Go to the documentation of this file.
   31 #define FILTER_ORDER 4 
   75 #define OFFSET(x) offsetof(AudioNEqualizerContext, x) 
   76 #define A AV_OPT_FLAG_AUDIO_PARAM 
   77 #define V AV_OPT_FLAG_VIDEO_PARAM 
   78 #define F AV_OPT_FLAG_FILTERING_PARAM 
   88     { 
"colors", 
"set channels curves colors",     
OFFSET(colors),      
AV_OPT_TYPE_STRING,     {.str = 
"red|green|blue|yellow|orange|lime|pink|magenta|brown" }, 0, 0, 
V|
F },
 
  104     memset(
out->data[0], 0, 
s->h * 
out->linesize[0]);
 
  106     for (ch = 0; ch < 
inlink->ch_layout.nb_channels; ch++) {
 
  107         uint8_t fg[4] = { 0xff, 0xff, 0xff, 0xff };
 
  115         for (
f = 0; 
f < 
s->w; 
f++) {
 
  116             double zr, zi, zr2, zi2;
 
  122             w = 
M_PI * (
s->fscale ? pow(
s->w - 1, 
f / 
s->w) : 
f) / (
s->w - 1);
 
  128             for (n = 0; n < 
s->nb_filters; n++) {
 
  129                 if (
s->filters[n].channel != ch ||
 
  130                     s->filters[n].ignore)
 
  139                     Hr = 
S->b4*(1-8*zr2*zi2) + 
S->b2*(zr2-zi2) + zr*(
S->b1+
S->b3*(zr2-3*zi2))+ 
S->b0;
 
  140                     Hi = zi*(
S->b3*(3*zr2-zi2) + 
S->b1 + 2*zr*(2*
S->b4*(zr2-zi2) + 
S->b2));
 
  141                     Hmag *= 
hypot(Hr, Hi);
 
  142                     Hr = 
S->a4*(1-8*zr2*zi2) + 
S->a2*(zr2-zi2) + zr*(
S->a1+
S->a3*(zr2-3*zi2))+ 
S->a0;
 
  143                     Hi = zi*(
S->a3*(3*zr2-zi2) + 
S->a1 + 2*zr*(2*
S->a4*(zr2-zi2) + 
S->a2));
 
  144                     Hmag /= 
hypot(Hr, Hi);
 
  148             v = 
av_clip((1. + -20 * log10(Hmag) / 
s->mag) * 
s->h / 2, 0, 
s->h - 1);
 
  153                 for (y = v; y <= prev_v; y++)
 
  156                 for (y = prev_v; y <= v; y++)
 
  203     if (
s->draw_curves) {
 
  231     if (
s->draw_curves) {
 
  267                                    double si, 
double g, 
double g0,
 
  270     if (c0 == 1 || c0 == -1) {
 
  271         S->b0 = (
g*
g*beta*beta + 2*
g*g0*si*beta + g0*g0)/
D;
 
  272         S->b1 = 2*c0*(
g*
g*beta*beta - g0*g0)/
D;
 
  273         S->b2 = (
g*
g*beta*beta - 2*g0*
g*beta*si + g0*g0)/
D;
 
  278         S->a1 = 2*c0*(beta*beta - 1)/
D;
 
  279         S->a2 = (beta*beta - 2*beta*si + 1)/
D;
 
  283         S->b0 = (
g*
g*beta*beta + 2*
g*g0*si*beta + g0*g0)/
D;
 
  284         S->b1 = -4*c0*(g0*g0 + 
g*g0*si*beta)/
D;
 
  285         S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - 
g*
g*beta*beta)/
D;
 
  286         S->b3 = -4*c0*(g0*g0 - 
g*g0*si*beta)/
D;
 
  287         S->b4 = (
g*
g*beta*beta - 2*
g*g0*si*beta + g0*g0)/
D;
 
  290         S->a1 = -4*c0*(1 + si*beta)/
D;
 
  291         S->a2 = 2*(1 + 2*c0*c0 - beta*beta)/
D;
 
  292         S->a3 = -4*c0*(1 - si*beta)/
D;
 
  293         S->a4 = (beta*beta - 2*si*beta + 1)/
D;
 
  298                                   int N, 
double w0, 
double wb,
 
  299                                   double G, 
double Gb, 
double G0)
 
  301     double g, c0, g0, beta;
 
  307     if (
G == 0 && G0 == 0) {
 
  308         f->section[0].a0 = 1;
 
  309         f->section[0].b0 = 1;
 
  310         f->section[1].a0 = 1;
 
  311         f->section[1].b0 = 1;
 
  319     epsilon = sqrt((
G * 
G - Gb * Gb) / (Gb * Gb - G0 * G0));
 
  321     g0 = pow(G0, 1.0 / 
N);
 
  322     beta = pow(epsilon, -1.0 / 
N) * tan(wb/2);
 
  325     for (
i = 1; 
i <= 
L; 
i++) {
 
  326         double ui = (2.0 * 
i - 1) / 
N;
 
  327         double si = sin(
M_PI * 
ui / 2.0);
 
  328         double Di = beta * beta + 2 * si * beta + 1;
 
  335                                   double c, 
double tetta_b,
 
  336                                   double g0, 
double si, 
double b,
 
  339     if (c0 == 1 || c0 == -1) {
 
  340         S->b0 = (tetta_b*tetta_b*(
b*
b+g0*g0*
c*
c) + 2*g0*
b*si*tetta_b*tetta_b + g0*g0)/
D;
 
  341         S->b1 = 2*c0*(tetta_b*tetta_b*(
b*
b+g0*g0*
c*
c) - g0*g0)/
D;
 
  342         S->b2 = (tetta_b*tetta_b*(
b*
b+g0*g0*
c*
c) - 2*g0*
b*si*tetta_b + g0*g0)/
D;
 
  347         S->a1 = 2*c0*(tetta_b*tetta_b*(
a*
a+
c*
c) - 1)/
D;
 
  348         S->a2 = (tetta_b*tetta_b*(
a*
a+
c*
c) - 2*
a*si*tetta_b + 1)/
D;
 
  352         S->b0 = ((
b*
b + g0*g0*
c*
c)*tetta_b*tetta_b + 2*g0*
b*si*tetta_b + g0*g0)/
D;
 
  353         S->b1 = -4*c0*(g0*g0 + g0*
b*si*tetta_b)/
D;
 
  354         S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - (
b*
b + g0*g0*
c*
c)*tetta_b*tetta_b)/
D;
 
  355         S->b3 = -4*c0*(g0*g0 - g0*
b*si*tetta_b)/
D;
 
  356         S->b4 = ((
b*
b + g0*g0*
c*
c)*tetta_b*tetta_b - 2*g0*
b*si*tetta_b + g0*g0)/
D;
 
  359         S->a1 = -4*c0*(1 + 
a*si*tetta_b)/
D;
 
  360         S->a2 = 2*(1 + 2*c0*c0 - (
a*
a + 
c*
c)*tetta_b*tetta_b)/
D;
 
  361         S->a3 = -4*c0*(1 - 
a*si*tetta_b)/
D;
 
  362         S->a4 = ((
a*
a + 
c*
c)*tetta_b*tetta_b - 2*
a*si*tetta_b + 1)/
D;
 
  367                                  int N, 
double w0, 
double wb,
 
  368                                  double G, 
double Gb, 
double G0)
 
  370     double a, 
b, c0, g0, alfa, beta, tetta_b;
 
  376     if (
G == 0 && G0 == 0) {
 
  377         f->section[0].a0 = 1;
 
  378         f->section[0].b0 = 1;
 
  379         f->section[1].a0 = 1;
 
  380         f->section[1].b0 = 1;
 
  388     epsilon = sqrt((
G*
G - Gb*Gb) / (Gb*Gb - G0*G0));
 
  390     alfa = pow(1.0/epsilon    + sqrt(1 + 1/(epsilon*epsilon)), 1.0/
N);
 
  391     beta = pow(
G/epsilon + Gb * sqrt(1 + 1/(epsilon*epsilon)), 1.0/
N);
 
  392     a = 0.5 * (alfa - 1.0/alfa);
 
  393     b = 0.5 * (beta - g0*g0*(1/beta));
 
  397     for (
i = 1; 
i <= 
L; 
i++) {
 
  398         double ui = (2.0*
i-1.0)/
N;
 
  399         double ci = cos(
M_PI*
ui/2.0);
 
  400         double si = sin(
M_PI*
ui/2.0);
 
  401         double Di = (
a*
a + ci*ci)*tetta_b*tetta_b + 2.0*
a*si*tetta_b + 1;
 
  408                                   double c, 
double tetta_b,
 
  409                                   double g, 
double si, 
double b,
 
  412     if (c0 == 1 || c0 == -1) {
 
  413         S->b0 = (
g*
g*tetta_b*tetta_b + 2*tetta_b*
g*
b*si + 
b*
b + 
g*
g*
c*
c)/
D;
 
  414         S->b1 = 2*c0*(
g*
g*tetta_b*tetta_b - 
b*
b - 
g*
g*
c*
c)/
D;
 
  415         S->b2 = (
g*
g*tetta_b*tetta_b - 2*tetta_b*
g*
b*si + 
b*
b + 
g*
g*
c*
c)/
D;
 
  420         S->a1 = 2*c0*(tetta_b*tetta_b - 
a*
a - 
c*
c)/
D;
 
  421         S->a2 = (tetta_b*tetta_b - 2*tetta_b*
a*si + 
a*
a + 
c*
c)/
D;
 
  425         S->b0 = (
g*
g*tetta_b*tetta_b + 2*
g*
b*si*tetta_b + 
b*
b + 
g*
g*
c*
c)/
D;
 
  426         S->b1 = -4*c0*(
b*
b + 
g*
g*
c*
c + 
g*
b*si*tetta_b)/
D;
 
  427         S->b2 = 2*((
b*
b + 
g*
g*
c*
c)*(1 + 2*c0*c0) - 
g*
g*tetta_b*tetta_b)/
D;
 
  428         S->b3 = -4*c0*(
b*
b + 
g*
g*
c*
c - 
g*
b*si*tetta_b)/
D;
 
  429         S->b4 = (
g*
g*tetta_b*tetta_b - 2*
g*
b*si*tetta_b + 
b*
b + 
g*
g*
c*
c)/
D;
 
  432         S->a1 = -4*c0*(
a*
a + 
c*
c + 
a*si*tetta_b)/
D;
 
  433         S->a2 = 2*((
a*
a + 
c*
c)*(1 + 2*c0*c0) - tetta_b*tetta_b)/
D;
 
  434         S->a3 = -4*c0*(
a*
a + 
c*
c - 
a*si*tetta_b)/
D;
 
  435         S->a4 = (tetta_b*tetta_b - 2*
a*si*tetta_b + 
a*
a + 
c*
c)/
D;
 
  440                                  int N, 
double w0, 
double wb,
 
  441                                  double G, 
double Gb, 
double G0)
 
  443     double a, 
b, c0, tetta_b;
 
  444     double epsilon, 
g, eu, ew;
 
  449     if (
G == 0 && G0 == 0) {
 
  450         f->section[0].a0 = 1;
 
  451         f->section[0].b0 = 1;
 
  452         f->section[1].a0 = 1;
 
  453         f->section[1].b0 = 1;
 
  461     epsilon = sqrt((
G*
G - Gb*Gb) / (Gb*Gb - G0*G0));
 
  463     eu = pow(epsilon + sqrt(1 + epsilon*epsilon), 1.0/
N);
 
  464     ew = pow(G0*epsilon + Gb*sqrt(1 + epsilon*epsilon), 1.0/
N);
 
  465     a = (eu - 1.0/eu)/2.0;
 
  466     b = (ew - 
g*
g/ew)/2.0;
 
  470     for (
i = 1; 
i <= 
L; 
i++) {
 
  471         double ui = (2.0 * 
i - 1.0)/
N;
 
  472         double ci = cos(
M_PI * 
ui / 2.0);
 
  473         double si = sin(
M_PI * 
ui / 2.0);
 
  474         double Di = tetta_b*tetta_b + 2*
a*si*tetta_b + 
a*
a + ci*ci;
 
  486     else if(gain > -6 && gain < 6)
 
  487         bw_gain = gain * 0.5;
 
  500     else if(gain > -6 && gain < 6)
 
  501         bw_gain = gain * 0.9;
 
  514     else if(gain > -6 && gain < 6)
 
  515         bw_gain = gain * 0.3;
 
  553     if (
s->nb_filters >= 
s->nb_allocated - 1) {
 
  559         memcpy(
filters, 
s->filters, 
sizeof(*
s->filters) * 
s->nb_allocated);
 
  562         s->nb_allocated *= 2;
 
  574     char *saveptr = 
NULL;
 
  580     s->nb_allocated = 32 * 
inlink->ch_layout.nb_channels;
 
  594         s->filters[
s->nb_filters].type = 0;
 
  595         if (sscanf(
arg, 
"c%d f=%lf w=%lf g=%lf t=%d", &
s->filters[
s->nb_filters].channel,
 
  596                                                      &
s->filters[
s->nb_filters].freq,
 
  597                                                      &
s->filters[
s->nb_filters].width,
 
  598                                                      &
s->filters[
s->nb_filters].gain,
 
  599                                                      &
s->filters[
s->nb_filters].type) != 5 &&
 
  600             sscanf(
arg, 
"c%d f=%lf w=%lf g=%lf", &
s->filters[
s->nb_filters].channel,
 
  601                                                 &
s->filters[
s->nb_filters].freq,
 
  602                                                 &
s->filters[
s->nb_filters].width,
 
  603                                                 &
s->filters[
s->nb_filters].gain) != 4 ) {
 
  608         if (
s->filters[
s->nb_filters].freq < 0 ||
 
  609             s->filters[
s->nb_filters].freq > 
inlink->sample_rate / 2.0)
 
  610             s->filters[
s->nb_filters].ignore = 1;
 
  612         if (
s->filters[
s->nb_filters].channel < 0 ||
 
  613             s->filters[
s->nb_filters].channel >= 
inlink->ch_layout.nb_channels)
 
  614             s->filters[
s->nb_filters].ignore = 1;
 
  628                            char *res, 
int res_len, 
int flags)
 
  634     if (!strcmp(cmd, 
"change")) {
 
  635         double freq, 
width, gain;
 
  638         if (sscanf(args, 
"%d|f=%lf|w=%lf|g=%lf", &
filter, &freq, &
width, &gain) != 4)
 
  641         if (filter < 0 || filter >= 
s->nb_filters)
 
  644         if (freq < 0 || freq > 
inlink->sample_rate / 2.0)
 
  647         s->filters[
filter].freq  = freq;
 
  649         s->filters[
filter].gain  = gain;
 
  665     out+= 
S->b1 * 
S->num[0] - 
S->denum[0] * 
S->a1;
 
  666     out+= 
S->b2 * 
S->num[1] - 
S->denum[1] * 
S->a2;
 
  667     out+= 
S->b3 * 
S->num[2] - 
S->denum[2] * 
S->a3;
 
  668     out+= 
S->b4 * 
S->num[3] - 
S->denum[3] * 
S->a4;
 
  670     S->num[3] = 
S->num[2];
 
  671     S->num[2] = 
S->num[1];
 
  672     S->num[1] = 
S->num[0];
 
  675     S->denum[3] = 
S->denum[2];
 
  676     S->denum[2] = 
S->denum[1];
 
  677     S->denum[1] = 
S->denum[0];
 
  697                            int jobnr, 
int nb_jobs)
 
  704     for (
int i = 0; 
i < 
s->nb_filters; 
i++) {
 
  708         if (
f->gain == 0. || 
f->ignore)
 
  710         if (
f->channel < start ||
 
  732     if (!
ctx->is_disabled)
 
  736     if (
s->draw_curves) {
 
  739         const int64_t 
pts = buf->
pts +
 
  767     .
name          = 
"anequalizer",
 
  770     .priv_class    = &anequalizer_class,
 
  
static int config_video(AVFilterLink *outlink)
 
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
 
A list of supported channel layouts.
 
AVPixelFormat
Pixel format.
 
static av_always_inline double ff_exp10(double x)
Compute 10^x for floating point values.
 
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
 
static void butterworth_fo_section(FoSection *S, double beta, double si, double g, double g0, double D, double c0)
 
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
 
static enum AVSampleFormat sample_fmts[]
 
enum MovChannelLayoutTag * layouts
 
int av_parse_color(uint8_t *rgba_color, const char *color_string, int slen, void *log_ctx)
Put the RGBA values that correspond to color_string in rgba_color.
 
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
 
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
 
This structure describes decoded (raw) audio or video data.
 
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
 
#define FILTER_QUERY_FUNC(func)
 
static int filter_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 
static void chebyshev1_bp_filter(EqualizatorFilter *f, int N, double w0, double wb, double G, double Gb, double G0)
 
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
 
const char * name
Filter name.
 
int nb_channels
Number of channels in this layout.
 
A link between two filters.
 
static void chebyshev2_bp_filter(EqualizatorFilter *f, int N, double w0, double wb, double G, double Gb, double G0)
 
static const AVOption anequalizer_options[]
 
static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
 
AVChannelLayout ch_layout
Channel layout of the audio data.
 
static int config_input(AVFilterLink *inlink)
 
AVFILTER_DEFINE_CLASS(anequalizer)
 
A filter pad used for either input or output.
 
static void equalizer(EqualizatorFilter *f, double sample_rate)
 
static void chebyshev2_fo_section(FoSection *S, double a, double c, double tetta_b, double g, double si, double b, double D, double c0)
 
char * av_strtok(char *s, const char *delim, char **saveptr)
Split the string into several tokens which can be accessed by successive calls to av_strtok().
 
AVRational sample_aspect_ratio
agreed upon sample aspect ratio
 
static void chebyshev1_fo_section(FoSection *S, double a, double c, double tetta_b, double g0, double si, double b, double D, double c0)
 
#define filters(fmt, type, inverse, clp, inverset, clip, one, clip_fn, packed)
 
static int query_formats(AVFilterContext *ctx)
 
static enum AVPixelFormat pix_fmts[]
 
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
 
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
 
#define FILTER_INPUTS(array)
 
static double hz_2_rad(double x, double fs)
 
@ AV_PIX_FMT_RGBA
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
 
static av_cold void uninit(AVFilterContext *ctx)
 
Describe the class of an AVClass context structure.
 
#define fs(width, name, subs,...)
 
static const AVFilterPad inputs[]
 
Rational number (pair of numerator and denominator).
 
@ AV_OPT_TYPE_IMAGE_SIZE
offset must point to two consecutive integers
 
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
 
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
 
#define AVFILTER_FLAG_DYNAMIC_OUTPUTS
The number of the filter outputs is not determined just by AVFilter.outputs.
 
static void draw_curves(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *out)
 
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
 
static av_const double hypot(double x, double y)
 
static const uint32_t color[16+AV_CLASS_CATEGORY_NB]
 
AVFilterContext * src
source filter
 
AVFilterFormatsConfig incfg
Lists of supported formats / etc.
 
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
 
static int add_filter(AudioNEqualizerContext *s, AVFilterLink *inlink)
 
int nb_samples
number of audio samples (per channel) described by this frame
 
#define i(width, name, range_min, range_max)
 
int w
agreed upon image width
 
uint8_t ** extended_data
pointers to the data planes/channels.
 
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
 
AVSampleFormat
Audio sample formats.
 
static double section_process(FoSection *S, double in)
 
static double chebyshev1_compute_bw_gain_db(double gain)
 
const char * name
Pad name.
 
void * av_calloc(size_t nmemb, size_t size)
 
static double chebyshev2_compute_bw_gain_db(double gain)
 
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
 
int h
agreed upon image height
 
static void butterworth_bp_filter(EqualizatorFilter *f, int N, double w0, double wb, double G, double Gb, double G0)
 
@ AV_SAMPLE_FMT_DBLP
double, planar
 
AVRational time_base
Define the time base used by the PTS of the frames/samples which will pass through this link.
 
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
 
char * av_strdup(const char *s)
Duplicate a string.
 
int ff_append_outpad(AVFilterContext *f, AVFilterPad *p)
 
static double process_sample(FoSection *s1, double in)
 
const AVFilter ff_af_anequalizer
 
EqualizatorFilter * filters
 
#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL
Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will have its filter_frame() c...
 
#define flags(name, subs,...)
 
static av_always_inline int ff_filter_execute(AVFilterContext *ctx, avfilter_action_func *func, void *arg, int *ret, int nb_jobs)
 
static av_cold int init(AVFilterContext *ctx)
 
static double butterworth_compute_bw_gain_db(double gain)
 
#define AVFILTERPAD_FLAG_NEEDS_WRITABLE
The filter expects writable frames from its input link, duplicating data buffers if needed.