diff options
Diffstat (limited to 'gst/audiofx/audiowsincband.c')
| -rw-r--r-- | gst/audiofx/audiowsincband.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/gst/audiofx/audiowsincband.c b/gst/audiofx/audiowsincband.c index d9690b6c..f86de8d0 100644 --- a/gst/audiofx/audiowsincband.c +++ b/gst/audiofx/audiowsincband.c @@ -31,6 +31,30 @@ * is probably the bottleneck * - Maybe allow cascading the filter to get a better stopband attenuation. * Can be done by convolving a filter kernel with itself + * - Drop the first kernel_length/2 samples and append the same number of + * samples on EOS as the first few samples are essentialy zero. + */ + +/** + * SECTION:element-bpwsinc + * @short_description: Windowed Sinc band pass and band reject filter + * + * <refsect2> + * <para> + * Attenuates all frequencies outside (bandpass) or inside (bandreject) of a frequency + * band. The length parameter controls the rolloff, the window parameter + * controls rolloff and stopband attenuation. The Hamming window provides a faster rolloff but a bit + * worse stopband attenuation, the other way around for the Blackman window. + * </para> + * <title>Example launch line</title> + * <para> + * <programlisting> + * gst-launch audiotestsrc freq=1500 ! audioconvert ! bpwsinc mode=band-pass lower-frequency=3000 upper-frequency=10000 length=501 window=blackman ! audioconvert ! alsasink + * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! bpwsinc mode=band-reject lower-frequency=59 upper-frequency=61 length=10001 window=hamming ! audioconvert ! alsasink + * gst-launch audiotestsrc wave=white-noise ! audioconvert ! bpwsinc mode=band-pass lower-frequency=1000 upper-frequency=2000 length=31 ! audioconvert ! alsasink + * </programlisting> + * </para> + * </refsect2> */ #ifdef HAVE_CONFIG_H @@ -49,7 +73,7 @@ GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); static const GstElementDetails bpwsinc_details = -GST_ELEMENT_DETAILS ("Band-pass Windowed sinc filter", +GST_ELEMENT_DETAILS ("Band-pass and Band-reject Windowed sinc filter", "Filter/Effect/Audio", "Band-pass Windowed sinc filter", "Thomas <thomas@apestaart.org>, " @@ -134,7 +158,7 @@ gst_bpwsinc_window_get_type (void) " channels = (int) [ 1, MAX ] " #define DEBUG_INIT(bla) \ - GST_DEBUG_CATEGORY_INIT (gst_bpwsinc_debug, "bpwsinc", 0, "Band-pass Windowed sinc filter plugin"); + GST_DEBUG_CATEGORY_INIT (gst_bpwsinc_debug, "bpwsinc", 0, "Band-pass and Band-reject Windowed sinc filter plugin"); GST_BOILERPLATE_FULL (GstBPWSinc, gst_bpwsinc, GstAudioFilter, GST_TYPE_AUDIO_FILTER, DEBUG_INIT); |