1/* libFLAC - Free Lossless Audio Codec
2 * Copyright (C) 2002,2003,2004,2005,2006,2007  Josh Coalson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * - Neither the name of the Xiph.org Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#if HAVE_CONFIG_H
33#  include <config.h>
34#endif
35
36#include <string.h> /* for memcpy() */
37#include "FLAC/assert.h"
38#include "private/ogg_decoder_aspect.h"
39#include "private/ogg_mapping.h"
40
41#ifdef max
42#undef max
43#endif
44#define max(x,y) ((x)>(y)?(x):(y))
45
46/***********************************************************************
47 *
48 * Public class methods
49 *
50 ***********************************************************************/
51
52FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
53{
54	/* we will determine the serial number later if necessary */
55	if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
56		return false;
57
58	if(ogg_sync_init(&aspect->sync_state) != 0)
59		return false;
60
61	aspect->version_major = ~(0u);
62	aspect->version_minor = ~(0u);
63
64	aspect->need_serial_number = aspect->use_first_serial_number;
65
66	aspect->end_of_stream = false;
67	aspect->have_working_page = false;
68
69	return true;
70}
71
72void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
73{
74	(void)ogg_sync_clear(&aspect->sync_state);
75	(void)ogg_stream_clear(&aspect->stream_state);
76}
77
78void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
79{
80	aspect->use_first_serial_number = false;
81	aspect->serial_number = value;
82}
83
84void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
85{
86	aspect->use_first_serial_number = true;
87}
88
89void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
90{
91	(void)ogg_stream_reset(&aspect->stream_state);
92	(void)ogg_sync_reset(&aspect->sync_state);
93	aspect->end_of_stream = false;
94	aspect->have_working_page = false;
95}
96
97void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
98{
99	FLAC__ogg_decoder_aspect_flush(aspect);
100
101	if(aspect->use_first_serial_number)
102		aspect->need_serial_number = true;
103}
104
105FLAC__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)
106{
107	static const size_t OGG_BYTES_CHUNK = 8192;
108	const size_t bytes_requested = *bytes;
109
110	/*
111	 * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
112	 * is push-based.  In libFLAC, when you ask to decode a frame, the
113	 * decoder will eventually call the read callback to supply some data,
114	 * but how much it asks for depends on how much free space it has in
115	 * its internal buffer.  It does not try to grow its internal buffer
116	 * to accomodate a whole frame because then the internal buffer size
117	 * could not be limited, which is necessary in embedded applications.
118	 *
119	 * Ogg however grows its internal buffer until a whole page is present;
120	 * only then can you get decoded data out.  So we can't just ask for
121	 * the same number of bytes from Ogg, then pass what's decoded down to
122	 * libFLAC.  If what libFLAC is asking for will not contain a whole
123	 * page, then we will get no data from ogg_sync_pageout(), and at the
124	 * same time cannot just read more data from the client for the purpose
125	 * of getting a whole decoded page because the decoded size might be
126	 * larger than libFLAC's internal buffer.
127	 *
128	 * Instead, whenever this read callback wrapper is called, we will
129	 * continually request data from the client until we have at least one
130	 * page, and manage pages internally so that we can send pieces of
131	 * pages down to libFLAC in such a way that we obey its size
132	 * requirement.  To limit the amount of callbacks, we will always try
133	 * to read in enough pages to return the full number of bytes
134	 * requested.
135	 */
136	*bytes = 0;
137	while (*bytes < bytes_requested && !aspect->end_of_stream) {
138		if (aspect->have_working_page) {
139			if (aspect->have_working_packet) {
140				size_t n = bytes_requested - *bytes;
141				if ((size_t)aspect->working_packet.bytes <= n) {
142					/* the rest of the packet will fit in the buffer */
143					n = aspect->working_packet.bytes;
144					memcpy(buffer, aspect->working_packet.packet, n);
145					*bytes += n;
146					buffer += n;
147					aspect->have_working_packet = false;
148				}
149				else {
150					/* only n bytes of the packet will fit in the buffer */
151					memcpy(buffer, aspect->working_packet.packet, n);
152					*bytes += n;
153					buffer += n;
154					aspect->working_packet.packet += n;
155					aspect->working_packet.bytes -= n;
156				}
157			}
158			else {
159				/* try and get another packet */
160				const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
161				if (ret > 0) {
162					aspect->have_working_packet = true;
163					/* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
164					if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
165						const FLAC__byte *b = aspect->working_packet.packet;
166						const unsigned header_length =
167							FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
168							FLAC__OGG_MAPPING_MAGIC_LENGTH +
169							FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
170							FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
171							FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
172						if (aspect->working_packet.bytes < (long)header_length)
173							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
174						b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
175						if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
176							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
177						b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
178						aspect->version_major = (unsigned)(*b);
179						b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
180						aspect->version_minor = (unsigned)(*b);
181						if (aspect->version_major != 1)
182							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
183						aspect->working_packet.packet += header_length;
184						aspect->working_packet.bytes -= header_length;
185					}
186				}
187				else if (ret == 0) {
188					aspect->have_working_page = false;
189				}
190				else { /* ret < 0 */
191					/* lost sync, we'll leave the working page for the next call */
192					return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
193				}
194			}
195		}
196		else {
197			/* try and get another page */
198			const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
199			if (ret > 0) {
200				/* got a page, grab the serial number if necessary */
201				if(aspect->need_serial_number) {
202					aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
203					aspect->need_serial_number = false;
204				}
205				if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
206					aspect->have_working_page = true;
207					aspect->have_working_packet = false;
208				}
209				/* else do nothing, could be a page from another stream */
210			}
211			else if (ret == 0) {
212				/* need more data */
213				const size_t ogg_bytes_to_read = max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
214				char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
215
216				if(0 == oggbuf) {
217					return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
218				}
219				else {
220					size_t ogg_bytes_read = ogg_bytes_to_read;
221
222					switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
223						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
224							break;
225						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
226							aspect->end_of_stream = true;
227							break;
228						case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
229							return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
230						default:
231							FLAC__ASSERT(0);
232					}
233
234					if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
235						/* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
236						FLAC__ASSERT(0);
237						return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
238					}
239				}
240			}
241			else { /* ret < 0 */
242				/* lost sync, bail out */
243				return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
244			}
245		}
246	}
247
248	if (aspect->end_of_stream && *bytes == 0) {
249		return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
250	}
251
252	return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
253}
254