text: /* libFLAC - Free Lossless Audio Codec library
   * Copyright (C) 2000-2009  Josh Coalson
   * Copyright (C) 2011-2014  Xiph.Org Foundation
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * - Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * - Neither the name of the Xiph.org Foundation nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifdef HAVE_CONFIG_H
  #  include <config.h>
  #endif
  
  #include <stdio.h>
  #include <stdlib.h> /* for qsort() */
  #include <string.h> /* for memset() */
  #include "FLAC/assert.h"
  #include "FLAC/format.h"
  #include "share/alloc.h"
  #include "share/compat.h"
  #include "private/format.h"
  #include "private/macros.h"
  
  /* VERSION should come from configure */
  FLAC_API const char *FLAC__VERSION_STRING = VERSION;
  
  FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC " VERSION " 20141125";
  
  FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4] = { 'f','L','a','C' };
  FLAC_API const unsigned FLAC__STREAM_SYNC = 0x664C6143;
  FLAC_API const unsigned FLAC__STREAM_SYNC_LEN = 32; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN = 16; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN = 16; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN = 24; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN = 24; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN = 20; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN = 3; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN = 5; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN = 36; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN = 128; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN = 32; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN = 64; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN = 64; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN = 16; /* bits */
  
  FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER = FLAC__U64L(0xffffffffffffffff);
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN = 32; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN = 64; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN = 8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN = 3*8; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN = 64; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN = 8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN = 12*8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN = 1; /* bit */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN = 1; /* bit */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN = 6+13*8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN = 8; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN = 128*8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN = 64; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN = 1; /* bit */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN = 7+258*8; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN = 8; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_TYPE_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_COLORS_LEN = 32; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN = 32; /* bits */
  
  FLAC_API const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN = 1; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_TYPE_LEN = 7; /* bits */
  FLAC_API const unsigned FLAC__STREAM_METADATA_LENGTH_LEN = 24; /* bits */
  
  FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC = 0x3ffe;
  FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC_LEN = 14; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_RESERVED_LEN = 1; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCKING_STRATEGY_LEN = 1; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN = 3; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN = 1; /* bits */
  FLAC_API const unsigned FLAC__FRAME_HEADER_CRC_LEN = 8; /* bits */
  
  FLAC_API const unsigned FLAC__FRAME_FOOTER_CRC_LEN = 16; /* bits */
  
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN = 2; /* bits */
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN = 5; /* bits */
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN = 5; /* bits */
  
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER = 15; /* == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
  FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_ESCAPE_PARAMETER = 31; /* == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN)-1 */
  
  FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[] = {
  	"PARTITIONED_RICE",
  	"PARTITIONED_RICE2"
  };
  
  FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN = 4; /* bits */
  FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN = 5; /* bits */
  
  FLAC_API const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN = 1; /* bits */
  FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LEN = 6; /* bits */
  FLAC_API const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN = 1; /* bits */
  
  FLAC_API const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK = 0x00;
  FLAC_API const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK = 0x02;
  FLAC_API const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK = 0x10;
  FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK = 0x40;
  
  FLAC_API const char * const FLAC__SubframeTypeString[] = {
  	"CONSTANT",
  	"VERBATIM",
  	"FIXED",
  	"LPC"
  };
  
  FLAC_API const char * const FLAC__ChannelAssignmentString[] = {
  	"INDEPENDENT",
  	"LEFT_SIDE",
  	"RIGHT_SIDE",
  	"MID_SIDE"
  };
  
  FLAC_API const char * const FLAC__FrameNumberTypeString[] = {
  	"FRAME_NUMBER_TYPE_FRAME_NUMBER",
  	"FRAME_NUMBER_TYPE_SAMPLE_NUMBER"
  };
  
  FLAC_API const char * const FLAC__MetadataTypeString[] = {
  	"STREAMINFO",
  	"PADDING",
  	"APPLICATION",
  	"SEEKTABLE",
  	"VORBIS_COMMENT",
  	"CUESHEET",
  	"PICTURE"
  };
  
  FLAC_API const char * const FLAC__StreamMetadata_Picture_TypeString[] = {
  	"Other",
  	"32x32 pixels 'file icon' (PNG only)",
  	"Other file icon",
  	"Cover (front)",
  	"Cover (back)",
  	"Leaflet page",
  	"Media (e.g. label side of CD)",
  	"Lead artist/lead performer/soloist",
  	"Artist/performer",
  	"Conductor",
  	"Band/Orchestra",
  	"Composer",
  	"Lyricist/text writer",
  	"Recording Location",
  	"During recording",
  	"During performance",
  	"Movie/video screen capture",
  	"A bright coloured fish",
  	"Illustration",
  	"Band/artist logotype",
  	"Publisher/Studio logotype"
  };
  
  FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(unsigned sample_rate)
  {
  	if(sample_rate == 0 || sample_rate > FLAC__MAX_SAMPLE_RATE) {
  		return false;
  	}
  	else
  		return true;
  }
  
  FLAC_API FLAC__bool FLAC__format_blocksize_is_subset(unsigned blocksize, unsigned sample_rate)
  {
  	if(blocksize > 16384)
  		return false;
  	else if(sample_rate <= 48000 && blocksize > 4608)
  		return false;
  	else
  		return true;
  }
  
  FLAC_API FLAC__bool FLAC__format_sample_rate_is_subset(unsigned sample_rate)
  {
  	if(
  		!FLAC__format_sample_rate_is_valid(sample_rate) ||
  		(
  			sample_rate >= (1u << 16) &&
  			!(sample_rate % 1000 == 0 || sample_rate % 10 == 0)
  		)
  	) {
  		return false;
  	}
  	else
  		return true;
  }
  
  /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
  FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table)
  {
  	unsigned i;
  	FLAC__uint64 prev_sample_number = 0;
  	FLAC__bool got_prev = false;
  
  	FLAC__ASSERT(0 != seek_table);
  
  	for(i = 0; i < seek_table->num_points; i++) {
  		if(got_prev) {
  			if(
  				seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER &&
  				seek_table->points[i].sample_number <= prev_sample_number
  			)
  				return false;
  		}
  		prev_sample_number = seek_table->points[i].sample_number;
  		got_prev = true;
  	}
  
  	return true;
  }
  
  /* used as the sort predicate for qsort() */
  static int seekpoint_compare_(const FLAC__StreamMetadata_SeekPoint *l, const FLAC__StreamMetadata_SeekPoint *r)
  {
  	/* we don't just 'return l->sample_number - r->sample_number' since the result (FLAC__int64) might overflow an 'int' */
  	if(l->sample_number == r->sample_number)
  		return 0;
  	else if(l->sample_number < r->sample_number)
  		return -1;
  	else
  		return 1;
  }
  
  /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
  FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table)
  {
  	unsigned i, j;
  	FLAC__bool first;
  
  	FLAC__ASSERT(0 != seek_table);
  
  	if (seek_table->num_points == 0)
  		return 0;
  
  	/* sort the seekpoints */
  	qsort(seek_table->points, seek_table->num_points, sizeof(FLAC__StreamMetadata_SeekPoint), (int (*)(const void *, const void *))seekpoint_compare_);
  
  	/* uniquify the seekpoints */
  	first = true;
  	for(i = j = 0; i < seek_table->num_points; i++) {
  		if(seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER) {
  			if(!first) {
  				if(seek_table->points[i].sample_number == seek_table->points[j-1].sample_number)
  					continue;
  			}
  		}
  		first = false;
  		seek_table->points[j++] = seek_table->points[i];
  	}
  
  	for(i = j; i < seek_table->num_points; i++) {
  		seek_table->points[i].sample_number = FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
  		seek_table->points[i].stream_offset = 0;
  		seek_table->points[i].frame_samples = 0;
  	}
  
  	return j;
  }
  
  /*
   * also disallows non-shortest-form encodings, c.f.
   *   http://www.unicode.org/versions/corrigendum1.html
   * and a more clear explanation at the end of this section:
   *   http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
   */
  static unsigned utf8len_(const FLAC__byte *utf8)
  {
  	FLAC__ASSERT(0 != utf8);
  	if ((utf8[0] & 0x80) == 0) {
  		return 1;
  	}
  	else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80) {
  		if ((utf8[0] & 0xFE) == 0xC0) /* overlong sequence check */
  			return 0;
  		return 2;
  	}
  	else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80) {
  		if (utf8[0] == 0xE0 && (utf8[1] & 0xE0) == 0x80) /* overlong sequence check */
  			return 0;
  		/* illegal surrogates check (U+D800...U+DFFF and U+FFFE...U+FFFF) */
  		if (utf8[0] == 0xED && (utf8[1] & 0xE0) == 0xA0) /* D800-DFFF */
  			return 0;
  		if (utf8[0] == 0xEF && utf8[1] == 0xBF && (utf8[2] & 0xFE) == 0xBE) /* FFFE-FFFF */
  			return 0;
  		return 3;
  	}
  	else if ((utf8[0] & 0xF8) == 0xF0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80) {
  		if (utf8[0] == 0xF0 && (utf8[1] & 0xF0) == 0x80) /* overlong sequence check */
  			return 0;
  		return 4;
  	}
  	else if ((utf8[0] & 0xFC) == 0xF8 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80) {
  		if (utf8[0] == 0xF8 && (utf8[1] & 0xF8) == 0x80) /* overlong sequence check */
  			return 0;
  		return 5;
  	}
  	else if ((utf8[0] & 0xFE) == 0xFC && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80 && (utf8[5] & 0xC0) == 0x80) {
  		if (utf8[0] == 0xFC && (utf8[1] & 0xFC) == 0x80) /* overlong sequence check */
  			return 0;
  		return 6;
  	}
  	else {
  		return 0;
  	}
  }
  
  FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name)
  {
  	char c;
  	for(c = *name; c; c = *(++name))
  		if(c < 0x20 || c == 0x3d || c > 0x7d)
  			return false;
  	return true;
  }
  
  FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, unsigned length)
  {
  	if(length == (unsigned)(-1)) {
  		while(*value) {
  			unsigned n = utf8len_(value);
  			if(n == 0)
  				return false;
  			value += n;
  		}
  	}
  	else {
  		const FLAC__byte *end = value + length;
  		while(value < end) {
  			unsigned n = utf8len_(value);
  			if(n == 0)
  				return false;
  			value += n;
  		}
  		if(value != end)
  			return false;
  	}
  	return true;
  }
  
  FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, unsigned length)
  {
  	const FLAC__byte *s, *end;
  
  	for(s = entry, end = s + length; s < end && *s != '='; s++) {
  		if(*s < 0x20 || *s > 0x7D)
  			return false;
  	}
  	if(s == end)
  		return false;
  
  	s++; /* skip '=' */
  
  	while(s < end) {
  		unsigned n = utf8len_(s);
  		if(n == 0)
  			return false;
  		s += n;
  	}
  	if(s != end)
  		return false;
  
  	return true;
  }
  
  /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
  FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation)
  {
  	unsigned i, j;
  
  	if(check_cd_da_subset) {
  		if(cue_sheet->lead_in < 2 * 44100) {
  			if(violation) *violation = "CD-DA cue sheet must have a lead-in length of at least 2 seconds";
  			return false;
  		}
  		if(cue_sheet->lead_in % 588 != 0) {
  			if(violation) *violation = "CD-DA cue sheet lead-in length must be evenly divisible by 588 samples";
  			return false;
  		}
  	}
  
  	if(cue_sheet->num_tracks == 0) {
  		if(violation) *violation = "cue sheet must have at least one track (the lead-out)";
  		return false;
  	}
  
  	if(check_cd_da_subset && cue_sheet->tracks[cue_sheet->num_tracks-1].number != 170) {
  		if(violation) *violation = "CD-DA cue sheet must have a lead-out track number 170 (0xAA)";
  		return false;
  	}
  
  	for(i = 0; i < cue_sheet->num_tracks; i++) {
  		if(cue_sheet->tracks[i].number == 0) {
  			if(violation) *violation = "cue sheet may not have a track number 0";
  			return false;
  		}
  
  		if(check_cd_da_subset) {
  			if(!((cue_sheet->tracks[i].number >= 1 && cue_sheet->tracks[i].number <= 99) || cue_sheet->tracks[i].number == 170)) {
  				if(violation) *violation = "CD-DA cue sheet track number must be 1-99 or 170";
  				return false;
  			}
  		}
  
  		if(check_cd_da_subset && cue_sheet->tracks[i].offset % 588 != 0) {
  			if(violation) {
  				if(i == cue_sheet->num_tracks-1) /* the lead-out track... */
  					*violation = "CD-DA cue sheet lead-out offset must be evenly divisible by 588 samples";
  				else
  					*violation = "CD-DA cue sheet track offset must be evenly divisible by 588 samples";
  			}
  			return false;
  		}
  
  		if(i < cue_sheet->num_tracks - 1) {
  			if(cue_sheet->tracks[i].num_indices == 0) {
  				if(violation) *violation = "cue sheet track must have at least one index point";
  				return false;
  			}
  
  			if(cue_sheet->tracks[i].indices[0].number > 1) {
  				if(violation) *violation = "cue sheet track's first index number must be 0 or 1";
  				return false;
  			}
  		}
  
  		for(j = 0; j < cue_sheet->tracks[i].num_indices; j++) {
  			if(check_cd_da_subset && cue_sheet->tracks[i].indices[j].offset % 588 != 0) {
  				if(violation) *violation = "CD-DA cue sheet track index offset must be evenly divisible by 588 samples";
  				return false;
  			}
  
  			if(j > 0) {
  				if(cue_sheet->tracks[i].indices[j].number != cue_sheet->tracks[i].indices[j-1].number + 1) {
  					if(violation) *violation = "cue sheet track index numbers must increase by 1";
  					return false;
  				}
  			}
  		}
  	}
  
  	return true;
  }
  
  /* @@@@ add to unit tests; it is already indirectly tested by the metadata_object tests */
  FLAC_API FLAC__bool FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture *picture, const char **violation)
  {
  	char *p;
  	FLAC__byte *b;
  
  	for(p = picture->mime_type; *p; p++) {
  		if(*p < 0x20 || *p > 0x7e) {
  			if(violation) *violation = "MIME type string must contain only printable ASCII characters (0x20-0x7e)";
  			return false;
  		}
  	}
  
  	for(b = picture->description; *b; ) {
  		unsigned n = utf8len_(b);
  		if(n == 0) {
  			if(violation) *violation = "description string must be valid UTF-8";
  			return false;
  		}
  		b += n;
  	}
  
  	return true;
  }
  
  /*
   * These routines are private to libFLAC
   */
  unsigned FLAC__format_get_max_rice_partition_order(unsigned blocksize, unsigned predictor_order)
  {
  	return
  		FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(
  			FLAC__format_get_max_rice_partition_order_from_blocksize(blocksize),
  			blocksize,
  			predictor_order
  		);
  }
  
  unsigned FLAC__format_get_max_rice_partition_order_from_blocksize(unsigned blocksize)
  {
  	unsigned max_rice_partition_order = 0;
  	while(!(blocksize & 1)) {
  		max_rice_partition_order++;
  		blocksize >>= 1;
  	}
  	return flac_min(FLAC__MAX_RICE_PARTITION_ORDER, max_rice_partition_order);
  }
  
  unsigned FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(unsigned limit, unsigned blocksize, unsigned predictor_order)
  {
  	unsigned max_rice_partition_order = limit;
  
  	while(max_rice_partition_order > 0 && (blocksize >> max_rice_partition_order) <= predictor_order)
  		max_rice_partition_order--;
  
  	FLAC__ASSERT(
  		(max_rice_partition_order == 0 && blocksize >= predictor_order) ||
  		(max_rice_partition_order > 0 && blocksize >> max_rice_partition_order > predictor_order)
  	);
  
  	return max_rice_partition_order;
  }
  
  void FLAC__format_entropy_coding_method_partitioned_rice_contents_init(FLAC__EntropyCodingMethod_PartitionedRiceContents *object)
  {
  	FLAC__ASSERT(0 != object);
  
  	object->parameters = 0;
  	object->raw_bits = 0;
  	object->capacity_by_order = 0;
  }
  
  void FLAC__format_entropy_coding_method_partitioned_rice_contents_clear(FLAC__EntropyCodingMethod_PartitionedRiceContents *object)
  {
  	FLAC__ASSERT(0 != object);
  
  	if(0 != object->parameters)
  		free(object->parameters);
  	if(0 != object->raw_bits)
  		free(object->raw_bits);
  	FLAC__format_entropy_coding_method_partitioned_rice_contents_init(object);
  }
  
  FLAC__bool FLAC__format_entropy_coding_method_partitioned_rice_contents_ensure_size(FLAC__EntropyCodingMethod_PartitionedRiceContents *object, unsigned max_partition_order)
  {
  	FLAC__ASSERT(0 != object);
  
  	FLAC__ASSERT(object->capacity_by_order > 0 || (0 == object->parameters && 0 == object->raw_bits));
  
  	if(object->capacity_by_order < max_partition_order) {
  		if(0 == (object->parameters = safe_realloc_(object->parameters, sizeof(unsigned)*(1 << max_partition_order))))
  			return false;
  		if(0 == (object->raw_bits = safe_realloc_(object->raw_bits, sizeof(unsigned)*(1 << max_partition_order))))
  			return false;
  		memset(object->raw_bits, 0, sizeof(unsigned)*(1 << max_partition_order));
  		object->capacity_by_order = max_partition_order;
  	}
  
  	return true;
  }
  