How to visualize Halide camera pipeline / generate HTML output of how Halide compiles? - halide

Question

I've tried adding the following line to the bottom of camera_pipe_generator.cpp to output how Halide compiles into a .html file, but I'm not sure what I'm doing wrong:
processed.compile_to_lowered_stmt("camera_pipe_debugging_trial.html", {}, HTML);
I think my second argument is wrong, but what should I pass in here?
Or is there a different way for me to visualize the schedule? This post seems to suggest a visualizer for Halide exists. Are there any resources available on how to use it?
Thank you!
Edit: I've tried running the command
../../tools/gengen.sh -c c++ -lcurses -l ../../lib/libHalide.a -o tmp/ -e html -s camera_pipe_generator.cpp target=host
However, that resulted in the following error:
Undefined symbols for architecture x86_64:
"_del_curterm", referenced from:
llvm::sys::Process::FileDescriptorHasColors(int) in libHalide.a(llvm_460_Process.cpp.o)
"_set_curterm", referenced from:
llvm::sys::Process::FileDescriptorHasColors(int) in libHalide.a(llvm_460_Process.cpp.o)
"_setupterm", referenced from:
llvm::sys::Process::FileDescriptorHasColors(int) in libHalide.a(llvm_460_Process.cpp.o)
"_tigetnum", referenced from:
llvm::sys::Process::FileDescriptorHasColors(int) in libHalide.a(llvm_460_Process.cpp.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Which I think might be related to running on mac OSX 10.12.3?
Final edit: Added option '-lcurses' to the gengen.sh file and it worked!

Answer 1

To visualize your Halide code to a MPEG file, the following is needed:
Halide filter compiled to AOT binary
Source code to exercise AOT binary
Bash shell script to build and execute HalideTraceViz
All of the above assets in the same folder
Regarding point 4, I'm sure this could altered, but for the trials I had, this was the only way I was able to get things working; anyone who can share their input on that last point is welcome to do so.
1: Halide filter compiled to AOT binary
I used the brighten filter listed on the halide-lang.org tutorial site to create the below listed filter and compile it to a usable binary:
http://halide-lang.org/tutorials/tutorial_lesson_10_aot_compilation_generate.html
#include "Halide.h"
#include <iostream>
namespace
{
auto input = Halide::ImageParam(Halide::type_of< uint8_t >(), 2, std::string{"input_image"});
auto offset = Halide::Param< uint8_t >{"offset"};
} // anonymous namespace
auto create_filter() -> Halide::Func
{
auto x = Halide::Var{"x"};
auto y = Halide::Var{"y"};
auto brighten = Halide::Func{"filter_output"};
brighten(x, y) = input(x, y) + offset;
return brighten;
}
auto schedule_filter(Halide::Func filter_ref) { filter_ref.vectorize(x, 16).parallel(y); }
auto create_aot_binary()
{
auto args = std::vector< Halide::Argument >{input, offset};
brighten.compile_to_file("brighten", args);
}
int main(int argc, const char* argv[])
{
printf("brighten filter AOT binary generator\n");
auto brighten = create_filter();
schedule_filter(brighten);
create_aot_binary();
return 0;
}
2. Source code to exercise AOT binary
#include "brighten.h" // header file created by aot generator in step 1
#include <cassert>
#include <vector>
namespace
{
constexpr auto width = 16 * 4;
constexpr auto height = 16 * 4;
} // anonymous namespace
auto create_input_image() -> std::vector< uint8_t >
{
auto image = std::vector< uint8_t >(width * height, 0);
for (auto y = 0; y < width; y++)
{
for (auto x = 0; x < height; x++)
{
const auto val = x ^ (y + 1);
const auto index = y * height + x;
image[index] = val;
}
}
return image;
}
auto create_buffer_t_with_data(const std::vector< uint8_t >& image) -> buffer_t
{
auto buff = buffer_t{0};
buff.host = image.data();
buff.stride[0] = 1;
buff.stride[1] = width;
buff.extent[0] = width;
buff.extent[1] = height;
buff.elem_size = 1;
}
int main(int argc, const char* argv[])
{
printf("brighten filter exercise\n");
auto input_image = create_input_image();
assert(input_image.size() != 0);
auto input_buf = create_buffer_t_with_data(input_image);
auto output_image = std::vector< uint8_t >(width * height, 0);
assert(output_image.size() != 0);
auto output_buf = create_buffer_t_with_data(output_image);
const auto offset = 1;
auto error = brighten(&input_buf, offset, &output_buf);
(void)error;
return 0;
}
3. Bash shell script to build and execute HalideTraceViz
Now, here is is the bash shell script, where I:
Build the HalideTraceViz.cpp code
Build the AOT generator and filter exerciser app
Copy the binaries into one directory
Call the apps with special parameters that are used for passing data to the HalideTraceViz app
#!/bin/bash
set -e
set -u
function build_binaries()
{
printf "${FUNCNAME[0]}\n"
printf "Building HalideTraceViz\n"
xcodebuild -project visualize_brighten.xcodeproj -scheme HalideTraceViz CONFIGURATION_BUILD_DIR=build/Debug -configuration "Debug" clean build
printf "Building generate_brighten_aot\n"
xcodebuild -project visualize_brighten.xcodeproj -scheme generate_brighten_aot CONFIGURATION_BUILD_DIR=build/Debug -configuration "Debug" clean build
printf "Generating AOT in order to build exercise app\n"
cd build/Debug
HL_TRACE=3 ./generate_brighten_aot
cd $CURRENT_PATH
printf "Building app to exercise brighten filter\n"
xcodebuild -project visualize_brighten.xcodeproj -scheme exercise_brighten_aot CONFIGURATION_BUILD_DIR=build/Debug -configuration "Debug" clean build
cd $CURRENT_PATH
}
function copy_binaries()
{
printf "${FUNCNAME[0]}\n"
if [[ -d $CURRENT_PATH/halide_visualizer ]]; then
rm -Rv $CURRENT_PATH/halide_visualizer
fi
mkdir $CURRENT_PATH/halide_visualizer
cp -Rv $CURRENT_PATH/build/Debug $CURRENT_PATH/halide_visualizer/Debug
}
function visualize_function()
{
printf "${FUNCNAME[0]}\n"
local BLANK=0
local DIMENSIONS=1
local ZOOM=8
local COST=4
local STRIDE0="1 0"
local STRIDE1="0 1"
local FFMPEG_BIN_PATH="YOU_HAVE_TO_DOWNLOAD_THIS_BIN_AND_SET_THE_PATH_HERE"
cd $CURRENT_PATH/halide_visualizer/Debug
echo "About to start visualizing brighten filter"
HL_TRACE=3 ./generate_brighten_aot && \
HL_TRACE_FILE=/dev/stdout ./exercise_brighten_aot | \
$CURRENT_PATH/build/Debug/HalideTraceViz -s 1024 516 -t 1 -d 100 \
-f brighten:input_image 0 255 $BLANK $ZOOM $COST 0 0 $STRIDE0 $STRIDE1 |\
$FFMPEG_BIN_PATH/ffmpeg -r 30 -f rawvideo -pix_fmt bgra -s 1024X516 -i - -y -pix_fmt yuv420p $CURRENT_PATH/movies/brighten_schedule.mp4
cd $CURRENT_PATH
}
main()
{
printf "${FUNCNAME[0]}\n"
CURRENT_PATH=$PWD
build_binaries
copy_binaries
visualize_function
printf "All done\n"
}
printf "Starting ${0##*/}\n"
main
A couple of things to note:
I used Xcode for compiling the projects, but obviously, you can use any tool you are comfortable with
HalideTraceViz comes with it's own cmake file in "Halide/util/"; that folder is part of the Halide git repo
For the bash shell script code, you will have to adjust the folder paths to work with your development setup
All the code that you see listed above was just created now, so I can't guarantee that it works as is :)
Hopefully this helps you get started; if you have any questions, let me know.

Answer 2

toIn the apps/camera_pipe directory, the following command line will generate the HTML stmt file into /tmp/camera_pipe.html:
../../tools/gengen.sh -c c++ -l ../../lib/libHalide.a -o /tmp/ -e html -s camera_pipe_generator.cpp target=host