On Wed, 13 Jun 2012 18:49:02 -0700, Alex Converse <[email protected]>
wrote:
> Inspired by MPlayer's af_channels filter and SoX's remix effect.
> ---
> Changelog | 1 +
> doc/filters.texi | 24 +++
> libavfilter/Makefile | 1 +
> libavfilter/af_channelmap.c | 406
> +++++++++++++++++++++++++++++++++++++++++++
> libavfilter/allfilters.c | 1 +
> 5 files changed, 433 insertions(+), 0 deletions(-)
> create mode 100644 libavfilter/af_channelmap.c
>
> diff --git a/Changelog b/Changelog
> index b80ff88..580381d 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -25,6 +25,7 @@ version <next>:
> be used with -of old.
> - Indeo Audio decoder
> - channelsplit audio filter
> +- audio channel mapping filter
>
>
> version 0.8:
> diff --git a/doc/filters.texi b/doc/filters.texi
> index f17dad8..00ab07e 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -232,6 +232,30 @@ front_center.wav -map '[LFE]' lfe.wav -map '[SL]'
> side_left.wav -map '[SR]'
> side_right.wav
> @end example
>
> +@section channelmap
> +Remap input channels to new locations.
> +
> +This filter accepts the following named parameters:
> +@table @option
> +@item channel_layout
> +Channel layout of the output stream.
> +
> +@item map
> +A comma-seperated list of input to output mappings.
You should specify what exactly are allowed forms of those mappings, so
the user doesn't have to derive it from examples.
Also if I'm reading the code right, while several forms are allowed,
the same one must be used in all mappings. That should be documented
too.
> +@end table
> +
> +For example, assuming a 5.1+downmix input MOV file
> +@example
> +avconv -i in.mov -filter 'channelmap=map=DL-FL\,DR-FR' out.wav
> +@end example
> +will create an output Wave file tagged as stereo from the downmix channels of
> +the input.
> +
> +To fix a 5.1 wav improperly encoded in AAC's native channel order
> +@example
> +avconv -i in.wav -filter 'channelmap=1\,2\,0\,5\,3\,4:channel_layout=5.1'
> out.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 955a97c..7d1ced0 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -30,6 +30,7 @@ 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-$(CONFIG_CHANNELMAP_FILTER) += af_channelmap.o
> OBJS-$(CONFIG_CHANNELSPLIT_FILTER) += af_channelsplit.o
> OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o
>
> diff --git a/libavfilter/af_channelmap.c b/libavfilter/af_channelmap.c
> new file mode 100644
> index 0000000..788affc
> --- /dev/null
> +++ b/libavfilter/af_channelmap.c
> @@ -0,0 +1,406 @@
> +/*
> + * Copyright (c) 2012 Google, Inc.
> + *
> + * 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
> + * audio channel mapping filter
> + */
> +
> +#include <ctype.h>
> +
> +#include "libavutil/audioconvert.h"
> +#include "libavutil/avstring.h"
> +#include "libavutil/mathematics.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/samplefmt.h"
> +
> +#include "audio.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "internal.h"
> +
> +struct ChannelMap {
> + uint64_t in_channel;
> + uint64_t out_channel;
> + int in_channel_idx;
> + int out_channel_idx;
> +};
> +
> +enum MappingMode {
> + MAP_NONE,
> + MAP_ONE_INT,
> + MAP_ONE_STR,
> + MAP_PAIR_INT_INT,
> + MAP_PAIR_INT_STR,
> + MAP_PAIR_STR_INT,
> + MAP_PAIR_STR_STR
> +};
> +
> +#define MAX_CH 64
> +typedef struct ChannelMapContext {
> + const AVClass *class;
> + AVFilterChannelLayouts *channel_layouts;
> + char *mapping_str;
> + char *channel_layout_str;
> + int nch;
> + int output_layout;
Wrong type?
> + struct ChannelMap map[MAX_CH];
> + enum MappingMode mode;
> +} ChannelMapContext;
> +
> +#define OFFSET(x) offsetof(ChannelMapContext, x)
> +#define A AV_OPT_FLAG_AUDIO_PARAM
> +static const AVOption options[] = {
> + { "map", "A comma-separated list of input channel numbers in output
> order.",
> + OFFSET(mapping_str), AV_OPT_TYPE_STRING, .flags = A },
> + { "channel_layout", "Output channel layout.",
> + OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, .flags = A },
> + { NULL },
> +};
> +
> +static const AVClass channelmap_class = {
> + .class_name = "channel map filter",
> + .item_name = av_default_item_name,
> + .option = options,
> + .version = LIBAVUTIL_VERSION_INT,
> +};
> +
> +static char* split(char *message, char delim) {
> + char *next = strchr(message, delim);
> + if (next) {
> + *next++ = '\0';
> + }
> + return next;
> +}
> +
> +static int get_channel_idx(char **map, int *ch, char delim, int max_ch) {
> + char *next = split(*map, delim);
> + int len;
> + int n = 0;
> + if (!next && delim == '-')
> + return AVERROR(EINVAL);
> + len = strlen(*map);
> + sscanf(*map, "%d%n", ch, &n);
> + if (n != len)
> + return AVERROR(EINVAL);
> + if (*ch < 0 || *ch > max_ch)
> + return AVERROR(EINVAL);
> + *map = next;
> + return 0;
> +}
> +
> +static int get_channel(char **map, uint64_t *ch, char delim) {
> + char *next = split(*map, delim);
> + if (!next && delim == '-')
> + return AVERROR(EINVAL);
> + *ch = av_get_channel_layout(*map);
> + if (av_get_channel_layout_nb_channels(*ch) != 1)
> + return AVERROR(EINVAL);
> + *map = next;
> + return 0;
> +}
> +
> +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
> +{
> + ChannelMapContext *s = ctx->priv;
> + int ret;
> + char *mapping;
> + enum mode;
> + int map_entries = 0;
> + char buf[256];
> + enum MappingMode mode;
> + uint64_t out_ch_mask = 0;
> + int i;
> +
> + if (!args) {
> + av_log(ctx, AV_LOG_ERROR, "No parameters supplied.\n");
> + return AVERROR(EINVAL);
> + }
> +
> + s->class = &channelmap_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;
> + }
> +
> + mapping = s->mapping_str;
> +
> + if (!mapping) {
> + mode = MAP_NONE;
> + } else {
> + char *dash = strchr(mapping, '-');
> + if (!dash) { // short mapping
> + if (isdigit(*mapping))
> + mode = MAP_ONE_INT;
> + else
> + mode = MAP_ONE_STR;
> + } else if (isdigit(*mapping)) {
> + if (isdigit(*(dash+1)))
> + mode = MAP_PAIR_INT_INT;
> + else
> + mode = MAP_PAIR_INT_STR;
> + } else {
> + if (isdigit(*(dash+1)))
> + mode = MAP_PAIR_STR_INT;
> + else
> + mode = MAP_PAIR_STR_STR;
> + }
> + }
> +
> + if (mode != MAP_NONE) {
> + char *comma = mapping;
> + map_entries = 1;
> + while ((comma = strchr(comma, ','))) {
> + if (*++comma) // Allow trailing comma
> + map_entries++;
> + }
> + }
> +
> + if (map_entries > MAX_CH) {
> + av_log(ctx, AV_LOG_ERROR, "Too many channels mapped: '%d'.\n",
> map_entries);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> +
> + for (i = 0; i < map_entries; i++) {
> + int in_ch_idx = -1, out_ch_idx = -1;
> + uint64_t in_ch = 0, out_ch = 0;
> + static const char err[] = "Failed to parse channel map\n";
> + switch (mode) {
> + case MAP_ONE_INT:
> + if (get_channel_idx(&mapping, &in_ch_idx, ',', MAX_CH) < 0) {
> + ret = AVERROR(EINVAL);
> + av_log(ctx, AV_LOG_ERROR, err);
> + goto fail;
> + }
> + s->map[i].in_channel_idx = in_ch_idx;
> + s->map[i].out_channel_idx = i;
> + break;
> + case MAP_ONE_STR:
> + if (!get_channel(&mapping, &in_ch, ',')) {
> + av_log(ctx, AV_LOG_ERROR, err);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->map[i].in_channel = in_ch;
> + s->map[i].out_channel_idx = i;
> + break;
> + case MAP_PAIR_INT_INT:
> + if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
> + get_channel_idx(&mapping, &out_ch_idx, ',', MAX_CH) < 0) {
> + av_log(ctx, AV_LOG_ERROR, err);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->map[i].in_channel_idx = in_ch_idx;
> + s->map[i].out_channel_idx = out_ch_idx;
> + break;
> + case MAP_PAIR_INT_STR:
> + if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
> + get_channel(&mapping, &out_ch, ',') < 0 ||
> + out_ch & out_ch_mask) {
> + av_log(ctx, AV_LOG_ERROR, err);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->map[i].in_channel_idx = in_ch_idx;
> + s->map[i].out_channel = out_ch;
> + out_ch_mask |= out_ch;
> + break;
> + case MAP_PAIR_STR_INT:
> + if (get_channel(&mapping, &in_ch, '-') < 0 ||
> + get_channel_idx(&mapping, &out_ch_idx, ',', MAX_CH) < 0) {
> + av_log(ctx, AV_LOG_ERROR, err);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->map[i].in_channel = in_ch;
> + s->map[i].out_channel_idx = out_ch_idx;
> + break;
> + case MAP_PAIR_STR_STR:
> + if (get_channel(&mapping, &in_ch, '-') < 0 ||
> + get_channel(&mapping, &out_ch, ',') < 0 ||
> + out_ch & out_ch_mask) {
> + av_log(ctx, AV_LOG_ERROR, err);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->map[i].in_channel = in_ch;
> + s->map[i].out_channel = out_ch;
> + out_ch_mask |= out_ch;
> + break;
> + }
> + }
> + s->mode = mode;
> + s->nch = map_entries;
> + s->output_layout = out_ch_mask ? out_ch_mask :
> + av_get_default_channel_layout(map_entries);
> +
> + if (s->channel_layout_str) {
> + uint64_t fmt;
> + if ((fmt = av_get_channel_layout(s->channel_layout_str)) == 0) {
> + av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout:
> '%s'.\n",
> + s->channel_layout_str);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + if (mode == MAP_NONE) {
> + int i;
> + s->nch = av_get_channel_layout_nb_channels(fmt);
> + for (i = 0; i < s->nch; i++) {
> + s->map[i].in_channel_idx = i;
> + s->map[i].out_channel_idx = i;
> + }
> + } else if (out_ch_mask && out_ch_mask != fmt) {
> + av_get_channel_layout_string(buf, sizeof(buf), 0, out_ch_mask);
> + av_log(ctx, AV_LOG_ERROR, "Output channel layout '%s' does not
> match the list of channel mapped: '%s'.\n",
> + s->channel_layout_str, buf);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + } else if (s->nch != av_get_channel_layout_nb_channels(fmt)) {
> + av_log(ctx, AV_LOG_ERROR, "Output channel layout %s does not
> match the number of channels mapped %d.\n",
> + s->channel_layout_str, s->nch);
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> + s->output_layout = fmt;
> + }
> + ff_add_channel_layout(&s->channel_layouts, s->output_layout);
> +
> +fail:
> + av_opt_free(s);
> + return ret;
> +}
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> + ChannelMapContext *s = ctx->priv;
> +
> + ff_set_common_formats(ctx, ff_planar_sample_fmts());
> + ff_set_common_samplerates(ctx, ff_all_samplerates());
> + ff_channel_layouts_ref(ff_all_channel_layouts(),
> &ctx->inputs[0]->out_channel_layouts);
> + ff_channel_layouts_ref(s->channel_layouts,
> &ctx->outputs[0]->in_channel_layouts);
> +
> + return 0;
> +}
> +
> +static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf)
> +{
> + AVFilterContext *ctx = inlink->dst;
> + AVFilterLink *outlink = ctx->outputs[0];
> + const ChannelMapContext *s = ctx->priv;
> + const int nch_in = FFMIN(
> + av_get_channel_layout_nb_channels(inlink->channel_layout), MAX_CH);
> + const int nch_out = s->nch;
> + int ch;
> + uint8_t *source_planes[MAX_CH];
> +
> + memcpy(source_planes, buf->extended_data,
> + nch_in * sizeof(source_planes[0]));
> +
> + if (nch_out > nch_in) {
> + if (nch_out > FF_ARRAY_ELEMS(buf->data)) {
> + uint8_t **new_extended_data =
> + av_mallocz(nch_out * sizeof(*buf->extended_data));
> + if (!new_extended_data)
> + return;
> + if (buf->extended_data == buf->data) {
> + buf->extended_data = new_extended_data;
> + } else {
> + buf->extended_data = new_extended_data;
> + av_free(buf->extended_data);
> + }
> + } else if (buf->extended_data != buf->data) {
> + av_free(buf->extended_data);
> + buf->extended_data = buf->data;
> + }
> + }
> +
> + switch (s->mode) {
> + case MAP_NONE:
> + case MAP_ONE_INT:
> + case MAP_PAIR_INT_INT:
> + for (ch = 0; ch < nch_out; ch++) {
> + buf->extended_data[s->map[ch].out_channel_idx] =
> + source_planes[s->map[ch].in_channel_idx];
> + }
> + break;
> + case MAP_PAIR_INT_STR:
> + for (ch = 0; ch < nch_out; ch++) {
> + int out_idx = av_get_channel_layout_channel_index(
> + s->output_layout, s->map[ch].out_channel);
> + buf->extended_data[out_idx] =
> + source_planes[s->map[ch].in_channel_idx];
> + }
> + break;
> + case MAP_ONE_STR:
> + case MAP_PAIR_STR_INT:
> + for (ch = 0; ch < nch_out; ch++) {
> + int in_idx = av_get_channel_layout_channel_index(
> + inlink->channel_layout, s->map[ch].in_channel);
> + buf->extended_data[s->map[ch].out_channel_idx] =
> + source_planes[in_idx];
> + }
> + break;
> + case MAP_PAIR_STR_STR:
> + for (ch = 0; ch < nch_out; ch++) {
> + int in_idx = av_get_channel_layout_channel_index(
> + inlink->channel_layout, s->map[ch].in_channel);
> + int out_idx = av_get_channel_layout_channel_index(
> + s->output_layout, s->map[ch].out_channel);
> + buf->extended_data[out_idx] = source_planes[in_idx];
> + }
> + break;
> + }
It should be cleaner to compute all indices once in config_output and
leave only data[out_idx] = source[in_idx] here.
--
Anton Khirnov
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