af_volume: add support for replaygain pre-amp and clipping prevention

This commit is contained in:
Alessandro Ghedini 2014-03-12 23:25:51 +01:00 committed by wm4
parent 3f0139e5db
commit d80dc885c6
2 changed files with 80 additions and 11 deletions

View File

@ -285,6 +285,12 @@ Available filters are:
tags, as written by mp3gain, metaflac, etc...
``replaygain-album``
Like replaygain-track, but using the album-gain value instead.
``replaygain-preamp``
Pre-amplification gain in dB to apply to the selected replaygain gain
(default: 0).
``replaygain-noclip``
Prevent clipping caused by replaygain by automatically lowering the
gain (default). Use no-replaygain-noclip to disable this.
``<softclip>``
Turns soft clipping on. Soft-clipping can make the
sound more smooth if very high volume levels are used. Enable this

View File

@ -34,11 +34,67 @@ struct priv {
float level; // Gain level for each channel
int rgain_track; // Enable/disable track based replaygain
int rgain_album; // Enable/disable album based replaygain
float rgain_preamp; // Set replaygain pre-amplification
int rgain_noclip; // Enable/disable clipping prevention
int soft; // Enable/disable soft clipping
int fast; // Use fix-point volume control
float cfg_volume;
};
static int decode_float(char *str, float *out)
{
char *rest;
float dec_val;
dec_val = strtod(str, &rest);
if (!rest || (rest == str) || !isfinite(dec_val))
return -1;
*out = dec_val;
return 0;
}
static int decode_gain(struct af_instance *af, const char *tag, float *out)
{
char *tag_val = NULL;
float dec_val;
tag_val = mp_tags_get_str(af->metadata, tag);
if (!tag_val) {
mp_msg(af->log, MSGL_ERR, "Replaygain tags not found\n");
return -1;
}
if (decode_float(tag_val, &dec_val)) {
mp_msg(af->log, MSGL_ERR, "Invalid replaygain value\n");
return -1;
}
*out = dec_val;
return 0;
}
static int decode_peak(struct af_instance *af, const char *tag, float *out)
{
char *tag_val = NULL;
float dec_val;
*out = 1.0;
tag_val = mp_tags_get_str(af->metadata, tag);
if (!tag_val)
return 0;
if (decode_float(tag_val, &dec_val))
return 0;
if (dec_val == 0.0)
return 0;
*out = dec_val;
return 0;
}
static int control(struct af_instance *af, int cmd, void *arg)
{
struct priv *s = af->priv;
@ -58,20 +114,25 @@ static int control(struct af_instance *af, int cmd, void *arg)
if (af_fmt_is_planar(in->format))
mp_audio_set_format(af->data, af_fmt_to_planar(af->data->format));
if ((s->rgain_track || s->rgain_album) && af->metadata) {
char *rgain = NULL, *rest;
float gain, peak;
char *gain_tag = NULL, *peak_tag = NULL;
if (s->rgain_track) {
rgain = mp_tags_get_str(af->metadata, "REPLAYGAIN_TRACK_GAIN");
gain_tag = "REPLAYGAIN_TRACK_GAIN";
peak_tag = "REPLAYGAIN_TRACK_PEAK";
} else if (s->rgain_album) {
rgain = mp_tags_get_str(af->metadata, "REPLAYGAIN_ALBUM_GAIN");
gain_tag = "REPLAYGAIN_ALBUM_GAIN";
peak_tag = "REPLAYGAIN_ALBUM_PEAK";
}
if (rgain) {
float db = strtod(rgain, &rest);
if (rest && (rest != rgain) && isfinite(db))
af_from_dB(1, &db, &s->level, 20.0, -200.0, 60.0);
else
mp_msg(af->log, MSGL_ERR, "Invalid replaygain value\n");
} else {
mp_msg(af->log, MSGL_ERR, "Replaygain tags not found\n");
if (!decode_gain(af, gain_tag, &gain) &&
!decode_peak(af, peak_tag, &peak))
{
gain += s->rgain_preamp;
af_from_dB(1, &gain, &s->level, 20.0, -200.0, 60.0);
if (s->rgain_noclip) // clipping prevention
s->level = MPMIN(s->level, 1.0 / peak);
}
}
return af_test_output(af, in);
@ -141,6 +202,8 @@ struct af_info af_info_volume = {
OPT_FLOATRANGE("volumedb", cfg_volume, 0, -200, 60),
OPT_FLAG("replaygain-track", rgain_track, 0),
OPT_FLAG("replaygain-album", rgain_album, 0),
OPT_FLOATRANGE("replaygain-preamp", rgain_preamp, 0, -15, 15),
OPT_FLAG("replaygain-noclip", rgain_noclip, 0, OPTDEF_INT(1)),
OPT_FLAG("softclip", soft, 0),
OPT_FLAG("s16", fast, 0),
{0}