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Fix asymetric crossfade cases that were broken, and also a not yet reported bug where a buffer underrun during crossfade would take a long time to resume playing

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9798 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Brandon Low 2006-04-25 12:34:28 +00:00
parent 1924769631
commit 9602dd7e60
1 changed files with 72 additions and 42 deletions
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114
apps/pcmbuf.c
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@ -65,7 +65,7 @@ static void (*position_callback)(size_t size) IDATA_ATTR;
/* Crossfade related state */
static bool crossfade_enabled;
static bool crossfade_mix;
static bool crossfade_mode;
static bool crossfade_active IDATA_ATTR;
static bool crossfade_init IDATA_ATTR;
@ -100,6 +100,7 @@ static bool pcmbuf_flush;
#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);
@ -308,7 +309,7 @@ bool pcmbuf_crossfade_init(bool manual_skip)
pcmbuf_boost(true);
/* Don't enable mix mode when skipping tracks manually. */
crossfade_mix = manual_skip && global_settings.crossfade_fade_out_mixmode;
crossfade_mode = manual_skip && global_settings.crossfade_fade_out_mixmode;
crossfade_init = true;
return true;
@ -450,7 +451,7 @@ static bool pcmbuf_flush_fillpos(void)
static void crossfade_process_buffer(size_t fade_in_delay,
size_t fade_out_delay, size_t fade_out_rem)
{
if (!crossfade_mix)
if (!crossfade_mode)
{
/* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem;
@ -577,33 +578,59 @@ static void crossfade_start(void)
crossfade_process_buffer(fade_in_delay, fade_out_delay, fade_out_rem);
}
static size_t fade_mix(int factor, const char *buf, size_t fade_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;
size_t samples = 0;
short *output_buf = (short *)(crossfade_chunk->addr);
short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
output_buf = &output_buf[crossfade_sample];
fade_rem /= 2;
while (samples < fade_rem)
while (fade_rem)
{
int sample = *input_buf++;
sample = ((sample * factor) >> 8) + *output_buf;
*output_buf++ = MIN(32767, MAX(-32768, sample));
samples++;
fade_rem -= 2;
if (output_buf >= chunk_end)
{
crossfade_chunk = crossfade_chunk->link;
if (!crossfade_chunk)
return samples * 2;
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 samples * 2;
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)
@ -626,33 +653,35 @@ static void pcmbuf_flush_buffer(const char *buf, size_t length)
static void flush_crossfade(char *buf, size_t length)
{
if (length && crossfade_fade_in_rem)
if (length)
{
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);
crossfade_fade_in_rem -= fade_rem;
if (crossfade_chunk)
{
/* Mix the data */
size_t complete = fade_mix(factor, buf, fade_rem);
length -= complete;
buf += complete;
fade_rem -= complete;
/* If there is still fading to be done */
if (fade_rem)
goto mix_done;
}
else
if (crossfade_fade_in_rem)
{
size_t samples;
short *input_buf;
mix_done:
/* Fade samples in place */
/* 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;
}
samples = fade_rem / 2;
input_buf = (short *)buf;
/* Fade remaining samples in place */
while (samples)
{
int sample = *input_buf;
@ -660,21 +689,23 @@ mix_done:
samples--;
}
}
}
if (length)
{
/* Flush samples to the buffer */
while (pcmbuf_free() < length)
if (crossfade_chunk)
{
pcmbuf_boost(false);
sleep(1);
/* Mix the data */
size_t mix_total = length;
length = crossfade_mix(buf, length);
buf += mix_total - length;
}
else if (!crossfade_fade_in_rem)
crossfade_active = false;
/* Flush samples to the buffer */
while (!prepare_insert(length))
sleep(1);
pcmbuf_flush_buffer(buf, length);
}
if (!crossfade_fade_in_rem)
crossfade_active = false;
}
static bool prepare_insert(size_t length)
@ -688,7 +719,7 @@ static bool prepare_insert(size_t length)
}
/* Need to save PCMBUF_MIN_CHUNK to prevent wrapping overwriting */
if (pcmbuf_free() < length + PCMBUF_MIN_CHUNK && !crossfade_active)
if (pcmbuf_free() < length + PCMBUF_MIN_CHUNK)
{
pcmbuf_boost(false);
return false;
@ -697,7 +728,6 @@ static bool prepare_insert(size_t length)
if (!pcm_is_playing())
{
pcmbuf_boost(true);
crossfade_active = false;
/* Pre-buffer 1s. */
if (!LOW_DATA(4))
{