[SCM] libav/experimental: af_volume: implement replaygain clipping prevention
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Aug 10 16:02:49 UTC 2014
The following commit has been merged in the experimental branch:
commit aaab192df24a90f4450285cfb73b395cf495b462
Author: Alessandro Ghedini <alessandro at ghedini.me>
Date: Sun Apr 6 16:25:08 2014 +0200
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 at khirnov.net>
diff --git a/doc/filters.texi b/doc/filters.texi
index 2798881..18531de 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.
+ at 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 823fa15..11d85a1 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 d831ec4..6bd89ac 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;
--
Libav/FFmpeg packaging
More information about the pkg-multimedia-commits
mailing list