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pcmbuf: consolidated some crossfade code

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23618 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jeffrey Goode 2009-11-12 04:24:41 +00:00
parent 1a8a1f4363
commit 15351e8137
1 changed files with 56 additions and 67 deletions
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123
apps/pcmbuf.c
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@ -690,63 +690,16 @@ static inline int32_t clip_sample_16(int32_t sample)
}
#ifdef HAVE_CROSSFADE
/* Completely process the crossfade fade-out effect with current PCM buffer */
static void crossfade_process_buffer(size_t fade_in_delay,
size_t fade_out_delay, size_t fade_out_rem)
/* Find the chunk that's (length) deep in the list. Return the position within
* the chunk, and leave the chunkdesc pointer pointing to the chunk. */
static size_t find_chunk(size_t length, struct chunkdesc **chunk)
{
if (!crossfade_mixmode)
while (*chunk && length >= (*chunk)->size)
{
/* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem;
size_t fade_out_sample;
struct chunkdesc *fade_out_chunk = crossfade_chunk;
/* Find the right chunk to start fading out */
fade_out_delay += crossfade_sample * 2;
while (fade_out_delay != 0 && fade_out_delay >= fade_out_chunk->size)
{
fade_out_delay -= fade_out_chunk->size;
fade_out_chunk = fade_out_chunk->link;
}
/* The start sample within the chunk */
fade_out_sample = fade_out_delay / 2;
while (fade_out_rem > 0)
{
/* Each 1/10 second of audio will have the same fade applied */
size_t block_rem = MIN(NATIVE_FREQUENCY * 4 / 10, fade_out_rem);
int factor = (fade_out_rem << 8) / total_fade_out;
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;
}
}
}
length -= (*chunk)->size;
*chunk = (*chunk)->link;
}
/* Find the right chunk and sample to start fading in */
fade_in_delay += crossfade_sample * 2;
while (fade_in_delay != 0 && fade_in_delay >= crossfade_chunk->size)
{
fade_in_delay -= crossfade_chunk->size;
crossfade_chunk = crossfade_chunk->link;
}
crossfade_sample = fade_in_delay / 2;
logf("process done!");
return length / 2;
}
/* Initializes crossfader, calculates all necessary parameters and performs
@ -777,25 +730,19 @@ static void crossfade_start(void)
crossfade_chunk = read_chunk->link;
crossfade_sample = 0;
/* Get fade out delay from settings. */
/* Get fade out info from settings. */
fade_out_delay =
NATIVE_FREQUENCY * global_settings.crossfade_fade_out_delay * 4;
/* Get fade out duration from settings. */
fade_out_rem =
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. */
/* 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)
{
size_t crossfade_extra = crossfade_rem - crossfade_need;
while (crossfade_extra > crossfade_chunk->size)
{
crossfade_extra -= crossfade_chunk->size;
crossfade_chunk = crossfade_chunk->link;
}
crossfade_sample = crossfade_extra / 2;
crossfade_sample = find_chunk(crossfade_rem - crossfade_need,
&crossfade_chunk);
}
/* Truncate fade out duration if necessary. */
else if (crossfade_rem < crossfade_need)
@ -810,7 +757,46 @@ static void crossfade_start(void)
}
}
/* Get also fade in duration and delays from settings. */
/* Completely process the crossfade fade-out effect with current PCM buffer */
if (!crossfade_mixmode)
{
/* Fade out the specified amount of the already processed audio */
size_t total_fade_out = fade_out_rem;
size_t fade_out_sample;
struct chunkdesc *fade_out_chunk = crossfade_chunk;
/* Find the right chunk and sample to start fading out */
fade_out_delay += crossfade_sample * 2;
fade_out_sample = find_chunk(fade_out_delay, &fade_out_chunk);
while (fade_out_rem > 0)
{
/* Each 1/10 second of audio will have the same fade applied */
size_t block_rem = MIN(NATIVE_FREQUENCY * 4 / 10, fade_out_rem);
int factor = (fade_out_rem << 8) / total_fade_out;
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;
}
}
}
}
/* Initialize fade-in counters */
crossfade_fade_in_total =
NATIVE_FREQUENCY * global_settings.crossfade_fade_in_duration * 4;
crossfade_fade_in_rem = crossfade_fade_in_total;
@ -818,7 +804,10 @@ static void crossfade_start(void)
fade_in_delay =
NATIVE_FREQUENCY * global_settings.crossfade_fade_in_delay * 4;
crossfade_process_buffer(fade_in_delay, fade_out_delay, fade_out_rem);
/* Find the right chunk and sample to start fading in */
fade_in_delay += crossfade_sample * 2;
crossfade_sample = find_chunk(fade_in_delay, &crossfade_chunk);
logf("crossfade_start done!");
}
/* Returns the number of bytes _NOT_ mixed */