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lavfi: Add the af_channelmap audio channel mapping filter.

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Inspired by MPlayer's af_channels filter and SoX's remix effect.
This commit is contained in:
Alex Converse 2012-06-08 18:42:53 -07:00
parent dc07fb6f7b
commit 41e637e449
5 changed files with 438 additions and 0 deletions
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1
Changelog
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@ -29,6 +29,7 @@ version <next>:
- iLBC encoding/decoding via libilbc
- Microsoft Screen 1 decoder
- join audio filter
- audio channel mapping filter
version 0.8:

33
doc/filters.texi
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@ -232,6 +232,39 @@ 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
Map channels from input to output. The argument is a comma-separated list of
mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
@var{in_channel} form. @var{in_channel} can be either the name of the input
channel (e.g. FL for front left) or its index in the input channel layout.
@var{out_channel} is the name of the output channel or its index in the output
channel layout. If @var{out_channel} is not given then it is implicitly an
index, starting with zero and increasing by one for each mapping.
@end table
If no mapping is present, the filter will implicitly map input channels to
output channels preserving index.
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 WAV 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 join
Join multiple input streams into one multi-channel stream.

1
libavfilter/Makefile
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@ -31,6 +31,7 @@ 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-$(CONFIG_JOIN_FILTER) += af_join.o
OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o

402
libavfilter/af_channelmap.c Normal file
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@ -0,0 +1,402 @@
/*
* 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;
uint64_t output_layout;
struct ChannelMap map[MAX_CH];
int nch;
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 channelmap_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);
if (mode == MAP_PAIR_INT_STR || mode == MAP_PAIR_STR_STR) {
for (i = 0; i < s->nch; i++) {
s->map[i].out_channel_idx = av_get_channel_layout_channel_index(
s->output_layout, s->map[i].out_channel);
}
}
fail:
av_opt_free(s);
return ret;
}
static int channelmap_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 channelmap_filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
const ChannelMapContext *s = ctx->priv;
const int nch_in = av_get_channel_layout_nb_channels(inlink->channel_layout);
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;
}
}
for (ch = 0; ch < nch_out; ch++) {
buf->extended_data[s->map[ch].out_channel_idx] =
source_planes[s->map[ch].in_channel_idx];
}
if (buf->data != buf->extended_data)
memcpy(buf->data, buf->extended_data,
FFMIN(FF_ARRAY_ELEMS(buf->data), nch_out) * sizeof(buf->data[0]));
ff_filter_samples(outlink, buf);
}
static int channelmap_config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
ChannelMapContext *s = ctx->priv;
int i, err = 0;
const char *channel_name;
char layout_name[256];
if (s->mode == MAP_PAIR_STR_INT || s->mode == MAP_PAIR_STR_STR) {
for (i = 0; i < s->nch; i++) {
s->map[i].in_channel_idx = av_get_channel_layout_channel_index(
inlink->channel_layout, s->map[i].in_channel);
if (s->map[i].in_channel_idx < 0) {
channel_name = av_get_channel_name(s->map[i].in_channel);
av_get_channel_layout_string(layout_name, sizeof(layout_name),
0, inlink->channel_layout);
av_log(ctx, AV_LOG_ERROR,
"input channel '%s' not available from input layout '%s'\n",
channel_name, layout_name);
err = AVERROR(EINVAL);
}
}
}
return err;
}
AVFilter avfilter_af_channelmap = {
.name = "channelmap",
.description = NULL_IF_CONFIG_SMALL("Remap audio channels."),
.init = channelmap_init,
.query_formats = channelmap_query_formats,
.priv_size = sizeof(ChannelMapContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_samples = channelmap_filter_samples,
.config_props = channelmap_config_input },
{ .name = NULL }},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_AUDIO },
{ .name = NULL }},
};

1
libavfilter/allfilters.c
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@ -40,6 +40,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (ANULL, anull, af);
REGISTER_FILTER (ASPLIT, asplit, af);
REGISTER_FILTER (ASYNCTS, asyncts, af);
REGISTER_FILTER (CHANNELMAP, channelmap, af);
REGISTER_FILTER (CHANNELSPLIT,channelsplit,af);
REGISTER_FILTER (JOIN, join, af);
REGISTER_FILTER (RESAMPLE, resample, af);