firmware/export/pcm_mixer.h

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2011 by Michael Sevakis
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #ifndef PCM_MIXER_H
  23 #define PCM_MIXER_H
  24
  25 #include <sys/types.h>
  26
  27 /** Simple config **/
  28
  29 /* Length of PCM frames (always) */
  30 #if CONFIG_CPU == PP5002
  31 /* There's far less time to do mixing because HW FIFOs are short */
  32 #define MIX_FRAME_SAMPLES 64
  33 #elif (CONFIG_PLATFORM & PLATFORM_MAEMO5)
  34 /* Maemo 5 needs 2048 samples for decent performance.
  35    Otherwise the locking overhead inside gstreamer costs too much */
  36 #define MIX_FRAME_SAMPLES 2048
  37 /* Assume HW DMA engine is available or sufficient latency exists in the
  38    PCM pathway */
  39 #else
  40 #define MIX_FRAME_SAMPLES 256
  41 #endif
  42
  43 #if defined(CPU_COLDFIRE) ||  defined(CPU_PP)
  44 /* For Coldfire, it's just faster
  45    For PortalPlayer, this also avoids more expensive cache coherency */
  46 #define DOWNMIX_BUF_IBSS        IBSS_ATTR
  47 #else
  48 /* Otherwise can't DMA from IRAM, IRAM is pointless or worse */
  49 #define DOWNMIX_BUF_IBSS
  50 #endif
  51
  52 #if defined(CPU_COLDFIRE) || defined(CPU_PP)
  53 #define MIXER_CALLBACK_ICODE    ICODE_ATTR
  54 #else
  55 #define MIXER_CALLBACK_ICODE
  56 #endif
  57
  58
  59 /** Definitions **/
  60
  61 /* Channels are preassigned for simplicity */
  62 enum pcm_mixer_channel
  63 {
  64     PCM_MIXER_CHAN_PLAYBACK = 0,
  65     PCM_MIXER_CHAN_VOICE,
  66 #ifndef HAVE_HARDWARE_BEEP
  67     PCM_MIXER_CHAN_BEEP,
  68 #endif
  69     /* Add new channel indexes above this line */
  70     PCM_MIXER_NUM_CHANNELS,
  71 };
  72
  73 /* Channel playback states */
  74 enum channel_status
  75 {
  76     CHANNEL_STOPPED = 0,
  77     CHANNEL_PLAYING,
  78     CHANNEL_PAUSED,
  79 };
  80
  81 #define MIX_AMP_UNITY    0x00010000
  82 #define MIX_AMP_MUTE     0x00000000
  83
  84
  85 /** Public interfaces **/
  86
  87 /* Start playback on a channel */
  88 void mixer_channel_play_data(enum pcm_mixer_channel channel,
  89                              pcm_play_callback_type get_more,
  90                              const void *start, size_t size);
  91
  92 /* Pause or resume a channel (when started) */
  93 void mixer_channel_play_pause(enum pcm_mixer_channel channel, bool play);
  94
  95 /* Stop playback on a channel */
  96 void mixer_channel_stop(enum pcm_mixer_channel channel);
  97
  98 /* Set channel's amplitude factor */
  99 void mixer_channel_set_amplitude(enum pcm_mixer_channel channel,
 100                                  unsigned int amplitude);
 101
 102 /* Return channel's playback status */
 103 enum channel_status mixer_channel_status(enum pcm_mixer_channel channel);
 104
 105 /* Returns amount data remaining in channel before next callback */
 106 size_t mixer_channel_get_bytes_waiting(enum pcm_mixer_channel channel);
 107
 108 /* Return pointer to channel's playing audio data and the size remaining */
 109 const void * mixer_channel_get_buffer(enum pcm_mixer_channel channel, int *count);
 110
 111 /* Calculate peak values for channel */
 112 void mixer_channel_calculate_peaks(enum pcm_mixer_channel channel,
 113                                    struct pcm_peaks *peaks);
 114
 115 /* Adjust channel pointer by a given offset to support movable buffers */
 116 void mixer_adjust_channel_address(enum pcm_mixer_channel channel,
 117                                   off_t offset);
 118
 119 /* Stop ALL channels and PCM and reset state */
 120 void mixer_reset(void);
 121
 122 #endif /* PCM_MIXER_H */