rockbox/apps/plugins/mpegplayer/pcm_output.c
Jeffrey Goode 6ef04a7f0e Eliminate %zd tag in printf format strings, replace them with %ld. The %z formatter kept generating type mismatch warnings.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26040 a1c6a512-1295-4272-9138-f99709370657
2010-05-15 03:34:31 +00:00

310 lines
8.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* PCM output buffer definitions
*
* Copyright (c) 2007 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.
*
****************************************************************************/
#include "plugin.h"
#include "mpegplayer.h"
/* Pointers */
/* Start of buffer */
static struct pcm_frame_header * ALIGNED_ATTR(4) pcm_buffer;
/* End of buffer (not guard) */
static struct pcm_frame_header * ALIGNED_ATTR(4) pcmbuf_end;
/* Read pointer */
static struct pcm_frame_header * ALIGNED_ATTR(4) pcmbuf_head IBSS_ATTR;
/* Write pointer */
static struct pcm_frame_header * ALIGNED_ATTR(4) pcmbuf_tail IBSS_ATTR;
/* Bytes */
static ssize_t pcmbuf_curr_size IBSS_ATTR; /* Size of currently playing frame */
static uint64_t pcmbuf_read IBSS_ATTR; /* Number of bytes read by DMA */
static uint64_t pcmbuf_written IBSS_ATTR; /* Number of bytes written by source */
static ssize_t pcmbuf_threshold IBSS_ATTR; /* Non-silence threshold */
/* Clock */
static uint32_t clock_base IBSS_ATTR; /* Our base clock */
static uint32_t clock_start IBSS_ATTR; /* Clock at playback start */
static int32_t clock_adjust IBSS_ATTR; /* Clock drift adjustment */
int pcm_skipped = 0;
int pcm_underruns = 0;
/* Small silence clip. ~5.80ms @ 44.1kHz */
static int16_t silence[256*2] ALIGNED_ATTR(4) = { 0 };
/* Advance a PCM buffer pointer by size bytes circularly */
static inline void pcm_advance_buffer(struct pcm_frame_header **p,
size_t size)
{
*p = SKIPBYTES(*p, size);
if (*p >= pcmbuf_end)
*p = SKIPBYTES(*p, -PCMOUT_BUFSIZE);
}
/* Inline internally but not externally */
inline ssize_t pcm_output_used(void)
{
return (ssize_t)(pcmbuf_written - pcmbuf_read);
}
inline ssize_t pcm_output_free(void)
{
return (ssize_t)(PCMOUT_BUFSIZE - pcmbuf_written + pcmbuf_read);
}
/* Audio DMA handler */
static void get_more(unsigned char **start, size_t *size)
{
ssize_t sz;
/* Free-up the last frame played frame if any */
pcmbuf_read += pcmbuf_curr_size;
pcmbuf_curr_size = 0;
sz = pcm_output_used();
if (sz > pcmbuf_threshold)
{
pcmbuf_threshold = PCMOUT_LOW_WM;
while (1)
{
uint32_t time = pcmbuf_head->time;
int32_t offset = time - (clock_base + clock_adjust);
sz = pcmbuf_head->size;
if (sz < (ssize_t)(sizeof(pcmbuf_head) + 4) ||
(sz & 3) != 0)
{
/* Just show a warning about this - will never happen
* without a bug in the audio thread code or a clobbered
* buffer */
DEBUGF("get_more: invalid size (%ld)\n", (long)sz);
}
if (offset < -100*CLOCK_RATE/1000)
{
/* Frame more than 100ms late - drop it */
pcm_advance_buffer(&pcmbuf_head, sz);
pcmbuf_read += sz;
pcm_skipped++;
if (pcmbuf_read < pcmbuf_written)
continue;
/* Ran out so revert to default watermark */
pcmbuf_threshold = PCMOUT_PLAY_WM;
}
else if (offset < 100*CLOCK_RATE/1000)
{
/* Frame less than 100ms early - play it */
*start = pcmbuf_head->data;
pcm_advance_buffer(&pcmbuf_head, sz);
pcmbuf_curr_size = sz;
sz -= sizeof (struct pcm_frame_header);
*size = sz;
/* Audio is time master - keep clock synchronized */
clock_adjust = time - clock_base;
/* Update base clock */
clock_base += sz >> 2;
return;
}
/* Frame will be dropped - play silence clip */
break;
}
}
else
{
/* Ran out so revert to default watermark */
if (pcmbuf_threshold == PCMOUT_LOW_WM)
pcm_underruns++;
pcmbuf_threshold = PCMOUT_PLAY_WM;
}
/* Keep clock going at all times */
*start = (unsigned char *)silence;
*size = sizeof (silence);
clock_base += sizeof (silence) / 4;
if (pcmbuf_read > pcmbuf_written)
pcmbuf_read = pcmbuf_written;
}
struct pcm_frame_header * pcm_output_get_buffer(void)
{
return pcmbuf_tail;
}
void pcm_output_add_data(void)
{
size_t size = pcmbuf_tail->size;
pcm_advance_buffer(&pcmbuf_tail, size);
pcmbuf_written += size;
}
/* Flushes the buffer - clock keeps counting */
void pcm_output_flush(void)
{
bool playing, paused;
rb->pcm_play_lock();
playing = rb->pcm_is_playing();
paused = rb->pcm_is_paused();
/* Stop PCM to clear current buffer */
if (playing)
rb->pcm_play_stop();
pcmbuf_threshold = PCMOUT_PLAY_WM;
pcmbuf_curr_size = pcmbuf_read = pcmbuf_written = 0;
pcmbuf_head = pcmbuf_tail = pcm_buffer;
pcm_skipped = pcm_underruns = 0;
/* Restart if playing state was current */
if (playing && !paused)
rb->pcm_play_data(get_more, NULL, 0);
rb->pcm_play_unlock();
}
/* Seek the reference clock to the specified time - next audio data ready to
go to DMA should be on the buffer with the same time index or else the PCM
buffer should be empty */
void pcm_output_set_clock(uint32_t time)
{
rb->pcm_play_lock();
clock_base = time;
clock_start = time;
clock_adjust = 0;
rb->pcm_play_unlock();
}
uint32_t pcm_output_get_clock(void)
{
return clock_base + clock_adjust
- (rb->pcm_get_bytes_waiting() >> 2);
}
uint32_t pcm_output_get_ticks(uint32_t *start)
{
if (start)
*start = clock_start;
return clock_base - (rb->pcm_get_bytes_waiting() >> 2);
}
/* Pauses/Starts pcm playback - and the clock */
void pcm_output_play_pause(bool play)
{
rb->pcm_play_lock();
if (rb->pcm_is_playing())
{
rb->pcm_play_pause(play);
}
else if (play)
{
rb->pcm_play_data(get_more, NULL, 0);
}
rb->pcm_play_unlock();
}
/* Stops all playback and resets the clock */
void pcm_output_stop(void)
{
rb->pcm_play_lock();
if (rb->pcm_is_playing())
rb->pcm_play_stop();
pcm_output_flush();
pcm_output_set_clock(0);
rb->pcm_play_unlock();
}
/* Drains any data if the start threshold hasn't been reached */
void pcm_output_drain(void)
{
rb->pcm_play_lock();
pcmbuf_threshold = PCMOUT_LOW_WM;
rb->pcm_play_unlock();
}
bool pcm_output_init(void)
{
pcm_buffer = mpeg_malloc(PCMOUT_ALLOC_SIZE, MPEG_ALLOC_PCMOUT);
if (pcm_buffer == NULL)
return false;
pcmbuf_threshold = PCMOUT_PLAY_WM;
pcmbuf_head = pcm_buffer;
pcmbuf_tail = pcm_buffer;
pcmbuf_end = SKIPBYTES(pcm_buffer, PCMOUT_BUFSIZE);
pcmbuf_curr_size = pcmbuf_read = pcmbuf_written = 0;
rb->pcm_set_frequency(NATIVE_FREQUENCY);
#if INPUT_SRC_CAPS != 0
/* Select playback */
rb->audio_set_input_source(AUDIO_SRC_PLAYBACK, SRCF_PLAYBACK);
rb->audio_set_output_source(AUDIO_SRC_PLAYBACK);
#endif
#if SILENCE_TEST_TONE
/* Make the silence clip a square wave */
const int16_t silence_amp = INT16_MAX / 16;
unsigned i;
for (i = 0; i < ARRAYLEN(silence); i += 2)
{
if (i < ARRAYLEN(silence)/2)
{
silence[i] = silence_amp;
silence[i+1] = silence_amp;
}
else
{
silence[i] = -silence_amp;
silence[i+1] = -silence_amp;
}
}
#endif
return true;
}
void pcm_output_exit(void)
{
rb->pcm_set_frequency(HW_SAMPR_DEFAULT);
}