rockbox/firmware/pcm_playback.c
Nils Wallménius cab33b64a0 Accept patch in FS#7751 by Catalin Patulea, move ifp port specific pcm code to a new file
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14670 a1c6a512-1295-4272-9138-f99709370657
2007-09-11 15:34:54 +00:00

281 lines
7 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "system.h"
#include "kernel.h"
#include "logf.h"
#include "audio.h"
#include "sound.h"
/**
* APIs implemented in the target-specific portion:
* Public -
* pcm_init
* pcm_get_bytes_waiting
* pcm_calculate_peaks
* Semi-private -
* pcm_play_dma_start
* pcm_play_dma_stop
* pcm_play_pause_pause
* pcm_play_pause_unpause
*/
/** These items may be implemented target specifically or need to
be shared semi-privately **/
/* the registered callback function to ask for more mp3 data */
volatile pcm_more_callback_type pcm_callback_for_more = NULL;
volatile bool pcm_playing = false;
volatile bool pcm_paused = false;
void pcm_play_dma_start(const void *addr, size_t size);
void pcm_play_dma_stop(void);
void pcm_play_pause_pause(void);
void pcm_play_pause_unpause(void);
/** Functions that require targeted implementation **/
#if defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440)
/* Implemented in target/... */
#else
/* dummy functions for those not actually supporting all this yet */
void pcm_apply_settings(void)
{
}
/** **/
void pcm_mute(bool mute)
{
#if defined(HAVE_WM8975) || defined(HAVE_WM8758) \
|| defined(HAVE_WM8731) || defined(HAVE_WM8721)
audiohw_mute(mute);
#endif
if (mute)
sleep(HZ/16);
}
#endif /* defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) */
#if defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) || defined(CPU_PP)
/* Implemented in target/... */
#else
static int pcm_freq = HW_SAMPR_DEFAULT; /* 44.1 is default */
unsigned short* p IBSS_ATTR;
size_t p_size IBSS_ATTR;
void pcm_play_dma_start(const void *addr, size_t size)
{
p = (unsigned short*)addr;
p_size = size;
pcm_playing = true;
}
void pcm_play_dma_stop(void)
{
pcm_playing = false;
if (!audio_status())
pcm_paused = false;
}
void pcm_play_pause_pause(void)
{
}
void pcm_play_pause_unpause(void)
{
}
void pcm_postinit(void)
{
audiohw_postinit();
}
void pcm_set_frequency(unsigned int frequency)
{
(void)frequency;
pcm_freq = HW_SAMPR_DEFAULT;
}
size_t pcm_get_bytes_waiting(void)
{
return p_size;
}
/*
* This function goes directly into the DMA buffer to calculate the left and
* right peak values. To avoid missing peaks it tries to look forward two full
* peek periods (2/HZ sec, 100% overlap), although it's always possible that
* the entire period will not be visible. To reduce CPU load it only looks at
* every third sample, and this can be reduced even further if needed (even
* every tenth sample would still be pretty accurate).
*/
/* Check for a peak every PEAK_STRIDE samples */
#define PEAK_STRIDE 3
/* Up to 1/50th of a second of audio for peak calculation */
/* This should use NATIVE_FREQUENCY, or eventually an adjustable freq. value */
#define PEAK_SAMPLES (44100/50)
void pcm_calculate_peaks(int *left, int *right)
{
short *addr;
short *end;
{
size_t samples = p_size / 4;
addr = p;
if (samples > PEAK_SAMPLES)
samples = PEAK_SAMPLES - (PEAK_STRIDE - 1);
else
samples -= MIN(PEAK_STRIDE - 1, samples);
end = &addr[samples * 2];
}
if (left && right) {
int left_peak = 0, right_peak = 0;
while (addr < end) {
int value;
if ((value = addr [0]) > left_peak)
left_peak = value;
else if (-value > left_peak)
left_peak = -value;
if ((value = addr [PEAK_STRIDE | 1]) > right_peak)
right_peak = value;
else if (-value > right_peak)
right_peak = -value;
addr = &addr[PEAK_STRIDE * 2];
}
*left = left_peak;
*right = right_peak;
}
else if (left || right) {
int peak_value = 0, value;
if (right)
addr += (PEAK_STRIDE | 1);
while (addr < end) {
if ((value = addr [0]) > peak_value)
peak_value = value;
else if (-value > peak_value)
peak_value = -value;
addr += PEAK_STRIDE * 2;
}
if (left)
*left = peak_value;
else
*right = peak_value;
}
}
#endif /* defined(CPU_COLDFIRE) || (CONFIG_CPU == S3C2440) || defined(CPU_PP) */
/****************************************************************************
* Functions that do not require targeted implementation but only a targeted
* interface
*/
/* Common code to pcm_play_data and pcm_play_pause
Returns true if DMA playback was started, else false. */
bool pcm_play_data_start(pcm_more_callback_type get_more,
unsigned char *start, size_t size)
{
if (!(start && size))
{
size = 0;
if (get_more)
get_more(&start, &size);
}
if (start && size)
{
pcm_play_dma_start(start, size);
return true;
}
return false;
}
void pcm_play_data(pcm_more_callback_type get_more,
unsigned char *start, size_t size)
{
pcm_callback_for_more = get_more;
if (pcm_play_data_start(get_more, start, size) && pcm_paused)
{
pcm_paused = false;
pcm_play_pause(false);
}
}
void pcm_play_pause(bool play)
{
bool needs_change = pcm_paused == play;
/* This needs to be done ahead of the rest to prevent infinite
recursion from pcm_play_data */
pcm_paused = !play;
if (pcm_playing && needs_change)
{
if (play)
{
if (pcm_get_bytes_waiting())
{
logf("unpause");
pcm_play_pause_unpause();
}
else
{
logf("unpause, no data waiting");
if (!pcm_play_data_start(pcm_callback_for_more, NULL, 0))
{
pcm_play_dma_stop();
logf("unpause attempted, no data");
}
}
}
else
{
logf("pause");
pcm_play_pause_pause();
}
} /* pcm_playing && needs_change */
}
void pcm_play_stop(void)
{
if (pcm_playing)
pcm_play_dma_stop();
}
bool pcm_is_playing(void)
{
return pcm_playing;
}
bool pcm_is_paused(void)
{
return pcm_paused;
}