0,0 → 1,422 |
/* |
* Copyright (c) 2002 Anders Johansson <ajh@atri.curtin.edu.au> |
* Copyright (c) 2011 Clément Bœsch <u pkh me> |
* Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org> |
* |
* 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 |
*/ |
|
/** |
* @file |
* Audio panning filter (channels mixing) |
* Original code written by Anders Johansson for MPlayer, |
* reimplemented for FFmpeg. |
*/ |
|
#include <stdio.h> |
#include "libavutil/avstring.h" |
#include "libavutil/channel_layout.h" |
#include "libavutil/opt.h" |
#include "libswresample/swresample.h" |
#include "audio.h" |
#include "avfilter.h" |
#include "formats.h" |
#include "internal.h" |
|
#define MAX_CHANNELS 63 |
|
typedef struct PanContext { |
const AVClass *class; |
char *args; |
int64_t out_channel_layout; |
double gain[MAX_CHANNELS][MAX_CHANNELS]; |
int64_t need_renorm; |
int need_renumber; |
int nb_input_channels; |
int nb_output_channels; |
|
int pure_gains; |
/* channel mapping specific */ |
int channel_map[SWR_CH_MAX]; |
struct SwrContext *swr; |
} PanContext; |
|
static void skip_spaces(char **arg) |
{ |
int len = 0; |
|
sscanf(*arg, " %n", &len); |
*arg += len; |
} |
|
static int parse_channel_name(char **arg, int *rchannel, int *rnamed) |
{ |
char buf[8]; |
int len, i, channel_id = 0; |
int64_t layout, layout0; |
|
skip_spaces(arg); |
/* try to parse a channel name, e.g. "FL" */ |
if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) { |
layout0 = layout = av_get_channel_layout(buf); |
/* channel_id <- first set bit in layout */ |
for (i = 32; i > 0; i >>= 1) { |
if (layout >= (int64_t)1 << i) { |
channel_id += i; |
layout >>= i; |
} |
} |
/* reject layouts that are not a single channel */ |
if (channel_id >= MAX_CHANNELS || layout0 != (int64_t)1 << channel_id) |
return AVERROR(EINVAL); |
*rchannel = channel_id; |
*rnamed = 1; |
*arg += len; |
return 0; |
} |
/* try to parse a channel number, e.g. "c2" */ |
if (sscanf(*arg, "c%d%n", &channel_id, &len) && |
channel_id >= 0 && channel_id < MAX_CHANNELS) { |
*rchannel = channel_id; |
*rnamed = 0; |
*arg += len; |
return 0; |
} |
return AVERROR(EINVAL); |
} |
|
static av_cold int init(AVFilterContext *ctx) |
{ |
PanContext *const pan = ctx->priv; |
char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args); |
int out_ch_id, in_ch_id, len, named, ret; |
int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels |
double gain; |
|
if (!pan->args) { |
av_log(ctx, AV_LOG_ERROR, |
"pan filter needs a channel layout and a set " |
"of channels definitions as parameter\n"); |
return AVERROR(EINVAL); |
} |
if (!args) |
return AVERROR(ENOMEM); |
arg = av_strtok(args, "|", &tokenizer); |
ret = ff_parse_channel_layout(&pan->out_channel_layout, arg, ctx); |
if (ret < 0) |
goto fail; |
pan->nb_output_channels = av_get_channel_layout_nb_channels(pan->out_channel_layout); |
|
/* parse channel specifications */ |
while ((arg = arg0 = av_strtok(NULL, "|", &tokenizer))) { |
/* channel name */ |
if (parse_channel_name(&arg, &out_ch_id, &named)) { |
av_log(ctx, AV_LOG_ERROR, |
"Expected out channel name, got \"%.8s\"\n", arg); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
if (named) { |
if (!((pan->out_channel_layout >> out_ch_id) & 1)) { |
av_log(ctx, AV_LOG_ERROR, |
"Channel \"%.8s\" does not exist in the chosen layout\n", arg0); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
/* get the channel number in the output channel layout: |
* out_channel_layout & ((1 << out_ch_id) - 1) are all the |
* channels that come before out_ch_id, |
* so their count is the index of out_ch_id */ |
out_ch_id = av_get_channel_layout_nb_channels(pan->out_channel_layout & (((int64_t)1 << out_ch_id) - 1)); |
} |
if (out_ch_id < 0 || out_ch_id >= pan->nb_output_channels) { |
av_log(ctx, AV_LOG_ERROR, |
"Invalid out channel name \"%.8s\"\n", arg0); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
skip_spaces(&arg); |
if (*arg == '=') { |
arg++; |
} else if (*arg == '<') { |
pan->need_renorm |= (int64_t)1 << out_ch_id; |
arg++; |
} else { |
av_log(ctx, AV_LOG_ERROR, |
"Syntax error after channel name in \"%.8s\"\n", arg0); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
/* gains */ |
while (1) { |
gain = 1; |
if (sscanf(arg, "%lf%n *%n", &gain, &len, &len)) |
arg += len; |
if (parse_channel_name(&arg, &in_ch_id, &named)){ |
av_log(ctx, AV_LOG_ERROR, |
"Expected in channel name, got \"%.8s\"\n", arg); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
nb_in_channels[named]++; |
if (nb_in_channels[!named]) { |
av_log(ctx, AV_LOG_ERROR, |
"Can not mix named and numbered channels\n"); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
pan->gain[out_ch_id][in_ch_id] = gain; |
skip_spaces(&arg); |
if (!*arg) |
break; |
if (*arg != '+') { |
av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg); |
ret = AVERROR(EINVAL); |
goto fail; |
} |
arg++; |
} |
} |
pan->need_renumber = !!nb_in_channels[1]; |
|
ret = 0; |
fail: |
av_free(args); |
return ret; |
} |
|
static int are_gains_pure(const PanContext *pan) |
{ |
int i, j; |
|
for (i = 0; i < MAX_CHANNELS; i++) { |
int nb_gain = 0; |
|
for (j = 0; j < MAX_CHANNELS; j++) { |
double gain = pan->gain[i][j]; |
|
/* channel mapping is effective only if 0% or 100% of a channel is |
* selected... */ |
if (gain != 0. && gain != 1.) |
return 0; |
/* ...and if the output channel is only composed of one input */ |
if (gain && nb_gain++) |
return 0; |
} |
} |
return 1; |
} |
|
static int query_formats(AVFilterContext *ctx) |
{ |
PanContext *pan = ctx->priv; |
AVFilterLink *inlink = ctx->inputs[0]; |
AVFilterLink *outlink = ctx->outputs[0]; |
AVFilterFormats *formats = NULL; |
AVFilterChannelLayouts *layouts; |
|
pan->pure_gains = are_gains_pure(pan); |
/* libswr supports any sample and packing formats */ |
ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO)); |
|
formats = ff_all_samplerates(); |
if (!formats) |
return AVERROR(ENOMEM); |
ff_set_common_samplerates(ctx, formats); |
|
// inlink supports any channel layout |
layouts = ff_all_channel_layouts(); |
ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts); |
|
// outlink supports only requested output channel layout |
layouts = NULL; |
ff_add_channel_layout(&layouts, pan->out_channel_layout); |
ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts); |
return 0; |
} |
|
static int config_props(AVFilterLink *link) |
{ |
AVFilterContext *ctx = link->dst; |
PanContext *pan = ctx->priv; |
char buf[1024], *cur; |
int i, j, k, r; |
double t; |
|
pan->nb_input_channels = av_get_channel_layout_nb_channels(link->channel_layout); |
if (pan->need_renumber) { |
// input channels were given by their name: renumber them |
for (i = j = 0; i < MAX_CHANNELS; i++) { |
if ((link->channel_layout >> i) & 1) { |
for (k = 0; k < pan->nb_output_channels; k++) |
pan->gain[k][j] = pan->gain[k][i]; |
j++; |
} |
} |
} |
|
// sanity check; can't be done in query_formats since the inlink |
// channel layout is unknown at that time |
if (pan->nb_input_channels > SWR_CH_MAX || |
pan->nb_output_channels > SWR_CH_MAX) { |
av_log(ctx, AV_LOG_ERROR, |
"libswresample support a maximum of %d channels. " |
"Feel free to ask for a higher limit.\n", SWR_CH_MAX); |
return AVERROR_PATCHWELCOME; |
} |
|
// init libswresample context |
pan->swr = swr_alloc_set_opts(pan->swr, |
pan->out_channel_layout, link->format, link->sample_rate, |
link->channel_layout, link->format, link->sample_rate, |
0, ctx); |
if (!pan->swr) |
return AVERROR(ENOMEM); |
|
// gains are pure, init the channel mapping |
if (pan->pure_gains) { |
|
// get channel map from the pure gains |
for (i = 0; i < pan->nb_output_channels; i++) { |
int ch_id = -1; |
for (j = 0; j < pan->nb_input_channels; j++) { |
if (pan->gain[i][j]) { |
ch_id = j; |
break; |
} |
} |
pan->channel_map[i] = ch_id; |
} |
|
av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0); |
av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0); |
swr_set_channel_mapping(pan->swr, pan->channel_map); |
} else { |
// renormalize |
for (i = 0; i < pan->nb_output_channels; i++) { |
if (!((pan->need_renorm >> i) & 1)) |
continue; |
t = 0; |
for (j = 0; j < pan->nb_input_channels; j++) |
t += pan->gain[i][j]; |
if (t > -1E-5 && t < 1E-5) { |
// t is almost 0 but not exactly, this is probably a mistake |
if (t) |
av_log(ctx, AV_LOG_WARNING, |
"Degenerate coefficients while renormalizing\n"); |
continue; |
} |
for (j = 0; j < pan->nb_input_channels; j++) |
pan->gain[i][j] /= t; |
} |
av_opt_set_int(pan->swr, "icl", link->channel_layout, 0); |
av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0); |
swr_set_matrix(pan->swr, pan->gain[0], pan->gain[1] - pan->gain[0]); |
} |
|
r = swr_init(pan->swr); |
if (r < 0) |
return r; |
|
// summary |
for (i = 0; i < pan->nb_output_channels; i++) { |
cur = buf; |
for (j = 0; j < pan->nb_input_channels; j++) { |
r = snprintf(cur, buf + sizeof(buf) - cur, "%s%.3g i%d", |
j ? " + " : "", pan->gain[i][j], j); |
cur += FFMIN(buf + sizeof(buf) - cur, r); |
} |
av_log(ctx, AV_LOG_VERBOSE, "o%d = %s\n", i, buf); |
} |
// add channel mapping summary if possible |
if (pan->pure_gains) { |
av_log(ctx, AV_LOG_INFO, "Pure channel mapping detected:"); |
for (i = 0; i < pan->nb_output_channels; i++) |
if (pan->channel_map[i] < 0) |
av_log(ctx, AV_LOG_INFO, " M"); |
else |
av_log(ctx, AV_LOG_INFO, " %d", pan->channel_map[i]); |
av_log(ctx, AV_LOG_INFO, "\n"); |
return 0; |
} |
return 0; |
} |
|
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples) |
{ |
int ret; |
int n = insamples->nb_samples; |
AVFilterLink *const outlink = inlink->dst->outputs[0]; |
AVFrame *outsamples = ff_get_audio_buffer(outlink, n); |
PanContext *pan = inlink->dst->priv; |
|
if (!outsamples) |
return AVERROR(ENOMEM); |
swr_convert(pan->swr, outsamples->data, n, (void *)insamples->data, n); |
av_frame_copy_props(outsamples, insamples); |
outsamples->channel_layout = outlink->channel_layout; |
av_frame_set_channels(outsamples, outlink->channels); |
|
ret = ff_filter_frame(outlink, outsamples); |
av_frame_free(&insamples); |
return ret; |
} |
|
static av_cold void uninit(AVFilterContext *ctx) |
{ |
PanContext *pan = ctx->priv; |
swr_free(&pan->swr); |
} |
|
#define OFFSET(x) offsetof(PanContext, x) |
|
static const AVOption pan_options[] = { |
{ "args", NULL, OFFSET(args), AV_OPT_TYPE_STRING, { .str = NULL }, CHAR_MIN, CHAR_MAX, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM }, |
{ NULL } |
}; |
|
AVFILTER_DEFINE_CLASS(pan); |
|
static const AVFilterPad pan_inputs[] = { |
{ |
.name = "default", |
.type = AVMEDIA_TYPE_AUDIO, |
.config_props = config_props, |
.filter_frame = filter_frame, |
}, |
{ NULL } |
}; |
|
static const AVFilterPad pan_outputs[] = { |
{ |
.name = "default", |
.type = AVMEDIA_TYPE_AUDIO, |
}, |
{ NULL } |
}; |
|
AVFilter avfilter_af_pan = { |
.name = "pan", |
.description = NULL_IF_CONFIG_SMALL("Remix channels with coefficients (panning)."), |
.priv_size = sizeof(PanContext), |
.priv_class = &pan_class, |
.init = init, |
.uninit = uninit, |
.query_formats = query_formats, |
.inputs = pan_inputs, |
.outputs = pan_outputs, |
}; |