mirror/taglib
1
0
Fork 0
mirror of https://github.com/taglib/taglib.git synced 2025-06-03 00:58:12 -04:00
Code Issues Packages Projects Releases Wiki Activity

APE: Reduce useless File::Find() operations.

Browse Source
This commit is contained in:
Tsuda Kageyu 2015-06-20 20:41:02 +09:00
parent dfee7020da
commit b56f4c4372
1 changed files with 29 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
taglib/ape/apeproperties.cpp
View File

@ -131,24 +131,36 @@ TagLib::uint APE::Properties::sampleFrames() const
// private members
////////////////////////////////////////////////////////////////////////////////
namespace
{
inline int headerVersion(const ByteVector &header)
{
if(header.size() < 6 || !header.startsWith("MAC "))
return -1;
return header.toUShort(4, false);
}
}
void APE::Properties::read(File *file, long streamLength)
{
// First we are searching the descriptor
const long offset = file->find("MAC ", file->tell());
if(offset < 0) {
// First, we assume that the file pointer is set at the first descriptor.
long offset = file->tell();
int version = headerVersion(file->readBlock(6));
// Next, we look for the descriptor.
if(version < 0) {
offset = file->find("MAC ", offset);
file->seek(offset);
version = headerVersion(file->readBlock(6));
}
if(version < 0) {
debug("APE::Properties::read() -- APE descriptor not found");
return;
}
// Then we read the header common for all versions of APE
file->seek(offset);
const ByteVector commonHeader = file->readBlock(6);
if(commonHeader.size() < 6) {
debug("APE::Properties::read() -- header is too short.");
return;
}
d->version = commonHeader.toUShort(4, false);
d->version = version;
if(d->version >= 3980)
analyzeCurrent(file);
@ -228,18 +240,13 @@ void APE::Properties::analyzeOld(File *file)
const uint finalFrameBlocks = header.toUInt(22, false);
d->sampleFrames = (totalFrames - 1) * blocksPerFrame + finalFrameBlocks;
// Seek the RIFF chunk and get the bit depth
long offset = file->tell();
offset = file->find("WAVEfmt ", offset);
if(offset < 0)
return;
file->seek(offset + 12);
const ByteVector fmt = file->readBlock(16);
if(fmt.size() < 16) {
// Get the bit depth from the RIFF-fmt chunk.
file->seek(16, File::Current);
const ByteVector fmt = file->readBlock(28);
if(fmt.size() < 28 || !fmt.startsWith("WAVEfmt ")) {
debug("APE::Properties::analyzeOld() -- fmt header is too short.");
return;
}
d->bitsPerSample = fmt.toShort(14, false);
d->bitsPerSample = fmt.toShort(26, false);
}