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|
/*****************************************************************
|
| AP4 - AC-4 Utilities
|
| Copyright 2002-2020 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL 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 General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4Ac4Utils.h"
AP4_UI32
AP4_Ac4VariableBits(AP4_BitReader &data, int nBits)
{
AP4_UI32 value = 0;
AP4_UI32 b_moreBits;
do{
value += data.ReadBits(nBits);
b_moreBits = data.ReadBit();
if (b_moreBits == 1) {
value <<= nBits;
value += (1<<nBits);
}
} while (b_moreBits == 1);
return value;
}
AP4_Result
AP4_Ac4ChannelCountFromSpeakerGroupIndexMask(unsigned int speakerGroupIndexMask)
{
unsigned int channelCount= 0;
if ((speakerGroupIndexMask & 1) != 0) { // 0: L,R 0b1
channelCount += 2;
}
if ((speakerGroupIndexMask & 2) != 0) { // 1: C 0b10
channelCount += 1;
}
if ((speakerGroupIndexMask & 4) != 0) { // 2: Ls,Rs 0b100
channelCount += 2;
}
if ((speakerGroupIndexMask & 8) != 0) { // 3: Lb,Rb 0b1000
channelCount += 2;
}
if ((speakerGroupIndexMask & 16) != 0) { // 4: Tfl,Tfr 0b10000
channelCount += 2;
}
if ((speakerGroupIndexMask & 32) != 0) { // 5: Tbl,Tbr 0b100000
channelCount += 2;
}
if ((speakerGroupIndexMask & 64) != 0) { // 6: LFE 0b1000000
channelCount += 1;
}
if ((speakerGroupIndexMask & 128) != 0) { // 7: TL,TR 0b10000000
channelCount += 2;
}
if ((speakerGroupIndexMask & 256) != 0) { // 8: Tsl,Tsr 0b100000000
channelCount += 2;
}
if ((speakerGroupIndexMask & 512) != 0) { // 9: Tfc
channelCount += 1;
}
if ((speakerGroupIndexMask & 1024) != 0) { // 10: Tbc
channelCount += 1;
}
if ((speakerGroupIndexMask & 2048) != 0) { // 11: Tc
channelCount += 1;
}
if ((speakerGroupIndexMask & 4096) != 0) { // 12: LFE2
channelCount += 1;
}
if ((speakerGroupIndexMask & 8192) != 0) { // 13: Bfl,Bfr
channelCount += 2;
}
if ((speakerGroupIndexMask & 16384) != 0) { // 14: Bfc
channelCount += 1;
}
if ((speakerGroupIndexMask & 32768) != 0) { // 15: Cb
channelCount += 1;
}
if ((speakerGroupIndexMask & 65536) != 0) { // 16: Lscr,Rscr
channelCount += 2;
}
if ((speakerGroupIndexMask & 131072) != 0) { // 17: Lw,Rw
channelCount += 2;
}
if ((speakerGroupIndexMask & 262144) != 0) { // 18: Vhl,Vhr
channelCount += 2;
}
return channelCount;
}
|
