yading@10: /* yading@10: * Copyright (c) 2011 Mina Nagy Zaki yading@10: * Copyright (c) 2000 Edward Beingessner And Sundry Contributors. yading@10: * This source code is freely redistributable and may be used for any purpose. yading@10: * This copyright notice must be maintained. Edward Beingessner And Sundry yading@10: * Contributors are not responsible for the consequences of using this yading@10: * software. yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: * Stereo Widening Effect. Adds audio cues to move stereo image in yading@10: * front of the listener. Adapted from the libsox earwax effect. yading@10: */ yading@10: yading@10: #include "libavutil/channel_layout.h" yading@10: #include "avfilter.h" yading@10: #include "audio.h" yading@10: #include "formats.h" yading@10: yading@10: #define NUMTAPS 64 yading@10: yading@10: static const int8_t filt[NUMTAPS] = { yading@10: /* 30° 330° */ yading@10: 4, -6, /* 32 tap stereo FIR filter. */ yading@10: 4, -11, /* One side filters as if the */ yading@10: -1, -5, /* signal was from 30 degrees */ yading@10: 3, 3, /* from the ear, the other as */ yading@10: -2, 5, /* if 330 degrees. */ yading@10: -5, 0, yading@10: 9, 1, yading@10: 6, 3, /* Input */ yading@10: -4, -1, /* Left Right */ yading@10: -5, -3, /* __________ __________ */ yading@10: -2, -5, /* | | | | */ yading@10: -7, 1, /* .---| Hh,0(f) | | Hh,0(f) |---. */ yading@10: 6, -7, /* / |__________| |__________| \ */ yading@10: 30, -29, /* / \ / \ */ yading@10: 12, -3, /* / X \ */ yading@10: -11, 4, /* / / \ \ */ yading@10: -3, 7, /* ____V_____ __________V V__________ _____V____ */ yading@10: -20, 23, /* | | | | | | | | */ yading@10: 2, 0, /* | Hh,30(f) | | Hh,330(f)| | Hh,330(f)| | Hh,30(f) | */ yading@10: 1, -6, /* |__________| |__________| |__________| |__________| */ yading@10: -14, -5, /* \ ___ / \ ___ / */ yading@10: 15, -18, /* \ / \ / _____ \ / \ / */ yading@10: 6, 7, /* `->| + |<--' / \ `-->| + |<-' */ yading@10: 15, -10, /* \___/ _/ \_ \___/ */ yading@10: -14, 22, /* \ / \ / \ / */ yading@10: -7, -2, /* `--->| | | |<---' */ yading@10: -4, 9, /* \_/ \_/ */ yading@10: 6, -12, /* */ yading@10: 6, -6, /* Headphones */ yading@10: 0, -11, yading@10: 0, -5, yading@10: 4, 0}; yading@10: yading@10: typedef struct { yading@10: int16_t taps[NUMTAPS * 2]; yading@10: } EarwaxContext; yading@10: yading@10: static int query_formats(AVFilterContext *ctx) yading@10: { yading@10: static const int sample_rates[] = { 44100, -1 }; yading@10: yading@10: AVFilterFormats *formats = NULL; yading@10: AVFilterChannelLayouts *layout = NULL; yading@10: yading@10: ff_add_format(&formats, AV_SAMPLE_FMT_S16); yading@10: ff_set_common_formats(ctx, formats); yading@10: ff_add_channel_layout(&layout, AV_CH_LAYOUT_STEREO); yading@10: ff_set_common_channel_layouts(ctx, layout); yading@10: ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates)); yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: //FIXME: replace with DSPContext.scalarproduct_int16 yading@10: static inline int16_t *scalarproduct(const int16_t *in, const int16_t *endin, int16_t *out) yading@10: { yading@10: int32_t sample; yading@10: int16_t j; yading@10: yading@10: while (in < endin) { yading@10: sample = 0; yading@10: for (j = 0; j < NUMTAPS; j++) yading@10: sample += in[j] * filt[j]; yading@10: *out = av_clip_int16(sample >> 6); yading@10: out++; yading@10: in++; yading@10: } yading@10: yading@10: return out; yading@10: } yading@10: yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *insamples) yading@10: { yading@10: AVFilterLink *outlink = inlink->dst->outputs[0]; yading@10: int16_t *taps, *endin, *in, *out; yading@10: AVFrame *outsamples = ff_get_audio_buffer(inlink, insamples->nb_samples); yading@10: yading@10: if (!outsamples) { yading@10: av_frame_free(&insamples); yading@10: return AVERROR(ENOMEM); yading@10: } yading@10: av_frame_copy_props(outsamples, insamples); yading@10: yading@10: taps = ((EarwaxContext *)inlink->dst->priv)->taps; yading@10: out = (int16_t *)outsamples->data[0]; yading@10: in = (int16_t *)insamples ->data[0]; yading@10: yading@10: // copy part of new input and process with saved input yading@10: memcpy(taps+NUMTAPS, in, NUMTAPS * sizeof(*taps)); yading@10: out = scalarproduct(taps, taps + NUMTAPS, out); yading@10: yading@10: // process current input yading@10: endin = in + insamples->nb_samples * 2 - NUMTAPS; yading@10: scalarproduct(in, endin, out); yading@10: yading@10: // save part of input for next round yading@10: memcpy(taps, endin, NUMTAPS * sizeof(*taps)); yading@10: yading@10: av_frame_free(&insamples); yading@10: return ff_filter_frame(outlink, outsamples); yading@10: } yading@10: yading@10: static const AVFilterPad earwax_inputs[] = { yading@10: { yading@10: .name = "default", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: .filter_frame = filter_frame, yading@10: }, yading@10: { NULL } yading@10: }; yading@10: yading@10: static const AVFilterPad earwax_outputs[] = { yading@10: { yading@10: .name = "default", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: }, yading@10: { NULL } yading@10: }; yading@10: yading@10: AVFilter avfilter_af_earwax = { yading@10: .name = "earwax", yading@10: .description = NULL_IF_CONFIG_SMALL("Widen the stereo image."), yading@10: .query_formats = query_formats, yading@10: .priv_size = sizeof(EarwaxContext), yading@10: .inputs = earwax_inputs, yading@10: .outputs = earwax_outputs, yading@10: };