@end example
@end itemize
+@anchor{afir}
@section afir
Apply an arbitrary Frequency Impulse Response filter.
Default is @code{average}. Can be @code{average} or @code{maximum}.
@end table
+@section aiir
+
+Apply an arbitrary Infinite Impulse Response filter.
+
+It accepts the following parameters:
+
+@table @option
+@item z
+Set numerator/zeros coefficients.
+
+@item p
+Set denominator/poles coefficients.
+
+@item k
+Set channels gains.
+
+@item dry_gain
+Set input gain.
+
+@item wet_gain
+Set output gain.
+
+@item f
+Set coefficients format.
+
+@table @samp
+@item tf
+transfer function
+@item zp
+Z-plane zeros/poles, cartesian (default)
+@item pr
+Z-plane zeros/poles, polar radians
+@item pd
+Z-plane zeros/poles, polar degrees
+@end table
+
+@item r
+Set kind of processing.
+Can be @code{d} - direct or @code{s} - serial cascading. Defauls is @code{s}.
+
+@item e
+Set filtering precision.
+
+@table @samp
+@item dbl
+double-precision floating-point (default)
+@item flt
+single-precision floating-point
+@item i32
+32-bit integers
+@item i16
+16-bit integers
+@end table
+
+@end table
+
+Coefficients in @code{tf} format are separated by spaces and are in ascending
+order.
+
+Coefficients in @code{zp} format are separated by spaces and order of coefficients
+doesn't matter. Coefficients in @code{zp} format are complex numbers with @var{i}
+imaginary unit.
+
+Different coefficients and gains can be provided for every channel, in such case
+use '|' to separate coefficients or gains. Last provided coefficients will be
+used for all remaining channels.
+
+@subsection Examples
+
+@itemize
+@item
+Apply 2 pole elliptic notch at arround 5000Hz for 48000 Hz sample rate:
+@example
+aiir=k=1:z=7.957584807809675810E-1 -2.575128568908332300 3.674839853930788710 -2.57512875289799137 7.957586296317130880E-1:p=1 -2.86950072432325953 3.63022088054647218 -2.28075678147272232 6.361362326477423500E-1:f=tf:r=d
+@end example
+
+@item
+Same as above but in @code{zp} format:
+@example
+aiir=k=0.79575848078096756:z=0.80918701+0.58773007i 0.80918701-0.58773007i 0.80884700+0.58784055i 0.80884700-0.58784055i:p=0.63892345+0.59951235i 0.63892345-0.59951235i 0.79582691+0.44198673i 0.79582691-0.44198673i:f=zp:r=s
+@end example
+@end itemize
+
@section alimiter
The limiter prevents an input signal from rising over a desired threshold.
@end example
@end itemize
+@section hilbert
+
+Generate odd-tap Hilbert transform FIR coefficients.
+
+The resulting stream can be used with @ref{afir} filter for phase-shifting
+the signal by 90 degrees.
+
+This is used in many matrix coding schemes and for analytic signal generation.
+The process is often written as a multiplication by i (or j), the imaginary unit.
+
+The filter accepts the following options:
+
+@table @option
+
+@item sample_rate, s
+Set sample rate, default is 44100.
+
+@item taps, t
+Set length of FIR filter, default is 22051.
+
+@item nb_samples, n
+Set number of samples per each frame.
+
+@item win_func, w
+Set window function to be used when generating FIR coefficients.
+@end table
+
@section sine
Generate an audio signal made of a sine wave with amplitude 1/8.
Set value which will be added to filtered result.
@end table
+@anchor{program_opencl}
+@section program_opencl
+
+Filter video using an OpenCL program.
+
+@table @option
+
+@item source
+OpenCL program source file.
+
+@item kernel
+Kernel name in program.
+
+@item inputs
+Number of inputs to the filter. Defaults to 1.
+
+@item size, s
+Size of output frames. Defaults to the same as the first input.
+
+@end table
+
+The program source file must contain a kernel function with the given name,
+which will be run once for each plane of the output. Each run on a plane
+gets enqueued as a separate 2D global NDRange with one work-item for each
+pixel to be generated. The global ID offset for each work-item is therefore
+the coordinates of a pixel in the destination image.
+
+The kernel function needs to take the following arguments:
+@itemize
+@item
+Destination image, @var{__write_only image2d_t}.
+
+This image will become the output; the kernel should write all of it.
+@item
+Frame index, @var{unsigned int}.
+
+This is a counter starting from zero and increasing by one for each frame.
+@item
+Source images, @var{__read_only image2d_t}.
+
+These are the most recent images on each input. The kernel may read from
+them to generate the output, but they can't be written to.
+@end itemize
+
+Example programs:
+
+@itemize
+@item
+Copy the input to the output (output must be the same size as the input).
+@verbatim
+__kernel void copy(__write_only image2d_t destination,
+ unsigned int index,
+ __read_only image2d_t source)
+{
+ const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE;
+
+ int2 location = (int2)(get_global_id(0), get_global_id(1));
+
+ float4 value = read_imagef(source, sampler, location);
+
+ write_imagef(destination, location, value);
+}
+@end verbatim
+
+@item
+Apply a simple transformation, rotating the input by an amount increasing
+with the index counter. Pixel values are linearly interpolated by the
+sampler, and the output need not have the same dimensions as the input.
+@verbatim
+__kernel void rotate_image(__write_only image2d_t dst,
+ unsigned int index,
+ __read_only image2d_t src)
+{
+ const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+ CLK_FILTER_LINEAR);
+
+ float angle = (float)index / 100.0f;
+
+ float2 dst_dim = convert_float2(get_image_dim(dst));
+ float2 src_dim = convert_float2(get_image_dim(src));
+
+ float2 dst_cen = dst_dim / 2.0f;
+ float2 src_cen = src_dim / 2.0f;
+
+ int2 dst_loc = (int2)(get_global_id(0), get_global_id(1));
+
+ float2 dst_pos = convert_float2(dst_loc) - dst_cen;
+ float2 src_pos = {
+ cos(angle) * dst_pos.x - sin(angle) * dst_pos.y,
+ sin(angle) * dst_pos.x + cos(angle) * dst_pos.y
+ };
+ src_pos = src_pos * src_dim / dst_dim;
+
+ float2 src_loc = src_pos + src_cen;
+
+ if (src_loc.x < 0.0f || src_loc.y < 0.0f ||
+ src_loc.x > src_dim.x || src_loc.y > src_dim.y)
+ write_imagef(dst, dst_loc, 0.5f);
+ else
+ write_imagef(dst, dst_loc, read_imagef(src, sampler, src_loc));
+}
+@end verbatim
+
+@item
+Blend two inputs together, with the amount of each input used varying
+with the index counter.
+@verbatim
+__kernel void blend_images(__write_only image2d_t dst,
+ unsigned int index,
+ __read_only image2d_t src1,
+ __read_only image2d_t src2)
+{
+ const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+ CLK_FILTER_LINEAR);
+
+ float blend = (cos((float)index / 50.0f) + 1.0f) / 2.0f;
+
+ int2 dst_loc = (int2)(get_global_id(0), get_global_id(1));
+ int2 src1_loc = dst_loc * get_image_dim(src1) / get_image_dim(dst);
+ int2 src2_loc = dst_loc * get_image_dim(src2) / get_image_dim(dst);
+
+ float4 val1 = read_imagef(src1, sampler, src1_loc);
+ float4 val2 = read_imagef(src2, sampler, src2_loc);
+
+ write_imagef(dst, dst_loc, val1 * blend + val2 * (1.0f - blend));
+}
+@end verbatim
+
+@end itemize
+
@section pseudocolor
Alter frame colors in video with pseudocolors.
Mean Square Error pixel-by-pixel average difference of the compared
frames, averaged over all the image components.
-@item mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a
+@item mse_y, mse_u, mse_v, mse_r, mse_g, mse_b, mse_a
Mean Square Error pixel-by-pixel average difference of the compared
frames for the component specified by the suffix.
@example
scale=w='min(500\, iw*3/2):h=-1'
@end example
+
+@item
+Make pixels square by combining scale and setsar:
+@example
+scale='trunc(ih*dar):ih',setsar=1/1
+@end example
+
+@item
+Make pixels square by combining scale and setsar,
+making sure the resulting resolution is even (required by some codecs):
+@example
+scale='trunc(ih*dar/2)*2:trunc(ih/2)*2',setsar=1/1
+@end example
@end itemize
@subsection Commands
corresponding @option{color} option.
@end table
+@section openclsrc
+
+Generate video using an OpenCL program.
+
+@table @option
+
+@item source
+OpenCL program source file.
+
+@item kernel
+Kernel name in program.
+
+@item size, s
+Size of frames to generate. This must be set.
+
+@item format
+Pixel format to use for the generated frames. This must be set.
+
+@item rate, r
+Number of frames generated every second. Default value is '25'.
+
+@end table
+
+For details of how the program loading works, see the @ref{program_opencl}
+filter.
+
+Example programs:
+
+@itemize
+@item
+Generate a colour ramp by setting pixel values from the position of the pixel
+in the output image. (Note that this will work with all pixel formats, but
+the generated output will not be the same.)
+@verbatim
+__kernel void ramp(__write_only image2d_t dst,
+ unsigned int index)
+{
+ int2 loc = (int2)(get_global_id(0), get_global_id(1));
+
+ float4 val;
+ val.xy = val.zw = convert_float2(loc) / convert_float2(get_image_dim(dst));
+
+ write_imagef(dst, loc, val);
+}
+@end verbatim
+
+@item
+Generate a Sierpinski carpet pattern, panning by a single pixel each frame.
+@verbatim
+__kernel void sierpinski_carpet(__write_only image2d_t dst,
+ unsigned int index)
+{
+ int2 loc = (int2)(get_global_id(0), get_global_id(1));
+
+ float4 value = 0.0f;
+ int x = loc.x + index;
+ int y = loc.y + index;
+ while (x > 0 || y > 0) {
+ if (x % 3 == 1 && y % 3 == 1) {
+ value = 1.0f;
+ break;
+ }
+ x /= 3;
+ y /= 3;
+ }
+
+ write_imagef(dst, loc, value);
+}
+@end verbatim
+
+@end itemize
+
@c man end VIDEO SOURCES
@chapter Video Sinks
projects / ffmpeg / blobdiff