[pulseaudio-discuss] [PATCH 6/7] lfe-filter: Add rewind support
David Henningsson
david.henningsson at canonical.com
Tue Feb 17 04:29:23 PST 2015
Store current filter state at every normal block process.
When a rewind happens, rewind back to the nearest saved state,
then calculate forward to the actual sample position.
Signed-off-by: David Henningsson <david.henningsson at canonical.com>
---
src/pulsecore/filter/lfe-filter.c | 101 ++++++++++++++++++++++++++++++--
src/pulsecore/filter/lfe-filter.c.orig | 103 +++++++++++++++++++++++++++++++++
src/pulsecore/filter/lfe-filter.c.rej | 58 +++++++++++++++++++
src/pulsecore/filter/lfe-filter.h | 5 +-
4 files changed, 259 insertions(+), 8 deletions(-)
create mode 100644 src/pulsecore/filter/lfe-filter.c.orig
create mode 100644 src/pulsecore/filter/lfe-filter.c.rej
diff --git a/src/pulsecore/filter/lfe-filter.c b/src/pulsecore/filter/lfe-filter.c
index 9b238fe..2953657 100644
--- a/src/pulsecore/filter/lfe-filter.c
+++ b/src/pulsecore/filter/lfe-filter.c
@@ -25,9 +25,20 @@
#include "lfe-filter.h"
#include <pulse/xmalloc.h>
+#include <pulsecore/flist.h>
+#include <pulsecore/llist.h>
#include <pulsecore/filter/biquad.h>
#include <pulsecore/filter/crossover.h>
+struct saved_state {
+ PA_LLIST_FIELDS(struct saved_state);
+ pa_memchunk chunk;
+ int64_t index;
+ struct lr4 lr4[PA_CHANNELS_MAX];
+};
+
+PA_STATIC_FLIST_DECLARE(lfe_state, 0, pa_xfree);
+
/* An LR4 filter, implemented as a chain of two Butterworth filters.
Currently the channel map is fixed so that a highpass filter is applied to all
@@ -37,24 +48,37 @@
*/
struct pa_lfe_filter {
+ int64_t index;
+ PA_LLIST_HEAD(struct saved_state, saved);
float crossover;
pa_channel_map cm;
pa_sample_spec ss;
+ size_t maxrewind;
bool active;
struct lr4 lr4[PA_CHANNELS_MAX];
};
-pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq) {
+static void remove_state(pa_lfe_filter_t *f, struct saved_state *s) {
+ PA_LLIST_REMOVE(struct saved_state, f->saved, s);
+ pa_memblock_unref(s->chunk.memblock);
+ pa_xfree(s);
+}
+
+pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq, size_t maxrewind) {
pa_lfe_filter_t *f = pa_xnew0(struct pa_lfe_filter, 1);
f->crossover = crossover_freq;
f->cm = *cm;
f->ss = *ss;
+ f->maxrewind = maxrewind;
pa_lfe_filter_update_rate(f, ss->rate);
return f;
}
void pa_lfe_filter_free(pa_lfe_filter_t *f) {
+ while (f->saved)
+ remove_state(f, f->saved);
+
pa_xfree(f);
}
@@ -62,26 +86,53 @@ void pa_lfe_filter_reset(pa_lfe_filter_t *f) {
pa_lfe_filter_update_rate(f, f->ss.rate);
}
-pa_memchunk * pa_lfe_filter_process(pa_lfe_filter_t *f, pa_memchunk *buf) {
+static void process_block(pa_lfe_filter_t *f, pa_memchunk *buf, bool store_result) {
int samples = buf->length / pa_sample_size_of_format(f->ss.format);
- if (!f->active)
- return buf;
+ void *garbage = store_result ? NULL : pa_xmalloc(buf->length);
+
if (f->ss.format == PA_SAMPLE_FLOAT32NE) {
int i;
float *data = pa_memblock_acquire_chunk(buf);
for (i = 0; i < f->cm.channels; i++)
- lr4_process_float32(&f->lr4[i], samples, f->cm.channels, &data[i], &data[i]);
+ lr4_process_float32(&f->lr4[i], samples, f->cm.channels, &data[i], garbage ? garbage : &data[i]);
pa_memblock_release(buf->memblock);
}
else if (f->ss.format == PA_SAMPLE_S16NE) {
int i;
short *data = pa_memblock_acquire_chunk(buf);
for (i = 0; i < f->cm.channels; i++)
- lr4_process_s16(&f->lr4[i], samples, f->cm.channels, &data[i], &data[i]);
+ lr4_process_s16(&f->lr4[i], samples, f->cm.channels, &data[i], garbage ? garbage : &data[i]);
pa_memblock_release(buf->memblock);
}
else pa_assert_not_reached();
+
+ pa_xfree(garbage);
+ f->index += samples;
+}
+
+pa_memchunk * pa_lfe_filter_process(pa_lfe_filter_t *f, pa_memchunk *buf) {
+ struct saved_state *s, *s2;
+
+ if (!f->active)
+ return buf;
+
+ // Remove old states (FIXME: we could do better than searching the entire array here?)
+ PA_LLIST_FOREACH_SAFE(s, s2, f->saved)
+ if (s->index + (int64_t) (s->chunk.length + f->maxrewind) < f->index)
+ remove_state(f, s);
+
+ // Insert our existing state into the flist
+ if ((s = pa_flist_pop(PA_STATIC_FLIST_GET(lfe_state))) == NULL)
+ s = pa_xnew(struct saved_state, 1);
+ PA_LLIST_INIT(struct saved_state, s);
+ s->index = f->index;
+ s->chunk = *buf;
+ pa_memblock_ref(buf->memblock);
+ memcpy(s->lr4, f->lr4, sizeof(struct lr4) * f->cm.channels);
+ PA_LLIST_PREPEND(struct saved_state, f->saved, s);
+
+ process_block(f, buf, true);
return buf;
}
@@ -89,6 +140,10 @@ void pa_lfe_filter_update_rate(pa_lfe_filter_t *f, uint32_t new_rate) {
int i;
float biquad_freq = f->crossover / (new_rate / 2);
+ while (f->saved)
+ remove_state(f, f->saved);
+
+ f->index = 0;
f->ss.rate = new_rate;
if (biquad_freq <= 0 || biquad_freq >= 1) {
pa_log_warn("Crossover frequency (%f) outside range for sample rate %d", f->crossover, new_rate);
@@ -101,3 +156,37 @@ void pa_lfe_filter_update_rate(pa_lfe_filter_t *f, uint32_t new_rate) {
f->active = true;
}
+
+void pa_lfe_filter_rewind(pa_lfe_filter_t *f, size_t amount) {
+ struct saved_state *i, *s = NULL;
+ size_t samples = amount / pa_sample_size_of_format(f->ss.format);
+ f->index -= samples;
+
+ // Find the closest saved position
+ PA_LLIST_FOREACH(i, f->saved) {
+ if (i->index > f->index)
+ continue;
+ if (s == NULL || i->index > s->index)
+ s = i;
+ }
+ if (s == NULL) {
+ pa_log_debug("Rewinding LFE filter %lu samples to position %lli. No saved state found", samples, (long long) f->index);
+ pa_lfe_filter_update_rate(f, f->ss.rate);
+ return;
+ }
+ pa_log_debug("Rewinding LFE filter %lu samples to position %lli. Found saved state at position %lli",
+ samples, (long long) f->index, (long long) s->index);
+ memcpy(f->lr4, s->lr4, sizeof(struct lr4) * f->cm.channels);
+
+ // now fast forward to the actual position
+ if (f->index > s->index) {
+ pa_memchunk x = s->chunk;
+ size_t left = f->index - s->index;
+ if (left > s->chunk.length) {
+ pa_log_error("Hole in stream, cannot fast forward LFE filter");
+ return;
+ }
+ f->index = s->index;
+ process_block(f, &x, false);
+ }
+}
diff --git a/src/pulsecore/filter/lfe-filter.c.orig b/src/pulsecore/filter/lfe-filter.c.orig
new file mode 100644
index 0000000..9b238fe
--- /dev/null
+++ b/src/pulsecore/filter/lfe-filter.c.orig
@@ -0,0 +1,103 @@
+/***
+ This file is part of PulseAudio.
+
+ Copyright 2014 David Henningsson, Canonical Ltd.
+
+ PulseAudio is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 2.1 of the License,
+ or (at your option) any later version.
+
+ PulseAudio is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with PulseAudio; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "lfe-filter.h"
+#include <pulse/xmalloc.h>
+#include <pulsecore/filter/biquad.h>
+#include <pulsecore/filter/crossover.h>
+
+/* An LR4 filter, implemented as a chain of two Butterworth filters.
+
+ Currently the channel map is fixed so that a highpass filter is applied to all
+ channels except for the LFE channel, where a lowpass filter is applied.
+ This works well for e g stereo to 2.1/5.1/7.1 scenarios, where the remap engine
+ has calculated the LFE channel to be the average of all source channels.
+*/
+
+struct pa_lfe_filter {
+ float crossover;
+ pa_channel_map cm;
+ pa_sample_spec ss;
+ bool active;
+ struct lr4 lr4[PA_CHANNELS_MAX];
+};
+
+pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq) {
+
+ pa_lfe_filter_t *f = pa_xnew0(struct pa_lfe_filter, 1);
+ f->crossover = crossover_freq;
+ f->cm = *cm;
+ f->ss = *ss;
+ pa_lfe_filter_update_rate(f, ss->rate);
+ return f;
+}
+
+void pa_lfe_filter_free(pa_lfe_filter_t *f) {
+ pa_xfree(f);
+}
+
+void pa_lfe_filter_reset(pa_lfe_filter_t *f) {
+ pa_lfe_filter_update_rate(f, f->ss.rate);
+}
+
+pa_memchunk * pa_lfe_filter_process(pa_lfe_filter_t *f, pa_memchunk *buf) {
+ int samples = buf->length / pa_sample_size_of_format(f->ss.format);
+
+ if (!f->active)
+ return buf;
+ if (f->ss.format == PA_SAMPLE_FLOAT32NE) {
+ int i;
+ float *data = pa_memblock_acquire_chunk(buf);
+ for (i = 0; i < f->cm.channels; i++)
+ lr4_process_float32(&f->lr4[i], samples, f->cm.channels, &data[i], &data[i]);
+ pa_memblock_release(buf->memblock);
+ }
+ else if (f->ss.format == PA_SAMPLE_S16NE) {
+ int i;
+ short *data = pa_memblock_acquire_chunk(buf);
+ for (i = 0; i < f->cm.channels; i++)
+ lr4_process_s16(&f->lr4[i], samples, f->cm.channels, &data[i], &data[i]);
+ pa_memblock_release(buf->memblock);
+ }
+ else pa_assert_not_reached();
+ return buf;
+}
+
+void pa_lfe_filter_update_rate(pa_lfe_filter_t *f, uint32_t new_rate) {
+ int i;
+ float biquad_freq = f->crossover / (new_rate / 2);
+
+ f->ss.rate = new_rate;
+ if (biquad_freq <= 0 || biquad_freq >= 1) {
+ pa_log_warn("Crossover frequency (%f) outside range for sample rate %d", f->crossover, new_rate);
+ f->active = false;
+ return;
+ }
+
+ for (i = 0; i < f->cm.channels; i++)
+ lr4_set(&f->lr4[i], f->cm.map[i] == PA_CHANNEL_POSITION_LFE ? BQ_LOWPASS : BQ_HIGHPASS, biquad_freq);
+
+ f->active = true;
+}
diff --git a/src/pulsecore/filter/lfe-filter.c.rej b/src/pulsecore/filter/lfe-filter.c.rej
new file mode 100644
index 0000000..7dec57f
--- /dev/null
+++ b/src/pulsecore/filter/lfe-filter.c.rej
@@ -0,0 +1,58 @@
+--- src/pulsecore/filter/lfe-filter.c
++++ src/pulsecore/filter/lfe-filter.c
+@@ -25,30 +25,54 @@
+
+ #include "lfe-filter.h"
+ #include <pulse/xmalloc.h>
++#include <pulsecore/flist.h>
++#include <pulsecore/llist.h>
+ #include <pulsecore/filter/biquad.h>
+ #include <pulsecore/filter/crossover.h>
+
++struct saved_state {
++ PA_LLIST_FIELDS(struct saved_state);
++ pa_memchunk chunk;
++ int64_t index;
++ struct lr4 lr4[PA_CHANNELS_MAX];
++};
++
++PA_STATIC_FLIST_DECLARE(lfe_state, 0, pa_xfree);
++
+ // An LR4 filter, implemented as a chain of two LR2 filters.
+
+ struct pa_lfe_filter {
++ int64_t index;
++ PA_LLIST_HEAD(struct saved_state, saved);
+ float crossover;
+ pa_channel_map cm;
+ pa_sample_spec ss;
++ size_t maxrewind;
+ bool active;
+ struct lr4 lr4[PA_CHANNELS_MAX];
+ };
+
+-pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq) {
++static void remove_state(pa_lfe_filter_t *f, struct saved_state *s) {
++ PA_LLIST_REMOVE(struct saved_state, f->saved, s);
++ pa_memblock_unref(s->chunk.memblock);
++ pa_xfree(s);
++}
++
++pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq, size_t maxrewind) {
+
+ pa_lfe_filter_t *f = pa_xnew0(struct pa_lfe_filter, 1);
+ f->crossover = crossover_freq;
+ f->cm = *cm;
+ f->ss = *ss;
++ f->maxrewind = maxrewind;
+ pa_lfe_filter_update_rate(f, ss->rate);
+ return f;
+ }
+
+ void pa_lfe_filter_free(pa_lfe_filter_t *f) {
++ while (f->saved)
++ remove_state(f, f->saved);
++
+ pa_xfree(f);
+ }
+
diff --git a/src/pulsecore/filter/lfe-filter.h b/src/pulsecore/filter/lfe-filter.h
index 25db8a0..54d695b 100644
--- a/src/pulsecore/filter/lfe-filter.h
+++ b/src/pulsecore/filter/lfe-filter.h
@@ -25,13 +25,14 @@
#include <pulse/sample.h>
#include <pulse/channelmap.h>
#include <pulsecore/memchunk.h>
-
+#include <pulsecore/memblockq.h>
typedef struct pa_lfe_filter pa_lfe_filter_t;
-pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq);
+pa_lfe_filter_t * pa_lfe_filter_new(const pa_sample_spec* ss, const pa_channel_map* cm, float crossover_freq, size_t maxrewind);
void pa_lfe_filter_free(pa_lfe_filter_t *);
void pa_lfe_filter_reset(pa_lfe_filter_t *);
+void pa_lfe_filter_rewind(pa_lfe_filter_t *, size_t amount);
pa_memchunk * pa_lfe_filter_process(pa_lfe_filter_t *filter, pa_memchunk *buf);
void pa_lfe_filter_update_rate(pa_lfe_filter_t *, uint32_t new_rate);
--
1.9.1
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