[FFmpeg-devel] [PATCH] lavfi/showspectrum: display multiple channels in separate row

Rudolf Polzer divverent at xonotic.org
Fri Feb 1 17:28:24 CET 2013


On Fri, Feb 01, 2013 at 04:19:35PM +0000, Paul B Mahol wrote:
> On 2/1/13, Rudolf Polzer <divverent at xonotic.org> wrote:
> > The showspectrum filter gets multiple channel (any count) support. Most
> > ideas here are from durandal_1707.
> >
> > Screenshots (temporary URL):
> > http://rm.sudo.rm-f.org/~xonotic/temp/ffmpeg-showspectrum/screenshots/
> >
> > New options:
> >
> > - combined=1: old ffplay-like combined view of all channels
> > - intensity=1: sox-like intensity spectrum
> > - logscale=1: sox-like logarithmic scale
> > - saturation=<float>: saturation modifier
> 
> If there are no objections i will commit this but with different
> logic in options and updated doxy:
> 
> mode: combined, separate

sure

> ???: intensity

color=intensity, color=channel, color=gray (latter would be kinda
redundant with saturation=0, but who cares)

> scale: logarithmic, square root

A bit long... maybe scale=log, scale=sqrt (and maybe scale=lin too?
didn't look very useful when I tried it, though...)

Will you do these changes? They certainly are fine by me.

> saturation is same as before
> 
> Feel free to propose something better.
> 
> >
> > Signed-off-by: Rudolf Polzer <divverent at xonotic.org>
> > ---
> >  Changelog                      |   1 +
> >  doc/filters.texi               |   4 +
> >  libavfilter/avf_showspectrum.c | 215
> > ++++++++++++++++++++++++++++++++++-------
> >  3 files changed, 186 insertions(+), 34 deletions(-)
> >
> > diff --git a/Changelog b/Changelog
> > index c509c4c..8d9befc 100644
> > --- a/Changelog
> > +++ b/Changelog
> > @@ -10,6 +10,7 @@ version <next>:
> >  - EVRC decoder
> >  - audio fade filter
> >  - filtering audio with unknown channel layout
> > +- showspectrum now with separate channel display and multichannel
> > (configurable)
> >
> >
> >  version 1.1:
> > diff --git a/doc/filters.texi b/doc/filters.texi
> > index 21e2cff..73674cb 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -5709,6 +5709,10 @@ Specify the video size for the output. Default value
> > is @code{640x480}.
> >  @item slide
> >  Specify if the spectrum should slide along the window. Default value is
> >  @code{0}.
> > + at item compat
> > +Specify if the old mode, where up to 2 channels are displayed in same row,
> > +should be used. Default value is
> > + at code{0}.
> >  @end table
> >
> >  The usage is very similar to the showwaves filter; see the examples in
> > that
> > diff --git a/libavfilter/avf_showspectrum.c
> > b/libavfilter/avf_showspectrum.c
> > index 977fca9..41f7a8e 100644
> > --- a/libavfilter/avf_showspectrum.c
> > +++ b/libavfilter/avf_showspectrum.c
> > @@ -37,14 +37,20 @@ typedef struct {
> >      int w, h;
> >      AVFilterBufferRef *outpicref;
> >      int req_fullfilled;
> > +    int nb_display_channels;
> >      int sliding;                ///< 1 if sliding mode, 0 otherwise
> > +    int combined;               ///< use combined channel display mode
> > +    int intensity_colors;       ///< use intensity-based coloring
> > +    int logscale;               ///< use logarithmic scale
> > +    float saturation;           ///< color saturation multiplier
> >      int xpos;                   ///< x position (current column)
> >      RDFTContext *rdft;          ///< Real Discrete Fourier Transform
> > context
> >      int rdft_bits;              ///< number of bits (RDFT window size =
> > 1<<rdft_bits)
> > -    FFTSample *rdft_data;       ///< bins holder for each (displayed)
> > channels
> > +    FFTSample **rdft_data;      ///< bins holder for each (displayed)
> > channels
> >      int filled;                 ///< number of samples (per channel) filled
> > in current rdft_buffer
> >      int consumed;               ///< number of samples (per channel)
> > consumed from the input frame
> >      float *window_func_lut;     ///< Window function LUT
> > +    float *combine_buffer;      ///< color combining buffer (3 * h items)
> >  } ShowSpectrumContext;
> >
> >  #define OFFSET(x) offsetof(ShowSpectrumContext, x)
> > @@ -54,11 +60,30 @@ static const AVOption showspectrum_options[] = {
> >      { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str =
> > "640x480"}, 0, 0, FLAGS },
> >      { "s",    "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str =
> > "640x480"}, 0, 0, FLAGS },
> >      { "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64
> > = 0}, 0, 1, FLAGS },
> > +    { "combined", "set combined mode", OFFSET(combined), AV_OPT_TYPE_INT,
> > {.i64 = 0}, 0, 1, FLAGS },
> > +    { "intensity", "set intensity based coloring",
> > OFFSET(intensity_colors), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
> > +    { "logscale", "set logarithmic scale", OFFSET(logscale),
> > AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
> > +    { "saturation", "color saturation multiplier", OFFSET(saturation),
> > AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },
> >      { NULL },
> >  };
> >
> >  AVFILTER_DEFINE_CLASS(showspectrum);
> >
> > +typedef struct {
> > +    float a, y, u, v;
> > +} intensity_color_table_item;
> > +static const intensity_color_table_item intensity_color_table[] =
> > +{
> > +    { 0, 0, 0, 0 },
> > +    { 0.13, .03587126228984074, .1573300977624594, -.02548747583751842 },
> > +    { 0.3, .1857228179456802, .1772436246393981, .1747555484041475 },
> > +    { 0.6, .2818498058365613, -.1593064119945782, .4713207455460892 },
> > +    { 0.73, .6583062117554781, -.3716070802232764, .2435275933125293 },
> > +    { 0.78, 0.763185357582429, -.4307467689263783, .1686649662231043 },
> > +    { 0.91, .9533636363636364, -.2045454545454546, .03313636363636363 },
> > +    { 1, 1, 0, 0 }
> > +};
> > +
> >  static av_cold int init(AVFilterContext *ctx, const char *args)
> >  {
> >      ShowSpectrumContext *showspectrum = ctx->priv;
> > @@ -76,8 +101,12 @@ static av_cold int init(AVFilterContext *ctx, const char
> > *args)
> >  static av_cold void uninit(AVFilterContext *ctx)
> >  {
> >      ShowSpectrumContext *showspectrum = ctx->priv;
> > +    int i;
> >
> > +    av_freep(&showspectrum->combine_buffer);
> >      av_rdft_end(showspectrum->rdft);
> > +    for (i = 0; i < showspectrum->nb_display_channels; i++)
> > +        av_freep(&showspectrum->rdft_data[i]);
> >      av_freep(&showspectrum->rdft_data);
> >      av_freep(&showspectrum->window_func_lut);
> >      avfilter_unref_bufferp(&showspectrum->outpicref);
> > @@ -90,7 +119,7 @@ static int query_formats(AVFilterContext *ctx)
> >      AVFilterLink *inlink = ctx->inputs[0];
> >      AVFilterLink *outlink = ctx->outputs[0];
> >      static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16P,
> > AV_SAMPLE_FMT_NONE };
> > -    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGB24,
> > AV_PIX_FMT_NONE };
> > +    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUVJ444P,
> > AV_PIX_FMT_NONE };
> >
> >      /* set input audio formats */
> >      formats = ff_make_format_list(sample_fmts);
> > @@ -120,19 +149,22 @@ static int query_formats(AVFilterContext *ctx)
> >  static int config_output(AVFilterLink *outlink)
> >  {
> >      AVFilterContext *ctx = outlink->src;
> > +    AVFilterLink *inlink = ctx->inputs[0];
> >      ShowSpectrumContext *showspectrum = ctx->priv;
> > -    int i, rdft_bits, win_size;
> > +    int i, rdft_bits, win_size, h;
> >
> >      outlink->w = showspectrum->w;
> >      outlink->h = showspectrum->h;
> >
> > +    h = showspectrum->combined ? outlink->h : outlink->h /
> > inlink->channels;
> > +
> >      /* RDFT window size (precision) according to the requested output frame
> > height */
> > -    for (rdft_bits = 1; 1<<rdft_bits < 2*outlink->h; rdft_bits++);
> > +    for (rdft_bits = 1; 1 << rdft_bits < 2 * h; rdft_bits++);
> >      win_size = 1 << rdft_bits;
> >
> >      /* (re-)configuration if the video output changed (or first init) */
> >      if (rdft_bits != showspectrum->rdft_bits) {
> > -        size_t rdft_size;
> > +        size_t rdft_size, rdft_listsize;
> >          AVFilterBufferRef *outpicref;
> >
> >          av_rdft_end(showspectrum->rdft);
> > @@ -142,12 +174,25 @@ static int config_output(AVFilterLink *outlink)
> >          /* RDFT buffers: x2 for each (display) channel buffer.
> >           * Note: we use free and malloc instead of a realloc-like function
> > to
> >           * make sure the buffer is aligned in memory for the FFT functions.
> > */
> > +        for (i = 0; i < showspectrum->nb_display_channels; i++)
> > +            av_freep(&showspectrum->rdft_data[i]);
> >          av_freep(&showspectrum->rdft_data);
> > -        if (av_size_mult(sizeof(*showspectrum->rdft_data), 2 * win_size,
> > &rdft_size) < 0)
> > +        showspectrum->nb_display_channels = inlink->channels;
> > +
> > +        if (av_size_mult(sizeof(*showspectrum->rdft_data),
> > +                         showspectrum->nb_display_channels, &rdft_listsize)
> > < 0)
> > +            return AVERROR(EINVAL);
> > +        if (av_size_mult(sizeof(**showspectrum->rdft_data),
> > +                         win_size, &rdft_size) < 0)
> >              return AVERROR(EINVAL);
> > -        showspectrum->rdft_data = av_malloc(rdft_size);
> > +        showspectrum->rdft_data = av_malloc(rdft_listsize);
> >          if (!showspectrum->rdft_data)
> >              return AVERROR(ENOMEM);
> > +        for (i = 0; i < showspectrum->nb_display_channels; i++) {
> > +            showspectrum->rdft_data[i] = av_malloc(rdft_size);
> > +            if (!showspectrum->rdft_data[i])
> > +                return AVERROR(ENOMEM);
> > +        }
> >          showspectrum->filled = 0;
> >
> >          /* pre-calc windowing function (hann here) */
> > @@ -173,6 +218,10 @@ static int config_output(AVFilterLink *outlink)
> >      if (showspectrum->xpos >= outlink->w)
> >          showspectrum->xpos = 0;
> >
> > +    showspectrum->combine_buffer =
> > av_realloc_f(showspectrum->combine_buffer,
> > +                                               outlink->h * 3,
> > +
> > sizeof(*showspectrum->combine_buffer));
> > +
> >      av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
> >             showspectrum->w, showspectrum->h, win_size);
> >      return 0;
> > @@ -213,62 +262,160 @@ static int plot_spectrum_column(AVFilterLink *inlink,
> > AVFilterBufferRef *insampl
> >      AVFilterLink *outlink = ctx->outputs[0];
> >      ShowSpectrumContext *showspectrum = ctx->priv;
> >      AVFilterBufferRef *outpicref = showspectrum->outpicref;
> > -    const int nb_channels =
> > av_get_channel_layout_nb_channels(insamples->audio->channel_layout);
> >
> >      /* nb_freq contains the power of two superior or equal to the output
> > image
> >       * height (or half the RDFT window size) */
> >      const int nb_freq = 1 << (showspectrum->rdft_bits - 1);
> >      const int win_size = nb_freq << 1;
> > +    const double w = 1. / (sqrt(nb_freq) * 32768.);
> >
> > -    int ch, n, y;
> > -    FFTSample *data[2];
> > -    const int nb_display_channels = FFMIN(nb_channels, 2);
> > +    int ch, plane, n, y;
> >      const int start = showspectrum->filled;
> >      const int add_samples = FFMIN(win_size - start, nb_samples);
> >
> >      /* fill RDFT input with the number of samples available */
> > -    for (ch = 0; ch < nb_display_channels; ch++) {
> > +    for (ch = 0; ch < showspectrum->nb_display_channels; ch++) {
> >          const int16_t *p = (int16_t *)insamples->extended_data[ch];
> >
> >          p += showspectrum->consumed;
> > -        data[ch] = showspectrum->rdft_data + win_size * ch; // select
> > channel buffer
> >          for (n = 0; n < add_samples; n++)
> > -            data[ch][start + n] = p[n] *
> > showspectrum->window_func_lut[start + n];
> > +            showspectrum->rdft_data[ch][start + n] = p[n] *
> > showspectrum->window_func_lut[start + n];
> >      }
> >      showspectrum->filled += add_samples;
> >
> >      /* complete RDFT window size? */
> >      if (showspectrum->filled == win_size) {
> >
> > +        /* channel height */
> > +        int h = showspectrum->combined ? outlink->h : outlink->h /
> > showspectrum->nb_display_channels;
> > +
> >          /* run RDFT on each samples set */
> > -        for (ch = 0; ch < nb_display_channels; ch++)
> > -            av_rdft_calc(showspectrum->rdft, data[ch]);
> > +        for (ch = 0; ch < showspectrum->nb_display_channels; ch++)
> > +            av_rdft_calc(showspectrum->rdft, showspectrum->rdft_data[ch]);
> >
> >          /* fill a new spectrum column */
> > -#define RE(ch) data[ch][2*y + 0]
> > -#define IM(ch) data[ch][2*y + 1]
> > -#define MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im))
> > +#define RE(y,ch) showspectrum->rdft_data[ch][2*y + 0]
> > +#define IM(y,ch) showspectrum->rdft_data[ch][2*y + 1]
> > +#define MAGNITUDE(y,ch) hypot(RE(y,ch), IM(y,ch))
> >
> > +        /* initialize buffer for combining to black */
> >          for (y = 0; y < outlink->h; y++) {
> > -            // FIXME: bin[0] contains first and last bins
> > -            uint8_t *p = outpicref->data[0] + (outlink->h - y - 1) *
> > outpicref->linesize[0];
> > -            const double w = 1. / sqrt(nb_freq);
> > -            int a =                           sqrt(w * MAGNITUDE(RE(0),
> > IM(0)));
> > -            int b = nb_display_channels > 1 ? sqrt(w * MAGNITUDE(RE(1),
> > IM(1))) : a;
> > -
> > -            if (showspectrum->sliding) {
> > -                memmove(p, p + 3, (outlink->w - 1) * 3);
> > -                p += (outlink->w - 1) * 3;
> > +            showspectrum->combine_buffer[3*y] = 0;
> > +            showspectrum->combine_buffer[3*y+1] = 127.5;
> > +            showspectrum->combine_buffer[3*y+2] = 127.5;
> > +        }
> > +
> > +        for (ch = 0; ch < showspectrum->nb_display_channels; ch++) {
> > +            float yf, uf, vf;
> > +
> > +            /* decide color range */
> > +            if (showspectrum->combined) {
> > +                // reduce range by channel count
> > +                yf = 256.0f / showspectrum->nb_display_channels;
> > +                if (showspectrum->intensity_colors) {
> > +                    uf = yf;
> > +                    vf = yf;
> > +                } else {
> > +                    /* adjust saturation for mixed UV coloring */
> > +                    /* this factor is correct for infinite channels, an
> > approximation otherwise */
> > +                    uf = yf * M_PI;
> > +                    vf = yf * M_PI;
> > +                }
> >              } else {
> > -                p += showspectrum->xpos * 3;
> > +                // full range
> > +                yf = 256.0f;
> > +                uf = 256.0f;
> > +                vf = 256.0f;
> > +            }
> > +
> > +            /* decide channel colors */
> > +            if (!showspectrum->intensity_colors) {
> > +                if (showspectrum->nb_display_channels >= 2) {
> > +                    uf *= 0.5 * sin((2 * M_PI * ch) /
> > showspectrum->nb_display_channels);
> > +                    vf *= 0.5 * cos((2 * M_PI * ch) /
> > showspectrum->nb_display_channels);
> > +                } else {
> > +                    uf = 0.0f;
> > +                    vf = 0.0f;
> > +                }
> > +            }
> > +            uf *= showspectrum->saturation;
> > +            vf *= showspectrum->saturation;
> > +
> > +            /* draw the channel */
> > +            for (y = 0; y < h; y++) {
> > +                int row = showspectrum->combined ? y : ch * h + y;
> > +                float *out = &showspectrum->combine_buffer[3 * row];
> > +
> > +                /* get magnitude */
> > +                float a = w * MAGNITUDE(y, ch);
> > +
> > +                /* apply scale */
> > +                if (showspectrum->logscale)
> > +                    a = 1 - log(FFMAX(FFMIN(1, a), 1e-6)) / log(1e-6); //
> > zero = -120dBFS
> > +                else
> > +                    a = sqrt(a);
> > +
> > +                if (showspectrum->intensity_colors) {
> > +                    float y, u, v;
> > +                    int i;
> > +
> > +                    for (i = 1; i < sizeof(intensity_color_table) /
> > sizeof(*intensity_color_table) - 1; i++)
> > +                        if (intensity_color_table[i].a >= a)
> > +                            break;
> > +                    // i now is the first item >= the color
> > +                    // now we know to interpolate between item i-1 and i
> > +                    if (a <= intensity_color_table[i-1].a) {
> > +                        y = intensity_color_table[i-1].y;
> > +                        u = intensity_color_table[i-1].u;
> > +                        v = intensity_color_table[i-1].v;
> > +                    } else if (a >= intensity_color_table[i].a) {
> > +                        y = intensity_color_table[i].y;
> > +                        u = intensity_color_table[i].u;
> > +                        v = intensity_color_table[i].v;
> > +                    } else {
> > +                        float start = intensity_color_table[i-1].a;
> > +                        float end = intensity_color_table[i].a;
> > +                        float lerpfrac = (a - start) / (end - start);
> > +                        y = intensity_color_table[i-1].y * (1.0f -
> > lerpfrac)
> > +                          + intensity_color_table[i].y * lerpfrac;
> > +                        u = intensity_color_table[i-1].u * (1.0f -
> > lerpfrac)
> > +                          + intensity_color_table[i].u * lerpfrac;
> > +                        v = intensity_color_table[i-1].v * (1.0f -
> > lerpfrac)
> > +                          + intensity_color_table[i].v * lerpfrac;
> > +                    }
> > +
> > +                    out[0] += y * yf;
> > +                    out[1] += u * uf;
> > +                    out[2] += v * vf;
> > +                } else {
> > +                    out[0] += a * yf;
> > +                    out[1] += a * uf;
> > +                    out[2] += a * vf;
> > +                }
> >              }
> > +        }
> >
> > -            a = FFMIN(a, 255);
> > -            b = FFMIN(b, 255);
> > -            p[0] = a;
> > -            p[1] = b;
> > -            p[2] = (a + b) / 2;
> > +        /* copy to output */
> > +        if (showspectrum->sliding) {
> > +            for (plane = 0; plane < 3; plane++) {
> > +                for (y = 0; y < outlink->h; y++) {
> > +                    uint8_t *p = outpicref->data[plane] +
> > +                                 y * outpicref->linesize[plane];
> > +                    memmove(p, p + 1, outlink->w - 1);
> > +                }
> > +            }
> > +            showspectrum->xpos = outlink->w - 1;
> >          }
> > +        for (plane = 0; plane < 3; plane++) {
> > +            uint8_t *p = outpicref->data[plane] +
> > +                         (outlink->h - 1) * outpicref->linesize[plane] +
> > +                         showspectrum->xpos;
> > +            for (y = 0; y < outlink->h; y++) {
> > +                *p = rint(FFMAX(0, FFMIN(showspectrum->combine_buffer[3*y +
> > plane], 255)));
> > +                p -= outpicref->linesize[plane];
> > +            }
> > +        }
> > +
> >          outpicref->pts = insamples->pts +
> >              av_rescale_q(showspectrum->consumed,
> >                           (AVRational){ 1, inlink->sample_rate },
> > --
> > 1.8.1.1
> >
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> >
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