breeze/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2026-02-04 14:30:55 +08:00
Code Issues Packages Projects Releases Wiki Activity

avfilter/af_crossfeed: add option for linear phase filtering

Browse Source 
But at expense of additional delay.
This commit is contained in:
Paul B Mahol
2022-05-09 21:59:03 +02:00
parent 1309867022
commit 5ccd8f492b
2 changed files with 167 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

174
libavfilter/af_crossfeed.c
View File

@@ -21,6 +21,7 @@
#include "libavutil/opt.h"
#include "avfilter.h"
#include "audio.h"
#include "filters.h"
#include "formats.h"
typedef struct CrossfeedContext {
@@ -31,11 +32,16 @@ typedef struct CrossfeedContext {
double slope;
double level_in;
double level_out;
int block_samples;
int block_size;
double a0, a1, a2;
double b0, b1, b2;
double w1, w2;
double *mid;
double *side[3];
} CrossfeedContext;
static int query_formats(AVFilterContext *ctx)
@@ -77,9 +83,49 @@ static int config_input(AVFilterLink *inlink)
s->b1 /= s->a0;
s->b2 /= s->a0;
if (s->block_samples == 0 && s->block_size > 0) {
s->block_samples = s->block_size;
s->mid = av_calloc(s->block_samples * 2, sizeof(*s->mid));
for (int i = 0; i < 3; i++) {
s->side[i] = av_calloc(s->block_samples * 2, sizeof(*s->side[0]));
if (!s->side[i])
return AVERROR(ENOMEM);
}
}
return 0;
}
static void reverse_samples(double *dst, const double *src,
int nb_samples)
{
for (int i = 0, j = nb_samples - 1; i < nb_samples; i++, j--)
dst[i] = src[j];
}
static void filter_samples(double *dst, const double *src,
int nb_samples,
double b0, double b1, double b2,
double a1, double a2,
double *sw1, double *sw2)
{
double w1 = *sw1;
double w2 = *sw2;
for (int n = 0; n < nb_samples; n++) {
double side = src[n];
double oside = side * b0 + w1;
w1 = b1 * side + w2 + a1 * oside;
w2 = b2 * side + a2 * oside;
dst[n] = oside;
}
*sw1 = w1;
*sw2 = w2;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
@@ -95,7 +141,6 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
const double a2 = -s->a2;
AVFrame *out;
double *dst;
int n;
if (av_frame_is_writable(in)) {
out = in;
@@ -109,21 +154,79 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
}
dst = (double *)out->data[0];
for (n = 0; n < out->nb_samples; n++, src += 2, dst += 2) {
double mid = (src[0] + src[1]) * level_in * .5;
double side = (src[0] - src[1]) * level_in * .5;
double oside = side * b0 + s->w1;
if (s->block_samples == 0) {
double w1 = s->w1;
double w2 = s->w2;
s->w1 = b1 * side + s->w2 + a1 * oside;
s->w2 = b2 * side + a2 * oside;
for (int n = 0; n < out->nb_samples; n++, src += 2, dst += 2) {
double mid = (src[0] + src[1]) * level_in * .5;
double side = (src[0] - src[1]) * level_in * .5;
double oside = side * b0 + w1;
if (ctx->is_disabled) {
dst[0] = src[0];
dst[1] = src[1];
} else {
dst[0] = (mid + oside) * level_out;
dst[1] = (mid - oside) * level_out;
w1 = b1 * side + w2 + a1 * oside;
w2 = b2 * side + a2 * oside;
if (ctx->is_disabled) {
dst[0] = src[0];
dst[1] = src[1];
} else {
dst[0] = (mid + oside) * level_out;
dst[1] = (mid - oside) * level_out;
}
}
s->w1 = w1;
s->w2 = w2;
} else {
double *mdst = s->mid + s->block_samples;
double *sdst = s->side[0] + s->block_samples;
double *ssrc = s->side[0];
double *msrc = s->mid;
double w1 = s->w1;
double w2 = s->w2;
for (int n = 0; n < out->nb_samples; n++, src += 2) {
mdst[n] = (src[0] + src[1]) * level_in * .5;
sdst[n] = (src[0] - src[1]) * level_in * .5;
}
sdst = s->side[1];
filter_samples(sdst, ssrc, s->block_samples,
b0, b1, b2, a1, a2,
&w1, &w2);
s->w1 = w1;
s->w2 = w2;
ssrc = s->side[0] + s->block_samples;
sdst = s->side[1] + s->block_samples;
filter_samples(sdst, ssrc, s->block_samples,
b0, b1, b2, a1, a2,
&w1, &w2);
reverse_samples(s->side[2], s->side[1], s->block_samples * 2);
w1 = w2 = 0.;
filter_samples(s->side[2], s->side[2], s->block_samples * 2,
b0, b1, b2, a1, a2,
&w1, &w2);
reverse_samples(s->side[1], s->side[2] + s->block_samples, s->block_samples);
src = (const double *)in->data[0];
ssrc = s->side[1];
for (int n = 0; n < out->nb_samples; n++, src += 2, dst += 2) {
if (ctx->is_disabled) {
dst[0] = src[0];
dst[1] = src[1];
} else {
dst[0] = (msrc[n] + ssrc[n]) * level_out;
dst[1] = (msrc[n] - ssrc[n]) * level_out;
}
}
memmove(s->mid, s->mid + s->block_samples,
s->block_samples * sizeof(*s->mid));
memmove(s->side[0], s->side[0] + s->block_samples,
s->block_samples * sizeof(*s->side[0]));
}
if (out != in)
@@ -131,6 +234,37 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
return ff_filter_frame(outlink, out);
}
static int activate(AVFilterContext *ctx)
{
AVFilterLink *inlink = ctx->inputs[0];
AVFilterLink *outlink = ctx->outputs[0];
CrossfeedContext *s = ctx->priv;
AVFrame *in = NULL;
int ret;
FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
if (s->block_samples > 0) {
ret = ff_inlink_consume_samples(inlink, s->block_samples, s->block_samples, &in);
} else {
ret = ff_inlink_consume_frame(inlink, &in);
}
if (ret < 0)
return ret;
if (ret > 0)
return filter_frame(inlink, in);
if (s->block_samples > 0 && ff_inlink_queued_samples(inlink) >= s->block_samples) {
ff_filter_set_ready(ctx, 10);
return 0;
}
FF_FILTER_FORWARD_STATUS(inlink, outlink);
FF_FILTER_FORWARD_WANTED(outlink, inlink);
return FFERROR_NOT_READY;
}
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
char *res, int res_len, int flags)
{
@@ -143,8 +277,18 @@ static int process_command(AVFilterContext *ctx, const char *cmd, const char *ar
return config_input(ctx->inputs[0]);
}
static av_cold void uninit(AVFilterContext *ctx)
{
CrossfeedContext *s = ctx->priv;
av_freep(&s->mid);
for (int i = 0; i < 3; i++)
av_freep(&s->side[i]);
}
#define OFFSET(x) offsetof(CrossfeedContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
#define AF AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption crossfeed_options[] = {
{ "strength", "set crossfeed strength", OFFSET(strength), AV_OPT_TYPE_DOUBLE, {.dbl=.2}, 0, 1, FLAGS },
@@ -152,6 +296,7 @@ static const AVOption crossfeed_options[] = {
{ "slope", "set curve slope", OFFSET(slope), AV_OPT_TYPE_DOUBLE, {.dbl=.5}, .01, 1, FLAGS },
{ "level_in", "set level in", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=.9}, 0, 1, FLAGS },
{ "level_out", "set level out", OFFSET(level_out), AV_OPT_TYPE_DOUBLE, {.dbl=1.}, 0, 1, FLAGS },
{ "block_size", "set the block size", OFFSET(block_size),AV_OPT_TYPE_INT, {.i64=0}, 0, 32768, AF },
{ NULL }
};
@@ -161,7 +306,6 @@ static const AVFilterPad inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_frame = filter_frame,
.config_props = config_input,
},
};
@@ -178,6 +322,8 @@ const AVFilter ff_af_crossfeed = {
.description = NULL_IF_CONFIG_SMALL("Apply headphone crossfeed filter."),
.priv_size = sizeof(CrossfeedContext),
.priv_class = &crossfeed_class,
.activate = activate,
.uninit = uninit,
FILTER_INPUTS(inputs),
FILTER_OUTPUTS(outputs),
FILTER_QUERY_FUNC(query_formats),