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FFmpeg/libavfilter/af_afade.c

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  1. /*

  2.  * Copyright (c) 2013-2015 Paul B Mahol

  3.  *

  4.  * This file is part of FFmpeg.

  5.  *

  6.  * FFmpeg is free software; you can redistribute it and/or

  7.  * modify it under the terms of the GNU Lesser General Public

  8.  * License as published by the Free Software Foundation; either

  9.  * version 2.1 of the License, or (at your option) any later version.

  10.  *

  11.  * FFmpeg is distributed in the hope that it will be useful,

  12.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  13.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  14.  * Lesser General Public License for more details.

  15.  *

  16.  * You should have received a copy of the GNU Lesser General Public

  17.  * License along with FFmpeg; if not, write to the Free Software

  18.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  19.  */

  20. 

  21. /**

  22.  * @file

  23.  * fade audio filter

  24.  */

  25. 

  26. #include "libavutil/audio_fifo.h"

  27. #include "libavutil/opt.h"

  28. #include "audio.h"

  29. #include "avfilter.h"

  30. #include "internal.h"

  31. 

  32. typedef struct {

  33.     const AVClass *class;

  34.     int type;

  35.     int curve, curve2;

  36.     int nb_samples;

  37.     int64_t start_sample;

  38.     int64_t duration;

  39.     int64_t start_time;

  40.     int overlap;

  41.     int cf0_eof;

  42.     int crossfade_is_over;

  43.     AVAudioFifo *fifo[2];

  44.     int64_t pts;

  45. 

  46.     void (*fade_samples)(uint8_t **dst, uint8_t * const *src,

  47.                          int nb_samples, int channels, int direction,

  48.                          int64_t start, int range, int curve);

  49.     void (*crossfade_samples)(uint8_t **dst, uint8_t * const *cf0,

  50.                               uint8_t * const *cf1,

  51.                               int nb_samples, int channels,

  52.                               int curve0, int curve1);

  53. } AudioFadeContext;

  54. 

  55. enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, IPAR, QUA, CUB, SQU, CBR, PAR, EXP, IQSIN, IHSIN, DESE, DESI, NB_CURVES };

  56. 

  57. #define OFFSET(x) offsetof(AudioFadeContext, x)

  58. #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

  59. 

  60. static int query_formats(AVFilterContext *ctx)

  61. {

  62.     AVFilterFormats *formats;

  63.     AVFilterChannelLayouts *layouts;

  64.     static const enum AVSampleFormat sample_fmts[] = {

  65.         AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16P,

  66.         AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32P,

  67.         AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,

  68.         AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,

  69.         AV_SAMPLE_FMT_NONE

  70.     };

  71.     int ret;

  72. 

  73.     layouts = ff_all_channel_layouts();

  74.     if (!layouts)

  75.         return AVERROR(ENOMEM);

  76.     ret = ff_set_common_channel_layouts(ctx, layouts);

  77.     if (ret < 0)

  78.         return ret;

  79. 

  80.     formats = ff_make_format_list(sample_fmts);

  81.     if (!formats)

  82.         return AVERROR(ENOMEM);

  83.     ret = ff_set_common_formats(ctx, formats);

  84.     if (ret < 0)

  85.         return ret;

  86. 

  87.     formats = ff_all_samplerates();

  88.     if (!formats)

  89.         return AVERROR(ENOMEM);

  90.     return ff_set_common_samplerates(ctx, formats);

  91. }

  92. 

  93. static double fade_gain(int curve, int64_t index, int range)

  94. {

  95.     double gain;

  96. 

  97.     gain = av_clipd(1.0 * index / range, 0, 1.0);

  98. 

  99.     switch (curve) {

  100.     case QSIN:

  101.         gain = sin(gain * M_PI / 2.0);

  102.         break;

  103.     case IQSIN:

  104.         gain = 0.636943 * asin(gain);

  105.         break;

  106.     case ESIN:

  107.         gain = 1.0 - cos(M_PI / 4.0 * (pow(2.0*gain - 1, 3) + 1));

  108.         break;

  109.     case HSIN:

  110.         gain = (1.0 - cos(gain * M_PI)) / 2.0;

  111.         break;

  112.     case IHSIN:

  113.         gain = 0.318471 * acos(1 - 2 * gain);

  114.         break;

  115.     case EXP:

  116.         gain = pow(0.1, (1 - gain) * 5.0);

  117.         break;

  118.     case LOG:

  119.         gain = av_clipd(0.0868589 * log(100000 * gain), 0, 1.0);

  120.         break;

  121.     case PAR:

  122.         gain = 1 - sqrt(1 - gain);

  123.         break;

  124.     case IPAR:

  125.         gain = (1 - (1 - gain) * (1 - gain));

  126.         break;

  127.     case QUA:

  128.         gain *= gain;

  129.         break;

  130.     case CUB:

  131.         gain = gain * gain * gain;

  132.         break;

  133.     case SQU:

  134.         gain = sqrt(gain);

  135.         break;

  136.     case CBR:

  137.         gain = cbrt(gain);

  138.         break;

  139.     case DESE:

  140.         gain = gain <= 0.5 ? pow(2 * gain, 1/3.) / 2: 1 - pow(2 * (1 - gain), 1/3.) / 2;

  141.         break;

  142.     case DESI:

  143.         gain = gain <= 0.5 ? pow(2 * gain, 3) / 2: 1 - pow(2 * (1 - gain), 3) / 2;

  144.         break;

  145.     }

  146. 

  147.     return gain;

  148. }

  149. 

  150. #define FADE_PLANAR(name, type)                                             \

  151. static void fade_samples_## name ##p(uint8_t **dst, uint8_t * const *src,   \

  152.                                      int nb_samples, int channels, int dir, \

  153.                                      int64_t start, int range, int curve)   \

  154. {                                                                           \

  155.     int i, c;                                                               \

  156.                                                                             \

  157.     for (i = 0; i < nb_samples; i++) {                                      \

  158.         double gain = fade_gain(curve, start + i * dir, range);             \

  159.         for (c = 0; c < channels; c++) {                                    \

  160.             type *d = (type *)dst[c];                                       \

  161.             const type *s = (type *)src[c];                                 \

  162.                                                                             \

  163.             d[i] = s[i] * gain;                                             \

  164.         }                                                                   \

  165.     }                                                                       \

  166. }

  167. 

  168. #define FADE(name, type)                                                    \

  169. static void fade_samples_## name (uint8_t **dst, uint8_t * const *src,      \

  170.                                   int nb_samples, int channels, int dir,    \

  171.                                   int64_t start, int range, int curve)      \

  172. {                                                                           \

  173.     type *d = (type *)dst[0];                                               \

  174.     const type *s = (type *)src[0];                                         \

  175.     int i, c, k = 0;                                                        \

  176.                                                                             \

  177.     for (i = 0; i < nb_samples; i++) {                                      \

  178.         double gain = fade_gain(curve, start + i * dir, range);             \

  179.         for (c = 0; c < channels; c++, k++)                                 \

  180.             d[k] = s[k] * gain;                                             \

  181.     }                                                                       \

  182. }

  183. 

  184. FADE_PLANAR(dbl, double)

  185. FADE_PLANAR(flt, float)

  186. FADE_PLANAR(s16, int16_t)

  187. FADE_PLANAR(s32, int32_t)

  188. 

  189. FADE(dbl, double)

  190. FADE(flt, float)

  191. FADE(s16, int16_t)

  192. FADE(s32, int32_t)

  193. 

  194. static int config_output(AVFilterLink *outlink)

  195. {

  196.     AVFilterContext *ctx = outlink->src;

  197.     AudioFadeContext *s  = ctx->priv;

  198. 

  199.     switch (outlink->format) {

  200.     case AV_SAMPLE_FMT_DBL:  s->fade_samples = fade_samples_dbl;  break;

  201.     case AV_SAMPLE_FMT_DBLP: s->fade_samples = fade_samples_dblp; break;

  202.     case AV_SAMPLE_FMT_FLT:  s->fade_samples = fade_samples_flt;  break;

  203.     case AV_SAMPLE_FMT_FLTP: s->fade_samples = fade_samples_fltp; break;

  204.     case AV_SAMPLE_FMT_S16:  s->fade_samples = fade_samples_s16;  break;

  205.     case AV_SAMPLE_FMT_S16P: s->fade_samples = fade_samples_s16p; break;

  206.     case AV_SAMPLE_FMT_S32:  s->fade_samples = fade_samples_s32;  break;

  207.     case AV_SAMPLE_FMT_S32P: s->fade_samples = fade_samples_s32p; break;

  208.     }

  209. 

  210.     if (s->duration)

  211.         s->nb_samples = av_rescale(s->duration, outlink->sample_rate, AV_TIME_BASE);

  212.     if (s->start_time)

  213.         s->start_sample = av_rescale(s->start_time, outlink->sample_rate, AV_TIME_BASE);

  214. 

  215.     return 0;

  216. }

  217. 

  218. #if CONFIG_AFADE_FILTER

  219. 

  220. static const AVOption afade_options[] = {

  221.     { "type",         "set the fade direction",                      OFFSET(type),         AV_OPT_TYPE_INT,    {.i64 = 0    }, 0, 1, FLAGS, "type" },

  222.     { "t",            "set the fade direction",                      OFFSET(type),         AV_OPT_TYPE_INT,    {.i64 = 0    }, 0, 1, FLAGS, "type" },

  223.     { "in",           "fade-in",                                     0,                    AV_OPT_TYPE_CONST,  {.i64 = 0    }, 0, 0, FLAGS, "type" },

  224.     { "out",          "fade-out",                                    0,                    AV_OPT_TYPE_CONST,  {.i64 = 1    }, 0, 0, FLAGS, "type" },

  225.     { "start_sample", "set number of first sample to start fading",  OFFSET(start_sample), AV_OPT_TYPE_INT64,  {.i64 = 0    }, 0, INT64_MAX, FLAGS },

  226.     { "ss",           "set number of first sample to start fading",  OFFSET(start_sample), AV_OPT_TYPE_INT64,  {.i64 = 0    }, 0, INT64_MAX, FLAGS },

  227.     { "nb_samples",   "set number of samples for fade duration",     OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX, FLAGS },

  228.     { "ns",           "set number of samples for fade duration",     OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX, FLAGS },

  229.     { "start_time",   "set time to start fading",                    OFFSET(start_time),   AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },

  230.     { "st",           "set time to start fading",                    OFFSET(start_time),   AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },

  231.     { "duration",     "set fade duration",                           OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },

  232.     { "d",            "set fade duration",                           OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },

  233.     { "curve",        "set fade curve type",                         OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve" },

  234.     { "c",            "set fade curve type",                         OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve" },

  235.     { "tri",          "linear slope",                                0,                    AV_OPT_TYPE_CONST,  {.i64 = TRI  }, 0, 0, FLAGS, "curve" },

  236.     { "qsin",         "quarter of sine wave",                        0,                    AV_OPT_TYPE_CONST,  {.i64 = QSIN }, 0, 0, FLAGS, "curve" },

  237.     { "esin",         "exponential sine wave",                       0,                    AV_OPT_TYPE_CONST,  {.i64 = ESIN }, 0, 0, FLAGS, "curve" },

  238.     { "hsin",         "half of sine wave",                           0,                    AV_OPT_TYPE_CONST,  {.i64 = HSIN }, 0, 0, FLAGS, "curve" },

  239.     { "log",          "logarithmic",                                 0,                    AV_OPT_TYPE_CONST,  {.i64 = LOG  }, 0, 0, FLAGS, "curve" },

  240.     { "ipar",         "inverted parabola",                           0,                    AV_OPT_TYPE_CONST,  {.i64 = IPAR }, 0, 0, FLAGS, "curve" },

  241.     { "qua",          "quadratic",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = QUA  }, 0, 0, FLAGS, "curve" },

  242.     { "cub",          "cubic",                                       0,                    AV_OPT_TYPE_CONST,  {.i64 = CUB  }, 0, 0, FLAGS, "curve" },

  243.     { "squ",          "square root",                                 0,                    AV_OPT_TYPE_CONST,  {.i64 = SQU  }, 0, 0, FLAGS, "curve" },

  244.     { "cbr",          "cubic root",                                  0,                    AV_OPT_TYPE_CONST,  {.i64 = CBR  }, 0, 0, FLAGS, "curve" },

  245.     { "par",          "parabola",                                    0,                    AV_OPT_TYPE_CONST,  {.i64 = PAR  }, 0, 0, FLAGS, "curve" },

  246.     { "exp",          "exponential",                                 0,                    AV_OPT_TYPE_CONST,  {.i64 = EXP  }, 0, 0, FLAGS, "curve" },

  247.     { "iqsin",        "inverted quarter of sine wave",               0,                    AV_OPT_TYPE_CONST,  {.i64 = IQSIN}, 0, 0, FLAGS, "curve" },

  248.     { "ihsin",        "inverted half of sine wave",                  0,                    AV_OPT_TYPE_CONST,  {.i64 = IHSIN}, 0, 0, FLAGS, "curve" },

  249.     { "dese",         "double-exponential seat",                     0,                    AV_OPT_TYPE_CONST,  {.i64 = DESE }, 0, 0, FLAGS, "curve" },

  250.     { "desi",         "double-exponential sigmoid",                  0,                    AV_OPT_TYPE_CONST,  {.i64 = DESI }, 0, 0, FLAGS, "curve" },

  251.     { NULL }

  252. };

  253. 

  254. AVFILTER_DEFINE_CLASS(afade);

  255. 

  256. static av_cold int init(AVFilterContext *ctx)

  257. {

  258.     AudioFadeContext *s = ctx->priv;

  259. 

  260.     if (INT64_MAX - s->nb_samples < s->start_sample)

  261.         return AVERROR(EINVAL);

  262. 

  263.     return 0;

  264. }

  265. 

  266. static int filter_frame(AVFilterLink *inlink, AVFrame *buf)

  267. {

  268.     AudioFadeContext *s     = inlink->dst->priv;

  269.     AVFilterLink *outlink   = inlink->dst->outputs[0];

  270.     int nb_samples          = buf->nb_samples;

  271.     AVFrame *out_buf;

  272.     int64_t cur_sample = av_rescale_q(buf->pts, inlink->time_base, (AVRational){1, inlink->sample_rate});

  273. 

  274.     if ((!s->type && (s->start_sample + s->nb_samples < cur_sample)) ||

  275.         ( s->type && (cur_sample + s->nb_samples < s->start_sample)))

  276.         return ff_filter_frame(outlink, buf);

  277. 

  278.     if (av_frame_is_writable(buf)) {

  279.         out_buf = buf;

  280.     } else {

  281.         out_buf = ff_get_audio_buffer(inlink, nb_samples);

  282.         if (!out_buf)

  283.             return AVERROR(ENOMEM);

  284.         av_frame_copy_props(out_buf, buf);

  285.     }

  286. 

  287.     if ((!s->type && (cur_sample + nb_samples < s->start_sample)) ||

  288.         ( s->type && (s->start_sample + s->nb_samples < cur_sample))) {

  289.         av_samples_set_silence(out_buf->extended_data, 0, nb_samples,

  290.                                av_frame_get_channels(out_buf), out_buf->format);

  291.     } else {

  292.         int64_t start;

  293. 

  294.         if (!s->type)

  295.             start = cur_sample - s->start_sample;

  296.         else

  297.             start = s->start_sample + s->nb_samples - cur_sample;

  298. 

  299.         s->fade_samples(out_buf->extended_data, buf->extended_data,

  300.                         nb_samples, av_frame_get_channels(buf),

  301.                         s->type ? -1 : 1, start,

  302.                         s->nb_samples, s->curve);

  303.     }

  304. 

  305.     if (buf != out_buf)

  306.         av_frame_free(&buf);

  307. 

  308.     return ff_filter_frame(outlink, out_buf);

  309. }

  310. 

  311. static const AVFilterPad avfilter_af_afade_inputs[] = {

  312.     {

  313.         .name         = "default",

  314.         .type         = AVMEDIA_TYPE_AUDIO,

  315.         .filter_frame = filter_frame,

  316.     },

  317.     { NULL }

  318. };

  319. 

  320. static const AVFilterPad avfilter_af_afade_outputs[] = {

  321.     {

  322.         .name         = "default",

  323.         .type         = AVMEDIA_TYPE_AUDIO,

  324.         .config_props = config_output,

  325.     },

  326.     { NULL }

  327. };

  328. 

  329. AVFilter ff_af_afade = {

  330.     .name          = "afade",

  331.     .description   = NULL_IF_CONFIG_SMALL("Fade in/out input audio."),

  332.     .query_formats = query_formats,

  333.     .priv_size     = sizeof(AudioFadeContext),

  334.     .init          = init,

  335.     .inputs        = avfilter_af_afade_inputs,

  336.     .outputs       = avfilter_af_afade_outputs,

  337.     .priv_class    = &afade_class,

  338.     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

  339. };

  340. 

  341. #endif /* CONFIG_AFADE_FILTER */

  342. 

  343. #if CONFIG_ACROSSFADE_FILTER

  344. 

  345. static const AVOption acrossfade_options[] = {

  346.     { "nb_samples",   "set number of samples for cross fade duration", OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX/10, FLAGS },

  347.     { "ns",           "set number of samples for cross fade duration", OFFSET(nb_samples),   AV_OPT_TYPE_INT,    {.i64 = 44100}, 1, INT32_MAX/10, FLAGS },

  348.     { "duration",     "set cross fade duration",                       OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, 60, FLAGS },

  349.     { "d",            "set cross fade duration",                       OFFSET(duration),     AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, 60, FLAGS },

  350.     { "overlap",      "overlap 1st stream end with 2nd stream start",  OFFSET(overlap),      AV_OPT_TYPE_INT,    {.i64 = 1    }, 0,  1, FLAGS },

  351.     { "o",            "overlap 1st stream end with 2nd stream start",  OFFSET(overlap),      AV_OPT_TYPE_INT,    {.i64 = 1    }, 0,  1, FLAGS },

  352.     { "curve1",       "set fade curve type for 1st stream",            OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve1" },

  353.     { "c1",           "set fade curve type for 1st stream",            OFFSET(curve),        AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve1" },

  354.     {     "tri",      "linear slope",                                  0,                    AV_OPT_TYPE_CONST,  {.i64 = TRI  }, 0, 0, FLAGS, "curve1" },

  355.     {     "qsin",     "quarter of sine wave",                          0,                    AV_OPT_TYPE_CONST,  {.i64 = QSIN }, 0, 0, FLAGS, "curve1" },

  356.     {     "esin",     "exponential sine wave",                         0,                    AV_OPT_TYPE_CONST,  {.i64 = ESIN }, 0, 0, FLAGS, "curve1" },

  357.     {     "hsin",     "half of sine wave",                             0,                    AV_OPT_TYPE_CONST,  {.i64 = HSIN }, 0, 0, FLAGS, "curve1" },

  358.     {     "log",      "logarithmic",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = LOG  }, 0, 0, FLAGS, "curve1" },

  359.     {     "ipar",     "inverted parabola",                             0,                    AV_OPT_TYPE_CONST,  {.i64 = IPAR }, 0, 0, FLAGS, "curve1" },

  360.     {     "qua",      "quadratic",                                     0,                    AV_OPT_TYPE_CONST,  {.i64 = QUA  }, 0, 0, FLAGS, "curve1" },

  361.     {     "cub",      "cubic",                                         0,                    AV_OPT_TYPE_CONST,  {.i64 = CUB  }, 0, 0, FLAGS, "curve1" },

  362.     {     "squ",      "square root",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = SQU  }, 0, 0, FLAGS, "curve1" },

  363.     {     "cbr",      "cubic root",                                    0,                    AV_OPT_TYPE_CONST,  {.i64 = CBR  }, 0, 0, FLAGS, "curve1" },

  364.     {     "par",      "parabola",                                      0,                    AV_OPT_TYPE_CONST,  {.i64 = PAR  }, 0, 0, FLAGS, "curve1" },

  365.     {     "exp",      "exponential",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = EXP  }, 0, 0, FLAGS, "curve1" },

  366.     {     "iqsin",    "inverted quarter of sine wave",                 0,                    AV_OPT_TYPE_CONST,  {.i64 = IQSIN}, 0, 0, FLAGS, "curve1" },

  367.     {     "ihsin",    "inverted half of sine wave",                    0,                    AV_OPT_TYPE_CONST,  {.i64 = IHSIN}, 0, 0, FLAGS, "curve1" },

  368.     {     "dese",     "double-exponential seat",                       0,                    AV_OPT_TYPE_CONST,  {.i64 = DESE }, 0, 0, FLAGS, "curve1" },

  369.     {     "desi",     "double-exponential sigmoid",                    0,                    AV_OPT_TYPE_CONST,  {.i64 = DESI }, 0, 0, FLAGS, "curve1" },

  370.     { "curve2",       "set fade curve type for 2nd stream",            OFFSET(curve2),       AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve2" },

  371.     { "c2",           "set fade curve type for 2nd stream",            OFFSET(curve2),       AV_OPT_TYPE_INT,    {.i64 = TRI  }, 0, NB_CURVES - 1, FLAGS, "curve2" },

  372.     {     "tri",      "linear slope",                                  0,                    AV_OPT_TYPE_CONST,  {.i64 = TRI  }, 0, 0, FLAGS, "curve2" },

  373.     {     "qsin",     "quarter of sine wave",                          0,                    AV_OPT_TYPE_CONST,  {.i64 = QSIN }, 0, 0, FLAGS, "curve2" },

  374.     {     "esin",     "exponential sine wave",                         0,                    AV_OPT_TYPE_CONST,  {.i64 = ESIN }, 0, 0, FLAGS, "curve2" },

  375.     {     "hsin",     "half of sine wave",                             0,                    AV_OPT_TYPE_CONST,  {.i64 = HSIN }, 0, 0, FLAGS, "curve2" },

  376.     {     "log",      "logarithmic",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = LOG  }, 0, 0, FLAGS, "curve2" },

  377.     {     "ipar",     "inverted parabola",                             0,                    AV_OPT_TYPE_CONST,  {.i64 = IPAR }, 0, 0, FLAGS, "curve2" },

  378.     {     "qua",      "quadratic",                                     0,                    AV_OPT_TYPE_CONST,  {.i64 = QUA  }, 0, 0, FLAGS, "curve2" },

  379.     {     "cub",      "cubic",                                         0,                    AV_OPT_TYPE_CONST,  {.i64 = CUB  }, 0, 0, FLAGS, "curve2" },

  380.     {     "squ",      "square root",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = SQU  }, 0, 0, FLAGS, "curve2" },

  381.     {     "cbr",      "cubic root",                                    0,                    AV_OPT_TYPE_CONST,  {.i64 = CBR  }, 0, 0, FLAGS, "curve2" },

  382.     {     "par",      "parabola",                                      0,                    AV_OPT_TYPE_CONST,  {.i64 = PAR  }, 0, 0, FLAGS, "curve2" },

  383.     {     "exp",      "exponential",                                   0,                    AV_OPT_TYPE_CONST,  {.i64 = EXP  }, 0, 0, FLAGS, "curve2" },

  384.     {     "iqsin",    "inverted quarter of sine wave",                 0,                    AV_OPT_TYPE_CONST,  {.i64 = IQSIN}, 0, 0, FLAGS, "curve2" },

  385.     {     "ihsin",    "inverted half of sine wave",                    0,                    AV_OPT_TYPE_CONST,  {.i64 = IHSIN}, 0, 0, FLAGS, "curve2" },

  386.     {     "dese",     "double-exponential seat",                       0,                    AV_OPT_TYPE_CONST,  {.i64 = DESE }, 0, 0, FLAGS, "curve2" },

  387.     {     "desi",     "double-exponential sigmoid",                    0,                    AV_OPT_TYPE_CONST,  {.i64 = DESI }, 0, 0, FLAGS, "curve2" },

  388.     { NULL }

  389. };

  390. 

  391. AVFILTER_DEFINE_CLASS(acrossfade);

  392. 

  393. #define CROSSFADE_PLANAR(name, type)                                           \

  394. static void crossfade_samples_## name ##p(uint8_t **dst, uint8_t * const *cf0, \

  395.                                           uint8_t * const *cf1,                \

  396.                                           int nb_samples, int channels,        \

  397.                                           int curve0, int curve1)              \

  398. {                                                                              \

  399.     int i, c;                                                                  \

  400.                                                                                \

  401.     for (i = 0; i < nb_samples; i++) {                                         \

  402.         double gain0 = fade_gain(curve0, nb_samples - 1 - i, nb_samples);      \

  403.         double gain1 = fade_gain(curve1, i, nb_samples);                       \

  404.         for (c = 0; c < channels; c++) {                                       \

  405.             type *d = (type *)dst[c];                                          \

  406.             const type *s0 = (type *)cf0[c];                                   \

  407.             const type *s1 = (type *)cf1[c];                                   \

  408.                                                                                \

  409.             d[i] = s0[i] * gain0 + s1[i] * gain1;                              \

  410.         }                                                                      \

  411.     }                                                                          \

  412. }

  413. 

  414. #define CROSSFADE(name, type)                                               \

  415. static void crossfade_samples_## name (uint8_t **dst, uint8_t * const *cf0, \

  416.                                        uint8_t * const *cf1,                \

  417.                                        int nb_samples, int channels,        \

  418.                                        int curve0, int curve1)              \

  419. {                                                                           \

  420.     type *d = (type *)dst[0];                                               \

  421.     const type *s0 = (type *)cf0[0];                                        \

  422.     const type *s1 = (type *)cf1[0];                                        \

  423.     int i, c, k = 0;                                                        \

  424.                                                                             \

  425.     for (i = 0; i < nb_samples; i++) {                                      \

  426.         double gain0 = fade_gain(curve0, nb_samples - 1 - i, nb_samples);   \

  427.         double gain1 = fade_gain(curve1, i, nb_samples);                    \

  428.         for (c = 0; c < channels; c++, k++)                                 \

  429.             d[k] = s0[k] * gain0 + s1[k] * gain1;                           \

  430.     }                                                                       \

  431. }

  432. 

  433. CROSSFADE_PLANAR(dbl, double)

  434. CROSSFADE_PLANAR(flt, float)

  435. CROSSFADE_PLANAR(s16, int16_t)

  436. CROSSFADE_PLANAR(s32, int32_t)

  437. 

  438. CROSSFADE(dbl, double)

  439. CROSSFADE(flt, float)

  440. CROSSFADE(s16, int16_t)

  441. CROSSFADE(s32, int32_t)

  442. 

  443. static int acrossfade_filter_frame(AVFilterLink *inlink, AVFrame *in)

  444. {

  445.     AVFilterContext *ctx  = inlink->dst;

  446.     AudioFadeContext *s   = ctx->priv;

  447.     AVFilterLink *outlink = ctx->outputs[0];

  448.     AVFrame *out, *cf[2] = { NULL };

  449.     int ret = 0, nb_samples;

  450. 

  451.     if (s->crossfade_is_over) {

  452.         in->pts = s->pts;

  453.         s->pts += av_rescale_q(in->nb_samples,

  454.             (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  455.         return ff_filter_frame(outlink, in);

  456.     } else if (inlink == ctx->inputs[0]) {

  457.         av_audio_fifo_write(s->fifo[0], (void **)in->extended_data, in->nb_samples);

  458. 

  459.         nb_samples = av_audio_fifo_size(s->fifo[0]) - s->nb_samples;

  460.         if (nb_samples > 0) {

  461.             out = ff_get_audio_buffer(outlink, nb_samples);

  462.             if (!out) {

  463.                 ret = AVERROR(ENOMEM);

  464.                 goto fail;

  465.             }

  466.             av_audio_fifo_read(s->fifo[0], (void **)out->extended_data, nb_samples);

  467.             out->pts = s->pts;

  468.             s->pts += av_rescale_q(nb_samples,

  469.                 (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  470.             ret = ff_filter_frame(outlink, out);

  471.         }

  472.     } else if (av_audio_fifo_size(s->fifo[1]) < s->nb_samples) {

  473.         if (!s->overlap && av_audio_fifo_size(s->fifo[0]) > 0) {

  474.             nb_samples = av_audio_fifo_size(s->fifo[0]);

  475. 

  476.             cf[0] = ff_get_audio_buffer(outlink, nb_samples);

  477.             out = ff_get_audio_buffer(outlink, nb_samples);

  478.             if (!out || !cf[0]) {

  479.                 ret = AVERROR(ENOMEM);

  480.                 goto fail;

  481.             }

  482.             av_audio_fifo_read(s->fifo[0], (void **)cf[0]->extended_data, nb_samples);

  483. 

  484.             s->fade_samples(out->extended_data, cf[0]->extended_data, nb_samples,

  485.                             outlink->channels, -1, nb_samples - 1, nb_samples, s->curve);

  486.             out->pts = s->pts;

  487.             s->pts += av_rescale_q(nb_samples,

  488.                 (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  489.             ret = ff_filter_frame(outlink, out);

  490.             if (ret < 0)

  491.                 goto fail;

  492.         }

  493. 

  494.         av_audio_fifo_write(s->fifo[1], (void **)in->extended_data, in->nb_samples);

  495.     } else if (av_audio_fifo_size(s->fifo[1]) >= s->nb_samples) {

  496.         if (s->overlap) {

  497.             cf[0] = ff_get_audio_buffer(outlink, s->nb_samples);

  498.             cf[1] = ff_get_audio_buffer(outlink, s->nb_samples);

  499.             out = ff_get_audio_buffer(outlink, s->nb_samples);

  500.             if (!out || !cf[0] || !cf[1]) {

  501.                 av_frame_free(&out);

  502.                 ret = AVERROR(ENOMEM);

  503.                 goto fail;

  504.             }

  505. 

  506.             av_audio_fifo_read(s->fifo[0], (void **)cf[0]->extended_data, s->nb_samples);

  507.             av_audio_fifo_read(s->fifo[1], (void **)cf[1]->extended_data, s->nb_samples);

  508. 

  509.             s->crossfade_samples(out->extended_data, cf[0]->extended_data,

  510.                                  cf[1]->extended_data,

  511.                                  s->nb_samples, av_frame_get_channels(in),

  512.                                  s->curve, s->curve2);

  513.             out->pts = s->pts;

  514.             s->pts += av_rescale_q(s->nb_samples,

  515.                 (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  516.             ret = ff_filter_frame(outlink, out);

  517.             if (ret < 0)

  518.                 goto fail;

  519.         } else {

  520.             out = ff_get_audio_buffer(outlink, s->nb_samples);

  521.             cf[1] = ff_get_audio_buffer(outlink, s->nb_samples);

  522.             if (!out || !cf[1]) {

  523.                 ret = AVERROR(ENOMEM);

  524.                 av_frame_free(&out);

  525.                 goto fail;

  526.             }

  527. 

  528.             av_audio_fifo_read(s->fifo[1], (void **)cf[1]->extended_data, s->nb_samples);

  529. 

  530.             s->fade_samples(out->extended_data, cf[1]->extended_data, s->nb_samples,

  531.                             outlink->channels, 1, 0, s->nb_samples, s->curve2);

  532.             out->pts = s->pts;

  533.             s->pts += av_rescale_q(s->nb_samples,

  534.                 (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  535.             ret = ff_filter_frame(outlink, out);

  536.             if (ret < 0)

  537.                 goto fail;

  538.         }

  539. 

  540.         nb_samples = av_audio_fifo_size(s->fifo[1]);

  541.         if (nb_samples > 0) {

  542.             out = ff_get_audio_buffer(outlink, nb_samples);

  543.             if (!out) {

  544.                 ret = AVERROR(ENOMEM);

  545.                 goto fail;

  546.             }

  547. 

  548.             av_audio_fifo_read(s->fifo[1], (void **)out->extended_data, nb_samples);

  549.             out->pts = s->pts;

  550.             s->pts += av_rescale_q(nb_samples,

  551.                 (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

  552.             ret = ff_filter_frame(outlink, out);

  553.         }

  554.         s->crossfade_is_over = 1;

  555.     }

  556. 

  557. fail:

  558.     av_frame_free(&in);

  559.     av_frame_free(&cf[0]);

  560.     av_frame_free(&cf[1]);

  561.     return ret;

  562. }

  563. 

  564. static int acrossfade_request_frame(AVFilterLink *outlink)

  565. {

  566.     AVFilterContext *ctx = outlink->src;

  567.     AudioFadeContext *s = ctx->priv;

  568.     int ret = 0;

  569. 

  570.     if (!s->cf0_eof) {

  571.         AVFilterLink *cf0 = ctx->inputs[0];

  572.         ret = ff_request_frame(cf0);

  573.         if (ret < 0 && ret != AVERROR_EOF)

  574.             return ret;

  575.         if (ret == AVERROR_EOF) {

  576.             s->cf0_eof = 1;

  577.             ret = 0;

  578.         }

  579.     } else {

  580.         AVFilterLink *cf1 = ctx->inputs[1];

  581.         int nb_samples = av_audio_fifo_size(s->fifo[1]);

  582. 

  583.         ret = ff_request_frame(cf1);

  584.         if (ret == AVERROR_EOF && nb_samples > 0) {

  585.             AVFrame *out = ff_get_audio_buffer(outlink, nb_samples);

  586.             if (!out)

  587.                 return AVERROR(ENOMEM);

  588. 

  589.             av_audio_fifo_read(s->fifo[1], (void **)out->extended_data, nb_samples);

  590.             ret = ff_filter_frame(outlink, out);

  591.         }

  592.     }

  593. 

  594.     return ret;

  595. }

  596. 

  597. static int acrossfade_config_output(AVFilterLink *outlink)

  598. {

  599.     AVFilterContext *ctx = outlink->src;

  600.     AudioFadeContext *s  = ctx->priv;

  601. 

  602.     if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {

  603.         av_log(ctx, AV_LOG_ERROR,

  604.                "Inputs must have the same sample rate "

  605.                "%d for in0 vs %d for in1\n",

  606.                ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);

  607.         return AVERROR(EINVAL);

  608.     }

  609. 

  610.     outlink->sample_rate = ctx->inputs[0]->sample_rate;

  611.     outlink->time_base   = ctx->inputs[0]->time_base;

  612.     outlink->channel_layout = ctx->inputs[0]->channel_layout;

  613.     outlink->channels = ctx->inputs[0]->channels;

  614.     outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;

  615. 

  616.     switch (outlink->format) {

  617.     case AV_SAMPLE_FMT_DBL:  s->crossfade_samples = crossfade_samples_dbl;  break;

  618.     case AV_SAMPLE_FMT_DBLP: s->crossfade_samples = crossfade_samples_dblp; break;

  619.     case AV_SAMPLE_FMT_FLT:  s->crossfade_samples = crossfade_samples_flt;  break;

  620.     case AV_SAMPLE_FMT_FLTP: s->crossfade_samples = crossfade_samples_fltp; break;

  621.     case AV_SAMPLE_FMT_S16:  s->crossfade_samples = crossfade_samples_s16;  break;

  622.     case AV_SAMPLE_FMT_S16P: s->crossfade_samples = crossfade_samples_s16p; break;

  623.     case AV_SAMPLE_FMT_S32:  s->crossfade_samples = crossfade_samples_s32;  break;

  624.     case AV_SAMPLE_FMT_S32P: s->crossfade_samples = crossfade_samples_s32p; break;

  625.     }

  626. 

  627.     config_output(outlink);

  628. 

  629.     s->fifo[0] = av_audio_fifo_alloc(outlink->format, outlink->channels, s->nb_samples);

  630.     s->fifo[1] = av_audio_fifo_alloc(outlink->format, outlink->channels, s->nb_samples);

  631.     if (!s->fifo[0] || !s->fifo[1])

  632.         return AVERROR(ENOMEM);

  633. 

  634.     return 0;

  635. }

  636. 

  637. static av_cold void uninit(AVFilterContext *ctx)

  638. {

  639.     AudioFadeContext *s = ctx->priv;

  640. 

  641.     av_audio_fifo_free(s->fifo[0]);

  642.     av_audio_fifo_free(s->fifo[1]);

  643. }

  644. 

  645. static const AVFilterPad avfilter_af_acrossfade_inputs[] = {

  646.     {

  647.         .name         = "crossfade0",

  648.         .type         = AVMEDIA_TYPE_AUDIO,

  649.         .filter_frame = acrossfade_filter_frame,

  650.     },

  651.     {

  652.         .name         = "crossfade1",

  653.         .type         = AVMEDIA_TYPE_AUDIO,

  654.         .filter_frame = acrossfade_filter_frame,

  655.     },

  656.     { NULL }

  657. };

  658. 

  659. static const AVFilterPad avfilter_af_acrossfade_outputs[] = {

  660.     {

  661.         .name          = "default",

  662.         .type          = AVMEDIA_TYPE_AUDIO,

  663.         .request_frame = acrossfade_request_frame,

  664.         .config_props  = acrossfade_config_output,

  665.     },

  666.     { NULL }

  667. };

  668. 

  669. AVFilter ff_af_acrossfade = {

  670.     .name          = "acrossfade",

  671.     .description   = NULL_IF_CONFIG_SMALL("Cross fade two input audio streams."),

  672.     .query_formats = query_formats,

  673.     .priv_size     = sizeof(AudioFadeContext),

  674.     .uninit        = uninit,

  675.     .priv_class    = &acrossfade_class,

  676.     .inputs        = avfilter_af_acrossfade_inputs,

  677.     .outputs       = avfilter_af_acrossfade_outputs,

  678. };

  679. 

  680. #endif /* CONFIG_ACROSSFADE_FILTER */