+
+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);
+
+ /* 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 = realloc(object->parameters, sizeof(unsigned)*(1 << max_partition_order))))
+ return false;
+ if(0 == (object->raw_bits = 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;
+}