[MPlayer-dev-eng] [PATCH] Statistics audio filter
Nicolas George
nicolas.george at normalesup.org
Sat Feb 21 16:54:55 CET 2009
Hi. Thanks for the review.
Le duodi 2 ventôse, an CCXVII, Uoti Urpala a écrit :
> I suppose it could be useful, though I haven't needed such functionality
> personally. I think the main question is how to display the resulting
> statistics. IMO it at least shouldn't use printf(); mp_msg would be
> preferable.
I changed into mp_msg(MSGT_AFILTER, MSGL_INFO, ...);
> Also maybe it should output _something_ when there were 0
> samples.
Changed: it just prints "stats:n_samples: 0".
> There are a couple of style issues where the code doesn't follow K&R
> style (function declarations are split on two lines (except af_open),
> space missing after 'if' and 'for'). I'd also use 'struct af_stats'
> instead of the typedef. At least drop the stupid '_s' from the struct
> name; it's already preceded by 'struct' in all uses...
Changed.
Regards,
--
Nicolas George
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diff --git a/DOCS/man/en/mplayer.1 b/DOCS/man/en/mplayer.1
index 289c0c5..d155be3 100644
--- a/DOCS/man/en/mplayer.1
+++ b/DOCS/man/en/mplayer.1
@@ -5483,6 +5483,11 @@ Changing playback speed, would change pitch, leaving audio tempo at 1.2x.
.
.
.
+.TP
+.B stats
+Collects and prints statistics about the audio stream, especially the volume.
+The volumes are printed in dB and compatible with the volume audio filter.
+.
.SH "VIDEO FILTERS"
Video filters allow you to modify the video stream and its properties.
The syntax is:
diff --git a/Makefile b/Makefile
index 51e6246..10a3438 100644
--- a/Makefile
+++ b/Makefile
@@ -67,6 +67,7 @@ SRCS_COMMON = asxparser.c \
libaf/af_resample.c \
libaf/af_scaletempo.c \
libaf/af_sinesuppress.c \
+ libaf/af_stats.c \
libaf/af_sub.c \
libaf/af_surround.c \
libaf/af_sweep.c \
diff --git a/libaf/af.c b/libaf/af.c
index 77fda8e..acb0522 100644
--- a/libaf/af.c
+++ b/libaf/af.c
@@ -51,6 +51,7 @@ extern af_info_t af_info_center;
extern af_info_t af_info_sinesuppress;
extern af_info_t af_info_karaoke;
extern af_info_t af_info_scaletempo;
+extern af_info_t af_info_stats;
static af_info_t* filter_list[]={
&af_info_dummy,
@@ -85,6 +86,7 @@ static af_info_t* filter_list[]={
&af_info_sinesuppress,
&af_info_karaoke,
&af_info_scaletempo,
+ &af_info_stats,
NULL
};
diff --git a/libaf/af_stats.c b/libaf/af_stats.c
new file mode 100644
index 0000000..f9175f9
--- /dev/null
+++ b/libaf/af_stats.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2009 Nicolas George <nicolas.george at normalesup.org>
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * MPlayer 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 General Public License along
+ * with MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <math.h>
+
+#include "af.h"
+
+#define MAX_DB 80
+#define MIN_VAL 1E-8
+
+struct af_stats
+{
+ long long n_samples;
+ double tsquare;
+ int max;
+ long long histogram[65536];
+};
+
+static inline int logdb(double v)
+{
+ return v > 1 ? 0 : v <= MIN_VAL ? MAX_DB - 1 :
+ log(v) / -0.23025850929940456840179914546843642076;
+}
+
+static int stats_init(af_instance_t *af, struct af_stats *s, af_data_t *data)
+{
+ int i;
+
+ if (!data)
+ return AF_ERROR;
+ *(af->data) = *data;
+ af->data->format = AF_FORMAT_S16_NE;
+ af->data->bps = 2;
+ s->n_samples = 0;
+ s->tsquare = 0;
+ s->max = 0;
+ for (i = 0; i < 65536; i++)
+ s->histogram[i] = 0;
+ return af_test_output(af, data);
+}
+
+static void stats_print(struct af_stats *s)
+{
+ int i;
+ long long sum;
+ float v;
+ long long h[MAX_DB];
+
+ s->tsquare /= 32768 * 32768;
+ mp_msg(MSGT_AFILTER, MSGL_INFO, "stats:n_samples: %lld\n", s->n_samples);
+ if (s->n_samples == 0)
+ return;
+ mp_msg(MSGT_AFILTER, MSGL_INFO, "stats:mean_volume: -%d dB\n",
+ logdb(s->tsquare / s->n_samples));
+ mp_msg(MSGT_AFILTER, MSGL_INFO, "stats:max_volume: -%d dB\n",
+ logdb(s->max / 32768.0));
+ for (i = 0; i < MAX_DB; i++)
+ h[i] = 0;
+ for (i = 0; i < 65536; i++) {
+ v = (i - 32768) / 32768.0;
+ h[logdb(v * v)] += s->histogram[i];
+ }
+ for (i = 0; i < MAX_DB; i++)
+ if (h[i] != 0)
+ break;
+ sum = 0;
+ for (; i < MAX_DB; i++) {
+ sum += h[i];
+ mp_msg(MSGT_AFILTER, MSGL_INFO, "stats:histogram_%ddb: %lld\n",
+ i, h[i]);
+ if (sum > s->n_samples / 1000)
+ break;
+ }
+}
+
+static int control(struct af_instance_s *af, int cmd, void *arg)
+{
+ struct af_stats *s = (struct af_stats *)af->setup;
+
+ switch(cmd) {
+ case AF_CONTROL_REINIT:
+ return stats_init(af, s, arg);
+
+ case AF_CONTROL_PRE_DESTROY:
+ stats_print(s);
+ return AF_OK;
+ }
+ return AF_UNKNOWN;
+}
+
+static void uninit(struct af_instance_s *af)
+{
+ if (af->data)
+ free(af->data);
+ if (af->setup)
+ free(af->setup);
+}
+
+static af_data_t *play(struct af_instance_s *af, af_data_t *data)
+{
+ struct af_stats *s = (struct af_stats *)af->setup;
+ int16_t *a, *aend;
+ int v, v2;
+
+ a = data->audio;
+ aend = (int16_t *)((char *)data->audio + data->len);
+ s->n_samples += aend - a;
+ for (; a < aend; a++) {
+ v = *a;
+ v2 = v * v;
+ s->tsquare += v2;
+ s->histogram[v + 32768]++;
+ if (v2 > s->max)
+ s->max = v2;
+ }
+ return data;
+}
+
+static int af_open(af_instance_t* af){
+ af->control = control;
+ af->uninit = uninit;
+ af->play = play;
+ af->mul = 1;
+ af->data = malloc(sizeof(af_data_t));
+ af->setup = malloc(sizeof(struct af_stats));
+ if (af->data == NULL || af->setup == NULL)
+ return AF_ERROR;
+ return AF_OK;
+}
+
+af_info_t af_info_stats = {
+ "Statistics audio filter",
+ "stats",
+ "Nicolas George",
+ "",
+ 0,
+ af_open
+};
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