yading@10: /*
yading@10:  * Copyright (c) 2013 Paul B Mahol
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:  * phaser audio filter
yading@10:  */
yading@10: 
yading@10: #include "libavutil/avassert.h"
yading@10: #include "libavutil/opt.h"
yading@10: #include "audio.h"
yading@10: #include "avfilter.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: enum WaveType {
yading@10:     WAVE_SIN,
yading@10:     WAVE_TRI,
yading@10:     WAVE_NB,
yading@10: };
yading@10: 
yading@10: typedef struct AudioPhaserContext {
yading@10:     const AVClass *class;
yading@10:     double in_gain, out_gain;
yading@10:     double delay;
yading@10:     double decay;
yading@10:     double speed;
yading@10: 
yading@10:     enum WaveType type;
yading@10: 
yading@10:     int delay_buffer_length;
yading@10:     double *delay_buffer;
yading@10: 
yading@10:     int modulation_buffer_length;
yading@10:     int32_t *modulation_buffer;
yading@10: 
yading@10:     int delay_pos, modulation_pos;
yading@10: 
yading@10:     void (*phaser)(struct AudioPhaserContext *p,
yading@10:                    uint8_t * const *src, uint8_t **dst,
yading@10:                    int nb_samples, int channels);
yading@10: } AudioPhaserContext;
yading@10: 
yading@10: #define OFFSET(x) offsetof(AudioPhaserContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
yading@10: 
yading@10: static const AVOption aphaser_options[] = {
yading@10:     { "in_gain",  "set input gain",            OFFSET(in_gain),  AV_OPT_TYPE_DOUBLE, {.dbl=.4},  0,  1,   FLAGS },
yading@10:     { "out_gain", "set output gain",           OFFSET(out_gain), AV_OPT_TYPE_DOUBLE, {.dbl=.74}, 0,  1e9, FLAGS },
yading@10:     { "delay",    "set delay in milliseconds", OFFSET(delay),    AV_OPT_TYPE_DOUBLE, {.dbl=3.},  0,  5,   FLAGS },
yading@10:     { "decay",    "set decay",                 OFFSET(decay),    AV_OPT_TYPE_DOUBLE, {.dbl=.4},  0, .99,  FLAGS },
yading@10:     { "speed",    "set modulation speed",      OFFSET(speed),    AV_OPT_TYPE_DOUBLE, {.dbl=.5}, .1,  2,   FLAGS },
yading@10:     { "type",     "set modulation type",       OFFSET(type),     AV_OPT_TYPE_INT,    {.i64=WAVE_TRI}, 0, WAVE_NB-1, FLAGS, "type" },
yading@10:     { "triangular",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_TRI}, 0, 0, FLAGS, "type" },
yading@10:     { "t",           NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_TRI}, 0, 0, FLAGS, "type" },
yading@10:     { "sinusoidal",  NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_SIN}, 0, 0, FLAGS, "type" },
yading@10:     { "s",           NULL, 0, AV_OPT_TYPE_CONST,  {.i64=WAVE_SIN}, 0, 0, FLAGS, "type" },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(aphaser);
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     AudioPhaserContext *p = ctx->priv;
yading@10: 
yading@10:     if (p->in_gain > (1 - p->decay * p->decay))
yading@10:         av_log(ctx, AV_LOG_WARNING, "in_gain may cause clipping\n");
yading@10:     if (p->in_gain / (1 - p->decay) > 1 / p->out_gain)
yading@10:         av_log(ctx, AV_LOG_WARNING, "out_gain may cause clipping\n");
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     AVFilterFormats *formats;
yading@10:     AVFilterChannelLayouts *layouts;
yading@10:     static const enum AVSampleFormat sample_fmts[] = {
yading@10:         AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
yading@10:         AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
yading@10:         AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32P,
yading@10:         AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16P,
yading@10:         AV_SAMPLE_FMT_NONE
yading@10:     };
yading@10: 
yading@10:     layouts = ff_all_channel_layouts();
yading@10:     if (!layouts)
yading@10:         return AVERROR(ENOMEM);
yading@10:     ff_set_common_channel_layouts(ctx, layouts);
yading@10: 
yading@10:     formats = ff_make_format_list(sample_fmts);
yading@10:     if (!formats)
yading@10:         return AVERROR(ENOMEM);
yading@10:     ff_set_common_formats(ctx, formats);
yading@10: 
yading@10:     formats = ff_all_samplerates();
yading@10:     if (!formats)
yading@10:         return AVERROR(ENOMEM);
yading@10:     ff_set_common_samplerates(ctx, formats);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void generate_wave_table(enum WaveType wave_type, enum AVSampleFormat sample_fmt,
yading@10:                                 void *table, int table_size,
yading@10:                                 double min, double max, double phase)
yading@10: {
yading@10:     uint32_t i, phase_offset = phase / M_PI / 2 * table_size + 0.5;
yading@10: 
yading@10:     for (i = 0; i < table_size; i++) {
yading@10:         uint32_t point = (i + phase_offset) % table_size;
yading@10:         double d;
yading@10: 
yading@10:         switch (wave_type) {
yading@10:         case WAVE_SIN:
yading@10:             d = (sin((double)point / table_size * 2 * M_PI) + 1) / 2;
yading@10:             break;
yading@10:         case WAVE_TRI:
yading@10:             d = (double)point * 2 / table_size;
yading@10:             switch (4 * point / table_size) {
yading@10:             case 0: d = d + 0.5; break;
yading@10:             case 1:
yading@10:             case 2: d = 1.5 - d; break;
yading@10:             case 3: d = d - 1.5; break;
yading@10:             }
yading@10:             break;
yading@10:         default:
yading@10:             av_assert0(0);
yading@10:         }
yading@10: 
yading@10:         d  = d * (max - min) + min;
yading@10:         switch (sample_fmt) {
yading@10:         case AV_SAMPLE_FMT_FLT: {
yading@10:             float *fp = (float *)table;
yading@10:             *fp++ = (float)d;
yading@10:             table = fp;
yading@10:             continue; }
yading@10:         case AV_SAMPLE_FMT_DBL: {
yading@10:             double *dp = (double *)table;
yading@10:             *dp++ = d;
yading@10:             table = dp;
yading@10:             continue; }
yading@10:         }
yading@10: 
yading@10:         d += d < 0 ? -0.5 : 0.5;
yading@10:         switch (sample_fmt) {
yading@10:         case AV_SAMPLE_FMT_S16: {
yading@10:             int16_t *sp = table;
yading@10:             *sp++ = (int16_t)d;
yading@10:             table = sp;
yading@10:             continue; }
yading@10:         case AV_SAMPLE_FMT_S32: {
yading@10:             int32_t *ip = table;
yading@10:             *ip++ = (int32_t)d;
yading@10:             table = ip;
yading@10:             continue; }
yading@10:         default:
yading@10:             av_assert0(0);
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: #define MOD(a, b) (((a) >= (b)) ? (a) - (b) : (a))
yading@10: 
yading@10: #define PHASER_PLANAR(name, type)                                      \
yading@10: static void phaser_## name ##p(AudioPhaserContext *p,                  \
yading@10:                                uint8_t * const *src, uint8_t **dst,    \
yading@10:                                int nb_samples, int channels)           \
yading@10: {                                                                      \
yading@10:     int i, c, delay_pos, modulation_pos;                               \
yading@10:                                                                        \
yading@10:     av_assert0(channels > 0);                                          \
yading@10:     for (c = 0; c < channels; c++) {                                   \
yading@10:         type *s = (type *)src[c];                                      \
yading@10:         type *d = (type *)dst[c];                                      \
yading@10:         double *buffer = p->delay_buffer +                             \
yading@10:                          c * p->delay_buffer_length;                   \
yading@10:                                                                        \
yading@10:         delay_pos      = p->delay_pos;                                 \
yading@10:         modulation_pos = p->modulation_pos;                            \
yading@10:                                                                        \
yading@10:         for (i = 0; i < nb_samples; i++, s++, d++) {                   \
yading@10:             double v = *s * p->in_gain + buffer[                       \
yading@10:                        MOD(delay_pos + p->modulation_buffer[           \
yading@10:                        modulation_pos],                                \
yading@10:                        p->delay_buffer_length)] * p->decay;            \
yading@10:                                                                        \
yading@10:             modulation_pos = MOD(modulation_pos + 1,                   \
yading@10:                              p->modulation_buffer_length);             \
yading@10:             delay_pos = MOD(delay_pos + 1, p->delay_buffer_length);    \
yading@10:             buffer[delay_pos] = v;                                     \
yading@10:                                                                        \
yading@10:             *d = v * p->out_gain;                                      \
yading@10:         }                                                              \
yading@10:     }                                                                  \
yading@10:                                                                        \
yading@10:     p->delay_pos      = delay_pos;                                     \
yading@10:     p->modulation_pos = modulation_pos;                                \
yading@10: }
yading@10: 
yading@10: #define PHASER(name, type)                                              \
yading@10: static void phaser_## name (AudioPhaserContext *p,                      \
yading@10:                             uint8_t * const *src, uint8_t **dst,        \
yading@10:                             int nb_samples, int channels)               \
yading@10: {                                                                       \
yading@10:     int i, c, delay_pos, modulation_pos;                                \
yading@10:     type *s = (type *)src[0];                                           \
yading@10:     type *d = (type *)dst[0];                                           \
yading@10:     double *buffer = p->delay_buffer;                                   \
yading@10:                                                                         \
yading@10:     delay_pos      = p->delay_pos;                                      \
yading@10:     modulation_pos = p->modulation_pos;                                 \
yading@10:                                                                         \
yading@10:     for (i = 0; i < nb_samples; i++) {                                  \
yading@10:         int pos = MOD(delay_pos + p->modulation_buffer[modulation_pos], \
yading@10:                    p->delay_buffer_length) * channels;                  \
yading@10:         int npos;                                                       \
yading@10:                                                                         \
yading@10:         delay_pos = MOD(delay_pos + 1, p->delay_buffer_length);         \
yading@10:         npos = delay_pos * channels;                                    \
yading@10:         for (c = 0; c < channels; c++, s++, d++) {                      \
yading@10:             double v = *s * p->in_gain + buffer[pos + c] * p->decay;    \
yading@10:                                                                         \
yading@10:             buffer[npos + c] = v;                                       \
yading@10:                                                                         \
yading@10:             *d = v * p->out_gain;                                       \
yading@10:         }                                                               \
yading@10:                                                                         \
yading@10:         modulation_pos = MOD(modulation_pos + 1,                        \
yading@10:                          p->modulation_buffer_length);                  \
yading@10:     }                                                                   \
yading@10:                                                                         \
yading@10:     p->delay_pos      = delay_pos;                                      \
yading@10:     p->modulation_pos = modulation_pos;                                 \
yading@10: }
yading@10: 
yading@10: PHASER_PLANAR(dbl, double)
yading@10: PHASER_PLANAR(flt, float)
yading@10: PHASER_PLANAR(s16, int16_t)
yading@10: PHASER_PLANAR(s32, int32_t)
yading@10: 
yading@10: PHASER(dbl, double)
yading@10: PHASER(flt, float)
yading@10: PHASER(s16, int16_t)
yading@10: PHASER(s32, int32_t)
yading@10: 
yading@10: static int config_output(AVFilterLink *outlink)
yading@10: {
yading@10:     AudioPhaserContext *p = outlink->src->priv;
yading@10:     AVFilterLink *inlink = outlink->src->inputs[0];
yading@10: 
yading@10:     p->delay_buffer_length = p->delay * 0.001 * inlink->sample_rate + 0.5;
yading@10:     p->delay_buffer = av_calloc(p->delay_buffer_length, sizeof(*p->delay_buffer) * inlink->channels);
yading@10:     p->modulation_buffer_length = inlink->sample_rate / p->speed + 0.5;
yading@10:     p->modulation_buffer = av_malloc(p->modulation_buffer_length * sizeof(*p->modulation_buffer));
yading@10: 
yading@10:     if (!p->modulation_buffer || !p->delay_buffer)
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     generate_wave_table(p->type, AV_SAMPLE_FMT_S32,
yading@10:                         p->modulation_buffer, p->modulation_buffer_length,
yading@10:                         1., p->delay_buffer_length, M_PI / 2.0);
yading@10: 
yading@10:     p->delay_pos = p->modulation_pos = 0;
yading@10: 
yading@10:     switch (inlink->format) {
yading@10:     case AV_SAMPLE_FMT_DBL:  p->phaser = phaser_dbl;  break;
yading@10:     case AV_SAMPLE_FMT_DBLP: p->phaser = phaser_dblp; break;
yading@10:     case AV_SAMPLE_FMT_FLT:  p->phaser = phaser_flt;  break;
yading@10:     case AV_SAMPLE_FMT_FLTP: p->phaser = phaser_fltp; break;
yading@10:     case AV_SAMPLE_FMT_S16:  p->phaser = phaser_s16;  break;
yading@10:     case AV_SAMPLE_FMT_S16P: p->phaser = phaser_s16p; break;
yading@10:     case AV_SAMPLE_FMT_S32:  p->phaser = phaser_s32;  break;
yading@10:     case AV_SAMPLE_FMT_S32P: p->phaser = phaser_s32p; break;
yading@10:     default: av_assert0(0);
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *inbuf)
yading@10: {
yading@10:     AudioPhaserContext *p = inlink->dst->priv;
yading@10:     AVFilterLink *outlink = inlink->dst->outputs[0];
yading@10:     AVFrame *outbuf;
yading@10: 
yading@10:     if (av_frame_is_writable(inbuf)) {
yading@10:         outbuf = inbuf;
yading@10:     } else {
yading@10:         outbuf = ff_get_audio_buffer(inlink, inbuf->nb_samples);
yading@10:         if (!outbuf)
yading@10:             return AVERROR(ENOMEM);
yading@10:         av_frame_copy_props(outbuf, inbuf);
yading@10:     }
yading@10: 
yading@10:     p->phaser(p, inbuf->extended_data, outbuf->extended_data,
yading@10:               outbuf->nb_samples, av_frame_get_channels(outbuf));
yading@10: 
yading@10:     if (inbuf != outbuf)
yading@10:         av_frame_free(&inbuf);
yading@10: 
yading@10:     return ff_filter_frame(outlink, outbuf);
yading@10: }
yading@10: 
yading@10: static av_cold void uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     AudioPhaserContext *p = ctx->priv;
yading@10: 
yading@10:     av_freep(&p->delay_buffer);
yading@10:     av_freep(&p->modulation_buffer);
yading@10: }
yading@10: 
yading@10: static const AVFilterPad aphaser_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 aphaser_outputs[] = {
yading@10:     {
yading@10:         .name         = "default",
yading@10:         .type         = AVMEDIA_TYPE_AUDIO,
yading@10:         .config_props = config_output,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_af_aphaser = {
yading@10:     .name          = "aphaser",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Add a phasing effect to the audio."),
yading@10:     .query_formats = query_formats,
yading@10:     .priv_size     = sizeof(AudioPhaserContext),
yading@10:     .init          = init,
yading@10:     .uninit        = uninit,
yading@10:     .inputs        = aphaser_inputs,
yading@10:     .outputs       = aphaser_outputs,
yading@10:     .priv_class    = &aphaser_class,
yading@10: };