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