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wma_common.c
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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  */
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 }
int version
Definition: avisynth_c.h:629
Macro definitions for various function/variable attributes.
#define av_cold
Definition: attributes.h:82
static uint8_t tmp[8]
Definition: des-test.c:38
sample_rate
av_cold int ff_wma_get_frame_len_bits(int sample_rate, int version, unsigned int decode_flags)
Get the samples per frame for this stream.
Definition: wma_common.c:32