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:  * fade audio filter
yading@10:  */
yading@10: 
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: typedef struct {
yading@10:     const AVClass *class;
yading@10:     int type;
yading@10:     int curve;
yading@10:     int nb_samples;
yading@10:     int64_t start_sample;
yading@10:     int64_t duration;
yading@10:     int64_t start_time;
yading@10: 
yading@10:     void (*fade_samples)(uint8_t **dst, uint8_t * const *src,
yading@10:                          int nb_samples, int channels, int direction,
yading@10:                          int64_t start, int range, int curve);
yading@10: } AudioFadeContext;
yading@10: 
yading@10: enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, PAR, QUA, CUB, SQU, CBR };
yading@10: 
yading@10: #define OFFSET(x) offsetof(AudioFadeContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
yading@10: 
yading@10: static const AVOption afade_options[] = {
yading@10:     { "type",         "set the fade direction",                      OFFSET(type),         AV_OPT_TYPE_INT,    {.i64 = 0    }, 0, 1, FLAGS, "type" },
yading@10:     { "t",            "set the fade direction",                      OFFSET(type),         AV_OPT_TYPE_INT,    {.i64 = 0    }, 0, 1, FLAGS, "type" },
yading@10:     { "in",           NULL,                                          0,                    AV_OPT_TYPE_CONST,  {.i64 = 0    }, 0, 0, FLAGS, "type" },
yading@10:     { "out",          NULL,                                          0,                    AV_OPT_TYPE_CONST,  {.i64 = 1    }, 0, 0, FLAGS, "type" },
yading@10:     { "start_sample", "set expression of sample to start fading",    OFFSET(start_sample), AV_OPT_TYPE_INT64,  {.i64 = 0    }, 0, INT64_MAX, FLAGS },
yading@10:     { "ss",           "set expression of sample to start fading",    OFFSET(start_sample), AV_OPT_TYPE_INT64,  {.i64 = 0    }, 0, INT64_MAX, FLAGS },
yading@10:     { "nb_samples",   "set expression for fade duration in samples", OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX, FLAGS },
yading@10:     { "ns",           "set expression for fade duration in samples", OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX, FLAGS },
yading@10:     { "start_time",   "set expression of time to start fading",      OFFSET(start_time),   AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
yading@10:     { "st",           "set expression of time to start fading",      OFFSET(start_time),   AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
yading@10:     { "duration",     "set expression for fade duration",            OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
yading@10:     { "d",            "set expression for fade duration",            OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
yading@10:     { "curve",        "set expression for fade curve",               OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, TRI, CBR, FLAGS, "curve" },
yading@10:     { "c",            "set expression for fade curve",               OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, TRI, CBR, FLAGS, "curve" },
yading@10:     { "tri",          "linear slope",                                0,                    AV_OPT_TYPE_CONST,  {.i64 = TRI  }, 0, 0, FLAGS, "curve" },
yading@10:     { "qsin",         "quarter of sine wave",                        0,                    AV_OPT_TYPE_CONST,  {.i64 = QSIN }, 0, 0, FLAGS, "curve" },
yading@10:     { "esin",         "exponential sine wave",                       0,                    AV_OPT_TYPE_CONST,  {.i64 = ESIN }, 0, 0, FLAGS, "curve" },
yading@10:     { "hsin",         "half of sine wave",                           0,                    AV_OPT_TYPE_CONST,  {.i64 = HSIN }, 0, 0, FLAGS, "curve" },
yading@10:     { "log",          "logarithmic",                                 0,                    AV_OPT_TYPE_CONST,  {.i64 = LOG  }, 0, 0, FLAGS, "curve" },
yading@10:     { "par",          "inverted parabola",                           0,                    AV_OPT_TYPE_CONST,  {.i64 = PAR  }, 0, 0, FLAGS, "curve" },
yading@10:     { "qua",          "quadratic",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = QUA  }, 0, 0, FLAGS, "curve" },
yading@10:     { "cub",          "cubic",                                       0,                    AV_OPT_TYPE_CONST,  {.i64 = CUB  }, 0, 0, FLAGS, "curve" },
yading@10:     { "squ",          "square root",                                 0,                    AV_OPT_TYPE_CONST,  {.i64 = SQU  }, 0, 0, FLAGS, "curve" },
yading@10:     { "cbr",          "cubic root",                                  0,                    AV_OPT_TYPE_CONST,  {.i64 = CBR  }, 0, 0, FLAGS, "curve" },
yading@10:     {NULL},
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(afade);
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     AudioFadeContext *afade = ctx->priv;
yading@10: 
yading@10:     if (INT64_MAX - afade->nb_samples < afade->start_sample)
yading@10:         return AVERROR(EINVAL);
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_S16, AV_SAMPLE_FMT_S16P,
yading@10:         AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32P,
yading@10:         AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
yading@10:         AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
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 double fade_gain(int curve, int64_t index, int range)
yading@10: {
yading@10:     double gain;
yading@10: 
yading@10:     gain = FFMAX(0.0, FFMIN(1.0, 1.0 * index / range));
yading@10: 
yading@10:     switch (curve) {
yading@10:     case QSIN:
yading@10:         gain = sin(gain * M_PI / 2.0);
yading@10:         break;
yading@10:     case ESIN:
yading@10:         gain = 1.0 - cos(M_PI / 4.0 * (pow(2.0*gain - 1, 3) + 1));
yading@10:         break;
yading@10:     case HSIN:
yading@10:         gain = (1.0 - cos(gain * M_PI)) / 2.0;
yading@10:         break;
yading@10:     case LOG:
yading@10:         gain = pow(0.1, (1 - gain) * 5.0);
yading@10:         break;
yading@10:     case PAR:
yading@10:         gain = (1 - (1 - gain) * (1 - gain));
yading@10:         break;
yading@10:     case QUA:
yading@10:         gain *= gain;
yading@10:         break;
yading@10:     case CUB:
yading@10:         gain = gain * gain * gain;
yading@10:         break;
yading@10:     case SQU:
yading@10:         gain = sqrt(gain);
yading@10:         break;
yading@10:     case CBR:
yading@10:         gain = cbrt(gain);
yading@10:         break;
yading@10:     }
yading@10: 
yading@10:     return gain;
yading@10: }
yading@10: 
yading@10: #define FADE_PLANAR(name, type)                                             \
yading@10: static void fade_samples_## name ##p(uint8_t **dst, uint8_t * const *src,   \
yading@10:                                      int nb_samples, int channels, int dir, \
yading@10:                                      int64_t start, int range, int curve)   \
yading@10: {                                                                           \
yading@10:     int i, c;                                                               \
yading@10:                                                                             \
yading@10:     for (i = 0; i < nb_samples; i++) {                                      \
yading@10:         double gain = fade_gain(curve, start + i * dir, range);             \
yading@10:         for (c = 0; c < channels; c++) {                                    \
yading@10:             type *d = (type *)dst[c];                                       \
yading@10:             const type *s = (type *)src[c];                                 \
yading@10:                                                                             \
yading@10:             d[i] = s[i] * gain;                                             \
yading@10:         }                                                                   \
yading@10:     }                                                                       \
yading@10: }
yading@10: 
yading@10: #define FADE(name, type)                                                    \
yading@10: static void fade_samples_## name (uint8_t **dst, uint8_t * const *src,      \
yading@10:                                   int nb_samples, int channels, int dir,    \
yading@10:                                   int64_t start, int range, int curve)      \
yading@10: {                                                                           \
yading@10:     type *d = (type *)dst[0];                                               \
yading@10:     const type *s = (type *)src[0];                                         \
yading@10:     int i, c, k = 0;                                                        \
yading@10:                                                                             \
yading@10:     for (i = 0; i < nb_samples; i++) {                                      \
yading@10:         double gain = fade_gain(curve, start + i * dir, range);             \
yading@10:         for (c = 0; c < channels; c++, k++)                                 \
yading@10:             d[k] = s[k] * gain;                                             \
yading@10:     }                                                                       \
yading@10: }
yading@10: 
yading@10: FADE_PLANAR(dbl, double)
yading@10: FADE_PLANAR(flt, float)
yading@10: FADE_PLANAR(s16, int16_t)
yading@10: FADE_PLANAR(s32, int32_t)
yading@10: 
yading@10: FADE(dbl, double)
yading@10: FADE(flt, float)
yading@10: FADE(s16, int16_t)
yading@10: FADE(s32, int32_t)
yading@10: 
yading@10: static int config_output(AVFilterLink *outlink)
yading@10: {
yading@10:     AVFilterContext *ctx    = outlink->src;
yading@10:     AudioFadeContext *afade = ctx->priv;
yading@10:     AVFilterLink *inlink    = ctx->inputs[0];
yading@10: 
yading@10:     switch (inlink->format) {
yading@10:     case AV_SAMPLE_FMT_DBL:  afade->fade_samples = fade_samples_dbl;  break;
yading@10:     case AV_SAMPLE_FMT_DBLP: afade->fade_samples = fade_samples_dblp; break;
yading@10:     case AV_SAMPLE_FMT_FLT:  afade->fade_samples = fade_samples_flt;  break;
yading@10:     case AV_SAMPLE_FMT_FLTP: afade->fade_samples = fade_samples_fltp; break;
yading@10:     case AV_SAMPLE_FMT_S16:  afade->fade_samples = fade_samples_s16;  break;
yading@10:     case AV_SAMPLE_FMT_S16P: afade->fade_samples = fade_samples_s16p; break;
yading@10:     case AV_SAMPLE_FMT_S32:  afade->fade_samples = fade_samples_s32;  break;
yading@10:     case AV_SAMPLE_FMT_S32P: afade->fade_samples = fade_samples_s32p; break;
yading@10:     }
yading@10: 
yading@10:     if (afade->duration)
yading@10:         afade->nb_samples = afade->duration * inlink->sample_rate / AV_TIME_BASE;
yading@10:     if (afade->start_time)
yading@10:         afade->start_sample = afade->start_time * inlink->sample_rate / AV_TIME_BASE;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
yading@10: {
yading@10:     AudioFadeContext *afade = inlink->dst->priv;
yading@10:     AVFilterLink *outlink   = inlink->dst->outputs[0];
yading@10:     int nb_samples          = buf->nb_samples;
yading@10:     AVFrame *out_buf;
yading@10:     int64_t cur_sample = av_rescale_q(buf->pts, (AVRational){1, outlink->sample_rate}, outlink->time_base);
yading@10: 
yading@10:     if ((!afade->type && (afade->start_sample + afade->nb_samples < cur_sample)) ||
yading@10:         ( afade->type && (cur_sample + afade->nb_samples < afade->start_sample)))
yading@10:         return ff_filter_frame(outlink, buf);
yading@10: 
yading@10:     if (av_frame_is_writable(buf)) {
yading@10:         out_buf = buf;
yading@10:     } else {
yading@10:         out_buf = ff_get_audio_buffer(inlink, nb_samples);
yading@10:         if (!out_buf)
yading@10:             return AVERROR(ENOMEM);
yading@10:         av_frame_copy_props(out_buf, buf);
yading@10:     }
yading@10: 
yading@10:     if ((!afade->type && (cur_sample + nb_samples < afade->start_sample)) ||
yading@10:         ( afade->type && (afade->start_sample + afade->nb_samples < cur_sample))) {
yading@10:         av_samples_set_silence(out_buf->extended_data, 0, nb_samples,
yading@10:                                av_frame_get_channels(out_buf), out_buf->format);
yading@10:     } else {
yading@10:         int64_t start;
yading@10: 
yading@10:         if (!afade->type)
yading@10:             start = cur_sample - afade->start_sample;
yading@10:         else
yading@10:             start = afade->start_sample + afade->nb_samples - cur_sample;
yading@10: 
yading@10:         afade->fade_samples(out_buf->extended_data, buf->extended_data,
yading@10:                             nb_samples, av_frame_get_channels(buf),
yading@10:                             afade->type ? -1 : 1, start,
yading@10:                             afade->nb_samples, afade->curve);
yading@10:     }
yading@10: 
yading@10:     if (buf != out_buf)
yading@10:         av_frame_free(&buf);
yading@10: 
yading@10:     return ff_filter_frame(outlink, out_buf);
yading@10: }
yading@10: 
yading@10: static const AVFilterPad avfilter_af_afade_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 avfilter_af_afade_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_afade = {
yading@10:     .name          = "afade",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Fade in/out input audio."),
yading@10:     .query_formats = query_formats,
yading@10:     .priv_size     = sizeof(AudioFadeContext),
yading@10:     .init          = init,
yading@10:     .inputs        = avfilter_af_afade_inputs,
yading@10:     .outputs       = avfilter_af_afade_outputs,
yading@10:     .priv_class    = &afade_class,
yading@10: };