[FFmpeg-cvslog] lavfi: add aformat filter
Anton Khirnov
git at videolan.org
Wed May 16 02:30:37 CEST 2012
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Sun May 6 09:00:53 2012 +0200| [fb604ae8500d4ee7de6af61387c11618b3dea25b] | committer: Anton Khirnov
lavfi: add aformat filter
Based on a patch by Mina Nagy Zaki <mnzaki at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fb604ae8500d4ee7de6af61387c11618b3dea25b
---
doc/filters.texi | 26 ++++++++
libavfilter/Makefile | 1 +
libavfilter/af_aformat.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
4 files changed, 176 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index 0314bfa..f066657 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -107,6 +107,32 @@ build.
Below is a description of the currently available audio filters.
+ at section aformat
+
+Convert the input audio to one of the specified formats. The framework will
+negotiate the most appropriate format to minimize conversions.
+
+The filter accepts the following named parameters:
+ at table @option
+
+ at item sample_fmts
+A comma-separated list of requested sample formats.
+
+ at item sample_rates
+A comma-separated list of requested sample rates.
+
+ at item channel_layouts
+A comma-separated list of requested channel layouts.
+
+ at end table
+
+If a parameter is omitted, all values are allowed.
+
+For example to force the output to either unsigned 8-bit or signed 16-bit stereo:
+ at example
+aformat=sample_fmts\=u8\,s16:channel_layouts\=stereo
+ at end example
+
@section anull
Pass the audio source unchanged to the output.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 6a6bfd6..df75bd5 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -22,6 +22,7 @@ OBJS = allfilters.o \
graphparser.o \
vf_scale.o \
+OBJS-$(CONFIG_AFORMAT_FILTER) += af_aformat.o
OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o
OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o
diff --git a/libavfilter/af_aformat.c b/libavfilter/af_aformat.c
new file mode 100644
index 0000000..84442d3
--- /dev/null
+++ b/libavfilter/af_aformat.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2011 Mina Nagy Zaki
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * format audio filter
+ */
+
+#include "libavutil/audioconvert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+
+#include "audio.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+
+typedef struct AFormatContext {
+ const AVClass *class;
+
+ AVFilterFormats *formats;
+ AVFilterFormats *sample_rates;
+ AVFilterChannelLayouts *channel_layouts;
+
+ char *formats_str;
+ char *sample_rates_str;
+ char *channel_layouts_str;
+} AFormatContext;
+
+#define OFFSET(x) offsetof(AFormatContext, x)
+#define A AV_OPT_FLAG_AUDIO_PARAM
+static const AVOption options[] = {
+ { "sample_fmts", "A comma-separated list of sample formats.", OFFSET(formats_str), AV_OPT_TYPE_STRING, .flags = A },
+ { "sample_rates", "A comma-separated list of sample rates.", OFFSET(sample_rates_str), AV_OPT_TYPE_STRING, .flags = A },
+ { "channel_layouts", "A comma-separated list of channel layouts.", OFFSET(channel_layouts_str), AV_OPT_TYPE_STRING, .flags = A },
+ { NULL },
+};
+
+static const AVClass aformat_class = {
+ .class_name = "aformat filter",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+#define PARSE_FORMATS(str, type, list, add_to_list, get_fmt, none, desc) \
+do { \
+ char *next, *cur = str; \
+ while (cur) { \
+ type fmt; \
+ next = strchr(cur, ','); \
+ if (next) \
+ *next++ = 0; \
+ \
+ if ((fmt = get_fmt(cur)) == none) { \
+ av_log(ctx, AV_LOG_ERROR, "Error parsing " desc ": %s.\n", cur);\
+ ret = AVERROR(EINVAL); \
+ goto fail; \
+ } \
+ add_to_list(&list, fmt); \
+ \
+ cur = next; \
+ } \
+} while (0)
+
+static int get_sample_rate(const char *samplerate)
+{
+ int ret = strtol(samplerate, NULL, 0);
+ return FFMAX(ret, 0);
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ AFormatContext *s = ctx->priv;
+ int ret;
+
+ if (!args) {
+ av_log(ctx, AV_LOG_ERROR, "No parameters supplied.\n");
+ return AVERROR(EINVAL);
+ }
+
+ s->class = &aformat_class;
+ av_opt_set_defaults(s);
+
+ if ((ret = av_set_options_string(s, args, "=", ":")) < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Error parsing options string '%s'.\n", args);
+ return ret;
+ }
+
+ PARSE_FORMATS(s->formats_str, enum AVSampleFormat, s->formats,
+ avfilter_add_format, av_get_sample_fmt, AV_SAMPLE_FMT_NONE, "sample format");
+ PARSE_FORMATS(s->sample_rates_str, int, s->sample_rates, avfilter_add_format,
+ get_sample_rate, 0, "sample rate");
+ PARSE_FORMATS(s->channel_layouts_str, uint64_t, s->channel_layouts,
+ ff_add_channel_layout, av_get_channel_layout, 0,
+ "channel layout");
+
+fail:
+ av_opt_free(s);
+ return ret;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ AFormatContext *s = ctx->priv;
+
+ avfilter_set_common_formats(ctx, s->formats ? s->formats :
+ avfilter_all_formats(AVMEDIA_TYPE_AUDIO));
+ ff_set_common_samplerates(ctx, s->sample_rates ? s->sample_rates :
+ ff_all_samplerates());
+ ff_set_common_channel_layouts(ctx, s->channel_layouts ? s->channel_layouts :
+ ff_all_channel_layouts());
+
+ return 0;
+}
+
+AVFilter avfilter_af_aformat = {
+ .name = "aformat",
+ .description = NULL_IF_CONFIG_SMALL("Convert the input audio to one of the specified formats."),
+ .init = init,
+ .query_formats = query_formats,
+ .priv_size = sizeof(AFormatContext),
+
+ .inputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_samples = ff_null_filter_samples },
+ { .name = NULL}},
+ .outputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO},
+ { .name = NULL}},
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index c84b3f2..4f5f852 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -34,6 +34,7 @@ void avfilter_register_all(void)
return;
initialized = 1;
+ REGISTER_FILTER (AFORMAT, aformat, af);
REGISTER_FILTER (ANULL, anull, af);
REGISTER_FILTER (RESAMPLE, resample, af);
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