src/libOggFLAC/ogg_helper.c

   1 /* libOggFLAC - Free Lossless Audio Codec + Ogg library
   2  * Copyright (C) 2004  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 #include <stdlib.h> /* for malloc() */
  33 #include <string.h> /* for memcmp(), memcpy() */
  34 #include "FLAC/assert.h"
  35 #include "private/ogg_helper.h"
  36 #include "protected/seekable_stream_encoder.h"
  37
  38
  39 static FLAC__bool full_read_(OggFLAC__SeekableStreamEncoder *encoder, FLAC__byte *buffer, unsigned bytes, OggFLAC__SeekableStreamEncoderReadCallback read_callback, void *client_data)
  40 {
  41         while(bytes > 0) {
  42                 unsigned bytes_read = bytes;
  43                 switch(read_callback(encoder, buffer, &bytes_read, client_data)) {
  44                         case OggFLAC__SEEKABLE_STREAM_ENCODER_READ_STATUS_CONTINUE:
  45                                 bytes -= bytes_read;
  46                                 buffer += bytes_read;
  47                                 break;
  48                         case OggFLAC__SEEKABLE_STREAM_ENCODER_READ_STATUS_END_OF_STREAM:
  49                                 if(bytes_read == 0) {
  50                                         encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_OGG_ERROR;
  51                                         return false;
  52                                 }
  53                                 bytes -= bytes_read;
  54                                 buffer += bytes_read;
  55                                 break;
  56                         case OggFLAC__SEEKABLE_STREAM_ENCODER_READ_STATUS_ABORT:
  57                                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_READ_ERROR;
  58                                 return false;
  59                         default:
  60                                 /* double protection: */
  61                                 FLAC__ASSERT(0);
  62                                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_READ_ERROR;
  63                                 return false;
  64                 }
  65         }
  66
  67         return true;
  68 }
  69
  70 void simple_ogg_page__init(ogg_page *page)
  71 {
  72         page->header = 0;
  73         page->header_len = 0;
  74         page->body = 0;
  75         page->body_len = 0;
  76 }
  77
  78 void simple_ogg_page__clear(ogg_page *page)
  79 {
  80         if(page->header)
  81                 free(page->header);
  82         if(page->body)
  83                 free(page->body);
  84         simple_ogg_page__init(page);
  85 }
  86
  87 FLAC__bool simple_ogg_page__get_at(OggFLAC__SeekableStreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, OggFLAC__SeekableStreamEncoderSeekCallback seek_callback, OggFLAC__SeekableStreamEncoderReadCallback read_callback, void *client_data)
  88 {
  89         static const unsigned OGG_HEADER_FIXED_PORTION_LEN = 27;
  90         static const unsigned OGG_MAX_HEADER_LEN = 27/*OGG_HEADER_FIXED_PORTION_LEN*/ + 255;
  91         FLAC__byte crc[4];
  92
  93         FLAC__ASSERT(page->header = 0);
  94         FLAC__ASSERT(page->header_len = 0);
  95         FLAC__ASSERT(page->body = 0);
  96         FLAC__ASSERT(page->body_len = 0);
  97
  98         /* move the stream pointer to the supposed beginning of the page */
  99         if(seek_callback(encoder, position, client_data) != FLAC__SEEKABLE_STREAM_ENCODER_SEEK_STATUS_OK) {
 100                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_SEEK_ERROR;
 101                 return false;
 102         }
 103
 104         /* allocate space for the page header */
 105         if(0 == (page->header = malloc(OGG_MAX_HEADER_LEN))) {
 106                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
 107                 return false;
 108         }
 109
 110         /* read in the fixed part of the page header (up to but not including
 111          * the segment table */
 112         if(!full_read_(encoder, page->header, OGG_HEADER_FIXED_PORTION_LEN, read_callback, client_data))
 113                 return false;
 114
 115         page->header_len = OGG_HEADER_FIXED_PORTION_LEN + page->header[26];
 116
 117         /* check to see if it's a correct, "simple" page (one packet only) */
 118         if(
 119                 memcmp(page->header, "OggS", 4) ||               /* doesn't start with OggS */
 120                 (page->header[5] & 0x01) ||                      /* continued packet */
 121                 memcmp(page->header+6, "\0\0\0\0\0\0\0\0", 8) || /* granulepos is non-zero */
 122                 page->header[26] == 0                            /* packet is 0-size */
 123         ) {
 124                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_OGG_ERROR;
 125                 return false;
 126         }
 127
 128         /* read in the segment table */
 129         if(!full_read_(encoder, page->header + OGG_HEADER_FIXED_PORTION_LEN, page->header[26], read_callback, client_data))
 130                 return false;
 131
 132         {
 133                 unsigned i;
 134
 135                 /* check to see that it specifies a single packet */
 136                 for(i = 0; i < (unsigned)page->header[26] - 1; i++) {
 137                         if(page->header[i + OGG_HEADER_FIXED_PORTION_LEN] != 255) {
 138                                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_OGG_ERROR;
 139                                 return false;
 140                         }
 141                 }
 142
 143                 page->body_len = 255 * i + page->header[i];
 144         }
 145
 146         /* allocate space for the page body */
 147         if(0 == (page->body = malloc(page->body_len))) {
 148                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
 149                 return false;
 150         }
 151
 152         /* read in the page body */
 153         if(!full_read_(encoder, page->body, page->body_len, read_callback, client_data))
 154                 return false;
 155
 156         /* check the CRC */
 157         memcpy(crc, page->header+22, 4);
 158         ogg_page_checksum_set(page);
 159         if(memcmp(crc, page->header+22, 4)) {
 160                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_OGG_ERROR;
 161                 return false;
 162         }
 163
 164         return true;
 165 }
 166
 167 FLAC__bool simple_ogg_page__set_at(OggFLAC__SeekableStreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, OggFLAC__SeekableStreamEncoderSeekCallback seek_callback, OggFLAC__SeekableStreamEncoderWriteCallback write_callback, void *client_data)
 168 {
 169         FLAC__ASSERT(page->header != 0);
 170         FLAC__ASSERT(page->header_len != 0);
 171         FLAC__ASSERT(page->body != 0);
 172         FLAC__ASSERT(page->body_len != 0);
 173
 174         /* move the stream pointer to the supposed beginning of the page */
 175         if(seek_callback(encoder, position, client_data) != FLAC__SEEKABLE_STREAM_ENCODER_SEEK_STATUS_OK) {
 176                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_SEEK_ERROR;
 177                 return false;
 178         }
 179
 180         ogg_page_checksum_set(page);
 181
 182         /* re-write the page */
 183         if(write_callback(encoder, page->header, page->header_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {
 184                 encoder->protected_->state = OggFLAC__SEEKABLE_STREAM_ENCODER_WRITE_ERROR;
 185                 return false;
 186         }
 187
 188         return true;
 189 }