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Diffstat (limited to 'src/decoder/plugins/DsdLib.cxx')
-rw-r--r-- | src/decoder/plugins/DsdLib.cxx | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/decoder/plugins/DsdLib.cxx b/src/decoder/plugins/DsdLib.cxx new file mode 100644 index 000000000..2bd532a05 --- /dev/null +++ b/src/decoder/plugins/DsdLib.cxx @@ -0,0 +1,161 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/* \file + * + * This file contains functions used by the DSF and DSDIFF decoders. + * + */ + +#include "config.h" +#include "DsdLib.hxx" +#include "../DecoderAPI.hxx" +#include "input/InputStream.hxx" +#include "tag/TagId3.hxx" +#include "util/Error.hxx" + +#include <string.h> + +#ifdef HAVE_ID3TAG +#include <id3tag.h> +#endif + +bool +DsdId::Equals(const char *s) const +{ + assert(s != nullptr); + assert(strlen(s) == sizeof(value)); + + return memcmp(value, s, sizeof(value)) == 0; +} + +bool +dsdlib_read(Decoder *decoder, InputStream &is, + void *data, size_t length) +{ + size_t nbytes = decoder_read(decoder, is, data, length); + return nbytes == length; +} + +/** + * Skip the #input_stream to the specified offset. + */ +bool +dsdlib_skip_to(Decoder *decoder, InputStream &is, + int64_t offset) +{ + if (is.IsSeekable()) + return is.Seek(offset, IgnoreError()); + + if (is.GetOffset() > offset) + return false; + + char buffer[8192]; + while (is.GetOffset() < offset) { + size_t length = sizeof(buffer); + if (offset - is.GetOffset() < (int64_t)length) + length = offset - is.GetOffset(); + + size_t nbytes = decoder_read(decoder, is, buffer, length); + if (nbytes == 0) + return false; + } + + assert(is.GetOffset() == offset); + return true; +} + +/** + * Skip some bytes from the #input_stream. + */ +bool +dsdlib_skip(Decoder *decoder, InputStream &is, + int64_t delta) +{ + assert(delta >= 0); + + if (delta == 0) + return true; + + if (is.IsSeekable()) + return is.Seek(is.GetOffset() + delta, IgnoreError()); + + char buffer[8192]; + while (delta > 0) { + size_t length = sizeof(buffer); + if ((int64_t)length > delta) + length = delta; + + size_t nbytes = decoder_read(decoder, is, buffer, length); + if (nbytes == 0) + return false; + + delta -= nbytes; + } + + return true; +} + +#ifdef HAVE_ID3TAG +void +dsdlib_tag_id3(InputStream &is, + const struct tag_handler *handler, + void *handler_ctx, int64_t tagoffset) +{ + assert(tagoffset >= 0); + + if (tagoffset == 0) + return; + + if (!dsdlib_skip_to(nullptr, is, tagoffset)) + return; + + struct id3_tag *id3_tag = nullptr; + id3_length_t count; + + /* Prevent broken files causing problems */ + const auto size = is.GetSize(); + const auto offset = is.GetOffset(); + if (offset >= size) + return; + + count = size - offset; + + /* Check and limit id3 tag size to prevent a stack overflow */ + if (count == 0 || count > 4096) + return; + + id3_byte_t dsdid3[count]; + id3_byte_t *dsdid3data; + dsdid3data = dsdid3; + + if (!dsdlib_read(nullptr, is, dsdid3data, count)) + return; + + id3_tag = id3_tag_parse(dsdid3data, count); + if (id3_tag == nullptr) + return; + + scan_id3_tag(id3_tag, handler, handler_ctx); + + id3_tag_delete(id3_tag); + + return; +} +#endif |