clAddAlgorithm(3dm) clAddAlgorithm(3dm)
clAddAlgorithm, clSetUnique, clGetUnique, clFetchParam, clStoreParam,
clError - Add a video or audio compression algorithm to the Compression
Library
#include <dmedia/cl.h>
int clAddAlgorithm(char *name, int algType, int maxHeaderSize,
FunctionPtr openCompressor, FunctionPtr compress,
FunctionPtr closeCompressor,
FunctionPtr openDecompressor, FunctionPtr decompress,
FunctionPtr closeDecompressor,
FunctionPtr readHeader, FunctionPtr queryScheme,
FunctionPtr queryLicense,
FunctionPtr getParams, FunctionPtr setParams,
int *scheme)
void *clSetUnique(CLhandle handle, void *unique)
void *clGetUnique(CLhandle handle)
int clFetchParam(CLhandle handle, int paramID)
void clStoreParam(CLhandle handle, int paramID, int value)
void clError(CLhandle handle, int code, const char *format, ...)
name A pointer to a string that contains the name of the
algorithm.
algType The type of the algorithm (CL_ALG_VIDEO or CL_ALG_AUDIO).
maxHeaderSize The maximum size of the stream header for the specified
algorithm.
openCompressor A pointer to the function that opens a compressor for the
new algorithm. The function must have the same arguments
as clOpenCompressor.
compress A pointer to the function that compresses for the new
algorithm. The function must have the same arguments as
clCompress.
closeCompressor
A pointer to the function that closes a compressor for the
new algorithm. The function must have the same arguments
as clCloseCompressor.
openDecompressor
A pointer to the function that opens a decompressor for
the new algorithm. The function must have the same
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clAddAlgorithm(3dm) clAddAlgorithm(3dm)
arguments as clOpenDecompressor.
decompress A pointer to the function that decompresses for the new
algorithm. The function must have the same arguments as
clDecompress.
closeDecompressor
A pointer to the function that closes a decompressor for
the new algorithm. The function must have the same
arguments as clCloseDecompressor.
readHeader A pointer to the function that reads the stream header for
the new algorithm. The function must have the same
arguments as clReadHeader.
queryScheme A pointer to the function that identifies the scheme from
the stream header for the new algorithm. The function must
have the same arguments as clQueryScheme.
queryLicense A pointer to the function that checks for a NetLS license.
The function must have the same arguments as
clQueryLicense.
getParams A pointer to the function that gets
compressor/decompressor parameters for the new algorithm.
The function must have the same arguments as clGetParams.
setParams A pointer to the function that sets
compressor/decompressor parameters for the new algorithm.
The function must have the same arguments as clSetParams.
scheme A pointer to an int value to receive the compression
scheme identifier.
handle A handle to a compressor/decompressor.
unique A pointer to the unique data structure used by the
algorithm.
paramID The parameter identifier.
value The new value of the parameter.
code The error code as specified in cl.h. For errors not
handled by the standard list, use
CL_ADDED_ALGORITHM_ERROR.
format A printf style format string.
... Parameters to the printf style format string.
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clAddAlgorithm(3dm) clAddAlgorithm(3dm)
Users can add compression algorithms to the compression library by using
clAddAlgorithm. When the user calls the compression library for this
added algorithm, some preprocessing is done and then the routines passed
to clAddAlgorithm are called.
clSetUnique and clGetUnique allow the algorithm implementation to store
and retrieve algorithm-specific information with each instantiation of a
compressor or decompressor. openCompressor and openDecompressor should
set the unique pointer to initialize algorithm-specific storage. Other
calls such as compress and decompress should get the unique pointer if
they need to access the information from the handle.
clFetchParam and clStoreParam permit algorithm implementations to access
a handle's parameters directly, with minimal overhead. Users of the
codec, however, should call the standard routines clGetParam and
clSetParam instead.
clError is used by new algorithm implementations to report errors.
Generally, the format string starts with the cl routine name within which
the error occurred followed by a description of the error.
clAddAlgorithm returns SUCCESS, or a negative error code on failure.
clSetUnique returns the previous unique pointer, or NULL on failure.
clGetUnique returns the current unique pointer, or NULL on failure.
clFetchParam returns the parameter value.
#include <dmedia/cl.h>
...
int newScheme;
...
/* Add the new algorithm */
clAddAlgorithm("New Algorithm", CL_ALG_VIDEO,
NEW_ALGORITHM_MAX_HEADER_SIZE,
OpenNewCompressor, CompressNew, CloseNewCompressor,
OpenNewDecompressor, DecompressNew, CloseNewDecompressor,
ReadNewHeader, QueryNewScheme, QueryNewLicense,
GetNewParams, SetNewParams,
&newScheme);
/* Compress a series of frames */
clOpenCompressor(newScheme, &handle);
for(i = 0; i < numberOfFrames; i++)
{
/* Get a frame from somewhere */
...
clCompress(handle, 1, frameBuffer, &compressedBufferSize,
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clAddAlgorithm(3dm) clAddAlgorithm(3dm)
compressedBuffer);
/* Write the compressed data to somewhere else */
...
}
clCloseCompressor(handle);
CLintro(3dm), clOpenCompressor(3dm), clCompress(3dm),
clCloseCompressor(3dm), clOpenDecompressor(3dm), clDecompress(3dm),
clCloseDecompressor(3dm), clReadHeader(3dm), clQueryScheme(3dm),
clQueryLicense(3dm), clGetParams(3dm), clSetParams(3dm) clAddParam(3dm),
clSetDefault(3dm), clSetMin(3dm), clSetMax(3dm), clSetMinMax(3dm),
clSetRange(3dm)
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