[FFmpeg-cvslog] avfilter/af_aiir: add support for arbitrary order lattice-ladder filter format
Paul B Mahol
git at videolan.org
Sun Nov 22 23:59:22 EET 2020
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Nov 22 21:57:39 2020 +0100| [9208b72a385ccd813c886a7115cd734eea4adba5] | committer: Paul B Mahol
avfilter/af_aiir: add support for arbitrary order lattice-ladder filter format
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9208b72a385ccd813c886a7115cd734eea4adba5
---
doc/filters.texi | 6 ++--
libavfilter/af_aiir.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 89 insertions(+), 8 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 2d2754c1c1..15acae9709 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1436,10 +1436,10 @@ It accepts the following parameters:
@table @option
@item zeros, z
-Set numerator/zeros coefficients.
+Set B/numerator/zeros/reflection coefficients.
@item poles, p
-Set denominator/poles coefficients.
+Set A/denominator/poles/ladder coefficients.
@item gains, k
Set channels gains.
@@ -1454,6 +1454,8 @@ Set output gain.
Set coefficients format.
@table @samp
+ at item ll
+lattice-ladder function
@item sf
analog transfer function
@item tf
diff --git a/libavfilter/af_aiir.c b/libavfilter/af_aiir.c
index 2e811cff35..59d2232ac9 100644
--- a/libavfilter/af_aiir.c
+++ b/libavfilter/af_aiir.c
@@ -299,6 +299,63 @@ PARALLEL_IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
PARALLEL_IIR_CH(fltp, float, -1., 1., 0)
PARALLEL_IIR_CH(dblp, double, -1., 1., 0)
+#define LATTICE_IIR_CH(name, type, min, max, need_clipping) \
+static int iir_ch_lattice_## name(AVFilterContext *ctx, void *arg, \
+ int ch, int nb_jobs) \
+{ \
+ AudioIIRContext *s = ctx->priv; \
+ const double ig = s->dry_gain; \
+ const double og = s->wet_gain; \
+ const double mix = s->mix; \
+ ThreadData *td = arg; \
+ AVFrame *in = td->in, *out = td->out; \
+ const type *src = (const type *)in->extended_data[ch]; \
+ double n0, n1, p0, *x = (double *)s->iir[ch].cache[0]; \
+ const int nb_stages = s->iir[ch].nb_ab[1]; \
+ const double *v = s->iir[ch].ab[0]; \
+ const double *k = s->iir[ch].ab[1]; \
+ const double g = s->iir[ch].g; \
+ int *clippings = &s->iir[ch].clippings; \
+ type *dst = (type *)out->extended_data[ch]; \
+ int n; \
+ \
+ for (n = 0; n < in->nb_samples; n++) { \
+ const double in = src[n] * ig; \
+ double out = 0.; \
+ \
+ n1 = in; \
+ for (int i = nb_stages - 1; i >= 0; i--) { \
+ n0 = n1 - k[i] * x[i]; \
+ p0 = n0 * k[i] + x[i]; \
+ out += p0 * v[i+1]; \
+ x[i] = p0; \
+ n1 = n0; \
+ } \
+ \
+ out += n1 * v[0]; \
+ memmove(&x[1], &x[0], nb_stages * sizeof(*x)); \
+ x[0] = n1; \
+ out *= og * g; \
+ out = out * mix + in * (1. - mix); \
+ if (need_clipping && out < min) { \
+ (*clippings)++; \
+ dst[n] = min; \
+ } else if (need_clipping && out > max) { \
+ (*clippings)++; \
+ dst[n] = max; \
+ } else { \
+ dst[n] = out; \
+ } \
+ } \
+ \
+ return 0; \
+}
+
+LATTICE_IIR_CH(s16p, int16_t, INT16_MIN, INT16_MAX, 1)
+LATTICE_IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
+LATTICE_IIR_CH(fltp, float, -1., 1., 0)
+LATTICE_IIR_CH(dblp, double, -1., 1., 0)
+
static void count_coefficients(char *item_str, int *nb_items)
{
char *p;
@@ -1266,6 +1323,9 @@ static int config_output(AVFilterLink *outlink)
ret = convert_zp2tf(ctx, inlink->channels);
if (ret < 0)
return ret;
+ } else if (s->format == -2 && s->process > 0) {
+ av_log(ctx, AV_LOG_ERROR, "Only direct processing is implemented for lattice-ladder function.\n");
+ return AVERROR_PATCHWELCOME;
} else if (s->format <= 0 && s->process == 1) {
av_log(ctx, AV_LOG_ERROR, "Serial processing is not implemented for transfer function.\n");
return AVERROR_PATCHWELCOME;
@@ -1287,6 +1347,15 @@ static int config_output(AVFilterLink *outlink)
return ret;
}
+ for (ch = 0; s->format == -2 && ch < inlink->channels; ch++) {
+ IIRChannel *iir = &s->iir[ch];
+
+ if (iir->nb_ab[0] != iir->nb_ab[1] + 1) {
+ av_log(ctx, AV_LOG_ERROR, "Number of ladder coefficients must be one more than number of reflection coefficients.\n");
+ return AVERROR(EINVAL);
+ }
+ }
+
for (ch = 0; s->format == 0 && ch < inlink->channels; ch++) {
IIRChannel *iir = &s->iir[ch];
@@ -1309,6 +1378,15 @@ static int config_output(AVFilterLink *outlink)
case AV_SAMPLE_FMT_S16P: s->iir_channel = s->process == 2 ? iir_ch_parallel_s16p : s->process == 1 ? iir_ch_serial_s16p : iir_ch_s16p; break;
}
+ if (s->format == -2) {
+ switch (inlink->format) {
+ case AV_SAMPLE_FMT_DBLP: s->iir_channel = iir_ch_lattice_dblp; break;
+ case AV_SAMPLE_FMT_FLTP: s->iir_channel = iir_ch_lattice_fltp; break;
+ case AV_SAMPLE_FMT_S32P: s->iir_channel = iir_ch_lattice_s32p; break;
+ case AV_SAMPLE_FMT_S16P: s->iir_channel = iir_ch_lattice_s16p; break;
+ }
+ }
+
return 0;
}
@@ -1459,16 +1537,17 @@ static const AVFilterPad inputs[] = {
#define VF AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption aiir_options[] = {
- { "zeros", "set B/numerator/zeros coefficients", OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
- { "z", "set B/numerator/zeros coefficients", OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
- { "poles", "set A/denominator/poles coefficients", OFFSET(a_str),AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
- { "p", "set A/denominator/poles coefficients", OFFSET(a_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
+ { "zeros", "set B/numerator/zeros/reflection coefficients", OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
+ { "z", "set B/numerator/zeros/reflection coefficients", OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
+ { "poles", "set A/denominator/poles/ladder coefficients", OFFSET(a_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
+ { "p", "set A/denominator/poles/ladder coefficients", OFFSET(a_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
{ "gains", "set channels gains", OFFSET(g_str), AV_OPT_TYPE_STRING, {.str="1|1"}, 0, 0, AF },
{ "k", "set channels gains", OFFSET(g_str), AV_OPT_TYPE_STRING, {.str="1|1"}, 0, 0, AF },
{ "dry", "set dry gain", OFFSET(dry_gain), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, AF },
{ "wet", "set wet gain", OFFSET(wet_gain), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, AF },
- { "format", "set coefficients format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=1}, -1, 4, AF, "format" },
- { "f", "set coefficients format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=1}, -1, 4, AF, "format" },
+ { "format", "set coefficients format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=1}, -2, 4, AF, "format" },
+ { "f", "set coefficients format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=1}, -2, 4, AF, "format" },
+ { "ll", "lattice-ladder function", 0, AV_OPT_TYPE_CONST, {.i64=-2}, 0, 0, AF, "format" },
{ "sf", "analog transfer function", 0, AV_OPT_TYPE_CONST, {.i64=-1}, 0, 0, AF, "format" },
{ "tf", "digital transfer function", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, AF, "format" },
{ "zp", "Z-plane zeros/poles", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AF, "format" },
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