libgig  4.3.0
DLS::Sample Class Reference

Encapsulates sample waves used for playback. More...

#include <DLS.h>

Inheritance diagram for DLS::Sample:
DLS::Resource DLS::Storage gig::Sample

Public Member Functions

void * LoadSampleData ()
 Load sample data into RAM. More...
 
void ReleaseSampleData ()
 Free sample data from RAM. More...
 
file_offset_t GetSize () const
 Returns sample size. More...
 
void Resize (file_offset_t NewSize)
 Resize sample. More...
 
file_offset_t SetPos (file_offset_t SampleCount, RIFF::stream_whence_t Whence=RIFF::stream_start)
 Sets the position within the sample (in sample points, not in bytes). More...
 
file_offset_t Read (void *pBuffer, file_offset_t SampleCount)
 Reads SampleCount number of sample points from the current position into the buffer pointed by pBuffer and increments the position within the sample. More...
 
file_offset_t Write (void *pBuffer, file_offset_t SampleCount)
 Write sample wave data. More...
 
virtual void UpdateChunks (progress_t *pProgress)
 Apply sample and its settings to the respective RIFF chunks. More...
 
virtual void DeleteChunks ()
 Remove all RIFF chunks associated with this Sample object. More...
 
virtual void CopyAssign (const Sample *orig)
 Make a deep copy of the Sample object given by orig and assign it to this object. More...
 
ResourceGetParent ()
 
const ResourceGetParent () const
 
void GenerateDLSID ()
 Generates a new DLSID for the resource.
 
virtual void CopyAssign (const Resource *orig)
 Make a deep copy of the Resource object given by orig and assign it to this object. More...
 

Static Public Member Functions

static void GenerateDLSID (dlsid_t *pDLSID)
 

Public Attributes

uint16_t FormatTag
 Format ID of the waveform data (should be DLS_WAVE_FORMAT_PCM for DLS1 compliant files, this is also the default value if Sample was created with Instrument::AddSample()).
 
uint16_t Channels
 Number of channels represented in the waveform data, e.g. 1 for mono, 2 for stereo (defaults to 1=mono if Sample was created with Instrument::AddSample() previously).
 
uint32_t SamplesPerSecond
 Sampling rate at which each channel should be played (defaults to 44100 if Sample was created with Instrument::AddSample() previously).
 
uint32_t AverageBytesPerSecond
 The average number of bytes per second at which the waveform data should be transferred (Playback software can estimate the buffer size using this value).
 
uint16_t BlockAlign
 The block alignment (in bytes) of the waveform data. Playback software needs to process a multiple of BlockAlign bytes of data at a time, so the value of BlockAlign can be used for buffer alignment.
 
uint16_t BitDepth
 Size of each sample per channel (only if known sample data format is used, 0 otherwise).
 
file_offset_t SamplesTotal
 Reflects total number of sample points (only if known sample data format is used, 0 otherwise), do not bother to change this value, it will not be saved.
 
uint FrameSize
 Reflects the size (in bytes) of one single sample point (only if known sample data format is used, 0 otherwise). Caution: with the current version of libgig you have to upate this field by yourself whenever you change one of the following fields: Channels, BitDepth ! Ignoring this might lead to undesired behavior when i.e. calling Resize(), SetPos(), Write() or Read().
 
InfopInfo
 Points (in any case) to an Info object, providing additional, optional infos and comments.
 
dlsid_tpDLSID
 Points to a dlsid_t structure if the file provided a DLS ID else is NULL.
 

Protected Member Functions

 Sample (File *pFile, RIFF::List *waveList, file_offset_t WavePoolOffset)
 Constructor. More...
 
virtual ~Sample ()
 Destructor. More...
 
void CopyAssignCore (const Sample *orig)
 Make a deep copy of the Sample object given by orig (without the actual sample waveform data however) and assign it to this object. More...
 

Protected Attributes

RIFF::ListpWaveList
 
RIFF::ChunkpCkData
 
RIFF::ChunkpCkFormat
 
file_offset_t ullWavePoolOffset
 
ResourcepParent
 
RIFF::ListpResourceList
 

Detailed Description

Encapsulates sample waves used for playback.

In case you created a new sample with File::AddSample(), you should first update all attributes with the desired meta informations (amount of channels, bit depth, sample rate, etc.), then call Resize() with the desired sample size. The latter will create the mandatory RIFF chunk which will hold the sample wave data.

Definition at line 456 of file DLS.h.

Constructor & Destructor Documentation

◆ Sample()

DLS::Sample::Sample ( File pFile,
RIFF::List waveList,
file_offset_t  WavePoolOffset 
)
protected

Constructor.

Load an existing sample or create a new one. A 'wave' list chunk must be given to this constructor. In case the given 'wave' list chunk contains a 'fmt' and 'data' chunk, the format and sample data will be loaded from there, otherwise default values will be used and those chunks will be created when File::Save() will be called later on.

Parameters
pFile- pointer to DLS::File where this sample is located (or will be located)
waveList- pointer to 'wave' list chunk which is (or will be) associated with this sample
WavePoolOffset- offset of this sample data from wave pool ('wvpl') list chunk

Definition at line 787 of file DLS.cpp.

References AverageBytesPerSecond, BitDepth, BlockAlign, Channels, FormatTag, FrameSize, RIFF::Chunk::GetFile(), RIFF::File::GetFileOffsetSize(), RIFF::Chunk::GetSize(), RIFF::List::GetSubChunk(), RIFF::Chunk::ReadUint16(), RIFF::Chunk::ReadUint32(), SamplesPerSecond, SamplesTotal, and RIFF::Chunk::SetPos().

◆ ~Sample()

DLS::Sample::~Sample ( )
protectedvirtual

Destructor.

Frees all memory occupied by this sample.

Reimplemented in gig::Sample.

Definition at line 827 of file DLS.cpp.

References RIFF::Chunk::ReleaseChunkData().

Member Function Documentation

◆ CopyAssign() [1/2]

void Resource::CopyAssign ( const Resource orig)
virtualinherited

Make a deep copy of the Resource object given by orig and assign it to this object.

Parameters
orig- original Resource object to be copied from

Definition at line 601 of file DLS.cpp.

References DLS::Info::CopyAssign(), and DLS::Resource::pInfo.

Referenced by DLS::Region::CopyAssign(), and CopyAssignCore().

◆ CopyAssign() [2/2]

void DLS::Sample::CopyAssign ( const Sample orig)
virtual

Make a deep copy of the Sample object given by orig and assign it to this object.

Parameters
orig- original Sample object to be copied from

Definition at line 881 of file DLS.cpp.

References CopyAssignCore(), FrameSize, RIFF::Chunk::GetPos(), GetSize(), LoadSampleData(), Read(), Resize(), SetPos(), and RIFF::Chunk::SetPos().

◆ CopyAssignCore()

void DLS::Sample::CopyAssignCore ( const Sample orig)
protected

Make a deep copy of the Sample object given by orig (without the actual sample waveform data however) and assign it to this object.

This is a special internal variant of CopyAssign() which only copies the most mandatory member variables. It will be called by gig::Sample descendent instead of CopyAssign() since gig::Sample has its own implementation to access and copy the actual sample waveform data.

Parameters
orig- original Sample object to be copied from

Definition at line 861 of file DLS.cpp.

References AverageBytesPerSecond, BitDepth, BlockAlign, Channels, DLS::Resource::CopyAssign(), FormatTag, FrameSize, SamplesPerSecond, and SamplesTotal.

Referenced by CopyAssign(), and gig::Sample::CopyAssignMeta().

◆ DeleteChunks()

void DLS::Sample::DeleteChunks ( )
virtual

Remove all RIFF chunks associated with this Sample object.

See Storage::DeleteChunks() for details.

Reimplemented from DLS::Resource.

Definition at line 838 of file DLS.cpp.

References DLS::Resource::DeleteChunks(), RIFF::List::DeleteSubChunk(), and RIFF::Chunk::GetParent().

Referenced by DLS::File::DeleteSample(), and gig::File::DeleteSample().

◆ GetSize()

file_offset_t DLS::Sample::GetSize ( ) const

Returns sample size.

Returns the sample wave form's data size (in sample points). This is actually the current, physical size (converted to sample points) of the RIFF chunk which encapsulates the sample's wave data. The returned value is dependant to the current FrameSize value.

Returns
number of sample points or 0 if FormatTag != DLS_WAVE_FORMAT_PCM
See also
FrameSize, FormatTag

Definition at line 950 of file DLS.cpp.

References FormatTag, FrameSize, and RIFF::Chunk::GetSize().

Referenced by CopyAssign(), gig::Sample::CopyAssignMeta(), Write(), and gig::Sample::Write().

◆ LoadSampleData()

void * DLS::Sample::LoadSampleData ( )

Load sample data into RAM.

In case the respective 'data' chunk exists, the sample data will be loaded into RAM (if not done already) and a pointer to the data in RAM will be returned. If this is a new sample, you have to call Resize() with the desired sample size to create the mandatory RIFF chunk for the sample wave data.

You can call LoadChunkData() again if you previously scheduled to enlarge the sample data RIFF chunk with a Resize() call. In that case the buffer will be enlarged to the new, scheduled size and you can already place the sample wave data to the buffer and finally call File::Save() to enlarge the sample data's chunk physically and write the new sample wave data in one rush. This approach is definitely recommended if you have to enlarge and write new sample data to a lot of samples.

Caution: the buffer pointer will be invalidated once File::Save() was called. You have to call LoadChunkData() again to get a new, valid pointer whenever File::Save() was called.

Returns
pointer to sample data in RAM, NULL in case respective 'data' chunk does not exist (yet)
Exceptions
Exceptionif data buffer could not be enlarged
See also
Resize(), File::Save()

Definition at line 927 of file DLS.cpp.

References RIFF::Chunk::LoadChunkData().

Referenced by CopyAssign().

◆ Read()

file_offset_t DLS::Sample::Read ( void *  pBuffer,
file_offset_t  SampleCount 
)

Reads SampleCount number of sample points from the current position into the buffer pointed by pBuffer and increments the position within the sample.

Use this method and SetPos() if you don't want to load the sample into RAM, thus for disk streaming.

Parameters
pBufferdestination buffer
SampleCountnumber of sample points to read

Definition at line 1028 of file DLS.cpp.

References FormatTag, FrameSize, and RIFF::Chunk::Read().

Referenced by CopyAssign().

◆ ReleaseSampleData()

void DLS::Sample::ReleaseSampleData ( )

Free sample data from RAM.

In case sample data was previously successfully loaded into RAM with LoadSampleData(), this method will free the sample data from RAM.

Definition at line 936 of file DLS.cpp.

References RIFF::Chunk::ReleaseChunkData().

◆ Resize()

void DLS::Sample::Resize ( file_offset_t  NewSize)

Resize sample.

Resizes the sample's wave form data, that is the actual size of sample wave data possible to be written for this sample. This call will return immediately and just schedule the resize operation. You should call File::Save() to actually perform the resize operation(s) "physically" to the file. As this can take a while on large files, it is recommended to call Resize() first on all samples which have to be resized and finally to call File::Save() to perform all those resize operations in one rush.

The actual size (in bytes) is dependant to the current FrameSize value. You may want to set FrameSize before calling Resize().

Caution: You cannot directly write to enlarged samples before calling File::Save() as this might exceed the current sample's boundary!

Also note: only DLS_WAVE_FORMAT_PCM is currently supported, that is FormatTag must be DLS_WAVE_FORMAT_PCM. Trying to resize samples with other formats will fail!

Parameters
NewSize- new sample wave data size in sample points (must be greater than zero)
Exceptions
Exceptionif FormatTag != DLS_WAVE_FORMAT_PCM
Exceptionif NewSize is less than 1 or unrealistic large
See also
File::Save(), FrameSize, FormatTag

Definition at line 983 of file DLS.cpp.

References RIFF::List::AddSubChunk(), FormatTag, FrameSize, RIFF::List::GetSubChunk(), and RIFF::Chunk::Resize().

Referenced by CopyAssign(), and gig::Sample::Resize().

◆ SetPos()

file_offset_t DLS::Sample::SetPos ( file_offset_t  SampleCount,
RIFF::stream_whence_t  Whence = RIFF::stream_start 
)

Sets the position within the sample (in sample points, not in bytes).

Use this method and Read() if you don't want to load the sample into RAM, thus for disk streaming.

Also note: only DLS_WAVE_FORMAT_PCM is currently supported, that is FormatTag must be DLS_WAVE_FORMAT_PCM. Trying to reposition the sample with other formats will fail!

Parameters
SampleCountnumber of sample points
Whenceto which relation SampleCount refers to
Returns
new position within the sample, 0 if FormatTag != DLS_WAVE_FORMAT_PCM
Exceptions
Exceptionif no data RIFF chunk was created for the sample yet
See also
FrameSize, FormatTag

Definition at line 1010 of file DLS.cpp.

References FormatTag, FrameSize, and RIFF::Chunk::SetPos().

Referenced by CopyAssign().

◆ UpdateChunks()

void DLS::Sample::UpdateChunks ( progress_t pProgress)
virtual

Apply sample and its settings to the respective RIFF chunks.

You have to call File::Save() to make changes persistent.

Parameters
pProgress- callback function for progress notification
Exceptions
Exceptionif FormatTag != DLS_WAVE_FORMAT_PCM or no sample data was provided yet

Reimplemented from DLS::Resource.

Reimplemented in gig::Sample.

Definition at line 1062 of file DLS.cpp.

References RIFF::List::AddSubChunk(), AverageBytesPerSecond, BitDepth, BlockAlign, Channels, FormatTag, RIFF::List::GetSubChunk(), RIFF::Chunk::LoadChunkData(), SamplesPerSecond, and DLS::Resource::UpdateChunks().

Referenced by gig::Sample::UpdateChunks().

◆ Write()

file_offset_t DLS::Sample::Write ( void *  pBuffer,
file_offset_t  SampleCount 
)

Write sample wave data.

Writes SampleCount number of sample points from the buffer pointed by pBuffer and increments the position within the sample. Use this method to directly write the sample data to disk, i.e. if you don't want or cannot load the whole sample data into RAM.

You have to Resize() the sample to the desired size and call File::Save() before using Write().

Parameters
pBuffer- source buffer
SampleCount- number of sample points to write
Exceptions
Exceptionif current sample size is too small
See also
LoadSampleData()

Definition at line 1048 of file DLS.cpp.

References FormatTag, FrameSize, GetSize(), and RIFF::Chunk::Write().


The documentation for this class was generated from the following files: