third_party_ffmpeg/libavcodec/flac.c
Justin Ruggles 0fb2182d46 add a function to calculate a more accurate estimate for maximum FLAC
frame size and use the function in the FLAC decoder and FLAC encoder

Originally committed as revision 18092 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-03-21 01:54:31 +00:00

44 lines
1.4 KiB
C

/*
* FLAC common code
* Copyright (c) 2009 Justin Ruggles
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "flac.h"
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
{
/* Technically, there is no limit to FLAC frame size, but an encoder
should not write a frame that is larger than if verbatim encoding mode
were to be used. */
int count;
count = 16; /* frame header */
count += ch * ((7+bps+7)/8); /* subframe headers */
if (ch == 2) {
/* for stereo, need to account for using decorrelation */
count += (( 2*bps+1) * blocksize + 7) / 8;
} else {
count += ( ch*bps * blocksize + 7) / 8;
}
count += 2; /* frame footer */
return count;
}