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rockbox/apps/pcmbuf.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Miika Pekkarinen
*
* 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 <stdbool.h>
#include <stdio.h>
#include "config.h"
#include "debug.h"
#include "panic.h"
#include <kernel.h>
#include "pcmbuf.h"
#include "pcm_playback.h"
#include "logf.h"
#ifndef SIMULATOR
#include "cpu.h"
#endif
#include "system.h"
#include <string.h>
#include "buffer.h"
#include "settings.h"
#include "audio.h"
#include "dsp.h"
#define PCMBUF_WATERMARK (NATIVE_FREQUENCY * 4 * 1)
/* Size of the PCM buffer. */
static size_t pcmbuf_size IDATA_ATTR = 0;
static char *audiobuffer IDATA_ATTR;
/* Current audio buffer write index. */
static size_t audiobuffer_pos IDATA_ATTR;
/* Amount of bytes left in the buffer. */
size_t audiobuffer_free IDATA_ATTR;
/* Amount audiobuffer_pos will be increased.*/
static size_t audiobuffer_fillpos IDATA_ATTR;
static char *guardbuf IDATA_ATTR;
static void (*pcmbuf_event_handler)(void) IDATA_ATTR;
static void (*position_callback)(size_t size) IDATA_ATTR;
/* Crossfade related. */
static int crossfade_mode IDATA_ATTR;
static bool crossfade_enabled IDATA_ATTR;
static bool crossfade_active IDATA_ATTR;
static bool crossfade_init IDATA_ATTR;
static size_t crossfade_pos IDATA_ATTR;
static size_t crossfade_rem IDATA_ATTR;
static struct mutex pcmbuf_mutex IDATA_ATTR;
/* Crossfade modes. If CFM_CROSSFADE is selected, normal
* crossfader will activate. Selecting CFM_FLUSH is a special
* operation that only overwrites the pcm buffer without crossfading.
*/
enum {
CFM_CROSSFADE,
CFM_MIX,
CFM_FLUSH
};
static size_t crossfade_fade_in_amount IDATA_ATTR;
static size_t crossfade_fade_in_rem IDATA_ATTR;
/* Structure we can use to queue pcm chunks in memory to be played
* by the driver code. */
struct pcmbufdesc
{
void *addr;
size_t size;
struct pcmbufdesc* link;
/* Call this when the buffer has been played */
void (*callback)(void);
};
static size_t pcmbuf_descsize;
static struct pcmbufdesc *pcmbuf_read IDATA_ATTR;
static struct pcmbufdesc *pcmbuf_read_end IDATA_ATTR;
static struct pcmbufdesc *pcmbuf_write IDATA_ATTR;
static struct pcmbufdesc *pcmbuf_write_end IDATA_ATTR;
static size_t last_chunksize IDATA_ATTR;
static size_t pcmbuf_unplayed_bytes IDATA_ATTR;
static size_t pcmbuf_mix_used_bytes IDATA_ATTR;
static size_t pcmbuf_watermark IDATA_ATTR;
static short *mixpos IDATA_ATTR;
static bool low_latency_mode = false;
/* Helpful macros for use in conditionals this assumes some of the above
* static variable names */
#define NEED_FLUSH(position) \
(audiobuffer_fillpos > PCMBUF_TARGET_CHUNK || position >= pcmbuf_size)
#define LOW_DATA(quarter_secs) \
(pcmbuf_unplayed_bytes < NATIVE_FREQUENCY * quarter_secs)
static void pcmbuf_flush_audio(void);
static void pcmbuf_under_watermark(void);
#if defined(HAVE_ADJUSTABLE_CPU_FREQ) && !defined(SIMULATOR)
static bool boost_mode;
void pcmbuf_boost(bool state)
{
static bool boost_state = false;
if (crossfade_init || crossfade_active || boost_mode)
return;
if (state != boost_state) {
cpu_boost(state);
boost_state = state;
}
}
void pcmbuf_set_boost_mode(bool state)
{
if (state)
pcmbuf_boost(true);
boost_mode = state;
}
#endif
#define CALL_IF_EXISTS(function, args...) if (function) function(args)
/* This function has 2 major logical parts (separated by brackets both for
* readability and variable scoping). The first part performs the
* operastions related to finishing off the last buffer we fed to the DMA.
* The second part performs the operations involved in sending a new buffer
* to the DMA. Finally the function checks the status of the buffer and
* boosts if necessary */
static void pcmbuf_callback(unsigned char** start, size_t* size) ICODE_ATTR;
static void pcmbuf_callback(unsigned char** start, size_t* size)
{
{
struct pcmbufdesc *pcmbuf_current = pcmbuf_read;
/* Take the finished buffer out of circulation */
pcmbuf_read = pcmbuf_current->link;
{
size_t finished_size = last_chunksize;
audiobuffer_free += finished_size;
/* The buffer is finished, call the callback functions */
CALL_IF_EXISTS(position_callback, finished_size);
}
CALL_IF_EXISTS(pcmbuf_current->callback);
/* Put the finished buffer back into circulation */
pcmbuf_write_end->link = pcmbuf_current;
pcmbuf_write_end = pcmbuf_current;
}
{
/* Send the new buffer to the pcm */
struct pcmbufdesc *pcmbuf_new = pcmbuf_read;
size_t *realsize = size;
unsigned char** realstart = start;
if(pcmbuf_new)
{
size_t current_size = pcmbuf_new->size;
pcmbuf_unplayed_bytes -= current_size;
*realsize = current_size;
last_chunksize = current_size;
*realstart = pcmbuf_new->addr;
}
else
{
/* No more buffers */
last_chunksize = 0;
*realsize = 0;
*realstart = NULL;
CALL_IF_EXISTS(pcmbuf_event_handler);
}
}
}
void pcmbuf_set_position_callback(void (*callback)(size_t size))
{
position_callback = callback;
}
static void pcmbuf_set_watermark_bytes(size_t numbytes)
{
pcmbuf_watermark = numbytes;
}
/* This is really just part of pcmbuf_flush_fillpos, but is easier to keep
* in a separate function for the moment */
static inline void pcmbuf_add_chunk(void)
{
register size_t size = audiobuffer_fillpos;
/* Grab the next description to write, and change the write pointer */
register struct pcmbufdesc *pcmbuf_current = pcmbuf_write;
pcmbuf_write = pcmbuf_current->link;
/* Fill in the values in the new buffer chunk */
pcmbuf_current->addr = &audiobuffer[audiobuffer_pos];
pcmbuf_current->size = size;
pcmbuf_current->callback = pcmbuf_event_handler;
pcmbuf_current->link = NULL;
/* This is single use only */
pcmbuf_event_handler = NULL;
if (pcmbuf_read) {
/* If there is already a read buffer setup, add to it */
pcmbuf_read_end->link = pcmbuf_current;
} else {
/* Otherwise create the buffer */
pcmbuf_read = pcmbuf_current;
}
/* This is now the last buffer to read */
pcmbuf_read_end = pcmbuf_current;
/* Update bytes counters */
pcmbuf_unplayed_bytes += size;
if (pcmbuf_mix_used_bytes > size)
pcmbuf_mix_used_bytes -= size;
else
pcmbuf_mix_used_bytes = 0;
audiobuffer_pos += size;
if (audiobuffer_pos >= pcmbuf_size)
audiobuffer_pos = 0;
audiobuffer_fillpos = 0;
}
static void pcmbuf_under_watermark(void)
{
/* Fill audio buffer by boosting cpu */
pcmbuf_boost(true);
/* Disable crossfade if < .5s of audio */
if (LOW_DATA(2) && crossfade_mode != CFM_FLUSH)
crossfade_active = false;
}
void pcmbuf_set_event_handler(void (*event_handler)(void))
{
pcmbuf_event_handler = event_handler;
}
unsigned int pcmbuf_get_latency(void)
{
/* Be careful how this calculation is rearranted, it's easy to overflow */
size_t bytes = pcmbuf_unplayed_bytes + pcm_get_bytes_waiting();
return bytes / 4 / (NATIVE_FREQUENCY/1000);
}
void pcmbuf_set_low_latency(bool state)
{
low_latency_mode = state;
}
bool pcmbuf_is_lowdata(void)
{
if (!pcm_is_playing() || pcm_is_paused() ||
crossfade_init || crossfade_active)
return false;
/* 0.5 seconds of buffer is low data */
return LOW_DATA(2);
}
bool pcmbuf_crossfade_init(bool manual_skip)
{
if (pcmbuf_unplayed_bytes < PCMBUF_TARGET_CHUNK * 8
|| !pcmbuf_is_crossfade_enabled()
|| crossfade_active || crossfade_init || low_latency_mode) {
pcmbuf_flush_audio();
return false;
}
logf("pcmbuf_crossfade_init");
pcmbuf_boost(true);
/* Don't enable mix mode when skipping tracks manually. */
if (manual_skip)
crossfade_mode = CFM_CROSSFADE;
else
crossfade_mode = global_settings.crossfade_fade_out_mixmode
? CFM_MIX : CFM_CROSSFADE;
crossfade_init = true;
return true;
}
void pcmbuf_play_stop(void)
{
mutex_lock(&pcmbuf_mutex);
/** Prevent a very tiny pop from happening by muting audio
* until dma has been initialized. */
pcm_mute(true);
pcm_play_stop();
pcm_mute(false);
pcmbuf_unplayed_bytes = 0;
pcmbuf_mix_used_bytes = 0;
if (pcmbuf_read) {
pcmbuf_write_end->link = pcmbuf_read;
pcmbuf_write_end = pcmbuf_read_end;
pcmbuf_read = pcmbuf_read_end = NULL;
}
audiobuffer_pos = 0;
audiobuffer_fillpos = 0;
audiobuffer_free = pcmbuf_size;
crossfade_init = false;
crossfade_active = false;
pcmbuf_set_boost_mode(false);
pcmbuf_boost(false);
mutex_unlock(&pcmbuf_mutex);
}
int pcmbuf_used_descs(void) {
struct pcmbufdesc *pcmbuf_temp = pcmbuf_read;
unsigned int i = 0;
while (pcmbuf_temp) {
pcmbuf_temp = pcmbuf_temp->link;
i++;
}
return i;
}
int pcmbuf_descs(void) {
return pcmbuf_size / PCMBUF_MINAVG_CHUNK;
}
size_t get_pcmbuf_descsize(void) {
return pcmbuf_descsize;
}
static void pcmbuf_init_pcmbuffers(void) {
struct pcmbufdesc *next = pcmbuf_write;
next++;
pcmbuf_write_end = pcmbuf_write;
while ((void *)next < (void *)audiobufend) {
pcmbuf_write_end->link=next;
pcmbuf_write_end=next;
next++;
}
}
/* Initialize the pcmbuffer the structure looks like this:
* ...CODECBUFFER|---------PCMBUF---------|GUARDBUF|DESCS| */
void pcmbuf_init(size_t bufsize)
{
mutex_init(&pcmbuf_mutex);
pcmbuf_size = bufsize;
pcmbuf_descsize = pcmbuf_descs()*sizeof(struct pcmbufdesc);
audiobuffer = (char *)&audiobuf[(audiobufend - audiobuf) -
(pcmbuf_size + PCMBUF_FADE_CHUNK + pcmbuf_descsize)];
guardbuf = &audiobuffer[pcmbuf_size];
pcmbuf_write = (struct pcmbufdesc *)(&guardbuf[PCMBUF_FADE_CHUNK]);
pcmbuf_init_pcmbuffers();
position_callback = NULL;
pcmbuf_event_handler = NULL;
pcmbuf_play_stop();
}
size_t pcmbuf_get_bufsize(void)
{
return pcmbuf_size;
}
/** Initialize a track switch so that audio playback will not stop but
* the switch to next track would happen as soon as possible.
*/
static void pcmbuf_flush_audio(void)
{
if (crossfade_init || crossfade_active || !pcm_is_playing()) {
pcmbuf_play_stop();
return ;
}
pcmbuf_boost(true);
crossfade_mode = CFM_FLUSH;
crossfade_init = true;
}
void pcmbuf_pause(bool pause) {
if (pause)
pcm_mute(true);
pcm_play_pause(!pause);
if (!pause)
pcm_mute(false);
pcmbuf_boost(!pause);
}
/* Force playback. */
void pcmbuf_play_start(void)
{
mutex_lock(&pcmbuf_mutex);
if (!pcm_is_playing() && pcmbuf_unplayed_bytes)
{
/** Prevent a very tiny pop from happening by muting audio
* until dma has been initialized. */
pcm_mute(true);
last_chunksize = pcmbuf_read->size;
pcmbuf_unplayed_bytes -= last_chunksize;
pcm_play_data(pcmbuf_callback,
(unsigned char *)pcmbuf_read->addr, last_chunksize);
/* Now unmute the audio. */
pcm_mute(false);
}
mutex_unlock(&pcmbuf_mutex);
}
/**
* Commit samples waiting to the pcm buffer.
*/
static void pcmbuf_flush_fillpos(void)
{
mutex_lock(&pcmbuf_mutex);
if (audiobuffer_fillpos) {
/* Never use the last buffer descriptor */
while (pcmbuf_write == pcmbuf_write_end) {
logf("pcmbuf_flush_fillpos no descriptors");
/* Deboost to let the playback catchup */
pcmbuf_boost(false);
/* If this happens, something is being stupid */
if (!pcm_is_playing()) {
logf("pcmbuf_flush_fillpos error");
pcmbuf_play_start();
}
/* Let approximately one chunk of data playback */
sleep(PCMBUF_TARGET_CHUNK/(NATIVE_FREQUENCY * 4) / 5);
}
pcmbuf_add_chunk();
}
mutex_unlock(&pcmbuf_mutex);
}
/**
* Completely process the crossfade fade out effect with current pcm buffer.
*/
static void crossfade_process_buffer(size_t fade_in_delay,
size_t fade_out_delay, size_t fade_out_rem)
{
if (crossfade_mode == CFM_CROSSFADE)
{
/* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem;
short *buf = (short *)&audiobuffer[crossfade_pos + fade_out_delay * 2];
short *buf_end = (short *)guardbuf;
/* Wrap the starting position if needed */
if (buf >= buf_end) buf -= pcmbuf_size / 2;
while (fade_out_rem > 0)
{
/* Each 1/10 second of audio will have the same fade applied */
size_t block_rem = MIN(NATIVE_FREQUENCY * 2 / 10, fade_out_rem);
unsigned int factor = (fade_out_rem << 8) / total_fade_out;
short *block_end = buf + block_rem;
fade_out_rem -= block_rem;
/* Fade this block */
while (buf < block_end)
{
/* Fade one sample */
*buf = (*buf * factor) >> 8;
buf++;
if (buf >= buf_end)
{
/* Wrap the pcmbuffer */
buf -= pcmbuf_size / 2;
/* Wrap the end pointer to ensure proper termination */
block_end -= pcmbuf_size / 2;
}
}
}
}
/* And finally set the mixing position where we should start fading in. */
crossfade_rem -= fade_in_delay;
crossfade_pos += fade_in_delay*2;
if (crossfade_pos >= pcmbuf_size)
crossfade_pos -= pcmbuf_size;
logf("process done!");
}
/**
* Initializes crossfader, calculates all necessary parameters and
* performs fade-out with the pcm buffer.
*/
static void crossfade_start(void)
{
size_t fade_out_rem = 0;
unsigned int fade_out_delay = 0;
unsigned fade_in_delay = 0;
crossfade_init = 0;
/* Reject crossfade if less than .5s of data */
if (LOW_DATA(2)) {
logf("crossfade rejected");
pcmbuf_play_stop();
return ;
}
logf("crossfade_start");
pcmbuf_boost(true);
pcmbuf_flush_fillpos();
crossfade_active = true;
crossfade_pos = audiobuffer_pos;
/* Initialize the crossfade buffer size to all of the buffered data that
* has not yet been sent to the DMA */
crossfade_rem = pcmbuf_unplayed_bytes / 2;
switch (crossfade_mode) {
case CFM_MIX:
case CFM_CROSSFADE:
/* Get fade out delay from settings. */
fade_out_delay = NATIVE_FREQUENCY
* global_settings.crossfade_fade_out_delay * 2;
/* Get fade out duration from settings. */
fade_out_rem = NATIVE_FREQUENCY
* global_settings.crossfade_fade_out_duration * 2;
/* We want only to modify the last part of the buffer. */
if (crossfade_rem > fade_out_rem + fade_out_delay)
crossfade_rem = fade_out_rem + fade_out_delay;
/* Truncate fade out duration if necessary. */
if (crossfade_rem < fade_out_rem + fade_out_delay)
fade_out_rem -= (fade_out_rem + fade_out_delay) - crossfade_rem;
/* Get also fade in duration and delays from settings. */
crossfade_fade_in_rem = NATIVE_FREQUENCY
* global_settings.crossfade_fade_in_duration * 2;
crossfade_fade_in_amount = crossfade_fade_in_rem;
/* We should avoid to divide by zero. */
if (crossfade_fade_in_amount == 0)
crossfade_fade_in_amount = 1;
fade_in_delay = NATIVE_FREQUENCY
* global_settings.crossfade_fade_in_delay * 2;
/* Decrease the fade out delay if necessary. */
if (crossfade_rem < fade_out_rem + fade_out_delay)
fade_out_delay -=
(fade_out_rem + fade_out_delay) - crossfade_rem;
break ;
case CFM_FLUSH:
crossfade_fade_in_rem = 0;
crossfade_fade_in_amount = 0;
break ;
}
if (crossfade_pos < crossfade_rem * 2)
crossfade_pos += pcmbuf_size;
crossfade_pos -= crossfade_rem*2;
if (crossfade_mode != CFM_FLUSH) {
/* Process the fade out part of the crossfade. */
crossfade_process_buffer(fade_in_delay, fade_out_delay, fade_out_rem);
}
}
/**
* Fades in samples passed to the function and inserts them
* to the pcm buffer.
*/
static void fade_insert(const short *inbuf, size_t length)
{
size_t copy_n;
int factor;
unsigned int i, samples;
short *buf;
factor = ((crossfade_fade_in_amount-crossfade_fade_in_rem)<<8)
/crossfade_fade_in_amount;
while (audiobuffer_free < length)
{
pcmbuf_boost(false);
sleep(1);
}
audiobuffer_free -= length;
while (length > 0) {
unsigned int audiobuffer_index = audiobuffer_pos + audiobuffer_fillpos;
/* Flush as needed */
if (NEED_FLUSH(audiobuffer_index))
{
pcmbuf_flush_fillpos();
audiobuffer_index = audiobuffer_pos + audiobuffer_fillpos;
}
copy_n = MIN(length, pcmbuf_size - audiobuffer_index);
buf = (short *)&audiobuffer[audiobuffer_index];
samples = copy_n / 2;
for (i = 0; i < samples; i++)
buf[i] = (inbuf[i] * factor) >> 8;
inbuf += samples;
audiobuffer_fillpos += copy_n;
length -= copy_n;
}
}
/**
* Fades in buf2 and mixes it with buf.
*/
static int crossfade(short *buf, const short *buf2, unsigned int length)
{
size_t size;
unsigned int i;
size_t size_insert = 0;
int factor;
size = MIN(length, crossfade_rem);
switch (crossfade_mode) {
/* Fade in the current stream and mix it. */
case CFM_MIX:
case CFM_CROSSFADE:
factor = ((crossfade_fade_in_amount-crossfade_fade_in_rem)<<8) /
crossfade_fade_in_amount;
for (i = 0; i < size; i++) {
buf[i] = MIN(32767, MAX(-32768,
buf[i] + ((buf2[i] * factor) >> 8)));
}
break ;
/* Join two streams. */
case CFM_FLUSH:
for (i = 0; i < size; i++) {
buf[i] = buf2[i];
}
//memcpy((char *)buf, (char *)buf2, size*2);
break ;
}
if (crossfade_fade_in_rem > size)
crossfade_fade_in_rem = crossfade_fade_in_rem - size;
else
crossfade_fade_in_rem = 0;
crossfade_rem -= size;
if (crossfade_rem == 0)
{
if (crossfade_fade_in_rem > 0 && crossfade_fade_in_amount > 0)
{
size_insert = MIN(crossfade_fade_in_rem, length - size);
fade_insert(&buf2[size], size_insert*2);
crossfade_fade_in_rem -= size_insert;
}
if (crossfade_fade_in_rem == 0)
crossfade_active = false;
}
return size + size_insert;
}
static void pcmbuf_flush_buffer(const char *buf, size_t length)
{
size_t copy_n;
audiobuffer_free -= length;
while (length > 0) {
size_t audiobuffer_index = audiobuffer_pos + audiobuffer_fillpos;
if (NEED_FLUSH(audiobuffer_index))
{
pcmbuf_flush_fillpos();
audiobuffer_index = audiobuffer_pos + audiobuffer_fillpos;
}
copy_n = MIN(length, pcmbuf_size - audiobuffer_index);
memcpy(&audiobuffer[audiobuffer_index], buf, copy_n);
buf += copy_n;
audiobuffer_fillpos += copy_n;
length -= copy_n;
}
}
static void flush_crossfade(const char *buf, size_t length) {
size_t copy_n;
while (length > 0 && crossfade_active) {
copy_n = MIN(length, pcmbuf_size - crossfade_pos);
copy_n = 2 * crossfade((short *)&audiobuffer[crossfade_pos],
(const short *)buf, copy_n/2);
buf += copy_n;
length -= copy_n;
crossfade_pos += copy_n;
if (crossfade_pos >= pcmbuf_size)
crossfade_pos = 0;
}
pcmbuf_flush_buffer(buf, length);
}
static bool prepare_insert(size_t length)
{
if (crossfade_init)
crossfade_start();
if (low_latency_mode)
{
/* 1/4s latency. */
if (pcmbuf_unplayed_bytes > NATIVE_FREQUENCY * 4 / 4
&& pcm_is_playing())
return false;
}
/* Need to save PCMBUF_MIN_CHUNK to prevent wrapping overwriting */
if (audiobuffer_free < length + PCMBUF_MIN_CHUNK && !crossfade_active)
{
pcmbuf_boost(false);
return false;
}
if (!pcm_is_playing())
{
pcmbuf_boost(true);
crossfade_active = false;
/* Pre-buffer 1s. */
if (!LOW_DATA(4))
{
logf("pcm starting");
pcmbuf_play_start();
}
} else if (pcmbuf_unplayed_bytes <= pcmbuf_watermark)
pcmbuf_under_watermark();
return true;
}
void* pcmbuf_request_buffer(size_t length, size_t *realsize)
{
if (crossfade_active) {
*realsize = MIN(length, PCMBUF_FADE_CHUNK);
return &guardbuf[0];
}
else
{
if(prepare_insert(length))
{
size_t audiobuffer_index = audiobuffer_pos + audiobuffer_fillpos;
*realsize = length;
if (pcmbuf_size - audiobuffer_index >= PCMBUF_MIN_CHUNK)
{
/* Usual case, there's space here */
return &audiobuffer[audiobuffer_index];
}
else
{
/* Flush and wrap the buffer */
pcmbuf_flush_fillpos();
audiobuffer_pos = 0;
return &audiobuffer[0];
}
}
else
{
*realsize = 0;
return NULL;
}
}
}
void* pcmbuf_request_voice_buffer(size_t length, size_t *realsize, bool mix)
{
if (mix)
{
*realsize = MIN(length, PCMBUF_FADE_CHUNK);
return &guardbuf[0];
}
else
return pcmbuf_request_buffer(length, realsize);
}
bool pcmbuf_is_crossfade_active(void)
{
return crossfade_active || crossfade_init;
}
void pcmbuf_write_complete(size_t length)
{
if (crossfade_active) {
length = MIN(length, PCMBUF_FADE_CHUNK);
flush_crossfade(&guardbuf[0],length);
}
else
{
audiobuffer_free -= length;
audiobuffer_fillpos += length;
if (NEED_FLUSH(audiobuffer_pos + audiobuffer_fillpos))
pcmbuf_flush_fillpos();
}
}
bool pcmbuf_insert_buffer(const char *buf, size_t length)
{
if (!prepare_insert(length))
return false;
if (crossfade_active) {
flush_crossfade(buf,length);
}
else
{
pcmbuf_flush_buffer(buf, length);
}
return true;
}
/* Get a pointer to where to mix immediate audio */
static inline short* get_mix_insert_pos(void) {
/* Give at least 1/8s clearance here */
size_t pcmbuf_mix_back_pos =
pcmbuf_unplayed_bytes - NATIVE_FREQUENCY * 4 / 8;
if (audiobuffer_pos < pcmbuf_mix_back_pos)
return (short *)&audiobuffer[pcmbuf_size +
audiobuffer_pos - pcmbuf_mix_back_pos];
else
return (short *)&audiobuffer[audiobuffer_pos - pcmbuf_mix_back_pos];
}
/* Generates a constant square wave sound with a given frequency
in Hertz for a duration in milliseconds. */
void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude)
{
unsigned int count = 0, i = 0;
bool state = false;
unsigned int interval = NATIVE_FREQUENCY / frequency;
short *buf;
short *pcmbuf_end = (short *)guardbuf;
bool playing = pcm_is_playing();
size_t samples = NATIVE_FREQUENCY / 1000 * duration;
if (playing) {
buf = get_mix_insert_pos();
} else {
buf = (short *)audiobuffer;
}
while (i++ < samples)
{
long sample = *buf;
if (state) {
*buf++ = MIN(MAX(sample + amplitude, -32768), 32767);
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
sample = *buf;
*buf++ = MIN(MAX(sample + amplitude, -32768), 32767);
} else {
*buf++ = MIN(MAX(sample - amplitude, -32768), 32767);
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
sample = *buf;
*buf++ = MIN(MAX(sample - amplitude, -32768), 32767);
}
if (++count >= interval)
{
count = 0;
state = !state;
}
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
}
if (!playing) {
pcm_play_data(NULL, (unsigned char *)audiobuffer, samples * 4);
}
}
/* Returns pcm buffer usage in percents (0 to 100). */
int pcmbuf_usage(void)
{
return pcmbuf_unplayed_bytes * 100 / pcmbuf_size;
}
int pcmbuf_mix_usage(void)
{
return pcmbuf_mix_used_bytes * 100 / pcmbuf_unplayed_bytes;
}
void pcmbuf_reset_mixpos(void)
{
mixpos = get_mix_insert_pos();
pcmbuf_mix_used_bytes = 0;
}
void pcmbuf_mix(char *buf, size_t length)
{
short *ibuf = (short *)buf;
short *pcmbuf_end = (short *)guardbuf;
if (pcmbuf_mix_used_bytes == 0)
pcmbuf_reset_mixpos();
pcmbuf_mix_used_bytes += length;
length /= 2;
while (length-- > 0) {
long sample = *ibuf++;
sample += *mixpos >> 2;
*mixpos++ = MIN(MAX(sample, -32768), 32767);
if (mixpos >= pcmbuf_end)
mixpos = (short *)audiobuffer;
}
}
void pcmbuf_crossfade_enable(bool on_off)
{
crossfade_enabled = on_off;
if (crossfade_enabled) {
/* If crossfading, try to keep the buffer full other than 2 second */
pcmbuf_set_watermark_bytes(pcmbuf_size - PCMBUF_WATERMARK * 2);
} else {
/* Otherwise, just keep it above 1 second */
pcmbuf_set_watermark_bytes(PCMBUF_WATERMARK);
}
}
bool pcmbuf_is_crossfade_enabled(void)
{
if (global_settings.crossfade == CROSSFADE_ENABLE_SHUFFLE)
return global_settings.playlist_shuffle;
return crossfade_enabled;
}
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