libavcodec/flac.c

   1 /*
   2  * FLAC common code
   3  * Copyright (c) 2009 Justin Ruggles
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "flac.h"
  23
  24 int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
  25 {
  26     /* Technically, there is no limit to FLAC frame size, but an encoder
  27        should not write a frame that is larger than if verbatim encoding mode
  28        were to be used. */
  29
  30     int count;
  31
  32     count = 16;                  /* frame header */
  33     count += ch * ((7+bps+7)/8); /* subframe headers */
  34     if (ch == 2) {
  35         /* for stereo, need to account for using decorrelation */
  36         count += (( 2*bps+1) * blocksize + 7) / 8;
  37     } else {
  38         count += ( ch*bps    * blocksize + 7) / 8;
  39     }
  40     count += 2; /* frame footer */
  41
  42     return count;
  43 }