diff options
Diffstat (limited to 'media/libstagefright/codecs/mp3dec/src/pvmp3_normalize.cpp')
-rw-r--r-- | media/libstagefright/codecs/mp3dec/src/pvmp3_normalize.cpp | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/mp3dec/src/pvmp3_normalize.cpp b/media/libstagefright/codecs/mp3dec/src/pvmp3_normalize.cpp new file mode 100644 index 0000000..e579bbd --- /dev/null +++ b/media/libstagefright/codecs/mp3dec/src/pvmp3_normalize.cpp @@ -0,0 +1,173 @@ +/* ------------------------------------------------------------------ + * Copyright (C) 1998-2009 PacketVideo + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either + * express or implied. + * See the License for the specific language governing permissions + * and limitations under the License. + * ------------------------------------------------------------------- + */ +/* +------------------------------------------------------------------------------ + PacketVideo Corp. + MP3 Decoder Library + + Filename: pvmp3_normalize.cpp + + Date: 10/02/2007 + +------------------------------------------------------------------------------ + REVISION HISTORY + + + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + +Input + Int32 x 32-bit integer non-zero input +Returns + Int32 i number of leading zeros on x + + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + Returns number of leading zeros on the non-zero input + +------------------------------------------------------------------------------ + REQUIREMENTS + + +------------------------------------------------------------------------------ + REFERENCES + +------------------------------------------------------------------------------ + PSEUDO-CODE + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ + +#include "pvmp3_audio_type_defs.h" +#include "pvmp3_normalize.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; EXTERNAL FUNCTION REFERENCES +; Declare functions defined elsewhere and referenced in this module +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES +; Declare variables used in this module but defined elsewhere +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; FUNCTION CODE +----------------------------------------------------------------------------*/ + +#if (defined(PV_ARM_V5)||defined(PV_ARM_V4)) +#elif (defined(PV_ARM_GCC_V5)||defined(PV_ARM_GCC_V4)) + + +/* function is inlined in header file */ + + +#else + +int32 pvmp3_normalize(int32 x) +{ + /*---------------------------------------------------------------------------- + ; Define all local variables + ----------------------------------------------------------------------------*/ + int32 i; + + + if (x > 0x0FFFFFFF) + { + i = 0; /* most likely case */ + } + else if (x > 0x00FFFFFF) + { + i = 3; /* second most likely case */ + } + else if (x > 0x0000FFFF) + { + i = x > 0x000FFFFF ? 7 : 11; + } + else + { + if (x > 0x000000FF) + { + i = x > 0x00000FFF ? 15 : 19; + } + else + { + i = x > 0x0000000F ? 23 : 27; + } + } + + + x <<= i; + + switch (x & 0x78000000) + { + case 0x08000000: + i += 3; + break; + + case 0x18000000: + case 0x10000000: + i += 2; + break; + case 0x28000000: + case 0x20000000: + case 0x38000000: + case 0x30000000: + i++; + + default: + ; + } + + return i; + +} + +#endif + |