47 lines
1.6 KiB
Text
47 lines
1.6 KiB
Text
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Library: libffmpegFLAC
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Imported: 2005-10-26 by Dave Chapman
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This directory contains a FLAC decoder based on the flac.c (and a small
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number of other files) from the ffmpeg project.
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LICENSING INFORMATION
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ffmpeg is licensed under the Lesser GNU General Public License and the
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file flac.c is Copyright 2003 Alex Beregszaszi.
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IMPORT DETAILS
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The decoder is based on ffmpeg-cvs from 26 October 2005.
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The file libavcodec/flac.c was renamed to decoder.c and all ffmpeg
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related code was removed. It was also heavily modified to remove
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debugging information and unused experiemental code.
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It was also changed to provide output as 32-bit integers (with the
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data left-shifted to 28 bit accuracy). The original flac.c provided
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16-bit output.
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In order to minimise memory usage, a small number of hard-coded limits
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are present in decoder.h - mainly limiting the supported blocksize
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(number of samples in a frame) to 4608. This is the default value
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used by the reference FLAC encoder at all standard compression
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settings.
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TESTING
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A test program is contained in the file main.c and this should compile
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in any Unix-like environment using the command "make -f Makefile.test".
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Running "test file.flac" will decode the audio data to a WAV file
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called "test.wav" in the current directory. This has been tested with
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16-bit and 24-bit mono and stereo FLAC files.
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This can be used to test the accuracy of the decoder by comparing the
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md5sum of the WAV file produced by this decoder with a WAV file
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produced by the official libFLAC decoder.
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This test program could be extended to perform an internal md5sum
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calculation and comparing that against the md5sum stored in the FLAC
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file's header.
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