metadata_iterators.c

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	}

	save = iterator->current->prev;

	if(replace_with_padding) {
		FLAC__metadata_object_delete_data(iterator->current->data);
		iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
	}
	else {
		chain_delete_node_(iterator->chain, iterator->current);
	}

	iterator->current = save;
	return true;
}

FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
{
	FLAC__Metadata_Node *node;

	FLAC__ASSERT(0 != iterator);
	FLAC__ASSERT(0 != iterator->current);
	FLAC__ASSERT(0 != block);

	if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
		return false;

	if(0 == iterator->current->prev) {
		FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
		return false;
	}

	if(0 == (node = node_new_()))
		return false;

	node->data = block;
	iterator_insert_node_(iterator, node);
	iterator->current = node;
	return true;
}

FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
{
	FLAC__Metadata_Node *node;

	FLAC__ASSERT(0 != iterator);
	FLAC__ASSERT(0 != iterator->current);
	FLAC__ASSERT(0 != block);

	if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
		return false;

	if(0 == (node = node_new_()))
		return false;

	node->data = block;
	iterator_insert_node_after_(iterator, node);
	iterator->current = node;
	return true;
}


/****************************************************************************
 *
 * Local function definitions
 *
 ***************************************************************************/

void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
{
	unsigned i;

	b += bytes;

	for(i = 0; i < bytes; i++) {
		*(--b) = (FLAC__byte)(val & 0xff);
		val >>= 8;
	}
}

void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
{
	unsigned i;

	for(i = 0; i < bytes; i++) {
		*(b++) = (FLAC__byte)(val & 0xff);
		val >>= 8;
	}
}

void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
{
	unsigned i;

	b += bytes;

	for(i = 0; i < bytes; i++) {
		*(--b) = (FLAC__byte)(val & 0xff);
		val >>= 8;
	}
}

FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
{
	FLAC__uint32 ret = 0;
	unsigned i;

	for(i = 0; i < bytes; i++)
		ret = (ret << 8) | (FLAC__uint32)(*b++);

	return ret;
}

FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
{
	FLAC__uint32 ret = 0;
	unsigned i;

	b += bytes;

	for(i = 0; i < bytes; i++)
		ret = (ret << 8) | (FLAC__uint32)(*--b);

	return ret;
}

FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
{
	FLAC__uint64 ret = 0;
	unsigned i;

	for(i = 0; i < bytes; i++)
		ret = (ret << 8) | (FLAC__uint64)(*b++);

	return ret;
}

FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
{
	FLAC__ASSERT(0 != iterator);
	FLAC__ASSERT(0 != iterator->file);

	if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
		iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
		return false;
	}

	return true;
}

FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
{
	FLAC__ASSERT(0 != iterator);
	FLAC__ASSERT(0 != iterator->file);

	iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);

	return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
}

FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
{
	FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];

	if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
		return false;

	*is_last = raw_header[0] & 0x80? true : false;
	*type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
	*length = unpack_uint32_(raw_header + 1, 3);

	/* Note that we don't check:
	 *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
	 * we just will read in an opaque block
	 */

	return true;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
{
	switch(block->type) {
		case FLAC__METADATA_TYPE_STREAMINFO:
			return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
		case FLAC__METADATA_TYPE_PADDING:
			return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
		case FLAC__METADATA_TYPE_APPLICATION:
			return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
		case FLAC__METADATA_TYPE_SEEKTABLE:
			return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
		case FLAC__METADATA_TYPE_VORBIS_COMMENT:
			return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
		case FLAC__METADATA_TYPE_CUESHEET:
			return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
		default:
			return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
	}
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
{
	FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;

	if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;

	b = buffer;

	/* we are using hardcoded numbers for simplicity but we should
	 * probably eventually write a bit-level unpacker and use the
	 * _STREAMINFO_ constants.
	 */
	block->min_blocksize = unpack_uint32_(b, 2); b += 2;
	block->max_blocksize = unpack_uint32_(b, 2); b += 2;
	block->min_framesize = unpack_uint32_(b, 3); b += 3;
	block->max_framesize = unpack_uint32_(b, 3); b += 3;
	block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
	block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
	block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
	block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
	memcpy(block->md5sum, b+8, 16);

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}


FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
{
	(void)block; /* nothing to do; we don't care about reading the padding bytes */

	if(0 != seek_cb(handle, block_length, SEEK_CUR))
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
{
	const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;

	if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;

	block_length -= id_bytes;

	if(block_length == 0) {
		block->data = 0;
	}
	else {
		if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
			return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;

		if(read_cb(block->data, 1, block_length, handle) != block_length)
			return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
	}

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
{
	unsigned i;
	FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];

	FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);

	block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;

	if(block->num_points == 0)
		block->points = 0;
	else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;

	for(i = 0; i < block->num_points; i++) {
		if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
			return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
		/* some MAGIC NUMBERs here */
		block->points[i].sample_number = unpack_uint64_(buffer, 8);
		block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
		block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
	}

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
{
	const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
	FLAC__byte buffer[4]; /* magic number is asserted below */

	FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == 4);

	if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
	entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);

	if(0 != entry->entry)
		free(entry->entry);

	if(entry->length == 0) {
		entry->entry = 0;
	}
	else {
		if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length+1)))
			return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;

		if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
			return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;

		entry->entry[entry->length] = '\0';
	}

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
{
	unsigned i;
	FLAC__Metadata_SimpleIteratorStatus status;
	const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
	FLAC__byte buffer[4]; /* magic number is asserted below */

	FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);

	if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
		return status;

	if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
	block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);

	if(block->num_comments == 0) {
		block->comments = 0;
	}
	else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;

	for(i = 0; i < block->num_comments; i++) {
		if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
			return status;
	}

	return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
}

FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
{
	unsigned i, len;
	FLAC__byte buffer[32]; /* asserted below that this is big enough */

	FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
	FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
	FLAC__ASSERT(sizeof(buffer) >= (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8);

	FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
	len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
	if(read_cb(buffer, 1, len, handle) != len)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
	track->offset = unpack_uint64_(buffer, len);

	FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
	len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
	if(read_cb(buffer, 1, len, handle) != len)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
	track->number = (FLAC__byte)unpack_uint32_(buffer, len);

	FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
	len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
	if(read_cb(track->isrc, 1, len, handle) != len)
		return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;

	FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) % 8 == 0);
	len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
	if(read_cb(buffer, 1, len, handle) != len)
		return FLAC__METADATA_SIMPLE_ITE