1
/* libFLAC - Free Lossless Audio Codec
2
* Copyright (C) 2002,2003,2004,2005,2006,2007 Josh Coalson
4
* Redistribution and use in source and binary forms, with or without
5
* modification, are permitted provided that the following conditions
8
* - Redistributions of source code must retain the above copyright
9
* notice, this list of conditions and the following disclaimer.
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.
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.
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.
36
#include <string.h> /* for memcpy() */
37
#include "FLAC/assert.h"
38
#include "private/ogg_decoder_aspect.h"
39
#include "private/ogg_mapping.h"
44
#define max(x,y) ((x)>(y)?(x):(y))
46
/***********************************************************************
48
* Public class methods
50
***********************************************************************/
52
FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
54
/* we will determine the serial number later if necessary */
55
if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
58
if(ogg_sync_init(&aspect->sync_state) != 0)
61
aspect->version_major = ~(0u);
62
aspect->version_minor = ~(0u);
64
aspect->need_serial_number = aspect->use_first_serial_number;
66
aspect->end_of_stream = false;
67
aspect->have_working_page = false;
72
void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
74
(void)ogg_sync_clear(&aspect->sync_state);
75
(void)ogg_stream_clear(&aspect->stream_state);
78
void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
80
aspect->use_first_serial_number = false;
81
aspect->serial_number = value;
84
void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
86
aspect->use_first_serial_number = true;
89
void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
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;
97
void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
99
FLAC__ogg_decoder_aspect_flush(aspect);
101
if(aspect->use_first_serial_number)
102
aspect->need_serial_number = true;
105
FLAC__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)
107
static const size_t OGG_BYTES_CHUNK = 8192;
108
const size_t bytes_requested = *bytes;
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.
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.
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
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);
147
aspect->have_working_packet = false;
150
/* only n bytes of the packet will fit in the buffer */
151
memcpy(buffer, aspect->working_packet.packet, n);
154
aspect->working_packet.packet += n;
155
aspect->working_packet.bytes -= n;
159
/* try and get another packet */
160
const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
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;
188
aspect->have_working_page = false;
191
/* lost sync, we'll leave the working page for the next call */
192
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
197
/* try and get another page */
198
const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
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;
205
if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
206
aspect->have_working_page = true;
207
aspect->have_working_packet = false;
209
/* else do nothing, could be a page from another stream */
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);
217
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
220
size_t ogg_bytes_read = ogg_bytes_to_read;
222
switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
223
case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
225
case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
226
aspect->end_of_stream = true;
228
case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
229
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
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 */
237
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
242
/* lost sync, bail out */
243
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
248
if (aspect->end_of_stream && *bytes == 0) {
249
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
252
return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
added
removed
src/libFLAC/ogg_decoder_aspect.c
