[FFmpeg-devel] [PATCH] lavfi: add asetrate filter.
Nicolas George
nicolas.george at normalesup.org
Thu Apr 18 17:02:11 CEST 2013
Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
Changelog | 1 +
doc/filters.texi | 12 +++++
libavfilter/Makefile | 1 +
libavfilter/af_asetrate.c | 119 +++++++++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
libavfilter/version.h | 4 +-
6 files changed, 136 insertions(+), 2 deletions(-)
create mode 100644 libavfilter/af_asetrate.c
diff --git a/Changelog b/Changelog
index c5383ff..1d6cdce 100644
--- a/Changelog
+++ b/Changelog
@@ -23,6 +23,7 @@ version <next>:
- new interlace filter
- smptehdbars source
- inverse telecine filters (fieldmatch and decimate)
+- asetrate filter
version 1.2:
diff --git a/doc/filters.texi b/doc/filters.texi
index adf6000..2e30b5d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -889,6 +889,18 @@ disable padding for the last frame, use:
asetnsamples=n=1234:p=0
@end example
+ at section asetrate
+
+Set the sample rate without altering the PCM data.
+This will result in a change of speed and pitch.
+
+The filter accepts the following options:
+
+ at table @option
+ at item sample_rate, r
+Set the output sample rate. Default is 44100 Hz.
+ at end table
+
@section ashowinfo
Show a line containing various information for each input audio frame.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 04a5b39..57f863c 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -64,6 +64,7 @@ OBJS-$(CONFIG_ASELECT_FILTER) += f_select.o
OBJS-$(CONFIG_ASENDCMD_FILTER) += f_sendcmd.o
OBJS-$(CONFIG_ASETNSAMPLES_FILTER) += af_asetnsamples.o
OBJS-$(CONFIG_ASETPTS_FILTER) += f_setpts.o
+OBJS-$(CONFIG_ASETRATE_FILTER) += af_asetrate.o
OBJS-$(CONFIG_ASETTB_FILTER) += f_settb.o
OBJS-$(CONFIG_ASHOWINFO_FILTER) += af_ashowinfo.o
OBJS-$(CONFIG_ASPLIT_FILTER) += split.o
diff --git a/libavfilter/af_asetrate.c b/libavfilter/af_asetrate.c
new file mode 100644
index 0000000..e031b89
--- /dev/null
+++ b/libavfilter/af_asetrate.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2013 Nicolas George
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "internal.h"
+
+typedef struct {
+ const AVClass *class;
+ int sample_rate;
+ int rescale_pts;
+} ASetRateContext;
+
+#define CONTEXT ASetRateContext
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+#define OPT_GENERIC(name, field, def, min, max, descr, type, deffield, ...) \
+ { name, descr, offsetof(CONTEXT, field), AV_OPT_TYPE_ ## type, \
+ { .deffield = def }, min, max, FLAGS, __VA_ARGS__ }
+
+#define OPT_INT(name, field, def, min, max, descr, ...) \
+ OPT_GENERIC(name, field, def, min, max, descr, INT, i64, __VA_ARGS__)
+
+static const AVOption asetrate_options[] = {
+ OPT_INT("sample_rate", sample_rate, 44100, 1, INT_MAX, "set the sample rate"),
+ OPT_INT("r", sample_rate, 44100, 1, INT_MAX, "set the sample rate"),
+ {NULL},
+};
+
+AVFILTER_DEFINE_CLASS(asetrate);
+
+static av_cold int query_formats(AVFilterContext *ctx)
+{
+ ASetRateContext *sr = ctx->priv;
+ int sample_rates[] = { sr->sample_rate, -1 };
+
+ ff_formats_ref(ff_make_format_list(sample_rates),
+ &ctx->outputs[0]->in_samplerates);
+ return 0;
+}
+
+static av_cold int config_props(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ ASetRateContext *sr = ctx->priv;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVRational intb = ctx->inputs[0]->time_base;
+ int inrate = inlink->sample_rate;
+
+ if (intb.num == 1 && intb.den == inrate) {
+ outlink->time_base.num = 1;
+ outlink->time_base.den = outlink->sample_rate;
+ } else {
+ outlink->time_base = intb;
+ sr->rescale_pts = 1;
+ if (av_q2d(intb) > 1.0 / FFMAX(inrate, outlink->sample_rate))
+ av_log(ctx, AV_LOG_WARNING, "Time base is inaccurate\n");
+ }
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ASetRateContext *sr = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ frame->sample_rate = outlink->sample_rate;
+ if (sr->rescale_pts)
+ frame->pts = av_rescale(frame->pts, inlink->sample_rate,
+ outlink->sample_rate);
+ return ff_filter_frame(outlink, frame);
+}
+
+static const AVFilterPad asetrate_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad asetrate_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_props,
+ },
+ { NULL }
+};
+
+AVFilter avfilter_af_asetrate = {
+ .name = "asetrate",
+ .description = NULL_IF_CONFIG_SMALL("Change the sample rate without "
+ "altering the data."),
+ .query_formats = query_formats,
+ .priv_size = sizeof(ASetRateContext),
+ .inputs = asetrate_inputs,
+ .outputs = asetrate_outputs,
+ .priv_class = &asetrate_class,
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 95bd270..1e3c22f 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -62,6 +62,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(ASENDCMD, asendcmd, af);
REGISTER_FILTER(ASETNSAMPLES, asetnsamples, af);
REGISTER_FILTER(ASETPTS, asetpts, af);
+ REGISTER_FILTER(ASETRATE, asetrate, af);
REGISTER_FILTER(ASETTB, asettb, af);
REGISTER_FILTER(ASHOWINFO, ashowinfo, af);
REGISTER_FILTER(ASPLIT, asplit, af);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index ba1ec0b..c751674 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,8 +29,8 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 3
-#define LIBAVFILTER_VERSION_MINOR 56
-#define LIBAVFILTER_VERSION_MICRO 103
+#define LIBAVFILTER_VERSION_MINOR 57
+#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
--
1.7.10.4
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