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1 /*
2 ** Copyright (C) 2002-2019 Erik de Castro Lopo <erikd@mega-nerd.com>
3 ** Copyright (C) 2007 John ffitch
4 ** Copyright (C) 2018 Arthur Taylor <art@ified.ca>
5 **
6 ** This program is free software ; you can redistribute it and/or modify
7 ** it under the terms of the GNU Lesser General Public License as published by
8 ** the Free Software Foundation ; either version 2.1 of the License, or
9 ** (at your option) any later version.
10 **
11 ** This program is distributed in the hope that it will be useful,
12 ** but WITHOUT ANY WARRANTY ; without even the implied warranty of
13 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
14 ** GNU Lesser General Public License for more details.
15 **
16 ** You should have received a copy of the GNU Lesser General Public License
17 ** along with this program ; if not, write to the Free Software
18 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20 
21 /*
22 ** This file contains code based on OpusFile and Opus-Tools, both by
23 ** Xiph.Org. COPYING from each is identical and is as follows:
24 **
25 ** Copyright (c) 1994-2013 Xiph.Org Foundation and contributors
26 **
27 ** Redistribution and use in source and binary forms, with or without
28 ** modification, are permitted provided that the following conditions
29 ** are met:
30 **
31 ** - Redistributions of source code must retain the above copyright
32 ** notice, this list of conditions and the following disclaimer.
33 **
34 ** - Redistributions in binary form must reproduce the above copyright
35 ** notice, this list of conditions and the following disclaimer in the
36 ** documentation and/or other materials provided with the distribution.
37 **
38 ** - Neither the name of the Xiph.Org Foundation nor the names of its
39 ** contributors may be used to endorse or promote products derived from
40 ** this software without specific prior written permission.
41 **
42 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
43 ** ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
44 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
45 ** A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION
46 ** OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
47 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
48 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
49 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
50 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
51 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
52 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
53 */
54 
55 #include "sfconfig.h"
56 
57 #include <stdio.h>
58 #include <fcntl.h>
59 #include <string.h>
60 #include <ctype.h>
61 #include <time.h>
62 #include <math.h>
63 
64 #if HAVE_UNISTD_H
65 #include <unistd.h>
66 #else
67 #include "sf_unistd.h"
68 #endif
69 
70 #include "sndfile.h"
71 #include "sfendian.h"
72 #include "common.h"
73 
74 #if HAVE_EXTERNAL_XIPH_LIBS
75 
76 #include <ogg/ogg.h>
77 
78 #include "ogg.h"
79 
80 #define OGG_SYNC_READ_SIZE (2048)
81 #define OGG_PAGE_SIZE_MAX (65307)
82 #define OGG_CHUNK_SIZE (65536)
83 #define OGG_CHUNK_SIZE_MAX (1024*1024)
84 
85 /*
86  * The Ogg container may seem overly complicated, particularly when used for a
87  * on-disk audio file format. This is probably because Ogg is designed with
88  * streaming rather than storage as a priority, and can handle multiple codec
89  * payloads multiplexed together, then possibly chained on top of that.
90  * Ogg achieves its goals well, but it does lend to a bit of a learning curve,
91  * with many internal structures to push data around in compared to most sound
92  * file formats which only have a header and raw data.
93  *
94  * See
95  *  - [https://xiph.org/ogg/doc/oggstream.html]
96  *  - [https://xiph.org/ogg/doc/framing.html]
97  *
98  * libogg Memory Management
99  * ===========================================================================
100  *
101  * libOgg's memory management is documented in code, not in headers or external
102  * documentation. What follows is not an attempt to completely document it, but
103  * an explanation of the basics.
104  *
105  * libOgg has two data structures which allocate and manage data buffers: The
106  * ogg_sync_state structure and the ogg_stream_state structure. The remaining
107  * structures of ogg_page and ogg_packet are views into the buffers managed by
108  * the previous structures.
109  *
110  * ogg_sync_state is used for reading purposes. It takes a physical bitstream
111  * and searches for, validates, and returns complete Ogg Pages. The
112  * ogg_sync_state buffers the returned page data, holding at most one
113  * complete page at a time. A returned Ogg page remains valid until any
114  * operation other than ogg_sync_check() is called.
115  *
116  * ogg_stream_state is used for both reading and writing. For reading, the
117  * contents of an ogg_page is copied into the stream state. This data is
118  * buffered to be split or joined as necessary into complete ogg_packets. If,
119  * after copying an ogg_page into an ogg_stream_state, packets are available to
120  * be read, then all of those packets remain in memory and valid until either
121  * the ogg_stream_state is reset, destroyed, or a new ogg_page is read into it.
122  * As the maximum number of packets an Ogg Page may contain is 255, at most 255
123  * packets may be available from an ogg_stream_state at one time.
124  *
125  * For writing, the life cycle of a buffer pointed to by a ogg_packet is the
126  * responsibility of the caller. Packets written into an ogg_stream_state are
127  * buffered until a complete page is ready for writing. Pages for writing out
128  * remain in the ogg_stream_state's buffer and valid until either the
129  * ogg_stream_state is reset, cleared, destroyed. Writing another packet into
130  * the ogg_stream_state might also invalidate such pages, but writing in
131  * packets when a page is ready to be written out is a caller bug anyways.
132  */
133 
134 /*-----------------------------------------------------------------------------------------------
135 ** Private function prototypes.
136 */
137 
138 static int		ogg_close (SF_PRIVATE *psf) ;
139 static int		ogg_stream_classify (SF_PRIVATE *psf, OGG_PRIVATE * odata) ;
140 static int		ogg_page_classify (SF_PRIVATE * psf, const ogg_page * og) ;
141 static uint64_t	ogg_page_search_do_rescale (uint64_t x, uint64_t from, uint64_t to) ;
142 static void		ogg_page_search_continued_data (OGG_PRIVATE *odata, ogg_page *page) ;
143 
144 /*-----------------------------------------------------------------------------------------------
145 ** Exported functions.
146 */
147 
148 int
ogg_read_first_page(SF_PRIVATE * psf,OGG_PRIVATE * odata)149 ogg_read_first_page (SF_PRIVATE *psf, OGG_PRIVATE *odata)
150 {	int ret ;
151 	char *buffer ;
152 
153 	/*
154 	** The ogg standard requires that the first pages of a physical ogg
155 	** bitstream be only the first pages of each logical bitstream. These
156 	** pages MUST have the Beginning-Of-Stream bit set, and must contain
157 	** only the stream's relevant header. Currently we only load the first
158 	** page and check that it contains a codec we support as supporting
159 	** multiplexed streams (video+audio(en)+audio(fs)+subtitles, etc) is
160 	** beyond the scope of this library.
161 	*/
162 
163 	ret = ogg_sync_fseek (psf, psf->header.indx, SEEK_SET) ;
164 	if (ret < 0)
165 		return SFE_NOT_SEEKABLE ;
166 
167 	buffer = ogg_sync_buffer (&odata->osync, psf->header.indx) ;
168 	memcpy (buffer, psf->header.ptr, psf->header.indx) ;
169 	ogg_sync_wrote (&odata->osync, psf->header.indx) ;
170 
171 	ret = ogg_sync_next_page (psf, &odata->opage, SF_MAX ((sf_count_t) 0, 4096 - psf->header.indx), NULL) ;
172 
173 	/* Have we simply run out of data?  If so, we're done. */
174 	if (ret == 0)
175 		return 0 ;
176 	if (ret < 0)
177 		return psf->error ;
178 
179 	if (!ogg_page_bos (&odata->opage))
180 	{	/*
181 		** Error case. Either must not be an Ogg bitstream, or is in the
182 		** middle of a bitstream (live capture), or in the middle of a
183 		** bitstream and no complete page was in the buffer.
184 		*/
185 		psf_log_printf (psf, "Input does not appear to be the start of an Ogg bitstream.\n") ;
186 		return SFE_MALFORMED_FILE ;
187 		} ;
188 
189 	/*
190 	**	Get the serial number and set up the rest of decode.
191 	**	Serialno first ; use it to set up a logical stream.
192 	*/
193 	ogg_stream_reset_serialno (&odata->ostream, ogg_page_serialno (&odata->opage)) ;
194 
195 	if (ogg_stream_pagein (&odata->ostream, &odata->opage) < 0)
196 	{	/* Error ; stream version mismatch perhaps. */
197 		psf_log_printf (psf, "Error reading first page of Ogg bitstream data\n") ;
198 		return SFE_MALFORMED_FILE ;
199 		} ;
200 
201 	if (ogg_stream_packetout (&odata->ostream, &odata->opacket) != 1)
202 	{	/* No page? */
203 		psf_log_printf (psf, "Error reading initial header page packet.\n") ;
204 		return SFE_MALFORMED_FILE ;
205 		} ;
206 
207 	return 0 ;
208 } /* ogg_read_first_page */
209 
210 int
ogg_write_page(SF_PRIVATE * psf,ogg_page * page)211 ogg_write_page (SF_PRIVATE *psf, ogg_page *page)
212 {	int bytes ;
213 
214 	bytes = psf_fwrite (page->header, 1, page->header_len, psf) ;
215 	bytes += psf_fwrite (page->body, 1, page->body_len, psf) ;
216 
217 	return bytes == page->header_len + page->body_len ;
218 } /* ogg_write_page */
219 
220 sf_count_t
ogg_sync_ftell(SF_PRIVATE * psf)221 ogg_sync_ftell (SF_PRIVATE *psf)
222 {	OGG_PRIVATE* odata = (OGG_PRIVATE *) psf->container_data ;
223 	sf_count_t position ;
224 
225 	position = psf_ftell (psf) ;
226 	if (position >= 0)
227 	{	/* success */
228 		if (position < odata->osync.fill)
229 		{	/* Really, this should be an assert. */
230 			psf->error = SFE_INTERNAL ;
231 			return -1 ;
232 			}
233 		position += (sf_count_t) (odata->osync.returned - odata->osync.fill) ;
234 		}
235 
236 	return position ;
237 } /* ogg_sync_ftell */
238 
239 sf_count_t
ogg_sync_fseek(SF_PRIVATE * psf,sf_count_t offset,int whence)240 ogg_sync_fseek (SF_PRIVATE *psf, sf_count_t offset, int whence)
241 {	OGG_PRIVATE* odata = (OGG_PRIVATE *) psf->container_data ;
242 	sf_count_t ret ;
243 
244 	ret = psf_fseek (psf, offset, whence) ;
245 	if (ret >= 0)
246 	{	/* success */
247 		odata->eos = 0 ;
248 		ogg_sync_reset (&odata->osync) ;
249 		}
250 
251 	return ret ;
252 } /* ogg_sync_fseek */
253 
254 int
ogg_sync_next_page(SF_PRIVATE * psf,ogg_page * og,sf_count_t readmax,sf_count_t * offset)255 ogg_sync_next_page (SF_PRIVATE * psf, ogg_page *og, sf_count_t readmax, sf_count_t *offset)
256 {	OGG_PRIVATE* odata = (OGG_PRIVATE *) psf->container_data ;
257 	sf_count_t position, nb_read, read_ret ;
258 	unsigned char *buffer ;
259 	int synced ;
260 	int report_hole = 0 ;
261 
262 	for (position = 0 ; readmax <= 0 || readmax > position ; )
263 	{	synced = ogg_sync_pageseek (&odata->osync, og) ;
264 		if (synced < 0)
265 		{	/*
266 			** Skipped -synced bytes before finding the start of a page.
267 			** If seeking, we have just landed in the middle of a page.
268 			** Otherwise, warn about junk in the bitstream.
269 			** Page might not yet be ready, hence the continue.
270 			*/
271 			if (!offset)
272 				report_hole = 1 ;
273 			position -= synced ;
274 			continue ;
275 			} ;
276 
277 		if (report_hole)
278 		{	psf_log_printf (psf, "Ogg : Skipped %d bytes looking for the next page. Corrupted bitstream?!\n", position) ;
279 			report_hole = 0 ;
280 			} ;
281 
282 		if (synced > 0)
283 		{	/* Have a page */
284 			if (offset)
285 				*offset += position ;
286 			return og->header_len + og->body_len ;
287 			} ;
288 
289 		/*
290 		** Else readmax == 0, Out of data. Try to read more in without
291 		** invalidating our boundary (readmax) constraint.
292 		*/
293 		if (readmax == 0)
294 			return 0 ;
295 		if (readmax > 0)
296 			nb_read = SF_MIN ((sf_count_t) OGG_SYNC_READ_SIZE, readmax - position) ;
297 		else
298 			nb_read = OGG_SYNC_READ_SIZE ;
299 		buffer = (unsigned char *) ogg_sync_buffer (&odata->osync, nb_read) ;
300 		read_ret = psf_fread (buffer, 1, nb_read, psf) ;
301 		if (read_ret == 0)
302 			return psf->error ? -1 : 0 ;
303 		ogg_sync_wrote (&odata->osync, read_ret) ;
304 		} ;
305 	return 0 ;
306 } /* ogg_sync_next_page */
307 
308 int
ogg_stream_next_page(SF_PRIVATE * psf,OGG_PRIVATE * odata)309 ogg_stream_next_page (SF_PRIVATE *psf, OGG_PRIVATE *odata)
310 {	int nn ;
311 
312 	if (odata->eos)
313 		return 0 ;
314 
315 	for ( ; ; )
316 	{	nn = ogg_sync_next_page (psf, &odata->opage, -1, NULL) ;
317 		if (nn == 0)
318 		{	psf_log_printf (psf, "Ogg : File ended unexpectedly without an End-Of-Stream flag set.\n") ;
319 			odata->eos = 1 ;
320 			}
321 		if (nn <= 0)
322 			return nn ;
323 
324 		if (ogg_page_serialno (&odata->opage) == odata->ostream.serialno)
325 			break ;
326 		} ;
327 
328 	if (ogg_page_eos (&odata->opage))
329 		odata->eos = 1 ;
330 
331 	if (ogg_stream_pagein (&odata->ostream, &odata->opage) < 0)
332 	{	psf->error = SFE_INTERNAL ;
333 		return -1 ;
334 		}
335 
336 	return 1 ;
337 } /* ogg_stream_next_page */
338 
339 int
ogg_stream_unpack_page(SF_PRIVATE * psf,OGG_PRIVATE * odata)340 ogg_stream_unpack_page (SF_PRIVATE *psf, OGG_PRIVATE *odata)
341 {	int nn ;
342 	int i ;
343 	int found_hole = 0 ;
344 	ogg_packet *ppkt = odata->pkt ;
345 
346 	odata->pkt_indx = 0 ;
347 	nn = ogg_stream_packetout (&odata->ostream, ppkt) ;
348 	if (nn == 0)
349 	{	/*
350 		** Steam is out of packets. Read in more pages until there is one, or
351 		** the stream ends, or an error occurs.
352 		*/
353 		for ( ; nn == 0 ; nn = ogg_stream_packetout (&odata->ostream, ppkt))
354 		{	nn = ogg_stream_next_page (psf, odata) ;
355 			if (nn <= 0)
356 			{	odata->pkt_len = 0 ;
357 				return nn ;
358 				}
359 			}
360 		/*
361 		** In the case of the for loop exiting because
362 		** ogg_stream_packetout() == -1, fall-through.
363 		*/
364 		}
365 
366 	if (nn == -1)
367 	{	/*
368 		** libOgg found a hole. That is, the next packet found was out of
369 		** sequence. As such, "flush" the hole marker by removing the invalid
370 		** packet, as the valid packets are queued behind it.
371 		*/
372 		psf_log_printf (psf, "Ogg : Warning, libogg reports a hole at %d bytes.\n", ogg_sync_ftell (psf)) ;
373 		nn = ogg_stream_packetout (&odata->ostream, ppkt) ;
374 		found_hole = 1 ;
375 		}
376 
377 	/*
378 	** Unpack all the packets on the page. It is undocumented (like much of
379 	** libOgg behavior) but all packets from a page read into the stream are
380 	** guarenteed to remain valid in memory until a new page is read into the
381 	** stream.
382 	*/
383 	for (i = 1 ; ; i++)
384 	{	/* Not an off-by-one, there are 255 not 256 packets max. */
385 		if (i == 255)
386 		{	if (ogg_stream_packetpeek (&odata->ostream, NULL) == 1)
387 			{	psf->error = SFE_INTERNAL ;
388 				return -1 ;
389 				}
390 			break ;
391 			}
392 		if (ogg_stream_packetout (&odata->ostream, ++ ppkt) != 1)
393 			break ;
394 		}
395 	odata->pkt_len = i ;
396 
397 	/* 1 = ok, 2 = ok, and found a hole. */
398 	return 1 + found_hole ;
399 } /* ogg_stream_unpack_page */
400 
401 sf_count_t
ogg_sync_last_page_before(SF_PRIVATE * psf,OGG_PRIVATE * odata,uint64_t * gp_out,sf_count_t offset,int32_t serialno)402 ogg_sync_last_page_before (SF_PRIVATE *psf, OGG_PRIVATE *odata, uint64_t *gp_out, sf_count_t offset, int32_t serialno)
403 {	sf_count_t begin, end, original_end, chunk_size, ret ;
404 	sf_count_t position = 0 ;
405 	uint64_t gp = -1 ;
406 	int left_link ;
407 
408 	/* Based on code from Xiph.org's Opusfile */
409 
410 	original_end = end = begin = offset ;
411 	offset = -1 ;
412 	chunk_size = OGG_CHUNK_SIZE ;
413 	do
414 	{	begin = SF_MAX (begin - chunk_size, (sf_count_t) 0) ;
415 		position = ogg_sync_fseek (psf, begin, SEEK_SET) ;
416 		if (position < 0)
417 			return position ;
418 		left_link = 0 ;
419 		while (position < end)
420 		{	ret = ogg_sync_next_page (psf, &odata->opage, end - position, &position) ;
421 			if (ret <= 0)
422 				return -1 ;
423 			if (ogg_page_serialno (&odata->opage) == serialno)
424 			{	uint64_t page_gp = ogg_page_granulepos (&odata->opage) ;
425 				if (page_gp != (uint64_t) -1)
426 				{	offset = position ;
427 					gp = page_gp ;
428 					}
429 				}
430 			else
431 				left_link = 1 ;
432 			position += ret ;
433 			}
434 
435 		if ((left_link || !begin) && offset < 0)
436 		{	psf->error = SFE_MALFORMED_FILE ;
437 			return -1 ;
438 			}
439 
440 		chunk_size = SF_MIN (2 * chunk_size, (sf_count_t) OGG_CHUNK_SIZE_MAX) ;
441 		end = SF_MIN (begin + OGG_PAGE_SIZE_MAX - 1, original_end) ;
442 		}
443 	while (offset < 0) ;
444 
445 	*gp_out = gp ;
446 	return offset ;
447 } /* ogg_sync_last_page_before */
448 
449 int
ogg_stream_seek_page_search(SF_PRIVATE * psf,OGG_PRIVATE * odata,uint64_t target_gp,uint64_t pcm_start,uint64_t pcm_end,uint64_t * best_gp,sf_count_t begin,sf_count_t end)450 ogg_stream_seek_page_search (SF_PRIVATE *psf, OGG_PRIVATE *odata, uint64_t target_gp, uint64_t pcm_start, uint64_t pcm_end, uint64_t *best_gp, sf_count_t begin, sf_count_t end)
451 {	ogg_page page ;
452 	uint64_t gp ;
453 	sf_count_t d0, d1, d2 ;
454 	sf_count_t best ;
455 	sf_count_t best_start ;
456 	sf_count_t boundary ;
457 	sf_count_t next_boundary ;
458 	sf_count_t page_offset = -1 ;
459 	sf_count_t seek_pos = -1 ;
460 	sf_count_t bisect ;
461 	sf_count_t chunk_size ;
462 	int buffering = SF_FALSE ;
463 	int force_bisect = SF_FALSE ;
464 	int ret ;
465 	int has_packets ;
466 
467 	*best_gp = pcm_start ;
468 	best = best_start = begin ;
469 	boundary = end ;
470 
471 	ogg_stream_reset_serialno (&odata->ostream, odata->ostream.serialno) ;
472 
473 	/*
474 	** This code is based on op_pcm_seek_page() from Opusfile, which is in turn
475 	** based on "new search algorithm by Nicholas Vinen" from libvorbisfile.
476 	*/
477 
478 	d2 = d1 = d0 = end - begin ;
479 	while (begin < end)
480 	{	/*
481 		** Figure out if and where to try and seek in the file.
482 		*/
483 		if (end - begin < OGG_CHUNK_SIZE)
484 			bisect = begin ;
485 		else
486 		{	/* Update the interval size history */
487 			d0 = d1 >> 1 ;
488 			d1 = d2 >> 1 ;
489 			d2 = (end - begin) >> 1 ;
490 			if (force_bisect == SF_TRUE)
491 				bisect = begin + ((end - begin) >> 1) ;
492 			else
493 			{	/* Take a decent guess. */
494 				bisect = begin + ogg_page_search_do_rescale (target_gp - pcm_start, pcm_end - pcm_start, end - begin) ;
495 				}
496 			if (bisect - OGG_CHUNK_SIZE < begin)
497 				bisect = begin ;
498 			else
499 				bisect -= OGG_CHUNK_SIZE ;
500 			force_bisect = SF_FALSE ;
501 			}
502 
503 		/*
504 		** Avoid an actual fseek if we can (common for final iterations.)
505 		*/
506 		if (seek_pos != bisect)
507 		{	if (buffering == SF_TRUE)
508 				ogg_stream_reset (&odata->ostream) ;
509 			buffering = SF_FALSE ;
510 			page_offset = -1 ;
511 			seek_pos = ogg_sync_fseek (psf, bisect, SEEK_SET) ;
512 			if (seek_pos < 0)
513 				return seek_pos ;
514 			}
515 
516 		chunk_size = OGG_CHUNK_SIZE ;
517 		next_boundary = boundary ;
518 
519 		/*
520 		** Scan forward, figure out where we landed.
521 		** The ideal case is we see a page that ends before our target followed
522 		** by a page that ends after our target.
523 		** If we are too far before or after, breaking out will bisect what we
524 		** have found so far.
525 		*/
526 		while (begin < end)
527 		{	ret = ogg_sync_next_page (psf, &page, boundary - seek_pos, &seek_pos) ;
528 			if (ret <= 0)
529 				return ret ;
530 			page_offset = seek_pos ;
531 			if (ret == 0)
532 			{	/*
533 				** There are no more pages in this interval from our stream
534 				** with a granulepos less than our target.
535 				*/
536 				if (bisect <= begin + 1)
537 				{	/* Scanned the whole interval, so we are done. */
538 					end = begin ;
539 					}
540 				else
541 				{	/*
542 					** Otherwise, back up one chunk. First discard any data
543 					** from a continued packet.
544 					*/
545 					if (buffering)
546 						ogg_stream_reset (&odata->ostream) ;
547 					buffering = SF_FALSE ;
548 					bisect = SF_MAX (bisect - chunk_size, begin) ;
549 					seek_pos = ogg_sync_fseek (psf, bisect, SEEK_SET) ;
550 					if (seek_pos < 0)
551 						return seek_pos ;
552 					/* Bump up the chunk size. */
553 					chunk_size = SF_MIN (2 * chunk_size, (sf_count_t) OGG_CHUNK_SIZE_MAX) ;
554 					/*
555 					** If we did find a page from another stream or without a
556 					** timestamp, don't read past it.
557 					*/
558 					boundary = next_boundary ;
559 					}
560 				continue ;
561 				}
562 
563 			/* Found a page. Advance seek_pos past it */
564 			seek_pos += page.header_len + page.body_len ;
565 			/*
566 			** Save the offset of the first page we found after the seek,
567 			** regardless of the stream it came from or whether or not it has a
568 			** timestamp.
569 			*/
570 			next_boundary = SF_MIN (page_offset, next_boundary) ;
571 
572 			/* If not from our stream, continue. */
573 			if (odata->ostream.serialno != ogg_page_serialno (&page))
574 				continue ;
575 
576 			/*
577 			** The Ogg spec says that a page with a granule pos of -1 must not
578 			** contain and packets which complete, but the lack of biconditional
579 			** wording means that /technically/ a packet which does not complete
580 			** any packets can have a granule pos other than -1. To make matters
581 			** worse, older versions of libogg did just that.
582 			*/
583 			has_packets = ogg_page_packets (&page) > 0 ;
584 			gp = has_packets ? ogg_page_granulepos (&page) : -1 ;
585 			if (gp == (uint64_t) -1)
586 			{	if (buffering == SF_TRUE)
587 				{	if (!has_packets)
588 						ogg_stream_pagein (&odata->ostream, &page) ;
589 					else
590 					{	/*
591 						** If packets did end on this page, but we still didn't
592 						** have a valid granule position (in violation of the
593 						** spec!), stop buffering continued packet data.
594 						** Otherwise we might continue past the packet we
595 						** actually wanted.
596 						*/
597 						ogg_stream_reset (&odata->ostream) ;
598 						buffering = SF_FALSE ;
599 						}
600 					}
601 				continue ;
602 				}
603 
604 			if (gp < target_gp)
605 			{	/*
606 				** We found a page that ends before our target. Advance to
607 				** the raw offset of the next page.
608 				*/
609 				begin = seek_pos ;
610 				if (pcm_start > gp || pcm_end < gp)
611 					break ;
612 				/* Save the byte offset of after this page. */
613 				best = best_start = begin ;
614 				if (buffering)
615 					ogg_stream_reset (&odata->ostream) ;
616 				/* Check to see if the last packet continues. */
617 				if (page.header [27 + page.header [26] - 1] == 255)
618 				{	ogg_page_search_continued_data (odata, &page) ;
619 					/*
620 					** If we have a continued packet, remember the offset of
621 					** this page's start, so that if we do wind up having to
622 					** seek back here later, we can prime the stream with the
623 					** continued packet data. With no continued packet, we
624 					** remember the end of the page.
625 					*/
626 					best_start = page_offset ;
627 					} ;
628 				/*
629 				** Then force buffering on, so that if a packet starts (but
630 				** does not end) on the next page, we still avoid the extra
631 				** seek back.
632 				*/
633 				buffering = SF_TRUE ;
634 				*best_gp = pcm_start = gp ;
635 				if (target_gp - gp > 48000)
636 				{	/* Out by over a second. Try another bisection. */
637 					break ;
638 					}
639 				/* Otherwise, keep scanning forward (do NOT use begin+1). */
640 				bisect = begin ;
641 				}
642 			else
643 			{	/*
644 				** Found a page that ends after our target. If we had just
645 				** scanned the whole interval before we found it, we're good.
646 				*/
647 				if (bisect <= begin + 1)
648 					end = begin ;
649 				else
650 				{	end = bisect ;
651 					/*
652 					** In later iterations, don't read past the first page we
653 					** found.
654 					*/
655 					boundary = next_boundary ;
656 					/*
657 					** If we're not making much progress shrinking the interval
658 					** size, start forcing straight bisection to limit the
659 					** worst case.
660 					*/
661 					force_bisect = end - begin > d0 * 2 ? SF_TRUE : SF_FALSE ;
662 					/*
663 					** Don't let pcm_end get out of range! That could happen
664 					** with an invalid timestamp.
665 					*/
666 					if (pcm_end > gp && pcm_start <= gp)
667 						pcm_end = gp ;
668 					}
669 				break ;
670 				}
671 			}
672 		}
673 
674 	/*
675 	** If we are buffering, the page we want is currently buffered in the
676 	** Ogg stream structure, or in the Ogg page which has not been submitted.
677 	** If not, we need to seek back and load it again.
678 	*/
679 	if (buffering == SF_FALSE)
680 	{	if (best_start != page_offset)
681 		{	page_offset = -1 ;
682 			seek_pos = ogg_sync_fseek (psf, best_start, SEEK_SET) ;
683 			if (seek_pos < 0)
684 				return seek_pos ;
685 			}
686 		if (best_start < best)
687 		{	if (page_offset < 0)
688 			{	ret = ogg_sync_next_page (psf, &page, -1, &seek_pos) ;
689 				if (seek_pos != best_start)
690 					return -1 ;
691 				}
692 			ogg_page_search_continued_data (odata, &page) ;
693 			page_offset = -1 ;
694 			}
695 		} ;
696 
697 	if (page_offset >= 0)
698 		ogg_stream_pagein (&odata->ostream, &page) ;
699 
700 	return 0 ;
701 } /* ogg_stream_seek_page_search */
702 
703 int
ogg_open(SF_PRIVATE * psf)704 ogg_open (SF_PRIVATE *psf)
705 {	OGG_PRIVATE* odata = calloc (1, sizeof (OGG_PRIVATE)) ;
706 	sf_count_t pos = psf_ftell (psf) ;
707 	int	error = 0 ;
708 
709 	psf->container_data = odata ;
710 	psf->container_close = ogg_close ;
711 
712 	if (psf->file.mode == SFM_RDWR)
713 		return SFE_BAD_MODE_RW ;
714 
715 	if (psf->file.mode == SFM_READ)
716 		if ((error = ogg_stream_classify (psf, odata)) != 0)
717 			return error ;
718 
719 	if (SF_ENDIAN (psf->sf.format) != 0)
720 		return SFE_BAD_ENDIAN ;
721 
722 	switch (psf->sf.format)
723 	{	case SF_FORMAT_OGG | SF_FORMAT_VORBIS :
724 			return ogg_vorbis_open (psf) ;
725 
726 		case SF_FORMAT_OGGFLAC :
727 			/* Reset everything to an initial state. */
728 			ogg_sync_clear (&odata->osync) ;
729 			ogg_stream_clear (&odata->ostream) ;
730 			psf_fseek (psf, pos, SEEK_SET) ;
731 			free (psf->container_data) ;
732 			psf->container_data = NULL ;
733 			psf->container_close = NULL ;
734 			return flac_open (psf) ;
735 
736 		case SF_FORMAT_OGG | SF_FORMAT_OPUS :
737 			return ogg_opus_open (psf) ;
738 
739 #if ENABLE_EXPERIMENTAL_CODE
740 		case SF_FORMAT_OGG | SF_FORMAT_SPEEX :
741 			return ogg_speex_open (psf) ;
742 
743 		case SF_FORMAT_OGG | SF_FORMAT_PCM_16 :
744 		case SF_FORMAT_OGG | SF_FORMAT_PCM_24 :
745 			return ogg_pcm_open (psf) ;
746 #endif
747 
748 		default :
749 			break ;
750 		} ;
751 
752 	psf_log_printf (psf, "%s : bad psf->sf.format 0x%x.\n", __func__, psf->sf.format) ;
753 	return SFE_INTERNAL ;
754 } /* ogg_open */
755 
756 /*==============================================================================
757 ** Private functions.
758 */
759 
760 static int
ogg_close(SF_PRIVATE * psf)761 ogg_close (SF_PRIVATE *psf)
762 {	OGG_PRIVATE* odata = psf->container_data ;
763 
764 	ogg_sync_clear (&odata->osync) ;
765 	ogg_stream_clear (&odata->ostream) ;
766 
767 	return 0 ;
768 } /* ogg_close */
769 
770 static int
ogg_stream_classify(SF_PRIVATE * psf,OGG_PRIVATE * odata)771 ogg_stream_classify (SF_PRIVATE *psf, OGG_PRIVATE* odata)
772 {	int error ;
773 
774 	/* Call this here so it only gets called once, so no memory is leaked. */
775 	ogg_sync_init (&odata->osync) ;
776 	ogg_stream_init (&odata->ostream, 0) ;
777 
778 	/* Load the first page in the physical bitstream. */
779 	if ((error = ogg_read_first_page (psf, odata)) != 0)
780 		return error ;
781 
782 	odata->codec = ogg_page_classify (psf, &odata->opage) ;
783 
784 	switch (odata->codec)
785 	{	case OGG_VORBIS :
786 			psf->sf.format = SF_FORMAT_OGG | SF_FORMAT_VORBIS ;
787 			return 0 ;
788 
789 		case OGG_FLAC :
790 		case OGG_FLAC0 :
791 			psf->sf.format = SF_FORMAT_OGGFLAC ;
792 			return 0 ;
793 
794 		case OGG_SPEEX :
795 			psf->sf.format = SF_FORMAT_OGG | SF_FORMAT_SPEEX ;
796 			return 0 ;
797 
798 		case OGG_OPUS :
799 			psf->sf.format = SF_FORMAT_OGG | SF_FORMAT_OPUS ;
800 			return 0 ;
801 
802 		case OGG_PCM :
803 			psf_log_printf (psf, "Detected Ogg/PCM data. This is not supported yet.\n") ;
804 			return SFE_UNIMPLEMENTED ;
805 
806 		default :
807 			break ;
808 		} ;
809 
810 	psf_log_printf (psf, "This Ogg bitstream contains some uknown data type.\n") ;
811 	return SFE_UNIMPLEMENTED ;
812 } /* ogg_stream_classify */
813 
814 /*==============================================================================
815 */
816 
817 static struct
818 {	const char *str, *name ;
819 	int len, codec ;
820 } codec_lookup [] =
821 {	{	"Annodex",		"Annodex",	8, OGG_ANNODEX },
822 	{	"AnxData",		"AnxData",	7, OGG_ANXDATA },
823 	{	"\177FLAC",		"Flac1",	5, OGG_FLAC },
824 	{	"fLaC",			"Flac0",	4, OGG_FLAC0 },
825 	{	"PCM     ",		"PCM",		8, OGG_PCM },
826 	{	"Speex",		"Speex",	5, OGG_SPEEX },
827 	{	"\001vorbis",	"Vorbis",	7, OGG_VORBIS },
828 	{	"OpusHead",		"Opus",		8, OGG_OPUS },
829 } ;
830 
831 static int
ogg_page_classify(SF_PRIVATE * psf,const ogg_page * og)832 ogg_page_classify (SF_PRIVATE * psf, const ogg_page * og)
833 {	int k, len ;
834 
835 	for (k = 0 ; k < ARRAY_LEN (codec_lookup) ; k++)
836 	{	if (codec_lookup [k].len > og->body_len)
837 			continue ;
838 
839 		if (memcmp (og->body, codec_lookup [k].str, codec_lookup [k].len) == 0)
840 		{	psf_log_printf (psf, "Ogg stream data : %s\n", codec_lookup [k].name) ;
841 			psf_log_printf (psf, "Stream serialno : %u\n", (uint32_t) ogg_page_serialno (og)) ;
842 			return codec_lookup [k].codec ;
843 			} ;
844 		} ;
845 
846 	len = og->body_len < 8 ? og->body_len : 8 ;
847 
848 	psf_log_printf (psf, "Ogg_stream data : '") ;
849 	for (k = 0 ; k < len ; k++)
850 		psf_log_printf (psf, "%c", isprint (og->body [k]) ? og->body [k] : '.') ;
851 	psf_log_printf (psf, "'     ") ;
852 	for (k = 0 ; k < len ; k++)
853 		psf_log_printf (psf, " %02x", og->body [k] & 0xff) ;
854 	psf_log_printf (psf, "\n") ;
855 
856 	return 0 ;
857 } /* ogg_page_classify */
858 
859 /*
860 ** Scale x from the range [0, from] to the range [0, to]
861 */
862 static uint64_t
ogg_page_search_do_rescale(uint64_t x,uint64_t from,uint64_t to)863 ogg_page_search_do_rescale (uint64_t x, uint64_t from, uint64_t to)
864 {	uint64_t frac ;
865 	uint64_t ret ;
866 	int i ;
867 
868 	/* I should have paid more attention in CSc 349A: Numerical Analysis */
869 	if (x >= from)
870 		return to ;
871 	if (x == 0)
872 		return 0 ;
873 	frac = 0 ;
874 	for (i = 0 ; i < 63 ; i++)
875 	{	frac <<= 1 ;
876 		if (x >= from >> 1)
877 		{	x -= from - x ;
878 			frac |= 1 ;
879 			}
880 		else
881 			x <<= 1 ;
882 		}
883 	ret = 0 ;
884 	for (i = 0 ; i < 63 ; i++)
885 	{	if (frac & 1)
886 			ret = (ret & to & 1) + (ret >> 1) + (to >> 1) ;
887 		else
888 			ret >>= 1 ;
889 		frac >>= 1 ;
890 		}
891 	return ret ;
892 } /* ogg_page_search_do_rescale */
893 
894 static void
ogg_page_search_continued_data(OGG_PRIVATE * odata,ogg_page * page)895 ogg_page_search_continued_data (OGG_PRIVATE *odata, ogg_page *page)
896 {	ogg_stream_pagein (&odata->ostream, page) ;
897 	while (ogg_stream_packetout (&odata->ostream, &odata->opacket)) ;
898 } /* ogg_page_search_continued_data */
899 
900 #else /* HAVE_EXTERNAL_XIPH_LIBS */
901 
902 int
ogg_open(SF_PRIVATE * psf)903 ogg_open	(SF_PRIVATE *psf)
904 {
905 	psf_log_printf (psf, "This version of libsndfile was compiled without Ogg/Vorbis support.\n") ;
906 	return SFE_UNIMPLEMENTED ;
907 } /* ogg_open */
908 
909 #endif
910