1/* libFLAC - Free Lossless Audio Codec
2 * Copyright (C) 2002-2009  Josh Coalson
3 * Copyright (C) 2011-2016  Xiph.Org Foundation
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * - Neither the name of the Xiph.org Foundation nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#ifdef HAVE_CONFIG_H
34#  include <config.h>
35#endif
36
37#include <string.h> /* for memcpy() */
38#include "FLAC/assert.h"
39#include "private/ogg_decoder_aspect.h"
40#include "private/ogg_mapping.h"
41#include "private/macros.h"
42
43
44/***********************************************************************
45 *
46 * Public class methods
47 *
48 ***********************************************************************/
49
50FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
51{
52	/* we will determine the serial number later if necessary */
53	if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
54		return false;
55
56	if(ogg_sync_init(&aspect->sync_state) != 0)
57		return false;
58
59	aspect->version_major = ~(0u);
60	aspect->version_minor = ~(0u);
61
62	aspect->need_serial_number = aspect->use_first_serial_number;
63
64	aspect->end_of_stream = false;
65	aspect->have_working_page = false;
66
67	return true;
68}
69
70void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
71{
72	(void)ogg_sync_clear(&aspect->sync_state);
73	(void)ogg_stream_clear(&aspect->stream_state);
74}
75
76void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
77{
78	aspect->use_first_serial_number = false;
79	aspect->serial_number = value;
80}
81
82void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
83{
84	aspect->use_first_serial_number = true;
85}
86
87void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
88{
89	(void)ogg_stream_reset(&aspect->stream_state);
90	(void)ogg_sync_reset(&aspect->sync_state);
91	aspect->end_of_stream = false;
92	aspect->have_working_page = false;
93}
94
95void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
96{
97	FLAC__ogg_decoder_aspect_flush(aspect);
98
99	if(aspect->use_first_serial_number)
100		aspect->need_serial_number = true;
101}
102
103FLAC__OggDecoderAspectReadStatus FLAC__ogg_decoder_aspect_read_callback_wrapper(FLAC__OggDecoderAspect *aspect, FLAC__byte buffer[], size_t *bytes, FLAC__OggDecoderAspectReadCallbackProxy read_callback, const FLAC__StreamDecoder *decoder, void *client_data)
104{
105	static const size_t OGG_BYTES_CHUNK = 8192;
106	const size_t bytes_requested = *bytes;
107
108	/*
109	 * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
110	 * is push-based.  In libFLAC, when you ask to decode a frame, the
111	 * decoder will eventually call the read callback to supply some data,
112	 * but how much it asks for depends on how much free space it has in
113	 * its internal buffer.  It does not try to grow its internal buffer
114	 * to accomodate a whole frame because then the internal buffer size
115	 * could not be limited, which is necessary in embedded applications.
116	 *
117	 * Ogg however grows its internal buffer until a whole page is present;
118	 * only then can you get decoded data out.  So we can't just ask for
119	 * the same number of bytes from Ogg, then pass what's decoded down to
120	 * libFLAC.  If what libFLAC is asking for will not contain a whole
121	 * page, then we will get no data from ogg_sync_pageout(), and at the
122	 * same time cannot just read more data from the client for the purpose
123	 * of getting a whole decoded page because the decoded size might be
124	 * larger than libFLAC's internal buffer.
125	 *
126	 * Instead, whenever this read callback wrapper is called, we will
127	 * continually request data from the client until we have at least one
128	 * page, and manage pages internally so that we can send pieces of
129	 * pages down to libFLAC in such a way that we obey its size
130	 * requirement.  To limit the amount of callbacks, we will always try
131	 * to read in enough pages to return the full number of bytes
132	 * requested.
133	 */
134	*bytes = 0;
135	while (*bytes < bytes_requested && !aspect->end_of_stream) {
136		if (aspect->have_working_page) {
137			if (aspect->have_working_packet) {
138				size_t n = bytes_requested - *bytes;
139				if ((size_t)aspect->working_packet.bytes <= n) {
140					/* the rest of the packet will fit in the buffer */
141					n = aspect->working_packet.bytes;
142					memcpy(buffer, aspect->working_packet.packet, n);
143					*bytes += n;
144					buffer += n;
145					aspect->have_working_packet = false;
146				}
147				else {
148					/* only n bytes of the packet will fit in the buffer */
149					memcpy(buffer, aspect->working_packet.packet, n);
150					*bytes += n;
151					buffer += n;
152					aspect->working_packet.packet += n;
153					aspect->working_packet.bytes -= n;
154				}
155			}
156			else {
157				/* try and get another packet */
158				const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
159				if (ret > 0) {
160					aspect->have_working_packet = true;
161					/* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
162					if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
163						const FLAC__byte *b = aspect->working_packet.packet;
164						const unsigned header_length =
165							FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
166							FLAC__OGG_MAPPING_MAGIC_LENGTH +
167							FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
168							FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
169							FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
170						if (aspect->working_packet.bytes < (long)header_length)
171							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
172						b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
173						if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
174							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
175						b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
176						aspect->version_major = (unsigned)(*b);
177						b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
178						aspect->version_minor = (unsigned)(*b);
179						if (aspect->version_major != 1)
180							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
181						aspect->working_packet.packet += header_length;
182						aspect->working_packet.bytes -= header_length;
183					}
184				}
185				else if (ret == 0) {
186					aspect->have_working_page = false;
187				}
188				else { /* ret < 0 */
189					/* lost sync, we'll leave the working page for the next call */
190					return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
191				}
192			}
193		}
194		else {
195			/* try and get another page */
196			const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
197			if (ret > 0) {
198				/* got a page, grab the serial number if necessary */
199				if(aspect->need_serial_number) {
200					aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
201					aspect->need_serial_number = false;
202				}
203				if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
204					aspect->have_working_page = true;
205					aspect->have_working_packet = false;
206				}
207				/* else do nothing, could be a page from another stream */
208			}
209			else if (ret == 0) {
210				/* need more data */
211				const size_t ogg_bytes_to_read = flac_max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
212				char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
213
214				if(0 == oggbuf) {
215					return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
216				}
217				else {
218					size_t ogg_bytes_read = ogg_bytes_to_read;
219
220					switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
221						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
222							break;
223						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
224							aspect->end_of_stream = true;
225							break;
226						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
227							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
228						default:
229							FLAC__ASSERT(0);
230					}
231
232					if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
233						/* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
234						FLAC__ASSERT(0);
235						return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
236					}
237				}
238			}
239			else { /* ret < 0 */
240				/* lost sync, bail out */
241				return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
242			}
243		}
244	}
245
246	if (aspect->end_of_stream && *bytes == 0) {
247		return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
248	}
249
250	return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
251}
252