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-rw-r--r--libavfilter/af_surround.c1264
1 files changed, 1264 insertions, 0 deletions
diff --git a/libavfilter/af_surround.c b/libavfilter/af_surround.c
new file mode 100644
index 0000000000..c7122379d6
--- /dev/null
+++ b/libavfilter/af_surround.c
@@ -0,0 +1,1264 @@
+/*
+ * Copyright (c) 2017 Paul B Mahol
+ *
+ * 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
+ */
+
+#include "libavutil/audio_fifo.h"
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
+#include "libavcodec/avfft.h"
+#include "avfilter.h"
+#include "audio.h"
+#include "formats.h"
+
+typedef struct AudioSurroundContext {
+ const AVClass *class;
+
+ char *out_channel_layout_str;
+ char *in_channel_layout_str;
+
+ float level_in;
+ float level_out;
+ float fc_in;
+ float fc_out;
+ float lfe_in;
+ float lfe_out;
+
+ float *input_levels;
+ float *output_levels;
+ int output_lfe;
+ int lowcutf;
+ int highcutf;
+
+ float lowcut;
+ float highcut;
+
+ uint64_t out_channel_layout;
+ uint64_t in_channel_layout;
+ int nb_in_channels;
+ int nb_out_channels;
+
+ AVFrame *input;
+ AVFrame *output;
+ AVFrame *overlap_buffer;
+
+ int buf_size;
+ int hop_size;
+ AVAudioFifo *fifo;
+ RDFTContext **rdft, **irdft;
+ float *window_func_lut;
+
+ int64_t pts;
+
+ void (*filter)(AVFilterContext *ctx);
+ void (*upmix_stereo)(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n);
+ void (*upmix_2_1)(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float lfe_im,
+ float lfe_re,
+ float x, float y,
+ int n);
+ void (*upmix_3_0)(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_mag,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n);
+ void (*upmix_5_1)(AVFilterContext *ctx,
+ float c_re, float c_im,
+ float lfe_re, float lfe_im,
+ float mag_totall, float mag_totalr,
+ float fl_phase, float fr_phase,
+ float bl_phase, float br_phase,
+ float sl_phase, float sr_phase,
+ float xl, float yl,
+ float xr, float yr,
+ int n);
+} AudioSurroundContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ AVFilterFormats *formats = NULL;
+ AVFilterChannelLayouts *layouts = NULL;
+ int ret;
+
+ ret = ff_add_format(&formats, AV_SAMPLE_FMT_FLTP);
+ if (ret)
+ return ret;
+ ret = ff_set_common_formats(ctx, formats);
+ if (ret)
+ return ret;
+
+ layouts = NULL;
+ ret = ff_add_channel_layout(&layouts, s->out_channel_layout);
+ if (ret)
+ return ret;
+
+ ret = ff_channel_layouts_ref(layouts, &ctx->outputs[0]->in_channel_layouts);
+ if (ret)
+ return ret;
+
+ layouts = NULL;
+ ret = ff_add_channel_layout(&layouts, s->in_channel_layout);
+ if (ret)
+ return ret;
+
+ ret = ff_channel_layouts_ref(layouts, &ctx->inputs[0]->out_channel_layouts);
+ if (ret)
+ return ret;
+
+ formats = ff_all_samplerates();
+ if (!formats)
+ return AVERROR(ENOMEM);
+ return ff_set_common_samplerates(ctx, formats);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AudioSurroundContext *s = ctx->priv;
+ int ch;
+
+ s->rdft = av_calloc(inlink->channels, sizeof(*s->rdft));
+ if (!s->rdft)
+ return AVERROR(ENOMEM);
+
+ for (ch = 0; ch < inlink->channels; ch++) {
+ s->rdft[ch] = av_rdft_init(ff_log2(s->buf_size), DFT_R2C);
+ if (!s->rdft[ch])
+ return AVERROR(ENOMEM);
+ }
+ s->nb_in_channels = inlink->channels;
+ s->input_levels = av_malloc_array(s->nb_in_channels, sizeof(*s->input_levels));
+ if (!s->input_levels)
+ return AVERROR(ENOMEM);
+ for (ch = 0; ch < s->nb_in_channels; ch++)
+ s->input_levels[ch] = s->level_in;
+ ch = av_get_channel_layout_channel_index(inlink->channel_layout, AV_CH_FRONT_CENTER);
+ if (ch >= 0)
+ s->input_levels[ch] *= s->fc_in;
+ ch = av_get_channel_layout_channel_index(inlink->channel_layout, AV_CH_LOW_FREQUENCY);
+ if (ch >= 0)
+ s->input_levels[ch] *= s->lfe_in;
+
+ s->input = ff_get_audio_buffer(inlink, s->buf_size * 2);
+ if (!s->input)
+ return AVERROR(ENOMEM);
+
+ s->fifo = av_audio_fifo_alloc(inlink->format, inlink->channels, s->buf_size);
+ if (!s->fifo)
+ return AVERROR(ENOMEM);
+
+ s->lowcut = 1.f * s->lowcutf / (inlink->sample_rate * 0.5) * (s->buf_size / 2);
+ s->highcut = 1.f * s->highcutf / (inlink->sample_rate * 0.5) * (s->buf_size / 2);
+
+ return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AudioSurroundContext *s = ctx->priv;
+ int ch;
+
+ s->irdft = av_calloc(outlink->channels, sizeof(*s->irdft));
+ if (!s->irdft)
+ return AVERROR(ENOMEM);
+
+ for (ch = 0; ch < outlink->channels; ch++) {
+ s->irdft[ch] = av_rdft_init(ff_log2(s->buf_size), IDFT_C2R);
+ if (!s->irdft[ch])
+ return AVERROR(ENOMEM);
+ }
+ s->nb_out_channels = outlink->channels;
+ s->output_levels = av_malloc_array(s->nb_out_channels, sizeof(*s->output_levels));
+ if (!s->output_levels)
+ return AVERROR(ENOMEM);
+ for (ch = 0; ch < s->nb_out_channels; ch++)
+ s->output_levels[ch] = s->level_out;
+ ch = av_get_channel_layout_channel_index(outlink->channel_layout, AV_CH_FRONT_CENTER);
+ if (ch >= 0)
+ s->output_levels[ch] *= s->fc_out;
+ ch = av_get_channel_layout_channel_index(outlink->channel_layout, AV_CH_LOW_FREQUENCY);
+ if (ch >= 0)
+ s->output_levels[ch] *= s->lfe_out;
+
+ s->output = ff_get_audio_buffer(outlink, s->buf_size * 2);
+ s->overlap_buffer = ff_get_audio_buffer(outlink, s->buf_size * 2);
+ if (!s->overlap_buffer || !s->output)
+ return AVERROR(ENOMEM);
+
+ return 0;
+}
+
+static void stereo_position(float a, float p, float *x, float *y)
+{
+ *x = av_clipf(a+FFMAX(0, sinf(p-M_PI_2))*FFDIFFSIGN(a,0), -1, 1);
+ *y = av_clipf(cosf(a*M_PI_2+M_PI)*cosf(M_PI_2-p/M_PI)*M_LN10+1, -1, 1);
+}
+
+static inline void get_lfe(int output_lfe, int n, float lowcut, float highcut,
+ float *lfe_mag, float *mag_total)
+{
+ if (output_lfe && n < highcut) {
+ *lfe_mag = n < lowcut ? 1.f : .5f*(1.f+cosf(M_PI*(lowcut-n)/(lowcut-highcut)));
+ *lfe_mag *= *mag_total;
+ *mag_total -= *lfe_mag;
+ } else {
+ *lfe_mag = 0.f;
+ }
+}
+
+static void upmix_1_0(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float mag, *dst;
+
+ dst = (float *)s->output->extended_data[0];
+
+ mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+
+ dst[2 * n ] = mag * cosf(c_phase);
+ dst[2 * n + 1] = mag * sinf(c_phase);
+}
+
+static void upmix_stereo(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float l_mag, r_mag, *dstl, *dstr;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+}
+
+static void upmix_2_1(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float lfe_mag, l_mag, r_mag, *dstl, *dstr, *dstlfe;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstlfe = (float *)s->output->extended_data[2];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &mag_total);
+
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+}
+
+static void upmix_3_0(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float l_mag, r_mag, c_mag, *dstc, *dstl, *dstr;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+}
+
+static void upmix_3_1(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float lfe_mag, l_mag, r_mag, c_mag, *dstc, *dstl, *dstr, *dstlfe;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &mag_total);
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+}
+
+static void upmix_3_1_surround(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float c_mag,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float lfe_mag, l_mag, r_mag, *dstc, *dstl, *dstr, *dstlfe;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &c_mag);
+
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+}
+
+static void upmix_4_0(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float b_mag, l_mag, r_mag, c_mag, *dstc, *dstl, *dstr, *dstb;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstb = (float *)s->output->extended_data[3];
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ b_mag = sqrtf(1.f - fabsf(x)) * ((1.f - y) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstb[2 * n ] = b_mag * cosf(c_phase);
+ dstb[2 * n + 1] = b_mag * sinf(c_phase);
+}
+
+static void upmix_4_1(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float lfe_mag, b_mag, l_mag, r_mag, c_mag, *dstc, *dstl, *dstr, *dstb, *dstlfe;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstb = (float *)s->output->extended_data[4];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &mag_total);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ b_mag = sqrtf(1.f - fabsf(x)) * ((1.f - y) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstb[2 * n ] = b_mag * cosf(c_phase);
+ dstb[2 * n + 1] = b_mag * sinf(c_phase);
+}
+
+static void upmix_5_0_back(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float l_mag, r_mag, ls_mag, rs_mag, c_mag, *dstc, *dstl, *dstr, *dstls, *dstrs;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstls = (float *)s->output->extended_data[3];
+ dstrs = (float *)s->output->extended_data[4];
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_5_1_back(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float lfe_mag, l_mag, r_mag, ls_mag, rs_mag, c_mag, *dstc, *dstl, *dstr, *dstls, *dstrs, *dstlfe;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstls = (float *)s->output->extended_data[4];
+ dstrs = (float *)s->output->extended_data[5];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &mag_total);
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_5_1_back_surround(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float c_mag,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float lfe_mag, l_mag, r_mag, *dstc, *dstl, *dstr, *dstlfe;
+ float ls_mag, rs_mag, *dstls, *dstrs;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstls = (float *)s->output->extended_data[4];
+ dstrs = (float *)s->output->extended_data[5];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &c_mag);
+
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_5_1_back_2_1(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float lfe_re,
+ float lfe_im,
+ float x, float y,
+ int n)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float c_mag, l_mag, r_mag, *dstc, *dstl, *dstr, *dstlfe;
+ float ls_mag, rs_mag, *dstls, *dstrs;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstls = (float *)s->output->extended_data[4];
+ dstrs = (float *)s->output->extended_data[5];
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_re;
+ dstlfe[2 * n + 1] = lfe_im;
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_7_0(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float l_mag, r_mag, ls_mag, rs_mag, c_mag, lb_mag, rb_mag;
+ float *dstc, *dstl, *dstr, *dstls, *dstrs, *dstlb, *dstrb;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlb = (float *)s->output->extended_data[3];
+ dstrb = (float *)s->output->extended_data[4];
+ dstls = (float *)s->output->extended_data[5];
+ dstrs = (float *)s->output->extended_data[6];
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ lb_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rb_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - fabsf(y)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - fabsf(y)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlb[2 * n ] = lb_mag * cosf(l_phase);
+ dstlb[2 * n + 1] = lb_mag * sinf(l_phase);
+
+ dstrb[2 * n ] = rb_mag * cosf(r_phase);
+ dstrb[2 * n + 1] = rb_mag * sinf(r_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_7_1(AVFilterContext *ctx,
+ float l_phase,
+ float r_phase,
+ float c_phase,
+ float mag_total,
+ float x, float y,
+ int n)
+{
+ float lfe_mag, l_mag, r_mag, ls_mag, rs_mag, c_mag, lb_mag, rb_mag;
+ float *dstc, *dstl, *dstr, *dstls, *dstrs, *dstlb, *dstrb, *dstlfe;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstlb = (float *)s->output->extended_data[4];
+ dstrb = (float *)s->output->extended_data[5];
+ dstls = (float *)s->output->extended_data[6];
+ dstrs = (float *)s->output->extended_data[7];
+
+ get_lfe(s->output_lfe, n, s->lowcut, s->highcut, &lfe_mag, &mag_total);
+
+ c_mag = sqrtf(1.f - fabsf(x)) * ((y + 1.f) * .5f) * mag_total;
+ l_mag = sqrtf(.5f * ( x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ r_mag = sqrtf(.5f * (-x + 1.f)) * ((y + 1.f) * .5f) * mag_total;
+ lb_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ rb_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - ((y + 1.f) * .5f)) * mag_total;
+ ls_mag = sqrtf(.5f * ( x + 1.f)) * (1.f - fabsf(y)) * mag_total;
+ rs_mag = sqrtf(.5f * (-x + 1.f)) * (1.f - fabsf(y)) * mag_total;
+
+ dstl[2 * n ] = l_mag * cosf(l_phase);
+ dstl[2 * n + 1] = l_mag * sinf(l_phase);
+
+ dstr[2 * n ] = r_mag * cosf(r_phase);
+ dstr[2 * n + 1] = r_mag * sinf(r_phase);
+
+ dstc[2 * n ] = c_mag * cosf(c_phase);
+ dstc[2 * n + 1] = c_mag * sinf(c_phase);
+
+ dstlfe[2 * n ] = lfe_mag * cosf(c_phase);
+ dstlfe[2 * n + 1] = lfe_mag * sinf(c_phase);
+
+ dstlb[2 * n ] = lb_mag * cosf(l_phase);
+ dstlb[2 * n + 1] = lb_mag * sinf(l_phase);
+
+ dstrb[2 * n ] = rb_mag * cosf(r_phase);
+ dstrb[2 * n + 1] = rb_mag * sinf(r_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(l_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(l_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(r_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(r_phase);
+}
+
+static void upmix_7_1_5_1(AVFilterContext *ctx,
+ float c_re, float c_im,
+ float lfe_re, float lfe_im,
+ float mag_totall, float mag_totalr,
+ float fl_phase, float fr_phase,
+ float bl_phase, float br_phase,
+ float sl_phase, float sr_phase,
+ float xl, float yl,
+ float xr, float yr,
+ int n)
+{
+ float fl_mag, fr_mag, ls_mag, rs_mag, lb_mag, rb_mag;
+ float *dstc, *dstl, *dstr, *dstls, *dstrs, *dstlb, *dstrb, *dstlfe;
+ AudioSurroundContext *s = ctx->priv;
+
+ dstl = (float *)s->output->extended_data[0];
+ dstr = (float *)s->output->extended_data[1];
+ dstc = (float *)s->output->extended_data[2];
+ dstlfe = (float *)s->output->extended_data[3];
+ dstlb = (float *)s->output->extended_data[4];
+ dstrb = (float *)s->output->extended_data[5];
+ dstls = (float *)s->output->extended_data[6];
+ dstrs = (float *)s->output->extended_data[7];
+
+ fl_mag = sqrtf(.5f * (xl + 1.f)) * ((yl + 1.f) * .5f) * mag_totall;
+ fr_mag = sqrtf(.5f * (xr + 1.f)) * ((yr + 1.f) * .5f) * mag_totalr;
+ lb_mag = sqrtf(.5f * (-xl + 1.f)) * ((yl + 1.f) * .5f) * mag_totall;
+ rb_mag = sqrtf(.5f * (-xr + 1.f)) * ((yr + 1.f) * .5f) * mag_totalr;
+ ls_mag = sqrtf(1.f - fabsf(xl)) * ((yl + 1.f) * .5f) * mag_totall;
+ rs_mag = sqrtf(1.f - fabsf(xr)) * ((yr + 1.f) * .5f) * mag_totalr;
+
+ dstl[2 * n ] = fl_mag * cosf(fl_phase);
+ dstl[2 * n + 1] = fl_mag * sinf(fl_phase);
+
+ dstr[2 * n ] = fr_mag * cosf(fr_phase);
+ dstr[2 * n + 1] = fr_mag * sinf(fr_phase);
+
+ dstc[2 * n ] = c_re;
+ dstc[2 * n + 1] = c_im;
+
+ dstlfe[2 * n ] = lfe_re;
+ dstlfe[2 * n + 1] = lfe_im;
+
+ dstlb[2 * n ] = lb_mag * cosf(bl_phase);
+ dstlb[2 * n + 1] = lb_mag * sinf(bl_phase);
+
+ dstrb[2 * n ] = rb_mag * cosf(br_phase);
+ dstrb[2 * n + 1] = rb_mag * sinf(br_phase);
+
+ dstls[2 * n ] = ls_mag * cosf(sl_phase);
+ dstls[2 * n + 1] = ls_mag * sinf(sl_phase);
+
+ dstrs[2 * n ] = rs_mag * cosf(sr_phase);
+ dstrs[2 * n + 1] = rs_mag * sinf(sr_phase);
+}
+
+static void filter_stereo(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float *srcl, *srcr;
+ int n;
+
+ srcl = (float *)s->input->extended_data[0];
+ srcr = (float *)s->input->extended_data[1];
+
+ for (n = 0; n < s->buf_size; n++) {
+ float l_re = srcl[2 * n], r_re = srcr[2 * n];
+ float l_im = srcl[2 * n + 1], r_im = srcr[2 * n + 1];
+ float c_phase = atan2f(l_im + r_im, l_re + r_re);
+ float l_mag = hypotf(l_re, l_im);
+ float r_mag = hypotf(r_re, r_im);
+ float l_phase = atan2f(l_im, l_re);
+ float r_phase = atan2f(r_im, r_re);
+ float phase_dif = fabsf(l_phase - r_phase);
+ float mag_dif = (l_mag - r_mag) / (l_mag + r_mag);
+ float mag_total = hypotf(l_mag, r_mag);
+ float x, y;
+
+ if (phase_dif > M_PI)
+ phase_dif = 2 * M_PI - phase_dif;
+
+ stereo_position(mag_dif, phase_dif, &x, &y);
+
+ s->upmix_stereo(ctx, l_phase, r_phase, c_phase, mag_total, x, y, n);
+ }
+}
+
+static void filter_surround(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float *srcl, *srcr, *srcc;
+ int n;
+
+ srcl = (float *)s->input->extended_data[0];
+ srcr = (float *)s->input->extended_data[1];
+ srcc = (float *)s->input->extended_data[2];
+
+ for (n = 0; n < s->buf_size; n++) {
+ float l_re = srcl[2 * n], r_re = srcr[2 * n];
+ float l_im = srcl[2 * n + 1], r_im = srcr[2 * n + 1];
+ float c_re = srcc[2 * n], c_im = srcc[2 * n + 1];
+ float c_mag = hypotf(c_re, c_im);
+ float c_phase = atan2f(c_im, c_re);
+ float l_mag = hypotf(l_re, l_im);
+ float r_mag = hypotf(r_re, r_im);
+ float l_phase = atan2f(l_im, l_re);
+ float r_phase = atan2f(r_im, r_re);
+ float phase_dif = fabsf(l_phase - r_phase);
+ float mag_dif = (l_mag - r_mag) / (l_mag + r_mag);
+ float mag_total = hypotf(l_mag, r_mag);
+ float x, y;
+
+ if (phase_dif > M_PI)
+ phase_dif = 2 * M_PI - phase_dif;
+
+ stereo_position(mag_dif, phase_dif, &x, &y);
+
+ s->upmix_3_0(ctx, l_phase, r_phase, c_phase, c_mag, mag_total, x, y, n);
+ }
+}
+
+static void filter_2_1(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float *srcl, *srcr, *srclfe;
+ int n;
+
+ srcl = (float *)s->input->extended_data[0];
+ srcr = (float *)s->input->extended_data[1];
+ srclfe = (float *)s->input->extended_data[2];
+
+ for (n = 0; n < s->buf_size; n++) {
+ float l_re = srcl[2 * n], r_re = srcr[2 * n];
+ float l_im = srcl[2 * n + 1], r_im = srcr[2 * n + 1];
+ float lfe_re = srclfe[2 * n], lfe_im = srclfe[2 * n + 1];
+ float c_phase = atan2f(l_im + r_im, l_re + r_re);
+ float l_mag = hypotf(l_re, l_im);
+ float r_mag = hypotf(r_re, r_im);
+ float l_phase = atan2f(l_im, l_re);
+ float r_phase = atan2f(r_im, r_re);
+ float phase_dif = fabsf(l_phase - r_phase);
+ float mag_dif = (l_mag - r_mag) / (l_mag + r_mag);
+ float mag_total = hypotf(l_mag, r_mag);
+ float x, y;
+
+ if (phase_dif > M_PI)
+ phase_dif = 2 * M_PI - phase_dif;
+
+ stereo_position(mag_dif, phase_dif, &x, &y);
+
+ s->upmix_2_1(ctx, l_phase, r_phase, c_phase, mag_total, lfe_re, lfe_im, x, y, n);
+ }
+}
+
+static void filter_5_1_back(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float *srcl, *srcr, *srcc, *srclfe, *srcbl, *srcbr;
+ int n;
+
+ srcl = (float *)s->input->extended_data[0];
+ srcr = (float *)s->input->extended_data[1];
+ srcc = (float *)s->input->extended_data[2];
+ srclfe = (float *)s->input->extended_data[3];
+ srcbl = (float *)s->input->extended_data[4];
+ srcbr = (float *)s->input->extended_data[5];
+
+ for (n = 0; n < s->buf_size; n++) {
+ float fl_re = srcl[2 * n], fr_re = srcr[2 * n];
+ float fl_im = srcl[2 * n + 1], fr_im = srcr[2 * n + 1];
+ float c_re = srcc[2 * n], c_im = srcc[2 * n + 1];
+ float lfe_re = srclfe[2 * n], lfe_im = srclfe[2 * n + 1];
+ float bl_re = srcbl[2 * n], bl_im = srcbl[2 * n + 1];
+ float br_re = srcbr[2 * n], br_im = srcbr[2 * n + 1];
+ float fl_mag = hypotf(fl_re, fl_im);
+ float fr_mag = hypotf(fr_re, fr_im);
+ float fl_phase = atan2f(fl_im, fl_re);
+ float fr_phase = atan2f(fr_im, fr_re);
+ float bl_mag = hypotf(bl_re, bl_im);
+ float br_mag = hypotf(br_re, br_im);
+ float bl_phase = atan2f(bl_im, bl_re);
+ float br_phase = atan2f(br_im, br_re);
+ float phase_difl = fabsf(fl_phase - bl_phase);
+ float phase_difr = fabsf(fr_phase - br_phase);
+ float mag_difl = (fl_mag - bl_mag) / (fl_mag + bl_mag);
+ float mag_difr = (fr_mag - br_mag) / (fr_mag + br_mag);
+ float mag_totall = hypotf(fl_mag, bl_mag);
+ float mag_totalr = hypotf(fr_mag, br_mag);
+ float sl_phase = atan2f(fl_im + bl_im, fl_re + bl_re);
+ float sr_phase = atan2f(fr_im + br_im, fr_re + br_re);
+ float xl, yl;
+ float xr, yr;
+
+ if (phase_difl > M_PI)
+ phase_difl = 2 * M_PI - phase_difl;
+
+ if (phase_difr > M_PI)
+ phase_difr = 2 * M_PI - phase_difr;
+
+ stereo_position(mag_difl, phase_difl, &xl, &yl);
+ stereo_position(mag_difr, phase_difr, &xr, &yr);
+
+ s->upmix_5_1(ctx, c_re, c_im, lfe_re, lfe_im,
+ mag_totall, mag_totalr,
+ fl_phase, fr_phase,
+ bl_phase, br_phase,
+ sl_phase, sr_phase,
+ xl, yl, xr, yr, n);
+ }
+}
+
+static int init(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ float overlap;
+ int i;
+
+ if (!(s->out_channel_layout = av_get_channel_layout(s->out_channel_layout_str))) {
+ av_log(ctx, AV_LOG_ERROR, "Error parsing output channel layout '%s'.\n",
+ s->out_channel_layout_str);
+ return AVERROR(EINVAL);
+ }
+
+ if (!(s->in_channel_layout = av_get_channel_layout(s->in_channel_layout_str))) {
+ av_log(ctx, AV_LOG_ERROR, "Error parsing input channel layout '%s'.\n",
+ s->in_channel_layout_str);
+ return AVERROR(EINVAL);
+ }
+
+ if (s->lowcutf >= s->highcutf) {
+ av_log(ctx, AV_LOG_ERROR, "Low cut-off '%d' should be less than high cut-off '%d'.\n",
+ s->lowcutf, s->highcutf);
+ return AVERROR(EINVAL);
+ }
+
+ switch (s->in_channel_layout) {
+ case AV_CH_LAYOUT_STEREO:
+ s->filter = filter_stereo;
+ switch (s->out_channel_layout) {
+ case AV_CH_LAYOUT_MONO:
+ s->upmix_stereo = upmix_1_0;
+ break;
+ case AV_CH_LAYOUT_STEREO:
+ s->upmix_stereo = upmix_stereo;
+ break;
+ case AV_CH_LAYOUT_2POINT1:
+ s->upmix_stereo = upmix_2_1;
+ break;
+ case AV_CH_LAYOUT_SURROUND:
+ s->upmix_stereo = upmix_3_0;
+ break;
+ case AV_CH_LAYOUT_3POINT1:
+ s->upmix_stereo = upmix_3_1;
+ break;
+ case AV_CH_LAYOUT_4POINT0:
+ s->upmix_stereo = upmix_4_0;
+ break;
+ case AV_CH_LAYOUT_4POINT1:
+ s->upmix_stereo = upmix_4_1;
+ break;
+ case AV_CH_LAYOUT_5POINT0_BACK:
+ s->upmix_stereo = upmix_5_0_back;
+ break;
+ case AV_CH_LAYOUT_5POINT1_BACK:
+ s->upmix_stereo = upmix_5_1_back;
+ break;
+ case AV_CH_LAYOUT_7POINT0:
+ s->upmix_stereo = upmix_7_0;
+ break;
+ case AV_CH_LAYOUT_7POINT1:
+ s->upmix_stereo = upmix_7_1;
+ break;
+ default:
+ goto fail;
+ }
+ break;
+ case AV_CH_LAYOUT_2POINT1:
+ s->filter = filter_2_1;
+ switch (s->out_channel_layout) {
+ case AV_CH_LAYOUT_5POINT1_BACK:
+ s->upmix_2_1 = upmix_5_1_back_2_1;
+ break;
+ default:
+ goto fail;
+ }
+ break;
+ case AV_CH_LAYOUT_SURROUND:
+ s->filter = filter_surround;
+ switch (s->out_channel_layout) {
+ case AV_CH_LAYOUT_3POINT1:
+ s->upmix_3_0 = upmix_3_1_surround;
+ break;
+ case AV_CH_LAYOUT_5POINT1_BACK:
+ s->upmix_3_0 = upmix_5_1_back_surround;
+ break;
+ default:
+ goto fail;
+ }
+ break;
+ case AV_CH_LAYOUT_5POINT1_BACK:
+ s->filter = filter_5_1_back;
+ switch (s->out_channel_layout) {
+ case AV_CH_LAYOUT_7POINT1:
+ s->upmix_5_1 = upmix_7_1_5_1;
+ break;
+ default:
+ goto fail;
+ }
+ break;
+ default:
+fail:
+ av_log(ctx, AV_LOG_ERROR, "Unsupported upmix: '%s' -> '%s'.\n",
+ s->in_channel_layout_str, s->out_channel_layout_str);
+ return AVERROR(EINVAL);
+ }
+
+ s->buf_size = 4096;
+ s->pts = AV_NOPTS_VALUE;
+
+ s->window_func_lut = av_calloc(s->buf_size, sizeof(*s->window_func_lut));
+ if (!s->window_func_lut)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < s->buf_size; i++)
+ s->window_func_lut[i] = sqrtf(0.5 * (1 - cosf(2 * M_PI * i / s->buf_size)) / s->buf_size);
+ overlap = .5;
+ s->hop_size = s->buf_size * (1. - overlap);
+
+ return 0;
+}
+
+static int fft_channel(AVFilterContext *ctx, void *arg, int ch, int nb_jobs)
+{
+ AudioSurroundContext *s = ctx->priv;
+ const float level_in = s->input_levels[ch];
+ float *dst;
+ int n;
+
+ memset(s->input->extended_data[ch] + s->buf_size * sizeof(float), 0, s->buf_size * sizeof(float));
+
+ dst = (float *)s->input->extended_data[ch];
+ for (n = 0; n < s->buf_size; n++) {
+ dst[n] *= s->window_func_lut[n] * level_in;
+ }
+
+ av_rdft_calc(s->rdft[ch], (float *)s->input->extended_data[ch]);
+
+ return 0;
+}
+
+static int ifft_channel(AVFilterContext *ctx, void *arg, int ch, int nb_jobs)
+{
+ AudioSurroundContext *s = ctx->priv;
+ const float level_out = s->output_levels[ch];
+ AVFrame *out = arg;
+ float *dst, *ptr;
+ int n;
+
+ av_rdft_calc(s->irdft[ch], (float *)s->output->extended_data[ch]);
+
+ dst = (float *)s->output->extended_data[ch];
+ ptr = (float *)s->overlap_buffer->extended_data[ch];
+
+ memmove(s->overlap_buffer->extended_data[ch],
+ s->overlap_buffer->extended_data[ch] + s->hop_size * sizeof(float),
+ s->buf_size * sizeof(float));
+ memset(s->overlap_buffer->extended_data[ch] + s->buf_size * sizeof(float),
+ 0, s->hop_size * sizeof(float));
+
+ for (n = 0; n < s->buf_size; n++) {
+ ptr[n] += dst[n] * s->window_func_lut[n] * level_out;
+ }
+
+ ptr = (float *)s->overlap_buffer->extended_data[ch];
+ dst = (float *)out->extended_data[ch];
+ memcpy(dst, ptr, s->hop_size * sizeof(float));
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AudioSurroundContext *s = ctx->priv;
+
+ av_audio_fifo_write(s->fifo, (void **)in->extended_data,
+ in->nb_samples);
+
+ if (s->pts == AV_NOPTS_VALUE)
+ s->pts = in->pts;
+
+ av_frame_free(&in);
+
+ while (av_audio_fifo_size(s->fifo) >= s->buf_size) {
+ AVFrame *out;
+ int ret;
+
+ ret = av_audio_fifo_peek(s->fifo, (void **)s->input->extended_data, s->buf_size);
+ if (ret < 0)
+ return ret;
+
+ ctx->internal->execute(ctx, fft_channel, NULL, NULL, inlink->channels);
+
+ s->filter(ctx);
+
+ out = ff_get_audio_buffer(outlink, s->hop_size);
+ if (!out)
+ return AVERROR(ENOMEM);
+
+ ctx->internal->execute(ctx, ifft_channel, out, NULL, outlink->channels);
+
+ out->pts = s->pts;
+ if (s->pts != AV_NOPTS_VALUE)
+ s->pts += av_rescale_q(out->nb_samples, (AVRational){1, outlink->sample_rate}, outlink->time_base);
+ av_audio_fifo_drain(s->fifo, s->hop_size);
+ ret = ff_filter_frame(outlink, out);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ AudioSurroundContext *s = ctx->priv;
+ int ch;
+
+ av_frame_free(&s->input);
+ av_frame_free(&s->output);
+ av_frame_free(&s->overlap_buffer);
+
+ for (ch = 0; ch < s->nb_in_channels; ch++) {
+ av_rdft_end(s->rdft[ch]);
+ }
+ for (ch = 0; ch < s->nb_out_channels; ch++) {
+ av_rdft_end(s->irdft[ch]);
+ }
+ av_freep(&s->input_levels);
+ av_freep(&s->output_levels);
+ av_freep(&s->rdft);
+ av_freep(&s->irdft);
+ av_audio_fifo_free(s->fifo);
+ av_freep(&s->window_func_lut);
+}
+
+#define OFFSET(x) offsetof(AudioSurroundContext, x)
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption surround_options[] = {
+ { "chl_out", "set output channel layout", OFFSET(out_channel_layout_str), AV_OPT_TYPE_STRING, {.str="5.1"}, 0, 0, FLAGS },
+ { "chl_in", "set input channel layout", OFFSET(in_channel_layout_str), AV_OPT_TYPE_STRING, {.str="stereo"},0, 0, FLAGS },
+ { "level_in", "set input level", OFFSET(level_in), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { "level_out", "set output level", OFFSET(level_out), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { "lfe", "output LFE", OFFSET(output_lfe), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
+ { "lfe_low", "LFE low cut off", OFFSET(lowcutf), AV_OPT_TYPE_INT, {.i64=128}, 0, 256, FLAGS },
+ { "lfe_high", "LFE high cut off", OFFSET(highcutf), AV_OPT_TYPE_INT, {.i64=256}, 0, 512, FLAGS },
+ { "fc_in", "set front center channel input level", OFFSET(fc_in), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { "fc_out", "set front center channel output level", OFFSET(fc_out), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { "lfe_in", "set lfe channel input level", OFFSET(lfe_in), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { "lfe_out", "set lfe channel output level", OFFSET(lfe_out), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 10, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(surround);
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+ { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_output,
+ },
+ { NULL }
+};
+
+AVFilter ff_af_surround = {
+ .name = "surround",
+ .description = NULL_IF_CONFIG_SMALL("Apply audio surround upmix filter."),
+ .query_formats = query_formats,
+ .priv_size = sizeof(AudioSurroundContext),
+ .priv_class = &surround_class,
+ .init = init,
+ .uninit = uninit,
+ .inputs = inputs,
+ .outputs = outputs,
+ .flags = AVFILTER_FLAG_SLICE_THREADS,
+};