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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Michael Sevakis
*
* This program 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
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef PCM_MIXER_H
#define PCM_MIXER_H
#include <sys/types.h>
/** Simple config **/
/* Length of PCM frames (always) */
#if CONFIG_CPU == PP5002
/* There's far less time to do mixing because HW FIFOs are short */
#define MIX_FRAME_SAMPLES 64
#elif (CONFIG_CPU == JZ4760B) || (CONFIG_CPU == JZ4732)
/* These MIPS32r1 targets have a very high interrupt latency, which
unfortunately causes a lot of audio underruns under even moderate load */
#define MIX_FRAME_SAMPLES 2048
#elif (CONFIG_PLATFORM & PLATFORM_MAEMO5) || defined(DX50) || defined(DX90)
/* Maemo 5 needs 2048 samples for decent performance.
Otherwise the locking overhead inside gstreamer costs too much */
/* iBasso Devices: Match Rockbox PCM buffer size to ALSA PCM buffer size
to minimize memory transfers. */
#define MIX_FRAME_SAMPLES 2048
#else
/* Assume HW DMA engine is available or sufficient latency exists in the
PCM pathway */
#define MIX_FRAME_SAMPLES 256
#endif
#if defined(CPU_COLDFIRE) || defined(CPU_PP)
/* For Coldfire, it's just faster
For PortalPlayer, this also avoids more expensive cache coherency */
#define DOWNMIX_BUF_IBSS IBSS_ATTR
#else
/* Otherwise can't DMA from IRAM, IRAM is pointless or worse */
#define DOWNMIX_BUF_IBSS
#endif
#if defined(CPU_COLDFIRE) || defined(CPU_PP)
#define MIXER_CALLBACK_ICODE ICODE_ATTR
#else
#define MIXER_CALLBACK_ICODE
#endif
/** Definitions **/
/* Channels are preassigned for simplicity */
enum pcm_mixer_channel
{
PCM_MIXER_CHAN_PLAYBACK = 0,
PCM_MIXER_CHAN_VOICE,
#ifndef HAVE_HARDWARE_BEEP
PCM_MIXER_CHAN_BEEP,
#endif
/* Add new channel indexes above this line */
PCM_MIXER_NUM_CHANNELS,
};
/* Channel playback states */
enum channel_status
{
CHANNEL_STOPPED = 0,
CHANNEL_PLAYING,
CHANNEL_PAUSED,
};
#define MIX_AMP_UNITY 0x00010000
#define MIX_AMP_MUTE 0x00000000
/** Public interfaces **/
/* Start playback on a channel */
void mixer_channel_play_data(enum pcm_mixer_channel channel,
pcm_play_callback_type get_more,
const void *start, size_t size);
/* Pause or resume a channel (when started) */
void mixer_channel_play_pause(enum pcm_mixer_channel channel, bool play);
/* Stop playback on a channel */
void mixer_channel_stop(enum pcm_mixer_channel channel);
/* Set channel's amplitude factor */
void mixer_channel_set_amplitude(enum pcm_mixer_channel channel,
unsigned int amplitude);
/* Return channel's playback status */
enum channel_status mixer_channel_status(enum pcm_mixer_channel channel);
/* Returns amount data remaining in channel before next callback */
size_t mixer_channel_get_bytes_waiting(enum pcm_mixer_channel channel);
/* Return pointer to channel's playing audio data and the size remaining */
const void * mixer_channel_get_buffer(enum pcm_mixer_channel channel,
int *count);
/* Calculate peak values for channel */
void mixer_channel_calculate_peaks(enum pcm_mixer_channel channel,
struct pcm_peaks *peaks);
/* Adjust channel pointer by a given offset to support movable buffers */
void mixer_adjust_channel_address(enum pcm_mixer_channel channel,
off_t offset);
/* Set a hook that is called upon getting a new source buffer for a channel
NOTE: Called for each buffer, not each mixer chunk */
typedef void (*chan_buffer_hook_fn_type)(const void *start, size_t size);
void mixer_channel_set_buffer_hook(enum pcm_mixer_channel channel,
chan_buffer_hook_fn_type fn);
/* Stop ALL channels and PCM and reset state */
void mixer_reset(void);
/* Set output samplerate */
void mixer_set_frequency(unsigned int samplerate);
/* Get output samplerate */
unsigned int mixer_get_frequency(void);
#endif /* PCM_MIXER_H */
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