rockbox/apps/pcmbuf.c

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22 KiB
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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 CHUNK_SIZE PCMBUF_GUARD
/* Must be a power of 2 */
#define NUM_PCM_BUFFERS 128
#define NUM_PCM_BUFFERS_MASK (NUM_PCM_BUFFERS - 1)
#define PCMBUF_WATERMARK (CHUNK_SIZE * 6)
/* Audio buffer related settings. */
static long pcmbuf_size = 0; /* Size of the PCM buffer. */
static char *audiobuffer;
static long audiobuffer_pos; /* Current audio buffer write index. */
long audiobuffer_free; /* Amount of bytes left in the buffer. */
static long audiobuffer_fillpos; /* Amount audiobuffer_pos will be increased. */
static char *guardbuf;
static void (*pcmbuf_event_handler)(void);
/* Crossfade related. */
static int crossfade_mode;
static bool crossfade_enabled;
static bool crossfade_active;
static bool crossfade_init;
static int crossfade_pos;
static int crossfade_rem;
/* 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 int crossfade_fade_in_amount;
static int crossfade_fade_in_rem;
/* Structure we can use to queue pcm chunks in memory to be played
* by the driver code. */
struct pcmbufdesc
{
void *addr;
int size;
/* Call this when the buffer has been played */
void (*callback)(void);
} pcmbuffers[NUM_PCM_BUFFERS];
volatile int pcmbuf_read_index;
volatile int pcmbuf_write_index;
int pcmbuf_unplayed_bytes;
int pcmbuf_mix_used_bytes;
int pcmbuf_watermark;
void (*pcmbuf_watermark_event)(int bytes_left);
static int last_chunksize;
static long mixpos = 0;
#ifdef HAVE_ADJUSTABLE_CPU_FREQ
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
int pcmbuf_num_used_buffers(void)
{
return (pcmbuf_write_index - pcmbuf_read_index) & NUM_PCM_BUFFERS_MASK;
}
static void pcmbuf_callback(unsigned char** start, long* size)
{
struct pcmbufdesc *desc = &pcmbuffers[pcmbuf_read_index];
pcmbuf_unplayed_bytes -= last_chunksize;
audiobuffer_free += last_chunksize;
if(desc->size == 0)
{
/* The buffer is finished, call the callback function */
if(desc->callback)
desc->callback();
/* Advance to the next buffer */
pcmbuf_read_index = (pcmbuf_read_index + 1) & NUM_PCM_BUFFERS_MASK;
desc = &pcmbuffers[pcmbuf_read_index];
}
if(pcmbuf_num_used_buffers())
{
*start = desc->addr;
*size = desc->size;
/* Update the buffer descriptor */
desc->addr += desc->size;
desc->size = 0;
}
else
{
/* No more buffers */
*size = 0;
if (pcmbuf_event_handler)
pcmbuf_event_handler();
}
last_chunksize = *size;
if(pcmbuf_unplayed_bytes <= pcmbuf_watermark)
{
if(pcmbuf_watermark_event)
{
pcmbuf_watermark_event(pcmbuf_unplayed_bytes);
}
}
}
void pcmbuf_set_watermark(int numbytes, void (*callback)(int bytes_left))
{
pcmbuf_watermark = numbytes;
pcmbuf_watermark_event = callback;
}
bool pcmbuf_add_chunk(void *addr, int size, void (*callback)(void))
{
/* We don't use the last buffer, since we can't see the difference
between the full and empty condition */
if(pcmbuf_num_used_buffers() < (NUM_PCM_BUFFERS - 2))
{
pcmbuffers[pcmbuf_write_index].addr = addr;
pcmbuffers[pcmbuf_write_index].size = size;
pcmbuffers[pcmbuf_write_index].callback = callback;
pcmbuf_write_index = (pcmbuf_write_index+1) & NUM_PCM_BUFFERS_MASK;
pcmbuf_unplayed_bytes += size;
pcmbuf_mix_used_bytes = MAX(0, pcmbuf_mix_used_bytes - size);
return true;
}
else
return false;
}
void pcmbuf_watermark_callback(int bytes_left)
{
/* Fill audio buffer by boosting cpu */
pcmbuf_boost(true);
if (bytes_left <= CHUNK_SIZE * 2 && crossfade_mode != CFM_FLUSH)
crossfade_active = false;
}
void pcmbuf_add_event(void (*event_handler)(void))
{
pcmbuf_event_handler = event_handler;
}
unsigned int pcmbuf_get_latency(void)
{
int latency;
latency = (pcmbuf_unplayed_bytes + pcm_get_bytes_waiting())
* 1000 / 4 / 44100;
if (latency < 0)
latency = 0;
return latency;
}
bool pcmbuf_is_lowdata(void)
{
if (!pcm_is_playing() || pcm_is_paused() || crossfade_init || crossfade_active)
return false;
if (pcmbuf_unplayed_bytes < CHUNK_SIZE * 4)
return true;
return false;
}
bool pcmbuf_crossfade_init(void)
{
if (pcmbuf_size - audiobuffer_free < CHUNK_SIZE * 8 || !crossfade_enabled
|| crossfade_active || crossfade_init) {
pcmbuf_flush_audio();
return false;
}
logf("pcmbuf_crossfade_init");
pcmbuf_boost(true);
crossfade_mode = global_settings.crossfade_fade_out_mixmode
? CFM_MIX : CFM_CROSSFADE;
crossfade_init = true;
return true;
}
void pcmbuf_play_stop(void)
{
pcm_play_stop();
last_chunksize = 0;
pcmbuf_unplayed_bytes = 0;
pcmbuf_mix_used_bytes = 0;
pcmbuf_read_index = 0;
pcmbuf_write_index = 0;
audiobuffer_pos = 0;
audiobuffer_fillpos = 0;
audiobuffer_free = pcmbuf_size;
crossfade_init = false;
crossfade_active = false;
pcmbuf_set_boost_mode(false);
pcmbuf_boost(false);
}
void pcmbuf_init(long bufsize)
{
pcmbuf_size = bufsize;
audiobuffer = &audiobuf[(audiobufend - audiobuf) -
pcmbuf_size - PCMBUF_GUARD];
guardbuf = &audiobuffer[pcmbuf_size];
pcmbuf_event_handler = NULL;
pcmbuf_play_stop();
}
long 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.
*/
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;
}
/* Force playback. */
void pcmbuf_play_start(void)
{
if (!pcm_is_playing() && pcmbuf_unplayed_bytes)
pcm_play_data(pcmbuf_callback);
}
/**
* Commit samples waiting to the pcm buffer.
*/
void pcmbuf_flush_fillpos(void)
{
int copy_n;
copy_n = MIN(audiobuffer_fillpos, CHUNK_SIZE);
if (copy_n) {
while (!pcmbuf_add_chunk(&audiobuffer[audiobuffer_pos],
copy_n, pcmbuf_event_handler)) {
pcmbuf_boost(false);
sleep(1);
/* This is a fatal error situation that should never happen. */
if (!pcm_is_playing()) {
logf("pcm_flush_fillpos error");
pcm_play_data(pcmbuf_callback);
return ;
}
}
pcmbuf_event_handler = NULL;
audiobuffer_pos += copy_n;
if (audiobuffer_pos >= pcmbuf_size)
audiobuffer_pos -= pcmbuf_size;
audiobuffer_free -= copy_n;
audiobuffer_fillpos -= copy_n;
}
}
/**
* Completely process the crossfade fade out effect with current pcm buffer.
*/
static void crossfade_process_buffer(
int fade_in_delay, int fade_out_delay, int fade_out_rem)
{
int amount;
int pos;
short *buf;
/* Fade out the entire current buffer according to settings. */
amount = fade_out_rem;
pos = crossfade_pos + fade_out_delay*2;
while (fade_out_rem > 0 && crossfade_mode == CFM_CROSSFADE)
{
int blocksize = MIN(8192, fade_out_rem);
int factor = (fade_out_rem<<8)/amount;
/* Prevent pcmbuffer from wrapping. */
if (pos >= pcmbuf_size)
pos -= pcmbuf_size;
blocksize = MIN(pcmbuf_size - pos, blocksize);
buf = (short *)&audiobuffer[pos];
fade_out_rem -= blocksize;
pos += blocksize * 2;
while (blocksize > 0)
{
*buf = (*buf * factor) >> 8;
*buf++;
blocksize--;
}
//yield();
}
/* 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)
{
int bytesleft = pcmbuf_unplayed_bytes;
int fade_out_rem = 0, fade_out_delay = 0;
int fade_in_delay = 0;
crossfade_init = 0;
if (bytesleft < CHUNK_SIZE * 4) {
logf("crossfade rejected");
pcmbuf_play_stop();
return ;
}
logf("crossfade_start");
pcmbuf_boost(true);
while (audiobuffer_fillpos != 0)
pcmbuf_flush_fillpos();
crossfade_active = true;
crossfade_pos = audiobuffer_pos;
switch (crossfade_mode) {
case CFM_MIX:
case CFM_CROSSFADE:
/* Initialize the crossfade buffer size. */
crossfade_rem = (bytesleft - (CHUNK_SIZE * 2))/2;
/* 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;
/* Truncate fade out duration if necessary. */
if (fade_out_rem > crossfade_rem)
fade_out_rem = crossfade_rem;
/* 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;
/* 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. */
fade_out_delay += MIN(crossfade_rem -
fade_out_rem -
fade_out_delay, 0);
if (fade_out_delay < 0)
fade_out_delay = 0;
break ;
case CFM_FLUSH:
crossfade_rem = bytesleft /2;
break ;
}
crossfade_pos -= crossfade_rem*2;
if (crossfade_pos < 0)
crossfade_pos += pcmbuf_size;
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, int length)
{
int copy_n;
int factor;
int i, samples;
short *buf;
factor = ((crossfade_fade_in_amount-crossfade_fade_in_rem)
<<8)/crossfade_fade_in_amount;
while (audiobuffer_free < length + audiobuffer_fillpos
+ CHUNK_SIZE)
{
pcmbuf_boost(false);
sleep(1);
}
while (length > 0) {
copy_n = MIN(length, pcmbuf_size - audiobuffer_pos -
audiobuffer_fillpos);
copy_n = MIN(CHUNK_SIZE - audiobuffer_fillpos, copy_n);
buf = (short *)&audiobuffer[audiobuffer_pos+audiobuffer_fillpos];
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;
/* Pre-buffer to meet CHUNK_SIZE requirement */
if (audiobuffer_fillpos < CHUNK_SIZE && length == 0) {
break ;
}
pcmbuf_flush_fillpos();
}
}
/**
* Fades in buf2 and mixes it with buf.
*/
static __inline
int crossfade(short *buf, const short *buf2, int length)
{
int size, i;
int size_insert = 0;
int factor;
size = MAX(0, 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(MAX(buf[i] + ((buf2[i] * factor) >> 8), -32768), 32767);
}
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 ;
}
crossfade_fade_in_rem = MAX(0, crossfade_fade_in_rem - size);
crossfade_rem -= size;
if (crossfade_rem <= 0)
{
size_insert = MAX(0, 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 bool prepare_insert(long length)
{
if (crossfade_init)
crossfade_start();
if (audiobuffer_free < length + audiobuffer_fillpos
+ CHUNK_SIZE && !crossfade_active) {
pcmbuf_boost(false);
return false;
}
if (!pcm_is_playing()) {
pcmbuf_boost(true);
crossfade_active = false;
if (audiobuffer_free < pcmbuf_size - CHUNK_SIZE*4) {
logf("pcm starting");
pcm_play_data(pcmbuf_callback);
}
}
return true;
}
void* pcmbuf_request_buffer(long length, long *realsize)
{
void *ptr = NULL;
if (!prepare_insert(length))
{
*realsize = 0;
return NULL;
}
if (crossfade_active) {
*realsize = MIN(length, PCMBUF_GUARD);
ptr = &guardbuf[0];
} else {
*realsize = MIN(length, pcmbuf_size - audiobuffer_pos
- audiobuffer_fillpos);
if (*realsize < length) {
*realsize += MIN((long)(length - *realsize), PCMBUF_GUARD);
}
ptr = &audiobuffer[audiobuffer_pos + audiobuffer_fillpos];
}
return ptr;
}
bool pcmbuf_is_crossfade_active(void)
{
return crossfade_active || crossfade_init;
}
void pcmbuf_flush_buffer(long length)
{
int copy_n;
char *buf;
if (crossfade_active) {
buf = &guardbuf[0];
length = MIN(length, PCMBUF_GUARD);
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 -= pcmbuf_size;
}
while (length > 0) {
pcmbuf_flush_fillpos();
copy_n = MIN(length, pcmbuf_size - audiobuffer_pos);
memcpy(&audiobuffer[audiobuffer_pos], buf, copy_n);
audiobuffer_fillpos = copy_n;
buf += copy_n;
length -= copy_n;
}
}
audiobuffer_fillpos += length;
try_flush:
if (audiobuffer_fillpos < CHUNK_SIZE && pcmbuf_size
- audiobuffer_pos - audiobuffer_fillpos > 0)
return ;
copy_n = audiobuffer_fillpos - (pcmbuf_size - audiobuffer_pos);
if (copy_n > 0) {
audiobuffer_fillpos -= copy_n;
pcmbuf_flush_fillpos();
copy_n = MIN(copy_n, PCMBUF_GUARD);
memcpy(&audiobuffer[0], &guardbuf[0], copy_n);
audiobuffer_fillpos = copy_n;
goto try_flush;
}
pcmbuf_flush_fillpos();
}
bool pcmbuf_insert_buffer(char *buf, long length)
{
long copy_n = 0;
if (!prepare_insert(length))
return false;
if (crossfade_active) {
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 -= pcmbuf_size;
}
while (length > 0) {
pcmbuf_flush_fillpos();
copy_n = MIN(length, pcmbuf_size - audiobuffer_pos);
memcpy(&audiobuffer[audiobuffer_pos], buf, copy_n);
audiobuffer_fillpos = copy_n;
buf += copy_n;
length -= copy_n;
}
}
while (length > 0) {
copy_n = MIN(length, pcmbuf_size - audiobuffer_pos -
audiobuffer_fillpos);
copy_n = MIN(CHUNK_SIZE - audiobuffer_fillpos, copy_n);
memcpy(&audiobuffer[audiobuffer_pos+audiobuffer_fillpos],
buf, copy_n);
buf += copy_n;
audiobuffer_fillpos += copy_n;
length -= copy_n;
/* Pre-buffer to meet CHUNK_SIZE requirement */
if (audiobuffer_fillpos < CHUNK_SIZE && length == 0) {
return true;
}
pcmbuf_flush_fillpos();
}
return true;
}
/* Generates a constant square wave sound with a given frequency
in Hertz for a duration in milliseconds. */
void pcmbuf_beep(int frequency, int duration, int amplitude)
{
int state = 0, count = 0;
int interval = NATIVE_FREQUENCY / frequency;
int pos;
short *buf = (short *)audiobuffer;
int bufsize = pcmbuf_size / 2;
/* FIXME: Should start playback. */
//if (pcmbuf_unplayed_bytes * 1000 < 4 * NATIVE_FREQUENCY * duration)
// return ;
pos = (audiobuffer_pos - pcmbuf_unplayed_bytes) / 2;
if (pos < 0)
pos += bufsize;
duration = NATIVE_FREQUENCY / 1000 * duration;
while (duration-- > 0)
{
if (state) {
buf[pos] = MIN(MAX(buf[pos] + amplitude, -32768), 32767);
if (++pos >= bufsize)
pos = 0;
buf[pos] = MIN(MAX(buf[pos] + amplitude, -32768), 32767);
} else {
buf[pos] = MIN(MAX(buf[pos] - amplitude, -32768), 32767);
if (++pos >= bufsize)
pos = 0;
buf[pos] = MIN(MAX(buf[pos] - amplitude, -32768), 32767);
}
if (++count >= interval)
{
count = 0;
if (state)
state = 0;
else
state = 1;
}
pos++;
if (pos >= bufsize)
pos = 0;
}
}
/* 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)
{
int bufsize = pcmbuf_size / 2;
pcmbuf_mix_used_bytes = 0;
mixpos = (audiobuffer_pos - pcmbuf_unplayed_bytes) / 2;
if (mixpos < 0)
mixpos += bufsize;
if (mixpos >= bufsize)
mixpos -= bufsize;
}
void pcmbuf_mix(char *buf, long length)
{
short *ibuf = (short *)buf;
short *obuf = (short *)audiobuffer;
int bufsize = pcmbuf_size / 2;
if (pcmbuf_mix_used_bytes == 0)
pcmbuf_reset_mixpos();
pcmbuf_mix_used_bytes += length;
length /= 2;
while (length-- > 0) {
obuf[mixpos] = MIN(MAX(obuf[mixpos]/4 + *ibuf, -32768), 32767);
ibuf++;
mixpos++;
if (mixpos >= bufsize)
mixpos = 0;
}
}
void pcmbuf_crossfade_enable(bool on_off)
{
crossfade_enabled = on_off;
if (crossfade_enabled) {
pcmbuf_set_watermark(pcmbuf_size - (CHUNK_SIZE*6), pcmbuf_watermark_callback);
} else {
pcmbuf_set_watermark(PCMBUF_WATERMARK, pcmbuf_watermark_callback);
}
}
bool pcmbuf_is_crossfade_enabled(void)
{
if (global_settings.crossfade == CROSSFADE_ENABLE_SHUFFLE)
return global_settings.playlist_shuffle;
return crossfade_enabled;
}