diff options
Diffstat (limited to 'apps/codecs/libffmpegFLAC/README.rockbox')
| -rw-r--r-- | apps/codecs/libffmpegFLAC/README.rockbox | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/apps/codecs/libffmpegFLAC/README.rockbox b/apps/codecs/libffmpegFLAC/README.rockbox new file mode 100644 index 0000000..850cdfc --- /dev/null +++ b/apps/codecs/libffmpegFLAC/README.rockbox @@ -0,0 +1,46 @@ +Library: libffmpegFLAC +Imported: 2005-10-26 by Dave Chapman + +This directory contains a FLAC decoder based on the flac.c (and a small +number of other files) from the ffmpeg project. + +LICENSING INFORMATION + +ffmpeg is licensed under the Lesser GNU General Public License and the +file flac.c is Copyright 2003 Alex Beregszaszi. + +IMPORT DETAILS + +The decoder is based on ffmpeg-cvs from 26 October 2005. + +The file libavcodec/flac.c was renamed to decoder.c and all ffmpeg +related code was removed. It was also heavily modified to remove +debugging information and unused experiemental code. + +It was also changed to provide output as 32-bit integers (with the +data left-shifted to 28 bit accuracy). The original flac.c provided +16-bit output. + +In order to minimise memory usage, a small number of hard-coded limits +are present in decoder.h - mainly limiting the supported blocksize +(number of samples in a frame) to 4608. This is the default value +used by the reference FLAC encoder at all standard compression +settings. + + +TESTING + +A test program is contained in the file main.c and this should compile +in any Unix-like environment using the command "make -f Makefile.test". + +Running "test file.flac" will decode the audio data to a WAV file +called "test.wav" in the current directory. This has been tested with +16-bit and 24-bit mono and stereo FLAC files. + +This can be used to test the accuracy of the decoder by comparing the +md5sum of the WAV file produced by this decoder with a WAV file +produced by the official libFLAC decoder. + +This test program could be extended to perform an internal md5sum +calculation and comparing that against the md5sum stored in the FLAC +file's header. |