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Crossfade: crossfaded manual skips now start fading immediately 

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23622 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jeffrey Goode 2009-11-13 21:58:41 +00:00
parent 29d2711115
commit d1963e14de
1 changed files with 45 additions and 21 deletions
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66
apps/pcmbuf.c
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@ -92,6 +92,7 @@ static char *fadebuf IDATA_ATTR;
static bool crossfade_enabled;
static bool crossfade_enable_request;
static bool crossfade_mixmode;
static bool crossfade_auto_skip;
static bool crossfade_active IDATA_ATTR;
static bool crossfade_track_change_started IDATA_ATTR;
@ -537,6 +538,8 @@ void pcmbuf_start_track_change(bool auto_skip)
#ifdef HAVE_CROSSFADE
/* Don't enable mix mode when skipping tracks manually. */
crossfade_mixmode = auto_skip && global_settings.crossfade_fade_out_mixmode;
crossfade_auto_skip = auto_skip;
crossfade_track_change_started = crossfade;
#endif
@ -702,6 +705,27 @@ static size_t find_chunk(size_t length, struct chunkdesc **chunk)
return length / 2;
}
/* Fade samples in the PCM buffer */
static void fade_block(int factor, size_t length, size_t *fade_sample,
struct chunkdesc **fade_chunk)
{
while (length > 0 && *fade_chunk != NULL)
{
/* Fade one sample */
int16_t *buf = (int16_t *)((*fade_chunk)->addr);
int32_t sample = buf[*fade_sample];
buf[(*fade_sample)++] = (sample * factor) >> 8;
length -= 2;
/* Move to the next chunk as needed */
if (*fade_sample * 2 >= (*fade_chunk)->size)
{
*fade_chunk = (*fade_chunk)->link;
*fade_sample = 0;
}
}
}
/* Initializes crossfader, calculates all necessary parameters and performs
* fade-out with the PCM buffer. */
static void crossfade_start(void)
@ -737,15 +761,25 @@ static void crossfade_start(void)
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, so find
* the right chunk and sample to start the crossfade */
if (crossfade_rem > crossfade_need)
{
crossfade_sample = find_chunk(crossfade_rem - crossfade_need,
&crossfade_chunk);
if (crossfade_auto_skip)
/* Automatic track changes only modify the last part of the buffer,
* so find the right chunk and sample to start the crossfade */
{
crossfade_sample = find_chunk(crossfade_rem - crossfade_need,
&crossfade_chunk);
crossfade_rem = crossfade_need;
}
else
/* Manual skips occur immediately, but give time to process */
{
crossfade_rem -= crossfade_chunk->size;
crossfade_chunk = crossfade_chunk->link;
}
}
/* Truncate fade out duration if necessary. */
else if (crossfade_rem < crossfade_need)
if (crossfade_rem < crossfade_need)
{
size_t crossfade_short = crossfade_need - crossfade_rem;
if (fade_out_rem >= crossfade_short)
@ -756,6 +790,7 @@ static void crossfade_start(void)
fade_out_rem = 0;
}
}
crossfade_rem -= fade_out_delay + fade_out_rem;
/* Completely process the crossfade fade-out effect with current PCM buffer */
if (!crossfade_mixmode)
@ -777,23 +812,11 @@ static void crossfade_start(void)
fade_out_rem -= block_rem;
/* Fade this block */
while (block_rem > 0 && fade_out_chunk != NULL)
{
/* Fade one sample */
int16_t *buf = (int16_t *)fade_out_chunk->addr;
int32_t 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;
}
}
fade_block(factor, block_rem, &fade_out_sample, &fade_out_chunk);
}
/* zero out the rest of the buffer */
fade_block(0, crossfade_rem, &fade_out_sample, &fade_out_chunk);
}
/* Initialize fade-in counters */
@ -890,6 +913,7 @@ static void write_to_crossfade(char *buf, size_t length)
{
/* Mix the data */
size_t mix_total = length;
/* A factor of 256 means no fading */
length = crossfade_mix(256, buf, length);
buf += mix_total - length;
if (!length)