@@ -616,6 +616,23 @@ precision of the volume scaling.

 @item double

 64-bit floating-point; limits input sample format to DBL.

 @end table

+

+@item replaygain

+Behaviour on encountering ReplayGain side data in input frames.

+

+@table @option

+@item drop

+Remove ReplayGain side data, ignoring its contents (the default).

+

+@item ignore

+Ignore ReplayGain side data, but leave it in the frame.

+

+@item track

+Prefer track gain, if present.

+

+@item album

+Prefer album gain, if present.

+@end table

 @end table

 @subsection Examples

@@ -28,7 +28,10 @@

 #include "libavutil/common.h"

 #include "libavutil/eval.h"

 #include "libavutil/float_dsp.h"

+#include "libavutil/intreadwrite.h"

 #include "libavutil/opt.h"

+#include "libavutil/replaygain.h"

+

 #include "audio.h"

 #include "avfilter.h"

 #include "formats.h"

@@ -50,6 +53,12 @@ static const AVOption options[] = {

         { "fixed",  "8-bit fixed-point.",     0, AV_OPT_TYPE_CONST, { .i64 = PRECISION_FIXED  }, INT_MIN, INT_MAX, A, "precision" },

         { "float",  "32-bit floating-point.", 0, AV_OPT_TYPE_CONST, { .i64 = PRECISION_FLOAT  }, INT_MIN, INT_MAX, A, "precision" },

         { "double", "64-bit floating-point.", 0, AV_OPT_TYPE_CONST, { .i64 = PRECISION_DOUBLE }, INT_MIN, INT_MAX, A, "precision" },

+    { "replaygain", "Apply replaygain side data when present",

+            OFFSET(replaygain), AV_OPT_TYPE_INT, { .i64 = REPLAYGAIN_DROP }, REPLAYGAIN_DROP, REPLAYGAIN_ALBUM, A, "replaygain" },

+        { "drop",   "replaygain side data is dropped", 0, AV_OPT_TYPE_CONST, { .i64 = REPLAYGAIN_DROP   }, 0, 0, A, "replaygain" },

+        { "ignore", "replaygain side data is ignored", 0, AV_OPT_TYPE_CONST, { .i64 = REPLAYGAIN_IGNORE }, 0, 0, A, "replaygain" },

+        { "track",  "track gain is preferred",         0, AV_OPT_TYPE_CONST, { .i64 = REPLAYGAIN_TRACK  }, 0, 0, A, "replaygain" },

+        { "album",  "album gain is preferred",         0, AV_OPT_TYPE_CONST, { .i64 = REPLAYGAIN_ALBUM  }, 0, 0, A, "replaygain" },

     { NULL },

 };

@@ -229,8 +238,38 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *buf)

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

     int nb_samples        = buf->nb_samples;

     AVFrame *out_buf;

+    AVFrameSideData *sd = av_frame_get_side_data(buf, AV_FRAME_DATA_REPLAYGAIN);

     int ret;

+    if (sd && vol->replaygain != REPLAYGAIN_IGNORE) {

+        if (vol->replaygain != REPLAYGAIN_DROP) {

+            AVReplayGain *replaygain = (AVReplayGain*)sd->data;

+            int32_t gain;

+            float g;

+

+            if (vol->replaygain == REPLAYGAIN_TRACK &&

+                replaygain->track_gain != INT32_MIN)

+                gain = replaygain->track_gain;

+            else if (replaygain->album_gain != INT32_MIN)

+                gain = replaygain->album_gain;

+            else {

+                av_log(inlink->dst, AV_LOG_WARNING, "Both ReplayGain gain "

+                       "values are unknown.\n");

+                gain = 100000;

+            }

+            g = gain / 100000.0f;

+

+            av_log(inlink->dst, AV_LOG_VERBOSE,

+                   "Using gain %f dB from replaygain side data.\n", g);

+

+            vol->volume   = pow(10, g / 20);

+            vol->volume_i = (int)(vol->volume * 256 + 0.5);

+

+            volume_init(vol);

+        }

+        av_frame_remove_side_data(buf, AV_FRAME_DATA_REPLAYGAIN);

+    }

+

     if (vol->volume == 1.0 || vol->volume_i == 256)

         return ff_filter_frame(outlink, buf);

@@ -35,10 +35,18 @@ enum PrecisionType {

     PRECISION_DOUBLE,

 };

+enum ReplayGainType {

+    REPLAYGAIN_DROP,

+    REPLAYGAIN_IGNORE,

+    REPLAYGAIN_TRACK,

+    REPLAYGAIN_ALBUM,

+};

+

 typedef struct VolumeContext {

     const AVClass *class;

     AVFloatDSPContext fdsp;

     enum PrecisionType precision;

+    enum ReplayGainType replaygain;

     double volume;

     int    volume_i;

     int    channels;