From 6c65de3db06c5379f2ca9173175bfb5f1553518b Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Sun, 7 Jan 2018 09:43:50 +0100 Subject: avfilter/af_aiir: add support for alternative coefficients format Support for zeros/poles syntax on Z-plane. Signed-off-by: Paul B Mahol --- libavfilter/af_aiir.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 147 insertions(+), 6 deletions(-) (limited to 'libavfilter/af_aiir.c') diff --git a/libavfilter/af_aiir.c b/libavfilter/af_aiir.c index e14e464211..62ad7ebfa1 100644 --- a/libavfilter/af_aiir.c +++ b/libavfilter/af_aiir.c @@ -18,6 +18,8 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include + #include "libavutil/avassert.h" #include "libavutil/avstring.h" #include "libavutil/opt.h" @@ -29,6 +31,7 @@ typedef struct AudioIIRContext { const AVClass *class; char *a_str, *b_str; double dry_gain, wet_gain; + int format; int *nb_a, *nb_b; double **a, **b; @@ -137,7 +140,7 @@ static void count_coefficients(char *item_str, int *nb_items) } } -static int read_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, double *dst) +static int read_tf_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, double *dst) { char *p, *arg, *old_str, *saveptr = NULL; int i; @@ -161,8 +164,40 @@ static int read_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, return 0; } -static int read_channels(AVFilterContext *ctx, int channels, uint8_t *item_str, int *nb, double **c, double **cache) +static int read_zp_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, double *dst, int is_zeros) { + char *p, *arg, *old_str, *saveptr = NULL; + int i; + + p = old_str = av_strdup(item_str); + if (!p) + return AVERROR(ENOMEM); + for (i = 0; i < nb_items; i++) { + if (!(arg = av_strtok(p, " ", &saveptr))) + break; + + p = NULL; + if (i == 0 && is_zeros) { + if (sscanf(arg, "%lf", &dst[i]) != 1) { + av_log(ctx, AV_LOG_ERROR, "Invalid gain supplied: %s\n", arg); + return AVERROR(EINVAL); + } + } else { + if (sscanf(arg, "%lf %lfi", &dst[i*2], &dst[i*2+1]) != 2) { + av_log(ctx, AV_LOG_ERROR, "Invalid coefficients supplied: %s\n", arg); + return AVERROR(EINVAL); + } + } + } + + av_freep(&old_str); + + return 0; +} + +static int read_channels(AVFilterContext *ctx, int channels, uint8_t *item_str, int *nb, double **c, double **cache, int is_zeros) +{ + AudioIIRContext *s = ctx->priv; char *p, *arg, *old_str, *prev_arg = NULL, *saveptr = NULL; int i, ret; @@ -180,11 +215,17 @@ static int read_channels(AVFilterContext *ctx, int channels, uint8_t *item_str, p = NULL; cache[i] = av_calloc(nb[i] + 1, sizeof(double)); - c[i] = av_calloc(nb[i], sizeof(double)); + c[i] = av_calloc(nb[i] * (s->format + 1), sizeof(double)); if (!c[i] || !cache[i]) return AVERROR(ENOMEM); - ret = read_coefficients(ctx, arg, nb[i], c[i]); + if (s->format) { + ret = read_zp_coefficients(ctx, arg, nb[i], c[i], is_zeros); + if (is_zeros) + nb[i]--; + } else { + ret = read_tf_coefficients(ctx, arg, nb[i], c[i]); + } if (ret < 0) return ret; prev_arg = arg; @@ -195,6 +236,97 @@ static int read_channels(AVFilterContext *ctx, int channels, uint8_t *item_str, return 0; } +static void multiply(double wre, double wim, int npz, double *coeffs) +{ + double nwre = -wre, nwim = -wim; + double cre, cim; + int i; + + for (i = npz; i >= 1; i--) { + cre = coeffs[2 * i + 0]; + cim = coeffs[2 * i + 1]; + + coeffs[2 * i + 0] = (nwre * cre - nwim * cim) + coeffs[2 * (i - 1) + 0]; + coeffs[2 * i + 1] = (nwre * cim + nwim * cre) + coeffs[2 * (i - 1) + 1]; + } + + cre = coeffs[0]; + cim = coeffs[1]; + coeffs[0] = nwre * cre - nwim * cim; + coeffs[1] = nwre * cim + nwim * cre; +} + +static int expand(AVFilterContext *ctx, double *pz, int nb, double *coeffs) +{ + int i; + + coeffs[0] = 1.0; + coeffs[1] = 0.0; + + for (i = 0; i < nb; i++) { + coeffs[2 * (i + 1) ] = 0.0; + coeffs[2 * (i + 1) + 1] = 0.0; + } + + for (i = 0; i < nb; i++) + multiply(pz[2 * i], pz[2 * i + 1], nb, coeffs); + + for (i = 0; i < nb + 1; i++) { + if (fabs(coeffs[2 * i + 1]) > DBL_EPSILON) { + av_log(ctx, AV_LOG_ERROR, "coeff: %lf of z^%d is not real; poles/zeros are not complex conjugates.\n", + coeffs[2 * i + i], i); + return AVERROR(EINVAL); + } + } + + return 0; +} + +static int convert_zp2tf(AVFilterContext *ctx, int channels) +{ + AudioIIRContext *s = ctx->priv; + int ch, i, j, ret; + + for (ch = 0; ch < channels; ch++) { + double *topc, *botc, gain; + + topc = av_calloc((s->nb_b[ch] + 1) * 2, sizeof(*topc)); + botc = av_calloc((s->nb_a[ch] + 1) * 2, sizeof(*botc)); + if (!topc || !botc) + return AVERROR(ENOMEM); + + ret = expand(ctx, s->a[ch], s->nb_a[ch], botc); + if (ret < 0) { + av_free(topc); + av_free(botc); + return ret; + } + + ret = expand(ctx, &s->b[ch][2], s->nb_b[ch], topc); + if (ret < 0) { + av_free(topc); + av_free(botc); + return ret; + } + + gain = s->b[ch][0]; + for (j = 0, i = s->nb_b[ch]; i >= 0; j++, i--) { + s->b[ch][j] = topc[2 * i] * gain; + } + s->nb_b[ch]++; + + for (j = 0, i = s->nb_a[ch]; i >= 0; j++, i--) { + s->a[ch][j] = botc[2 * i]; + } + s->nb_a[ch]++; + + av_free(topc); + av_free(botc); + } + + return 0; +} + static int config_output(AVFilterLink *outlink) { AVFilterContext *ctx = outlink->src; @@ -212,14 +344,20 @@ static int config_output(AVFilterLink *outlink) if (!s->a || !s->b || !s->nb_a || !s->nb_b || !s->input || !s->output) return AVERROR(ENOMEM); - ret = read_channels(ctx, inlink->channels, s->a_str, s->nb_a, s->a, s->output); + ret = read_channels(ctx, inlink->channels, s->a_str, s->nb_a, s->a, s->output, 0); if (ret < 0) return ret; - ret = read_channels(ctx, inlink->channels, s->b_str, s->nb_b, s->b, s->input); + ret = read_channels(ctx, inlink->channels, s->b_str, s->nb_b, s->b, s->input, 1); if (ret < 0) return ret; + if (s->format) { + ret = convert_zp2tf(ctx, inlink->channels); + if (ret < 0) + return ret; + } + for (ch = 0; ch < inlink->channels; ch++) { for (i = 1; i < s->nb_a[ch]; i++) { s->a[ch][i] /= s->a[ch][0]; @@ -336,6 +474,9 @@ static const AVOption aiir_options[] = { { "b", "set B/numerator/zeros coefficients", OFFSET(b_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 }, + { "f", "set coefficients format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AF, "format" }, + { "tf", "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" }, { NULL }, }; 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