1 /* libFLAC - Free Lossless Audio Codec
2  * Copyright (C) 2002-2009  Josh Coalson
3  * Copyright (C) 2011-2013  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 memset() */
38 #include "FLAC/assert.h"
39 #include "private/ogg_encoder_aspect.h"
40 #include "private/ogg_mapping.h"
41 
42 static const FLAC__byte FLAC__OGG_MAPPING_VERSION_MAJOR = 1;
43 static const FLAC__byte FLAC__OGG_MAPPING_VERSION_MINOR = 0;
44 
45 /***********************************************************************
46  *
47  * Public class methods
48  *
49  ***********************************************************************/
50 
FLAC__ogg_encoder_aspect_init(FLAC__OggEncoderAspect * aspect)51 FLAC__bool FLAC__ogg_encoder_aspect_init(FLAC__OggEncoderAspect *aspect)
52 {
53 	/* we will determine the serial number later if necessary */
54 	if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
55 		return false;
56 
57 	aspect->seen_magic = false;
58 	aspect->is_first_packet = true;
59 	aspect->samples_written = 0;
60 
61 	return true;
62 }
63 
FLAC__ogg_encoder_aspect_finish(FLAC__OggEncoderAspect * aspect)64 void FLAC__ogg_encoder_aspect_finish(FLAC__OggEncoderAspect *aspect)
65 {
66 	(void)ogg_stream_clear(&aspect->stream_state);
67 	/*@@@ what about the page? */
68 }
69 
FLAC__ogg_encoder_aspect_set_serial_number(FLAC__OggEncoderAspect * aspect,long value)70 void FLAC__ogg_encoder_aspect_set_serial_number(FLAC__OggEncoderAspect *aspect, long value)
71 {
72 	aspect->serial_number = value;
73 }
74 
FLAC__ogg_encoder_aspect_set_num_metadata(FLAC__OggEncoderAspect * aspect,unsigned value)75 FLAC__bool FLAC__ogg_encoder_aspect_set_num_metadata(FLAC__OggEncoderAspect *aspect, unsigned value)
76 {
77 	if(value < (1u << FLAC__OGG_MAPPING_NUM_HEADERS_LEN)) {
78 		aspect->num_metadata = value;
79 		return true;
80 	}
81 	else
82 		return false;
83 }
84 
FLAC__ogg_encoder_aspect_set_defaults(FLAC__OggEncoderAspect * aspect)85 void FLAC__ogg_encoder_aspect_set_defaults(FLAC__OggEncoderAspect *aspect)
86 {
87 	aspect->serial_number = 0;
88 	aspect->num_metadata = 0;
89 }
90 
91 /*
92  * The basic FLAC -> Ogg mapping goes like this:
93  *
94  * - 'fLaC' magic and STREAMINFO block get combined into the first
95  *   packet.  The packet is prefixed with
96  *   + the one-byte packet type 0x7F
97  *   + 'FLAC' magic
98  *   + the 2 byte Ogg FLAC mapping version number
99  *   + tne 2 byte big-endian # of header packets
100  * - The first packet is flushed to the first page.
101  * - Each subsequent metadata block goes into its own packet.
102  * - Each metadata packet is flushed to page (this is not required,
103  *   the mapping only requires that a flush must occur after all
104  *   metadata is written).
105  * - Each subsequent FLAC audio frame goes into its own packet.
106  *
107  * WATCHOUT:
108  * This depends on the behavior of FLAC__StreamEncoder that we get a
109  * separate write callback for the fLaC magic, and then separate write
110  * callbacks for each metadata block and audio frame.
111  */
FLAC__ogg_encoder_aspect_write_callback_wrapper(FLAC__OggEncoderAspect * aspect,const FLAC__byte buffer[],size_t bytes,unsigned samples,unsigned current_frame,FLAC__bool is_last_block,FLAC__OggEncoderAspectWriteCallbackProxy write_callback,void * encoder,void * client_data)112 FLAC__StreamEncoderWriteStatus FLAC__ogg_encoder_aspect_write_callback_wrapper(FLAC__OggEncoderAspect *aspect, const FLAC__byte buffer[], size_t bytes, unsigned samples, unsigned current_frame, FLAC__bool is_last_block, FLAC__OggEncoderAspectWriteCallbackProxy write_callback, void *encoder, void *client_data)
113 {
114 	/* WATCHOUT:
115 	 * This depends on the behavior of FLAC__StreamEncoder that 'samples'
116 	 * will be 0 for metadata writes.
117 	 */
118 	const FLAC__bool is_metadata = (samples == 0);
119 
120 	/*
121 	 * Treat fLaC magic packet specially.  We will note when we see it, then
122 	 * wait until we get the STREAMINFO and prepend it in that packet
123 	 */
124 	if(aspect->seen_magic) {
125 		ogg_packet packet;
126 		FLAC__byte synthetic_first_packet_body[
127 			FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
128 			FLAC__OGG_MAPPING_MAGIC_LENGTH +
129 			FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
130 			FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
131 			FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH +
132 			FLAC__STREAM_SYNC_LENGTH +
133 			FLAC__STREAM_METADATA_HEADER_LENGTH +
134 			FLAC__STREAM_METADATA_STREAMINFO_LENGTH
135 		];
136 
137 		memset(&packet, 0, sizeof(packet));
138 		packet.granulepos = aspect->samples_written + samples;
139 
140 		if(aspect->is_first_packet) {
141 			FLAC__byte *b = synthetic_first_packet_body;
142 			if(bytes != FLAC__STREAM_METADATA_HEADER_LENGTH + FLAC__STREAM_METADATA_STREAMINFO_LENGTH) {
143 				/*
144 				 * If we get here, our assumption about the way write callbacks happen
145 				 * (explained above) is wrong
146 				 */
147 				FLAC__ASSERT(0);
148 				return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
149 			}
150 			/* add first header packet type */
151 			*b = FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE;
152 			b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
153 			/* add 'FLAC' mapping magic */
154 			memcpy(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH);
155 			b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
156 			/* add Ogg FLAC mapping major version number */
157 			memcpy(b, &FLAC__OGG_MAPPING_VERSION_MAJOR, FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH);
158 			b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
159 			/* add Ogg FLAC mapping minor version number */
160 			memcpy(b, &FLAC__OGG_MAPPING_VERSION_MINOR, FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH);
161 			b += FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH;
162 			/* add number of header packets */
163 			*b = (FLAC__byte)(aspect->num_metadata >> 8);
164 			b++;
165 			*b = (FLAC__byte)(aspect->num_metadata);
166 			b++;
167 			/* add native FLAC 'fLaC' magic */
168 			memcpy(b, FLAC__STREAM_SYNC_STRING, FLAC__STREAM_SYNC_LENGTH);
169 			b += FLAC__STREAM_SYNC_LENGTH;
170 			/* add STREAMINFO */
171 			memcpy(b, buffer, bytes);
172 			FLAC__ASSERT(b + bytes - synthetic_first_packet_body == sizeof(synthetic_first_packet_body));
173 			packet.packet = (unsigned char *)synthetic_first_packet_body;
174 			packet.bytes = sizeof(synthetic_first_packet_body);
175 
176 			packet.b_o_s = 1;
177 			aspect->is_first_packet = false;
178 		}
179 		else {
180 			packet.packet = (unsigned char *)buffer;
181 			packet.bytes = bytes;
182 		}
183 
184 		if(is_last_block) {
185 			/* we used to check:
186 			 * FLAC__ASSERT(total_samples_estimate == 0 || total_samples_estimate == aspect->samples_written + samples);
187 			 * but it's really not useful since total_samples_estimate is an estimate and can be inexact
188 			 */
189 			packet.e_o_s = 1;
190 		}
191 
192 		if(ogg_stream_packetin(&aspect->stream_state, &packet) != 0)
193 			return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
194 
195 		/*@@@ can't figure out a way to pass a useful number for 'samples' to the write_callback, so we'll just pass 0 */
196 		if(is_metadata) {
197 			while(ogg_stream_flush(&aspect->stream_state, &aspect->page) != 0) {
198 				if(write_callback(encoder, aspect->page.header, aspect->page.header_len, 0, current_frame, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK)
199 					return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
200 				if(write_callback(encoder, aspect->page.body, aspect->page.body_len, 0, current_frame, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK)
201 					return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
202 			}
203 		}
204 		else {
205 			while(ogg_stream_pageout(&aspect->stream_state, &aspect->page) != 0) {
206 				if(write_callback(encoder, aspect->page.header, aspect->page.header_len, 0, current_frame, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK)
207 					return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
208 				if(write_callback(encoder, aspect->page.body, aspect->page.body_len, 0, current_frame, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK)
209 					return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
210 			}
211 		}
212 	}
213 	else if(is_metadata && current_frame == 0 && samples == 0 && bytes == 4 && 0 == memcmp(buffer, FLAC__STREAM_SYNC_STRING, sizeof(FLAC__STREAM_SYNC_STRING))) {
214 		aspect->seen_magic = true;
215 	}
216 	else {
217 		/*
218 		 * If we get here, our assumption about the way write callbacks happen
219 		 * explained above is wrong
220 		 */
221 		FLAC__ASSERT(0);
222 		return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;
223 	}
224 
225 	aspect->samples_written += samples;
226 
227 	return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;
228 }
229