 0;
273	int16_t *samples = data;
274	if(s->max_framesize == 0){
275	s->max_framesize= 1024; // should hopefully be enough for the first header
276	s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize);
277	}
278
279	if(1 && s->max_framesize){//FIXME truncated
280	buf_size= FFMIN(buf_size, s->max_framesize - s->bitstream_size);
281	input_buf_size= buf_size;
282
283	if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){
284	// printf("memmove\n");
285	memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
286	s->bitstream_index=0;
287	}
288	memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size);
289	buf= &s->bitstream[s->bitstream_index];
290	buf_size += s->bitstream_size;
291	s->bitstream_size= buf_size;
292
293	if(buf_size < s->max_framesize){
294	//dprintf("wanna more data ... %d\n", buf_size);
295	return input_buf_size;
296	}
297	}
298	init_get_bits(&s->gb, buf, buf_size*8);
299	get_bits(&s->gb, s->bitindex);
300	if (!s->blocksize)
301	{
302	int maxnlpc = 0;
303	/* shorten signature */
304	if (get_bits_long(&s->gb, 32) != bswap_32(ff_get_fourcc("ajkg"))) {
305	av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
306	return -1;
307	}
308
309	s->lpcqoffset = 0;
310	s->blocksize = DEFAULT_BLOCK_SIZE;
311	s->channels = 1;
312	s->nmean = -1;
313	s->version = get_bits(&s->gb, 8);
314	s->internal_ftype = get_uint(s, TYPESIZE);
315
316	s->channels = get_uint(s, CHANSIZE);
317	if (s->channels > MAX_CHANNELS) {
318	av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
319	return -1;
320	}
321
322	/* get blocksize if version > 0 */
323	if (s->version > 0) {
324	int skip_bytes;
325	s->blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
326	maxnlpc = get_uint(s, LPCQSIZE);
327	s->nmean = get_uint(s, 0);
328
329	skip_bytes = get_uint(s, NSKIPSIZE);
330	for (i=0; i<skip_bytes; i++) {
331	skip_bits(&s->gb, 8);
332	}
333	}
334	s->nwrap = FFMAX(NWRAP, maxnlpc);
335
336	allocate_buffers(s);
337
338	init_offset(s);
339
340	if (s->version > 1)
341	s->lpcqoffset = V2LPCQOFFSET;
342
343	if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
344	av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at begining of stream\n");
345	return -1;
346	}
347
348	s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
349	if (s->header_size >= OUT_BUFFER_SIZE \|\| s->header_size < CANONICAL_HEADER_SIZE) {
350	av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size);
351	return -1;
352	}
353
354	for (i=0; i<s->header_size; i++)
355	s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
356
357	if (decode_wave_header(avctx, s->header, s->header_size) < 0)
358	return -1;
359
360	s->cur_chan = 0;
361	s->bitshift = 0;
362	}
363	else
364	{
365	int cmd;
366	int len;
367	cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
368	switch (cmd) {
369	case FN_ZERO:
370	case FN_DIFF0:
371	case FN_DIFF1:
372	case FN_DIFF2:
373	case FN_DIFF3:
374	case FN_QLPC:
375	{
376	int residual_size = 0;
377	int channel = s->cur_chan;
378	int32_t coffset;
379	if (cmd != FN_ZERO) {
380	residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
381	/* this is a hack as version 0 differed in defintion of get_sr_golomb_shorten */
382	if (s->version == 0)
383	residual_size--;
384	}
385
386	if (s->nmean == 0)
387	coffset = s->offset[channel][0];
388	else {
389	int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
390	for (i=0; i<s->nmean; i++)
391	sum += s->offset[channel][i];
392	coffset = sum / s->nmean;
393	if (s->version >= 2)
394	coffset >>= FFMIN(1, s->bitshift);
395	}
396	switch (cmd) {
397	case FN_ZERO:
398	for (i=0; i<s->blocksize; i++)
399	s->decoded[channel][i] = 0;
400	break;
401	case FN_DIFF0:
402	for (i=0; i<s->blocksize; i++)
403	s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + coffset;
404	break;
405	case FN_DIFF1:
406	for (i=0; i<s->blocksize; i++)
407	s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + s->decoded[channel][i - 1];
408	break;
409	case FN_DIFF2:
410	for (i=0; i<s->blocksize; i++)
411	s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 2*s->decoded[channel][i-1]
412	- s->decoded[channel][i-2];
413	break;
414	case FN_DIFF3:
415	for (i=0; i<s->blocksize; i++)
416	s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) + 3*s->decoded[channel][i-1]
417	- 3*s->decoded[channel][i-2]
418	+ s->decoded[channel][i-3];
419	break;
420	case FN_QLPC:
421	{
422	int pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
423	for (i=0; i<pred_order; i++)
424	s->decoded[channel][i - pred_order] -= coffset;
425	decode_subframe_lpc(s, channel, residual_size, pred_order);
426	if (coffset != 0)
427	for (i=0; i < s->blocksize; i++)
428	s->decoded[channel][i] += coffset;
429	}
430	}
431	if (s->nmean > 0) {
432	int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
433	for (i=0; i<s->blocksize; i++)
434	sum += s->decoded[channel][i];
435
436	for (i=1; i<s->nmean; i++)
437	s->offset[channel][i-1] = s->offset[channel][i];
438
439	if (s->version < 2)
440	s->offset[channel][s->nmean - 1] = sum / s->blocksize;
441	else
442	s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
443	}
444	for (i=-s->nwrap; i<0; i++)
445	s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
446
447	fix_bitshift(s, s->decoded[channel]);
448
449	s->cur_chan++;
450	if (s->cur_chan == s->channels) {
451	samples = interleave_buffer(samples, s->channels, s->blocksize, s->decoded);
452	s->cur_chan = 0;
453	goto frame_done;
454	}
455	break;
456	}
457	break;
458	case FN_VERBATIM:
459	len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
460	while (len--) {
461	get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
462	}
463	break;
464	case FN_BITSHIFT:
465	s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
466	break;
467	case FN_BLOCKSIZE:
468	s->blocksize = get_uint(s, av_log2(s->blocksize));
469	break;
470	case FN_QUIT:
471	return buf_size;
472	break;
473	default:
474	av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
475	return -1;
476	break;
477	}
478	}
479	frame_done:
480	data_size = (int8_t )samples - (int8_t *)data;
481
482	// s->last_blocksize = s->blocksize;
483	s->bitindex = get_bits_count(&s->gb) - 8*((get_bits_count(&s->gb))/8);
484	i= (get_bits_count(&s->gb))/8;
485	if (i > buf_size) {
486	av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
487	s->bitstream_size=0;
488	s->bitstream_index=0;
489	return -1;
490	}
491	if (s->bitstream_size) {
492	s->bitstream_index += i;
493	s->bitstream_size -= i;
494	return input_buf_size;
495	} else
496	return i;
497	}
498
499	static int shorten_decode_close(AVCodecContext *avctx)
500	{
501	ShortenContext *s = avctx->priv_data;
502	int i;
503
504	for (i = 0; i < s->channels; i++) {
505	s->decoded[i] -= s->nwrap;
506	av_freep(&s->decoded[i]);
507	av_freep(&s->offset[i]);
508	}
509	av_freep(&s->bitstream);
510	return 0;
511	}
512
513	static void shorten_flush(AVCodecContext *avctx){
514	ShortenContext *s = avctx->priv_data;
515
516	s->bitstream_size=
517	s->bitstream_index= 0;
518	}
519
520	AVCodec shorten_decoder = {
521	"shorten",
522	CODEC_TYPE_AUDIO,
523	CODEC_ID_SHORTEN,
524	sizeof(ShortenContext),
525	shorten_decode_init,
526	NULL,
527	shorten_decode_close,
528	shorten_decode_frame,
529	.flush= shorten_flush,
530	};

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source: vbox/trunk/src/libs/ffmpeg-20060710/libavcodec/shorten.c@ 7692

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