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      1 /* libFLAC - Free Lossless Audio Codec
      2  * Copyright (C) 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 <stdlib.h> /* for malloc() */
     37 #include <string.h> /* for memcmp(), memcpy() */
     38 #include "FLAC/assert.h"
     39 #include "share/alloc.h"
     40 #include "private/ogg_helper.h"
     41 #include "protected/stream_encoder.h"
     42 
     43 
     44 static FLAC__bool full_read_(FLAC__StreamEncoder *encoder, FLAC__byte *buffer, size_t bytes, FLAC__StreamEncoderReadCallback read_callback, void *client_data)
     45 {
     46 	while(bytes > 0) {
     47 		size_t bytes_read = bytes;
     48 		switch(read_callback(encoder, buffer, &bytes_read, client_data)) {
     49 			case FLAC__STREAM_ENCODER_READ_STATUS_CONTINUE:
     50 				bytes -= bytes_read;
     51 				buffer += bytes_read;
     52 				break;
     53 			case FLAC__STREAM_ENCODER_READ_STATUS_END_OF_STREAM:
     54 				if(bytes_read == 0) {
     55 					encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
     56 					return false;
     57 				}
     58 				bytes -= bytes_read;
     59 				buffer += bytes_read;
     60 				break;
     61 			case FLAC__STREAM_ENCODER_READ_STATUS_ABORT:
     62 				encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
     63 				return false;
     64 			case FLAC__STREAM_ENCODER_READ_STATUS_UNSUPPORTED:
     65 				return false;
     66 			default:
     67 				/* double protection: */
     68 				FLAC__ASSERT(0);
     69 				encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
     70 				return false;
     71 		}
     72 	}
     73 
     74 	return true;
     75 }
     76 
     77 void simple_ogg_page__init(ogg_page *page)
     78 {
     79 	page->header = 0;
     80 	page->header_len = 0;
     81 	page->body = 0;
     82 	page->body_len = 0;
     83 }
     84 
     85 void simple_ogg_page__clear(ogg_page *page)
     86 {
     87 	if(page->header)
     88 		free(page->header);
     89 	if(page->body)
     90 		free(page->body);
     91 	simple_ogg_page__init(page);
     92 }
     93 
     94 FLAC__bool simple_ogg_page__get_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderReadCallback read_callback, void *client_data)
     95 {
     96 	static const unsigned OGG_HEADER_FIXED_PORTION_LEN = 27;
     97 	static const unsigned OGG_MAX_HEADER_LEN = 27/*OGG_HEADER_FIXED_PORTION_LEN*/ + 255;
     98 	FLAC__byte crc[4];
     99 	FLAC__StreamEncoderSeekStatus seek_status;
    100 
    101 	FLAC__ASSERT(page->header == 0);
    102 	FLAC__ASSERT(page->header_len == 0);
    103 	FLAC__ASSERT(page->body == 0);
    104 	FLAC__ASSERT(page->body_len == 0);
    105 
    106 	/* move the stream pointer to the supposed beginning of the page */
    107 	if(0 == seek_callback)
    108 		return false;
    109 	if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {
    110 		if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)
    111 			encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    112 		return false;
    113 	}
    114 
    115 	/* allocate space for the page header */
    116 	if(0 == (page->header = (unsigned char *)safe_malloc_(OGG_MAX_HEADER_LEN))) {
    117 		encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
    118 		return false;
    119 	}
    120 
    121 	/* read in the fixed part of the page header (up to but not including
    122 	 * the segment table */
    123 	if(!full_read_(encoder, page->header, OGG_HEADER_FIXED_PORTION_LEN, read_callback, client_data))
    124 		return false;
    125 
    126 	page->header_len = OGG_HEADER_FIXED_PORTION_LEN + page->header[26];
    127 
    128 	/* check to see if it's a correct, "simple" page (one packet only) */
    129 	if(
    130 		memcmp(page->header, "OggS", 4) ||               /* doesn't start with OggS */
    131 		(page->header[5] & 0x01) ||                      /* continued packet */
    132 		memcmp(page->header+6, "\0\0\0\0\0\0\0\0", 8) || /* granulepos is non-zero */
    133 		page->header[26] == 0                            /* packet is 0-size */
    134 	) {
    135 		encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    136 		return false;
    137 	}
    138 
    139 	/* read in the segment table */
    140 	if(!full_read_(encoder, page->header + OGG_HEADER_FIXED_PORTION_LEN, page->header[26], read_callback, client_data))
    141 		return false;
    142 
    143 	{
    144 		unsigned i;
    145 
    146 		/* check to see that it specifies a single packet */
    147 		for(i = 0; i < (unsigned)page->header[26] - 1; i++) {
    148 			if(page->header[i + OGG_HEADER_FIXED_PORTION_LEN] != 255) {
    149 				encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    150 				return false;
    151 			}
    152 		}
    153 
    154 		page->body_len = 255 * i + page->header[i + OGG_HEADER_FIXED_PORTION_LEN];
    155 	}
    156 
    157 	/* allocate space for the page body */
    158 	if(0 == (page->body = (unsigned char *)safe_malloc_(page->body_len))) {
    159 		encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
    160 		return false;
    161 	}
    162 
    163 	/* read in the page body */
    164 	if(!full_read_(encoder, page->body, page->body_len, read_callback, client_data))
    165 		return false;
    166 
    167 	/* check the CRC */
    168 	memcpy(crc, page->header+22, 4);
    169 	ogg_page_checksum_set(page);
    170 	if(memcmp(crc, page->header+22, 4)) {
    171 		encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    172 		return false;
    173 	}
    174 
    175 	return true;
    176 }
    177 
    178 FLAC__bool simple_ogg_page__set_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderWriteCallback write_callback, void *client_data)
    179 {
    180 	FLAC__StreamEncoderSeekStatus seek_status;
    181 
    182 	FLAC__ASSERT(page->header != 0);
    183 	FLAC__ASSERT(page->header_len != 0);
    184 	FLAC__ASSERT(page->body != 0);
    185 	FLAC__ASSERT(page->body_len != 0);
    186 
    187 	/* move the stream pointer to the supposed beginning of the page */
    188 	if(0 == seek_callback)
    189 		return false;
    190 	if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {
    191 		if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)
    192 			encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    193 		return false;
    194 	}
    195 
    196 	ogg_page_checksum_set(page);
    197 
    198 	/* re-write the page */
    199 	if(write_callback((FLAC__StreamEncoder*)encoder, page->header, page->header_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {
    200 		encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    201 		return false;
    202 	}
    203 	if(write_callback((FLAC__StreamEncoder*)encoder, page->body, page->body_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {
    204 		encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    205 		return false;
    206 	}
    207 
    208 	return true;
    209 }
    210