devs/foxbox
1
0
Fork 0
forked from len0rd/rockbox
Code Pull requests Activity

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

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

102
apps/pcmbuf.c
View file

@ -65,7 +65,7 @@ static void (*position_callback)(size_t size) IDATA_ATTR;
/* Crossfade related state */ /* Crossfade related state */
static bool crossfade_enabled; static bool crossfade_enabled;
static bool crossfade_mix; static bool crossfade_mode;
static bool crossfade_active IDATA_ATTR; static bool crossfade_active IDATA_ATTR;
static bool crossfade_init IDATA_ATTR; static bool crossfade_init IDATA_ATTR;
@ -100,6 +100,7 @@ static bool pcmbuf_flush;
#define LOW_DATA(quarter_secs) \ #define LOW_DATA(quarter_secs) \
(pcmbuf_unplayed_bytes < NATIVE_FREQUENCY * quarter_secs) (pcmbuf_unplayed_bytes < NATIVE_FREQUENCY * quarter_secs)
static bool prepare_insert(size_t length);
static void pcmbuf_under_watermark(void); static void pcmbuf_under_watermark(void);
static bool pcmbuf_flush_fillpos(void); static bool pcmbuf_flush_fillpos(void);
@ -308,7 +309,7 @@ bool pcmbuf_crossfade_init(bool manual_skip)
pcmbuf_boost(true); pcmbuf_boost(true);
/* Don't enable mix mode when skipping tracks manually. */ /* 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; crossfade_init = true;
return true; return true;
@ -450,7 +451,7 @@ static bool pcmbuf_flush_fillpos(void)
static void crossfade_process_buffer(size_t fade_in_delay, static void crossfade_process_buffer(size_t fade_in_delay,
size_t fade_out_delay, size_t fade_out_rem) 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 */ /* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem; 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); 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; const short *input_buf = (const short *)buf;
size_t samples = 0;
short *output_buf = (short *)(crossfade_chunk->addr); short *output_buf = (short *)(crossfade_chunk->addr);
short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
output_buf = &output_buf[crossfade_sample]; output_buf = &output_buf[crossfade_sample];
fade_rem /= 2; while (fade_rem)
while (samples < fade_rem)
{ {
int sample = *input_buf++; int sample = *input_buf++;
sample = ((sample * factor) >> 8) + *output_buf; sample = ((sample * factor) >> 8) + *output_buf;
*output_buf++ = MIN(32767, MAX(-32768, sample)); *output_buf++ = MIN(32767, MAX(-32768, sample));
samples++; fade_rem -= 2;
if (output_buf >= chunk_end) if (output_buf >= chunk_end)
{ {
crossfade_chunk = crossfade_chunk->link; crossfade_chunk = crossfade_chunk->link;
if (!crossfade_chunk) if (!crossfade_chunk)
return samples * 2; return fade_rem;
output_buf = (short *)(crossfade_chunk->addr); output_buf = (short *)(crossfade_chunk->addr);
chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size);
} }
} }
crossfade_sample = (size_t)(output_buf - (short *)(crossfade_chunk->addr)); 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) 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) 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) / 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; crossfade_fade_in_total;
/* Bytes to fade */ /* Bytes to fade */
size_t fade_rem = MIN(length, crossfade_fade_in_rem); size_t fade_rem = MIN(length, crossfade_fade_in_rem);
/* We _will_ fade this many bytes */
crossfade_fade_in_rem -= fade_rem; crossfade_fade_in_rem -= fade_rem;
if (crossfade_chunk) if (crossfade_chunk)
{ {
/* Mix the data */ /* Mix the data */
size_t complete = fade_mix(factor, buf, fade_rem); size_t fade_total = fade_rem;
length -= complete; fade_rem = crossfade_fade_mix(factor, buf, fade_rem);
buf += complete; length -= fade_total - fade_rem;
fade_rem -= complete; buf += fade_total - fade_rem;
/* If there is still fading to be done */
if (fade_rem)
goto mix_done;
} }
else
{
size_t samples;
short *input_buf;
mix_done:
/* Fade samples in place */
samples = fade_rem / 2; samples = fade_rem / 2;
input_buf = (short *)buf; input_buf = (short *)buf;
/* Fade remaining samples in place */
while (samples) while (samples)
{ {
int sample = *input_buf; int sample = *input_buf;
@ -660,21 +689,23 @@ mix_done:
samples--; samples--;
} }
} }
}
if (length) if (crossfade_chunk)
{ {
/* Flush samples to the buffer */ /* Mix the data */
while (pcmbuf_free() < length) size_t mix_total = length;
{ length = crossfade_mix(buf, length);
pcmbuf_boost(false); buf += mix_total - length;
sleep(1);
} }
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); pcmbuf_flush_buffer(buf, length);
} }
if (!crossfade_fade_in_rem)
crossfade_active = false;
} }
static bool prepare_insert(size_t length) 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 */ /* 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); pcmbuf_boost(false);
return false; return false;
@ -697,7 +728,6 @@ static bool prepare_insert(size_t length)
if (!pcm_is_playing()) if (!pcm_is_playing())
{ {
pcmbuf_boost(true); pcmbuf_boost(true);
crossfade_active = false;
/* Pre-buffer 1s. */ /* Pre-buffer 1s. */
if (!LOW_DATA(4)) if (!LOW_DATA(4))
{ {