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authorAlessandro Ghedini <alessandro@ghedini.me>2014-04-06 16:25:08 +0200
committerAnton Khirnov <anton@khirnov.net>2014-04-13 11:25:06 +0200
commitaaab192df24a90f4450285cfb73b395cf495b462 (patch)
treedfc16fafb9c61083be568afd6b7e99f21dd37a20
parentac976ed91e323754e9a84509873ebdb437372797 (diff)
downloadffmpeg-aaab192df24a90f4450285cfb73b395cf495b462.tar.gz
af_volume: implement replaygain clipping prevention
This adds a new "replaygain_noclip" option to the filter, and, if enabled, limits the gain applied for tracks where clipping would occur. Signed-off-by: Anton Khirnov <anton@khirnov.net>
-rw-r--r--doc/filters.texi5
-rw-r--r--libavfilter/af_volume.c23
-rw-r--r--libavfilter/af_volume.h1
3 files changed, 23 insertions, 6 deletions
diff --git a/doc/filters.texi b/doc/filters.texi
index 2798881cc1..18531de295 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -676,6 +676,11 @@ Pre-amplification gain in dB to apply to the selected replaygain gain.
Default value for @var{replaygain_preamp} is 0.0.
+@item replaygain_noclip
+Prevent clipping by limiting the gain applied.
+
+Default value for @var{replaygain_noclip} is 1.
+
@end table
@subsection Examples
diff --git a/libavfilter/af_volume.c b/libavfilter/af_volume.c
index 823fa15144..11d85a17eb 100644
--- a/libavfilter/af_volume.c
+++ b/libavfilter/af_volume.c
@@ -61,6 +61,8 @@ static const AVOption options[] = {
{ "album", "album gain is preferred", 0, AV_OPT_TYPE_CONST, { .i64 = REPLAYGAIN_ALBUM }, 0, 0, A, "replaygain" },
{ "replaygain_preamp", "Apply replaygain pre-amplification",
OFFSET(replaygain_preamp), AV_OPT_TYPE_DOUBLE, { .dbl = 0.0 }, -15.0, 15.0, A },
+ { "replaygain_noclip", "Apply replaygain clipping prevention",
+ OFFSET(replaygain_noclip), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, A },
{ NULL },
};
@@ -246,25 +248,34 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
if (sd && vol->replaygain != REPLAYGAIN_IGNORE) {
if (vol->replaygain != REPLAYGAIN_DROP) {
AVReplayGain *replaygain = (AVReplayGain*)sd->data;
- int32_t gain;
- float g;
+ int32_t gain = 100000;
+ uint32_t peak = 100000;
+ float g, p;
if (vol->replaygain == REPLAYGAIN_TRACK &&
- replaygain->track_gain != INT32_MIN)
+ replaygain->track_gain != INT32_MIN) {
gain = replaygain->track_gain;
- else if (replaygain->album_gain != INT32_MIN)
+
+ if (replaygain->track_peak != 0)
+ peak = replaygain->track_peak;
+ } else if (replaygain->album_gain != INT32_MIN) {
gain = replaygain->album_gain;
- else {
+
+ if (replaygain->album_peak != 0)
+ peak = replaygain->album_peak;
+ } else {
av_log(inlink->dst, AV_LOG_WARNING, "Both ReplayGain gain "
"values are unknown.\n");
- gain = 100000;
}
g = gain / 100000.0f;
+ p = peak / 100000.0f;
av_log(inlink->dst, AV_LOG_VERBOSE,
"Using gain %f dB from replaygain side data.\n", g);
vol->volume = pow(10, (g + vol->replaygain_preamp) / 20);
+ if (vol->replaygain_noclip)
+ vol->volume = FFMIN(vol->volume, 1.0 / p);
vol->volume_i = (int)(vol->volume * 256 + 0.5);
volume_init(vol);
diff --git a/libavfilter/af_volume.h b/libavfilter/af_volume.h
index d831ec4a3d..6bd89acc4d 100644
--- a/libavfilter/af_volume.h
+++ b/libavfilter/af_volume.h
@@ -48,6 +48,7 @@ typedef struct VolumeContext {
enum PrecisionType precision;
enum ReplayGainType replaygain;
double replaygain_preamp;
+ int replaygain_noclip;
double volume;
int volume_i;
int channels;