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rockbox/apps/pcmbuf.c
Brandon Low 1f3360f021 Just take out some out-of-date TODOs from playback.c and put a big FIXME in pcmbuf.c 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11217 a1c6a512-1295-4272-9138-f99709370657
2006-10-13 20:48:23 +00:00

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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"
#include "thread.h"
/* Keep watermark high for iPods at least (2s) */
#define PCMBUF_WATERMARK (NATIVE_FREQUENCY * 4 * 2)
/* 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);
};
/* 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 audiobuffer_pos will be increased.*/
static size_t audiobuffer_fillpos IDATA_ATTR;
static char *fadebuf IDATA_ATTR;
static char *voicebuf IDATA_ATTR;
static void (*pcmbuf_event_handler)(void) IDATA_ATTR;
static void (*position_callback)(size_t size) IDATA_ATTR;
/* Crossfade related state */
static bool crossfade_enabled;
static bool crossfade_mixmode;
static bool crossfade_active IDATA_ATTR;
static bool crossfade_init IDATA_ATTR;
/* Track the current location for processing crossfade */
static struct pcmbufdesc *crossfade_chunk IDATA_ATTR;
static size_t crossfade_sample IDATA_ATTR;
/* Counters for fading in new data */
static size_t crossfade_fade_in_total IDATA_ATTR;
static size_t crossfade_fade_in_rem IDATA_ATTR;
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_watermark IDATA_ATTR;
static struct pcmbufdesc *pcmbuf_mix_chunk IDATA_ATTR;
static size_t pcmbuf_mix_sample IDATA_ATTR;
static bool low_latency_mode = false;
static bool pcmbuf_flush;
extern struct thread_entry *codec_thread_p;
/* 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 bool prepare_insert(size_t length);
static void pcmbuf_under_watermark(void);
static bool pcmbuf_flush_fillpos(void);
#if defined(HAVE_ADJUSTABLE_CPU_FREQ) && !defined(SIMULATOR)
void pcmbuf_boost(bool state)
{
static bool boost_state = false;
#ifdef HAVE_PRIORITY_SCHEDULING
static bool priority_modified = false;
#endif
if (crossfade_init || crossfade_active)
return;
if (state != boost_state)
{
cpu_boost_id(state, CPUBOOSTID_PCMBUF);
boost_state = state;
}
#ifdef HAVE_PRIORITY_SCHEDULING
if (state && LOW_DATA(2) && pcm_is_playing())
{
if (!priority_modified)
{
/* Buffer is critically low so override UI priority. */
priority_modified = true;
thread_set_priority(codec_thread_p, PRIORITY_REALTIME);
}
}
else if (priority_modified)
{
/* Set back the original priority. */
thread_set_priority(codec_thread_p, PRIORITY_PLAYBACK);
priority_modified = false;
}
#endif
}
#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;
/* The buffer is finished, call the callback functions */
CALL_IF_EXISTS(position_callback, last_chunksize);
CALL_IF_EXISTS(pcmbuf_current->callback);
/* Put the finished buffer back into circulation */
pcmbuf_write_end->link = pcmbuf_current;
pcmbuf_write_end = pcmbuf_current;
/* If we've read over the mix chunk while it's still mixing there */
if (pcmbuf_current == pcmbuf_mix_chunk)
pcmbuf_mix_chunk = NULL;
/* If we've read over the crossfade chunk while it's still fading */
if (pcmbuf_current == crossfade_chunk)
crossfade_chunk = pcmbuf_read;
}
process_new_buffer:
{
/* 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;
last_chunksize = current_size;
*realsize = current_size;
*realstart = pcmbuf_new->addr;
}
else
{
/* There may be more data waiting to flush, try to use it */
if (pcmbuf_flush_fillpos())
goto process_new_buffer;
/* No more buffers */
last_chunksize = 0;
*realsize = 0;
*realstart = NULL;
CALL_IF_EXISTS(pcmbuf_event_handler);
/* FIXME: We need to find another way to keep the CPU from
* being left boosted, because this is boosting in interrupt
* context. This is also not a good thing, because it will
* result in the CPU being deboosted if there is a legitimate
* buffer underrun (albeit only temporarily, because someone
* will reboost it soon, but it will make the skip longer
* than necessary. */
pcmbuf_boost(false);
}
}
}
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 != NULL) {
if (pcmbuf_flush)
{
pcmbuf_write_end->link = pcmbuf_read->link;
pcmbuf_read->link = pcmbuf_current;
while (pcmbuf_write_end->link)
{
pcmbuf_write_end = pcmbuf_write_end->link;
pcmbuf_unplayed_bytes -= pcmbuf_write_end->size;
}
pcmbuf_flush = false;
}
/* If there is already a read buffer setup, add to it */
else
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;
audiobuffer_pos += size;
if (audiobuffer_pos >= pcmbuf_size)
audiobuffer_pos -= pcmbuf_size;
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_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;
/* 1 seconds of buffer is low data */
return LOW_DATA(4);
}
/* Amount of bytes left in the buffer. */
inline size_t pcmbuf_free(void)
{
if (pcmbuf_read != NULL)
{
void *read = pcmbuf_read->addr;
void *write = &audiobuffer[audiobuffer_pos + audiobuffer_fillpos];
if (read < write)
return (size_t)(read - write) + pcmbuf_size;
else
return (size_t) (read - write);
}
return pcmbuf_size;
}
bool pcmbuf_crossfade_init(bool manual_skip)
{
/* Can't do two crossfades at once and, no fade if pcm is off now */
if (crossfade_init || crossfade_active || !pcm_is_playing())
{
pcmbuf_play_stop();
return false;
}
/* Not enough data, or crossfade disabled, flush the old data instead */
if (LOW_DATA(2) || !pcmbuf_is_crossfade_enabled() || low_latency_mode)
{
pcmbuf_boost(true);
pcmbuf_flush_fillpos();
pcmbuf_flush = true;
return false;
}
pcmbuf_boost(true);
/* Don't enable mix mode when skipping tracks manually. */
if (manual_skip)
crossfade_mixmode = false;
else
crossfade_mixmode = global_settings.crossfade_fade_out_mixmode;
crossfade_init = true;
return true;
}
void pcmbuf_play_stop(void)
{
/** 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_chunk = NULL;
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;
crossfade_init = false;
crossfade_active = false;
pcmbuf_flush = false;
pcmbuf_boost(false);
}
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)
{
pcmbuf_size = bufsize;
pcmbuf_descsize = pcmbuf_descs()*sizeof(struct pcmbufdesc);
audiobuffer = (char *)&audiobuf[(audiobufend - audiobuf) -
(pcmbuf_size + PCMBUF_MIX_CHUNK * 2 + pcmbuf_descsize)];
fadebuf = &audiobuffer[pcmbuf_size];
voicebuf = &fadebuf[PCMBUF_MIX_CHUNK];
pcmbuf_write = (struct pcmbufdesc *)(&voicebuf[PCMBUF_MIX_CHUNK]);
pcmbuf_init_pcmbuffers();
position_callback = NULL;
pcmbuf_event_handler = NULL;
pcmbuf_play_stop();
}
size_t pcmbuf_get_bufsize(void)
{
return pcmbuf_size;
}
void pcmbuf_pause(bool pause) {
if (pause)
pcm_mute(true);
pcm_play_pause(!pause);
if (!pause)
pcm_mute(false);
pcmbuf_boost(!pause && pcm_is_playing());
}
/* Force playback. */
void pcmbuf_play_start(void)
{
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);
if (pcmbuf_read != NULL)
{
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);
}
}
/**
* Commit samples waiting to the pcm buffer.
*/
static bool pcmbuf_flush_fillpos(void)
{
if (audiobuffer_fillpos) {
/* Never use the last buffer descriptor */
while (pcmbuf_write == pcmbuf_write_end) {
/* 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(HZ*PCMBUF_TARGET_CHUNK/(NATIVE_FREQUENCY*4));
}
pcmbuf_add_chunk();
return true;
}
return false;
}
/**
* 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_mixmode)
{
/* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem;
size_t fade_out_sample;
struct pcmbufdesc *fade_out_chunk = crossfade_chunk;
/* Find the right chunk to start fading out */
fade_out_delay += crossfade_sample * 2;
while (fade_out_delay != 0 && fade_out_delay >= fade_out_chunk->size)
{
fade_out_delay -= fade_out_chunk->size;
fade_out_chunk = fade_out_chunk->link;
}
/* The start sample within the chunk */
fade_out_sample = fade_out_delay / 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 * 4 / 10, fade_out_rem);
int factor = (fade_out_rem << 8) / total_fade_out;
fade_out_rem -= block_rem;
/* Fade this block */
while (block_rem > 0 && fade_out_chunk != NULL)
{
/* Fade one sample */
short *buf = (short *)(fade_out_chunk->addr);
int sample = buf[fade_out_sample];
buf[fade_out_sample++] = (sample * factor) >> 8;
block_rem -= 2;
/* Move to the next chunk as needed */
if (fade_out_sample * 2 >= fade_out_chunk->size)
{
fade_out_chunk = fade_out_chunk->link;
fade_out_sample = 0;
}
}
}
}
/* Find the right chunk and sample to start fading in */
fade_in_delay += crossfade_sample * 2;
while (fade_in_delay != 0 && fade_in_delay >= crossfade_chunk->size)
{
fade_in_delay -= crossfade_chunk->size;
crossfade_chunk = crossfade_chunk->link;
}
crossfade_sample = fade_in_delay / 2;
logf("process done!");
}
/* Initializes crossfader, calculates all necessary parameters and
* performs fade-out with the pcm buffer. */
static void crossfade_start(void)
{
size_t crossfade_rem;
size_t crossfade_need;
size_t fade_out_rem;
size_t fade_out_delay;
size_t fade_in_delay;
crossfade_init = false;
/* Reject crossfade if less than .5s of data */
if (LOW_DATA(2)) {
logf("crossfade rejected");
pcmbuf_play_stop();
return ;
}
logf("crossfade_start");
pcmbuf_flush_fillpos();
crossfade_active = true;
/* 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;
crossfade_chunk = pcmbuf_read->link;
crossfade_sample = 0;
/* Get fade out delay from settings. */
fade_out_delay =
NATIVE_FREQUENCY * global_settings.crossfade_fade_out_delay * 4;
/* Get fade out duration from settings. */
fade_out_rem =
NATIVE_FREQUENCY * global_settings.crossfade_fade_out_duration * 4;
crossfade_need = fade_out_delay + fade_out_rem;
/* We want only to modify the last part of the buffer. */
if (crossfade_rem > crossfade_need)
{
size_t crossfade_extra = crossfade_rem - crossfade_need;
while (crossfade_extra > crossfade_chunk->size)
{
crossfade_extra -= crossfade_chunk->size;
crossfade_chunk = crossfade_chunk->link;
}
crossfade_sample = crossfade_extra / 2;
}
/* Truncate fade out duration if necessary. */
else if (crossfade_rem < crossfade_need)
{
size_t crossfade_short = crossfade_need - crossfade_rem;
if (fade_out_rem >= crossfade_short)
fade_out_rem -= crossfade_short;
else
{
fade_out_delay -= crossfade_short - fade_out_rem;
fade_out_rem = 0;
}
}
/* Get also fade in duration and delays from settings. */
crossfade_fade_in_total =
NATIVE_FREQUENCY * global_settings.crossfade_fade_in_duration * 4;
crossfade_fade_in_rem = crossfade_fade_in_total;
fade_in_delay =
NATIVE_FREQUENCY * global_settings.crossfade_fade_in_delay * 4;
crossfade_process_buffer(fade_in_delay, fade_out_delay, fade_out_rem);
}
/* Returns the number of bytes _NOT_ mixed */
static size_t crossfade_fade_mix(int factor, const char *buf, size_t fade_rem)
{
const short *input_buf = (const short *)buf;
short *output_buf = (short *)(crossfade_chunk->addr);
short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
output_buf = &output_buf[crossfade_sample];
while (fade_rem)
{
int sample = *input_buf++;
sample = ((sample * factor) >> 8) + *output_buf;
*output_buf++ = MIN(32767, MAX(-32768, sample));
fade_rem -= 2;
if (output_buf >= chunk_end)
{
crossfade_chunk = crossfade_chunk->link;
if (!crossfade_chunk)
return fade_rem;
output_buf = (short *)(crossfade_chunk->addr);
chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
}
}
crossfade_sample = (size_t)(output_buf - (short *)(crossfade_chunk->addr));
return 0;
}
/* Returns the number of bytes _NOT_ mixed */
static size_t crossfade_mix(const char *buf, size_t length)
{
const short *input_buf = (const short *)buf;
short *output_buf = (short *)(crossfade_chunk->addr);
short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
output_buf = &output_buf[crossfade_sample];
while (length)
{
int sample = *input_buf++ + *output_buf;
*output_buf++ = MIN(32767, MAX(-32768, sample));
length -= 2;
if (output_buf >= chunk_end)
{
crossfade_chunk = crossfade_chunk->link;
if (!crossfade_chunk)
return length;
output_buf = (short *)(crossfade_chunk->addr);
chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
}
}
crossfade_sample = (size_t)(output_buf - (short *)(crossfade_chunk->addr));
return 0;
}
static void pcmbuf_flush_buffer(const char *buf, size_t length)
{
size_t copy_n;
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(char *buf, size_t length)
{
if (length)
{
if (crossfade_fade_in_rem)
{
size_t samples;
short *input_buf;
/* Fade factor for this packet */
int factor =
((crossfade_fade_in_total - crossfade_fade_in_rem) << 8) /
crossfade_fade_in_total;
/* Bytes to fade */
size_t fade_rem = MIN(length, crossfade_fade_in_rem);
/* We _will_ fade this many bytes */
crossfade_fade_in_rem -= fade_rem;
if (crossfade_chunk)
{
/* Mix the data */
size_t fade_total = fade_rem;
fade_rem = crossfade_fade_mix(factor, buf, fade_rem);
length -= fade_total - fade_rem;
buf += fade_total - fade_rem;
if (!length)
return;
if (!fade_rem)
goto fade_done;
}
samples = fade_rem / 2;
input_buf = (short *)buf;
/* Fade remaining samples in place */
while (samples)
{
int sample = *input_buf;
*input_buf++ = (sample * factor) >> 8;
samples--;
}
}
fade_done:
if (crossfade_chunk)
{
/* Mix the data */
size_t mix_total = length;
length = crossfade_mix(buf, length);
buf += mix_total - length;
if (!length)
return;
}
/* Flush samples to the buffer */
while (!prepare_insert(length))
sleep(1);
pcmbuf_flush_buffer(buf, length);
}
}
static bool prepare_insert(size_t length)
{
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 (pcmbuf_free() < length + PCMBUF_MIN_CHUNK)
{
pcmbuf_boost(false);
return false;
}
if (!pcm_is_playing())
{
pcmbuf_boost(true);
/* Pre-buffer 1s. */
#if MEM <= 1
if (!LOW_DATA(1))
#else
if (!LOW_DATA(4))
#endif
{
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_init)
crossfade_start();
if (crossfade_active) {
*realsize = MIN(length, PCMBUF_MIX_CHUNK);
return fadebuf;
}
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)
{
if (pcmbuf_read == NULL)
{
*realsize = 0;
return NULL;
}
else if (pcmbuf_mix_chunk || pcmbuf_read->link)
{
*realsize = MIN(length, PCMBUF_MIX_CHUNK);
return voicebuf;
}
else
{
*realsize = 0;
return NULL;
}
}
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)
{
flush_crossfade(fadebuf, length);
if (!(crossfade_fade_in_rem || crossfade_chunk))
crossfade_active = false;
}
else
{
audiobuffer_fillpos += length;
if (NEED_FLUSH(audiobuffer_pos + audiobuffer_fillpos))
pcmbuf_flush_fillpos();
}
}
bool pcmbuf_insert_buffer(char *buf, size_t length)
{
if (crossfade_active)
{
flush_crossfade(buf, length);
if (!(crossfade_fade_in_rem || crossfade_chunk))
crossfade_active = false;
}
else
{
if (!prepare_insert(length))
return false;
pcmbuf_flush_buffer(buf, length);
}
return true;
}
/* 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;
unsigned int interval = NATIVE_FREQUENCY / frequency;
long sample;
short *buf;
short *pcmbuf_end = (short *)fadebuf;
size_t samples = NATIVE_FREQUENCY / 1000 * duration;
if (pcm_is_playing() && pcmbuf_read != NULL)
{
if (pcmbuf_read->link)
{
/* Get the next chunk */
char *pcmbuf_mix_buf = pcmbuf_read->link->addr;
/* Give at least 1/8s clearance. */
buf = (short *)&pcmbuf_mix_buf[NATIVE_FREQUENCY * 4 / 8];
}
else
{
logf("No place to beep");
return;
}
while (i++ < samples)
{
sample = *buf;
*buf++ = MIN(MAX(sample + amplitude, -32768), 32767);
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
sample = *buf;
*buf++ = MIN(MAX(sample + amplitude, -32768), 32767);
/* Toggle square wav side */
if (++count >= interval)
{
count = 0;
amplitude = -amplitude;
}
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
}
}
else
{
buf = (short *)audiobuffer;
while (i++ < samples)
{
*buf++ = amplitude;
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
*buf++ = amplitude;
/* Toggle square wav side */
if (++count >= interval)
{
count = 0;
amplitude = -amplitude;
}
if (buf > pcmbuf_end)
buf = (short *)audiobuffer;
}
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_free(void)
{
if (pcmbuf_mix_chunk)
{
size_t my_mix_end =
(size_t)&((short *)pcmbuf_mix_chunk->addr)[pcmbuf_mix_sample];
size_t my_write_pos = (size_t)&audiobuffer[audiobuffer_pos];
if (my_write_pos < my_mix_end)
my_write_pos += pcmbuf_size;
return (my_write_pos - my_mix_end) * 100 / pcmbuf_unplayed_bytes;
}
return 100;
}
void pcmbuf_mix_voice(size_t length)
{
short *ibuf = (short *)voicebuf;
short *obuf;
size_t chunk_samples;
if (pcmbuf_mix_chunk == NULL && pcmbuf_read != NULL)
{
pcmbuf_mix_chunk = pcmbuf_read->link;
/* Start 1/8s into the next chunk */
pcmbuf_mix_sample = NATIVE_FREQUENCY * 4 / 16;
}
if (!pcmbuf_mix_chunk)
return;
obuf = (short *)pcmbuf_mix_chunk->addr;
chunk_samples = pcmbuf_mix_chunk->size / 2;
length /= 2;
while (length-- > 0) {
int sample = *ibuf++;
if (pcmbuf_mix_sample >= chunk_samples)
{
pcmbuf_mix_chunk = pcmbuf_mix_chunk->link;
if (!pcmbuf_mix_chunk)
return;
pcmbuf_mix_sample = 0;
obuf = pcmbuf_mix_chunk->addr;
chunk_samples = pcmbuf_mix_chunk->size / 2;
}
sample += obuf[pcmbuf_mix_sample] >> 2;
obuf[pcmbuf_mix_sample++] = MIN(MAX(sample, -32768), 32767);
}
}
void pcmbuf_crossfade_enable(bool on_off)
{
crossfade_enabled = on_off;
if (crossfade_enabled) {
/* If crossfading, try to keep the buffer full other than 1 second */
pcmbuf_set_watermark_bytes(pcmbuf_size - (NATIVE_FREQUENCY * 4 * 1));
} else {
/* Otherwise, just keep it above 2 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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