Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * common code shared by all WMA variants
  3.  *
  4.  * This file is part of FFmpeg.
  5.  *
  6.  * FFmpeg is free software; you can redistribute it and/or
  7.  * modify it under the terms of the GNU Lesser General Public
  8.  * License as published by the Free Software Foundation; either
  9.  * version 2.1 of the License, or (at your option) any later version.
  10.  *
  11.  * FFmpeg is distributed in the hope that it will be useful,
  12.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14.  * Lesser General Public License for more details.
  15.  *
  16.  * You should have received a copy of the GNU Lesser General Public
  17.  * License along with FFmpeg; if not, write to the Free Software
  18.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19.  */
  20.  
  21. #include "libavutil/attributes.h"
  22.  
  23. #include "wma_common.h"
  24.  
  25. /**
  26.  *@brief Get the samples per frame for this stream.
  27.  *@param sample_rate output sample_rate
  28.  *@param version wma version
  29.  *@param decode_flags codec compression features
  30.  *@return log2 of the number of output samples per frame
  31.  */
  32. av_cold int ff_wma_get_frame_len_bits(int sample_rate, int version,
  33.                                       unsigned int decode_flags)
  34. {
  35.     int frame_len_bits;
  36.  
  37.     if (sample_rate <= 16000)
  38.         frame_len_bits = 9;
  39.     else if (sample_rate <= 22050 || (sample_rate <= 32000 && version == 1))
  40.         frame_len_bits = 10;
  41.     else if (sample_rate <= 48000 || version < 3)
  42.         frame_len_bits = 11;
  43.     else if (sample_rate <= 96000)
  44.         frame_len_bits = 12;
  45.     else
  46.         frame_len_bits = 13;
  47.  
  48.     if (version == 3) {
  49.         int tmp = decode_flags & 0x6;
  50.         if (tmp == 0x2)
  51.             ++frame_len_bits;
  52.         else if (tmp == 0x4)
  53.             --frame_len_bits;
  54.         else if (tmp == 0x6)
  55.             frame_len_bits -= 2;
  56.     }
  57.  
  58.     return frame_len_bits;
  59. }
  60.