avfilter: add showfreqs filter

Changelog

@@ -31,6 +31,7 @@ version <next>:
 - atadenoise video filter
 - OS X VideoToolbox support
 - aphasemeter filter
+- showfreqs filter
 
 
 version 2.7:

configure

@@ -2785,6 +2785,8 @@ select_filter_select="pixelutils"
 smartblur_filter_deps="gpl swscale"
 showcqt_filter_deps="avcodec"
 showcqt_filter_select="fft"
+showfreqs_filter_deps="avcodec"
+showfreqs_filter_select="fft"
 showspectrum_filter_deps="avcodec"
 showspectrum_filter_select="rdft"
 spp_filter_deps="gpl avcodec"

doc/filters.texi

@@ -12704,6 +12704,121 @@ gamma=2:gamma2=2
 
 @end itemize
 
+@section showfreqs
+
+Convert input audio to video output representing the audio power spectrum.
+Audio amplitude is on Y-axis while frequency is on X-axis.
+
+The filter accepts the following options:
+
+@table @option
+@item size, s
+Specify size of video. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default is @code{1024x512}.
+
+@item mode
+Set display mode.
+This set how each frequency bin will be represented.
+
+It accepts the following values:
+@table @samp
+@item line
+@item bar
+@item dot
+@end table
+Default is @code{bar}.
+
+@item ascale
+Set amplitude scale.
+
+It accepts the following values:
+@table @samp
+@item lin
+Linear scale.
+
+@item sqrt
+Square root scale.
+
+@item cbrt
+Cubic root scale.
+
+@item log
+Logarithmic scale.
+@end table
+Default is @code{log}.
+
+@item fscale
+Set frequency scale.
+
+It accepts the following values:
+@table @samp
+@item lin
+Linear scale.
+
+@item log
+Logarithmic scale.
+
+@item rlog
+Reverse logarithmic scale.
+@end table
+Default is @code{lin}.
+
+@item win_size
+Set window size.
+
+It accepts the following values:
+@table @samp
+@item w16
+@item w32
+@item w64
+@item w128
+@item w256
+@item w512
+@item w1024
+@item w2048
+@item w4096
+@item w8192
+@item w16384
+@item w32768
+@item w65536
+@end table
+Default is @code{w2048}
+
+@item win_func
+Set windowing function.
+
+It accepts the following values:
+@table @samp
+@item rect
+@item bartlett
+@item hanning
+@item hamming
+@item blackman
+@item welch
+@item flattop
+@item bharris
+@item bnuttall
+@item bhann
+@item sine
+@item nuttall
+@end table
+Default is @code{hanning}.
+
+@item overlap
+Set window overlap. In range @code{[0, 1]}. Default is @code{1},
+which means optimal overlap for selected window function will be picked.
+
+@item averaging
+Set time averaging. Setting this to 0 will display current maximal peaks.
+Default is @code{1}, which means time averaging is disabled.
+
+@item color
+Specify list of colors separated by space or by '|' which will be used to
+draw channel frequencies. Unrecognized or missing colors will be replaced
+by white color.
+@end table
+
 @section showspectrum
 
 Convert input audio to a video output, representing the audio frequency

libavfilter/Makefile

@@ -258,6 +258,7 @@ OBJS-$(CONFIG_APHASEMETER_FILTER)            += avf_aphasemeter.o
 OBJS-$(CONFIG_AVECTORSCOPE_FILTER)           += avf_avectorscope.o
 OBJS-$(CONFIG_CONCAT_FILTER)                 += avf_concat.o
 OBJS-$(CONFIG_SHOWCQT_FILTER)                += avf_showcqt.o
+OBJS-$(CONFIG_SHOWFREQS_FILTER)              += avf_showfreqs.o
 OBJS-$(CONFIG_SHOWSPECTRUM_FILTER)           += avf_showspectrum.o
 OBJS-$(CONFIG_SHOWVOLUME_FILTER)             += avf_showvolume.o
 OBJS-$(CONFIG_SHOWWAVES_FILTER)              += avf_showwaves.o

libavfilter/allfilters.c

@@ -273,6 +273,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(AVECTORSCOPE,   avectorscope,   avf);
     REGISTER_FILTER(CONCAT,         concat,         avf);
     REGISTER_FILTER(SHOWCQT,        showcqt,        avf);
+    REGISTER_FILTER(SHOWFREQS,      showfreqs,      avf);
     REGISTER_FILTER(SHOWSPECTRUM,   showspectrum,   avf);
     REGISTER_FILTER(SHOWVOLUME,     showvolume,     avf);
     REGISTER_FILTER(SHOWWAVES,      showwaves,      avf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  5
-#define LIBAVFILTER_VERSION_MINOR  34
+#define LIBAVFILTER_VERSION_MINOR  35
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavutil/audio_fifo.c

@@ -136,6 +136,25 @@ int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples)
     return nb_samples;
 }
 
+int av_audio_fifo_peek(AVAudioFifo *af, void **data, int nb_samples)
+{
+    int i, ret, size;
+
+    if (nb_samples < 0)
+        return AVERROR(EINVAL);
+    nb_samples = FFMIN(nb_samples, af->nb_samples);
+    if (!nb_samples)
+        return 0;
+
+    size = nb_samples * af->sample_size;
+    for (i = 0; i < af->nb_buffers; i++) {
+        if ((ret = av_fifo_generic_peek(af->buf[i], data[i], size, NULL)) < 0)
+            return AVERROR_BUG;
+    }
+
+    return nb_samples;
+}
+
 int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples)
 {
     int i, ret, size;

libavutil/audio_fifo.h

@@ -93,6 +93,22 @@ int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples);
  */
 int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples);
 
+/**
+ * Peek data from an AVAudioFifo.
+ *
+ * @see enum AVSampleFormat
+ * The documentation for AVSampleFormat describes the data layout.
+ *
+ * @param af          AVAudioFifo to read from
+ * @param data        audio data plane pointers
+ * @param nb_samples  number of samples to peek
+ * @return            number of samples actually peek, or negative AVERROR code
+ *                    on failure. The number of samples actually peek will not
+ *                    be greater than nb_samples, and will only be less than
+ *                    nb_samples if av_audio_fifo_size is less than nb_samples.
+ */
+int av_audio_fifo_peek(AVAudioFifo *af, void **data, int nb_samples);
+
 /**
  * Read data from an AVAudioFifo.
  *

libavutil/fifo.c

@@ -148,6 +148,32 @@ int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size,
     return total - size;
 }
 
+int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size,
+                         void (*func)(void *, void *, int))
+{
+// Read memory barrier needed for SMP here in theory
+    uint8_t *rptr = f->rptr;
+    uint32_t rndx = f->rndx;
+
+    do {
+        int len = FFMIN(f->end - f->rptr, buf_size);
+        if (func)
+            func(dest, f->rptr, len);
+        else {
+            memcpy(dest, f->rptr, len);
+            dest = (uint8_t *)dest + len;
+        }
+// memory barrier needed for SMP here in theory
+        av_fifo_drain(f, len);
+        buf_size -= len;
+    } while (buf_size > 0);
+
+    f->rptr = rptr;
+    f->rndx = rndx;
+
+    return 0;
+}
+
 int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size,
                          void (*func)(void *, void *, int))
 {

libavutil/fifo.h

@@ -83,6 +83,16 @@ int av_fifo_size(const AVFifoBuffer *f);
  */
 int av_fifo_space(const AVFifoBuffer *f);
 
+/**
+ * Feed data from an AVFifoBuffer to a user-supplied callback.
+ * Similar as av_fifo_gereric_read but without discarding data.
+ * @param f AVFifoBuffer to read from
+ * @param buf_size number of bytes to read
+ * @param func generic read function
+ * @param dest data destination
+ */
+int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
+
 /**
  * Feed data from an AVFifoBuffer to a user-supplied callback.
  * @param f AVFifoBuffer to read from