speex_stereo.h

00001 /* Copyright (C) 2002 Jean-Marc Valin*/
00002 /**
00003    @file speex_stereo.h
00004    @brief Describes the handling for intensity stereo
00005 */
00006 /*
00007    Redistribution and use in source and binary forms, with or without
00008    modification, are permitted provided that the following conditions
00009    are met:
00010    
00011    - Redistributions of source code must retain the above copyright
00012    notice, this list of conditions and the following disclaimer.
00013    
00014    - Redistributions in binary form must reproduce the above copyright
00015    notice, this list of conditions and the following disclaimer in the
00016    documentation and/or other materials provided with the distribution.
00017    
00018    - Neither the name of the Xiph.org Foundation nor the names of its
00019    contributors may be used to endorse or promote products derived from
00020    this software without specific prior written permission.
00021    
00022    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00023    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00024    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00025    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
00026    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00027    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
00028    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00029    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00030    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00031    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00032    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00033 */
00034 
00035 #ifndef STEREO_H
00036 #define STEREO_H
00037 /** @defgroup SpeexStereoState SpeexStereoState: Handling Speex stereo files
00038  *  This describes the Speex intensity stereo encoding/decoding
00039  *  @{
00040  */
00041 
00042 #include "speex/speex_types.h"
00043 #include "speex/speex_bits.h"
00044 
00045 #ifdef __cplusplus
00046 extern "C" {
00047 #endif
00048 
00049 /** State used for decoding (intensity) stereo information */
00050 typedef struct SpeexStereoState {
00051    float balance;      /**< Left/right balance info */
00052    float e_ratio;      /**< Ratio of energies: E(left+right)/[E(left)+E(right)]  */
00053    float smooth_left;  /**< Smoothed left channel gain */
00054    float smooth_right; /**< Smoothed right channel gain */
00055    float reserved1;    /**< Reserved for future use */
00056    float reserved2;    /**< Reserved for future use */
00057 } SpeexStereoState;
00058 
00059 /** Initialization value for a stereo state */
00060 #define SPEEX_STEREO_STATE_INIT {1,.5,1,1,0,0}
00061 
00062 /** Transforms a stereo frame into a mono frame and stores intensity stereo info in 'bits' */
00063 void speex_encode_stereo(float *data, int frame_size, SpeexBits *bits);
00064 
00065 /** Transforms a stereo frame into a mono frame and stores intensity stereo info in 'bits' */
00066 void speex_encode_stereo_int(spx_int16_t *data, int frame_size, SpeexBits *bits);
00067 
00068 /** Transforms a mono frame into a stereo frame using intensity stereo info */
00069 void speex_decode_stereo(float *data, int frame_size, SpeexStereoState *stereo);
00070 
00071 /** Transforms a mono frame into a stereo frame using intensity stereo info */
00072 void speex_decode_stereo_int(spx_int16_t *data, int frame_size, SpeexStereoState *stereo);
00073 
00074 /** Callback handler for intensity stereo info */
00075 int speex_std_stereo_request_handler(SpeexBits *bits, void *state, void *data);
00076 
00077 #ifdef __cplusplus
00078 }
00079 #endif
00080 
00081 /** @} */
00082 #endif