From d6251368772a170987387bdc508433c8fcf54cda Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Wed, 30 May 2012 13:59:30 +0200 Subject: lavfi: add channelsplit audio filter. --- Changelog | 1 + doc/filters.texi | 25 ++++++++ libavfilter/Makefile | 1 + libavfilter/af_channelsplit.c | 146 ++++++++++++++++++++++++++++++++++++++++++ libavfilter/allfilters.c | 1 + libavfilter/formats.c | 12 ++++ libavfilter/formats.h | 5 ++ libavfilter/version.h | 2 +- 8 files changed, 192 insertions(+), 1 deletion(-) create mode 100644 libavfilter/af_channelsplit.c diff --git a/Changelog b/Changelog index 898a247..b80ff88 100644 --- a/Changelog +++ b/Changelog @@ -24,6 +24,7 @@ version : - avprobe output is now standard INI or JSON. The old format can still be used with -of old. - Indeo Audio decoder +- channelsplit audio filter version 0.8: diff --git a/doc/filters.texi b/doc/filters.texi index 0179682..f17dad8 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -207,6 +207,31 @@ Maximum compensation in samples per second. @end table +@section channelsplit +Split each channel in input audio stream into a separate output stream. + +This filter accepts the following named parameters: +@table @option +@item channel_layout +Channel layout of the input stream. Default is "stereo". +@end table + +For example, assuming a stereo input MP3 file +@example +avconv -i in.mp3 -filter_complex channelsplit out.mkv +@end example +will create an output Matroska file with two audio streams, one containing only +the left channel and the other the right channel. + +To split a 5.1 WAV file into per-channel files +@example +avconv -i in.wav -filter_complex +'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]' +-map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]' +front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]' +side_right.wav +@end example + @section resample Convert the audio sample format, sample rate and channel layout. This filter is not meant to be used directly, it is inserted automatically by libavfilter diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 914f0c6..7e1a6d1 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -29,6 +29,7 @@ OBJS-$(CONFIG_AMIX_FILTER) += af_amix.o OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o OBJS-$(CONFIG_ASPLIT_FILTER) += split.o OBJS-$(CONFIG_ASYNCTS_FILTER) += af_asyncts.o +OBJS-$(CONFIG_CHANNELSPLIT_FILTER) += af_channelsplit.o OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o OBJS-$(CONFIG_ANULLSRC_FILTER) += asrc_anullsrc.o diff --git a/libavfilter/af_channelsplit.c b/libavfilter/af_channelsplit.c new file mode 100644 index 0000000..c3e7ccf --- /dev/null +++ b/libavfilter/af_channelsplit.c @@ -0,0 +1,146 @@ +/* + * 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 + * Channel split filter + * + * Split an audio stream into per-channel streams. + */ + +#include "libavutil/audioconvert.h" +#include "libavutil/opt.h" + +#include "audio.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" + +typedef struct ChannelSplitContext { + const AVClass *class; + + uint64_t channel_layout; + char *channel_layout_str; +} ChannelSplitContext; + +#define OFFSET(x) offsetof(ChannelSplitContext, x) +#define A AV_OPT_FLAG_AUDIO_PARAM +static const AVOption options[] = { + { "channel_layout", "Input channel layout.", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, { .str = "stereo" }, .flags = A }, + { NULL }, +}; + +static const AVClass channelsplit_class = { + .class_name = "channelsplit filter", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +static int init(AVFilterContext *ctx, const char *arg, void *opaque) +{ + ChannelSplitContext *s = ctx->priv; + int nb_channels; + int ret = 0, i; + + s->class = &channelsplit_class; + av_opt_set_defaults(s); + if ((ret = av_set_options_string(s, arg, "=", ":")) < 0) { + av_log(ctx, AV_LOG_ERROR, "Error parsing options string '%s'.\n", arg); + return ret; + } + if (!(s->channel_layout = av_get_channel_layout(s->channel_layout_str))) { + av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout '%s'.\n", + s->channel_layout_str); + ret = AVERROR(EINVAL); + goto fail; + } + + nb_channels = av_get_channel_layout_nb_channels(s->channel_layout); + for (i = 0; i < nb_channels; i++) { + uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i); + AVFilterPad pad = { 0 }; + + pad.type = AVMEDIA_TYPE_AUDIO; + pad.name = av_get_channel_name(channel); + + ff_insert_outpad(ctx, i, &pad); + } + +fail: + av_opt_free(s); + return ret; +} + +static int query_formats(AVFilterContext *ctx) +{ + ChannelSplitContext *s = ctx->priv; + AVFilterChannelLayouts *in_layouts = NULL; + int i; + + ff_set_common_formats (ctx, ff_planar_sample_fmts()); + ff_set_common_samplerates(ctx, ff_all_samplerates()); + + ff_add_channel_layout(&in_layouts, s->channel_layout); + ff_channel_layouts_ref(in_layouts, &ctx->inputs[0]->out_channel_layouts); + + for (i = 0; i < ctx->output_count; i++) { + AVFilterChannelLayouts *out_layouts = NULL; + uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i); + + ff_add_channel_layout(&out_layouts, channel); + ff_channel_layouts_ref(out_layouts, &ctx->outputs[i]->in_channel_layouts); + } + + return 0; +} + +static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf) +{ + AVFilterContext *ctx = inlink->dst; + int i; + + for (i = 0; i < ctx->output_count; i++) { + AVFilterBufferRef *buf_out = avfilter_ref_buffer(buf, ~AV_PERM_WRITE); + + if (!buf_out) + return; + + buf_out->data[0] = buf_out->extended_data[0] = buf_out->extended_data[i]; + buf_out->audio->channel_layout = + av_channel_layout_extract_channel(buf->audio->channel_layout, i); + + ff_filter_samples(ctx->outputs[i], buf_out); + } + avfilter_unref_buffer(buf); +} + +AVFilter avfilter_af_channelsplit = { + .name = "channelsplit", + .description = NULL_IF_CONFIG_SMALL("Split audio into per-channel streams"), + .priv_size = sizeof(ChannelSplitContext), + + .init = init, + .query_formats = query_formats, + + .inputs = (const AVFilterPad[]){{ .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_samples = filter_samples, }, + { NULL }}, + .outputs = (const AVFilterPad[]){{ NULL }}, +}; diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 941ca6a..6814871 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -39,6 +39,7 @@ void avfilter_register_all(void) REGISTER_FILTER (ANULL, anull, af); REGISTER_FILTER (ASPLIT, asplit, af); REGISTER_FILTER (ASYNCTS, asyncts, af); + REGISTER_FILTER (CHANNELSPLIT,channelsplit,af); REGISTER_FILTER (RESAMPLE, resample, af); REGISTER_FILTER (ANULLSRC, anullsrc, asrc); diff --git a/libavfilter/formats.c b/libavfilter/formats.c index 83bdcd7..1d58d95 100644 --- a/libavfilter/formats.c +++ b/libavfilter/formats.c @@ -220,6 +220,18 @@ AVFilterFormats *ff_all_formats(enum AVMediaType type) return ret; } +AVFilterFormats *ff_planar_sample_fmts(void) +{ + AVFilterFormats *ret = NULL; + int fmt; + + for (fmt = 0; fmt < AV_SAMPLE_FMT_NB; fmt++) + if (av_sample_fmt_is_planar(fmt)) + ff_add_format(&ret, fmt); + + return ret; +} + AVFilterFormats *ff_all_samplerates(void) { AVFilterFormats *ret = av_mallocz(sizeof(*ret)); diff --git a/libavfilter/formats.h b/libavfilter/formats.h index 8961cb1..c3e9522 100644 --- a/libavfilter/formats.h +++ b/libavfilter/formats.h @@ -160,6 +160,11 @@ int ff_add_format(AVFilterFormats **avff, int fmt); AVFilterFormats *ff_all_formats(enum AVMediaType type); /** + * Construct a formats list containing all planar sample formats. + */ +AVFilterFormats *ff_planar_sample_fmts(void); + +/** * Return a format list which contains the intersection of the formats of * a and b. Also, all the references of a, all the references of b, and * a and b themselves will be deallocated. diff --git a/libavfilter/version.h b/libavfilter/version.h index 9a64316..09cf4c6 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -29,7 +29,7 @@ #include "libavutil/avutil.h" #define LIBAVFILTER_VERSION_MAJOR 2 -#define LIBAVFILTER_VERSION_MINOR 20 +#define LIBAVFILTER_VERSION_MINOR 21 #define LIBAVFILTER_VERSION_MICRO 0 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ -- cgit v1.1