Radeon LoomShell reference

Radeon LoomShell reference#

LoomShell is an interpreter that enables stitching 360 degree videos using a script. It provides direct access to Live Stitch API by encapsulating the calls to enable rapid prototyping.

Command-line Usage#

% loom_shell.exe [-v] [-help] [script.lss]

Available Commands#

~ context creation
    ls_context context;
    context = lsCreateContext();
    lsReleaseContext(&context);

~ rig and image configuration
    rig_params rig_par = {yaw,pitch,roll,d};
    camera_params cam_par = { {yaw,pitch,roll,tx,ty,tz},{hfov,haw,r_crop,du0,dv0,lens_type,k1,k2,k3} };
    lsSetOutputConfig(context,format,width,height);
    lsSetCameraConfig(context,rows,columns,format,width,height);
    lsSetOverlayConfig(context,rows,columns,format,width,height);
    lsSetCameraParams(context,index,&cam_par);
    lsSetOverlayParams(context,index,&cam_par);
    lsSetRigParams(context,&rig_par);
    showOutputConfig(context);
    showCameraConfig(context);
    showOverlayConfig(context);
    showRigParams(context);

~ import/export configuration
    showConfiguration(context,"exportType");
    lsExportConfiguration(context,"exportType","fileName");
    lsImportConfiguration(context,"importType","fileName");

~ LoomIO configuration
    lsSetCameraModule(context,"module","kernelName","kernelArguments");
    lsSetOutputModule(context,"module","kernelName","kernelArguments");
    lsSetOverlayModule(context,"module","kernelName","kernelArguments");
    lsSetViewingModule(context,"module","kernelName","kernelArguments");
    showCameraModule(context);
    showOutputModule(context);
    showOverlayModule(context);
    showViewingModule(context);

~ initialize and schedule
    lsInitialize(context);
    lsScheduleFrame(context);
    lsWaitForCompletion(context);
    run(context,frameCount);
    runParallel(contextArray,contextCount,frameCount);

~ image I/O configuration (not supported with LoomIO)
    lsSetCameraBufferStride(context,stride);
    lsSetOutputBufferStride(context,stride);
    lsSetOverlayBufferStride(context,stride);
    lsSetCameraBuffer(context,&buf[#]|NULL);
    lsSetOutputBuffer(context,&buf[#]|NULL);
    lsSetOverlayBuffer(context,&buf[#]|NULL);
    showCameraBufferStride(context);
    showOutputBufferStride(context);
    showOverlayBufferStride(context);

~ OpenCL/OpenVX contexts
    cl_context opencl_context;
    vx_context openvx_context;
    lsGetOpenCLContext(context,&opencl_context);
    lsGetOpenVXContext(context,&openvx_context);

~ OpenCL buffers
    cl_mem buf[count];
    createBuffer(opencl_context,size,&buf[#]);
    releaseBuffer(&buf[#]);

~ load/save OpenCL buffers
    saveBufferToImage(buf[#],"image.bmp",format,width,height,stride);
    loadBufferFromImage(buf[#],"image.bmp",format,width,height,stride);
    saveBufferToMultipleImages(buf[#],"image%02d.bmp",rows,columns,format,width,height,stride);
    loadBufferFromMultipleImages(buf[#],"image%02d.bmp",rows,columns,format,width,height,stride);
    loadBuffer(buf[#],"image.bin"[,offset]); // default: 0
    saveBuffer(buf[#],"image.bin"[,flags]); // flags: 0:write 1:append, deault: 0

~ OpenVX/OpenVX contexts (advanced)
    createOpenCLContext("platform","device",&opencl_context);
    createOpenVXContext(&openvx_context);
    lsSetOpenCLContext(context,opencl_context);
    lsSetOpenVXContext(context,openvx_context);
    releaseOpenCLContext(&opencl_context);
    releaseOpenVXContext(&openvx_context);

~ attributes (advanced)
    setGlobalAttribute(offset,value);
    showGlobalAttributes(offset,count);
    saveGlobalAttributes(offset,count,"attr.txt");
    loadGlobalAttributes(offset,count,"attr.txt");
    setAttribute(context,offset,value);
    showAttributes(context,offset,count);
    saveAttributes(context,offset,count,"attr.txt");
    loadAttributes(context,offset,count,"attr.txt");

~ components (advanced)
    showExpCompGains(context,num_entries);
    loadExpCompGains(context,num_entries,\"gains.txt\");
    saveExpCompGains(context,num_entries,\"gains.txt\");

~ miscellaneous
    help
    include "script.lss"
    exit
    quit

Parameter	Description
format	buffer format: VX_DF_IMAGE_RGB, VX_DF_IMAGE_UYVY, VX_DF_IMAGE_YUYV, VX_DF_IMAGE_RGBX
width	buffer width in pixel units
height	buffer height in pixel units
rows	number of image tile rows inside the buffer (veritical direction)
columns	number of image tile columns inside the buffer (horizontal direction)
index	camera or overlay index
yaw	yaw in degrees
pitch	pitch in degrees
roll	roll in degrees
d	reserved (should be zero)
tx	reserved (should be zero)
ty	reserved (should be zero)
tz	reserved (should be zero)
lens_type	ptgui_lens_rectilinear, ptgui_lens_fisheye_ff, ptgui_lens_fisheye_circ, adobe_lens_rectilinear, or adobe_lens_fisheye
haw	horizontal active pixel count
hfov	horizontal field of view in degrees
k1,k2,k3	lens distortion correction parameters
du0,dv0	optical center correction in pixel units
r_crop	crop radius in pixel units
importType	supported values: pts
exportType	supported values: pts, loom_shell
frameCount	number of frames to process (for live capture, use 0)
size	size of a buffer in bytes
stride	stride of an image inside buffer in bytes
platform	OpenCL platform name or platform index (default: 0)
device	OpenCL device name or device index (default: 0)
module	LoomIO plug-in: OpenVX module name
kernelName	LoomIO plug-in: OpenVX kernel name
kernelArguments	LoomIO plug-in: custom kernel arguments
offset	start index of an attribute
count	number of attributes
value	value of attribute
contextCount	number of stitch instances in context[] allocated using `ls_context context[N];`

Example #1: Simple Example#

Let’s consider a 360 rig that has three 1080p cameras with circular fishEye lenses. The following example demonstrates how to stitch images from these cameras into a 4K equi-rectangular buffer.

# define camera orientation and lens parameters
camera_params cam1_par = { { 120,0,90,0,0,0},{176,1094,547,0,-37,ptgui_lens_fisheye_circ,-0.1719,0.1539,1.0177} };
camera_params cam2_par = { {   0,0,90,0,0,0},{176,1094,547,0,-37,ptgui_lens_fisheye_circ,-0.1719,0.1539,1.0177} };
camera_params cam3_par = { {-120,0,90,0,0,0},{176,1094,547,0,-37,ptgui_lens_fisheye_circ,-0.1719,0.1539,1.0177} };

# create a live stitch instance and initialize
ls_context context;
context = lsCreateContext();
lsSetOutputConfig(context,VX_DF_IMAGE_RGB,3840,1920);
lsSetCameraConfig(context,3,1,VX_DF_IMAGE_RGB,1920,1080*3);
lsSetCameraParams(context, 0, &cam1_par);
lsSetCameraParams(context, 1, &cam2_par);
lsSetCameraParams(context, 2, &cam3_par);
lsInitialize(context);

# Get OpenCL context and create OpenCL buffers for input and output
cl_context opencl_context;
cl_mem buf[2];
lsGetOpenCLContext(context,&opencl_context);
createBuffer(opencl_context,3*1920*1080*3, &buf[0]);
createBuffer(opencl_context,3*3840*1920  , &buf[1]);

# load CAM00.bmp, CAM01.bmp, and CAM02.bmp (1920x1080 each) into buf[0]
loadBufferFromMultipleImages(buf[0],"CAM%02d.bmp",3,1,VX_DF_IMAGE_RGB,1920,1080*3);

# set input and output buffers and stitch a frame
lsSetCameraBuffer(context, &buf[0]);
lsSetOutputBuffer(context, &buf[1]);
run(context, 1);

# save the stitched output into "output.bmp"
saveBufferToImage(buf[1],"output.bmp",VX_DF_IMAGE_RGB,3840,1920);

# release resources
releaseBuffer(&buf[0]);
releaseBuffer(&buf[1]);
lsReleaseContext(&context);

Example #2: Stitching Workflow using PTGui Pro Tool for Camera Calibration#

It is easy to import camera parameters from PTGui Pro project file (.pts) into loom_shell. In this example, let’s consider a 360 rig that has sixteen 1080p cameras.

Step 1: Calibrate cameras

Save test input images from all cameras into BMP files: CAM00.bmp, CAM01.bmp, CAM02.bmp, …, and CAM15.bmp. Align these test input images using PTGui Pro and save the project into myrig.pts (it should be in ASCII text format).

Step 2: Use the following script to generate stitched 4K output:

# create context, configure, and initialize
ls_context context;
context = lsCreateContext();
lsSetOutputConfig(context, VX_DF_IMAGE_RGB, 3840, 1920);
lsSetCameraConfig(context, 16, 1, VX_DF_IMAGE_RGB, 1920, 1080*16);
lsImportConfiguration(context, "pts", "myrig.pts");
showConfiguration(context, "loom_shell");
lsInitialize(context);

# create buffers for input and output
cl_context opencl_context;
cl_mem mem[2];
lsGetOpenCLContext(context, &opencl_context);
createBuffer(opencl_context, 3*1920*1080*16, &buf[0]);
createBuffer(opencl_context, 3*3840*1920, &buf[1]);

# load input images into buf[0]
loadBufferFromMultipleImages(buf[0], "CAM%02d.bmp", 16, 1, VX_DF_IMAGE_RGB, 1920, 1080*16);

# process camera inputs from buf[0] into stitched output in buf[1]
lsSetCameraBuffer(context, &buf[0]);
lsSetCameraBuffer(context, &buf[1]);
run(context, 1);

# save the output
saveBufferToImage(buf[1], "output.bmp", VX_DF_IMAGE_RGB, 3840, 1920);

# release all resources
releaseBuffer(&buf[0]);
releaseBuffer(&buf[1]);
lsReleaseContext(&context);

Example #3: Real-time Live Stitch using LoomIO#

This example makes use of a 3rd party LoomIO plug-ins for live camera capture and display.

# create context, configure, and initialize
ls_context context;
context = lsCreateContext();
lsSetOutputConfig(context, VX_DF_IMAGE_RGB, 3840, 1920);
lsSetCameraConfig(context, 16, 1, VX_DF_IMAGE_RGB, 1920, 1080*16);
lsImportConfiguration(context, "pts", "myrig.pts");
lsSetCameraModule(context, "vx_loomio_bm", "com.amd.loomio_bm.capture", "30,0,0,16");
lsSetOutputModule(context, "vx_loomio_bm", "com.amd.loomio_bm.display", "30,0,0");
lsInitialize(context);

# process live from camera until aborted by input capture plug-in
run(context, 0);

# release the context
lsReleaseContext(&context);

Example #4: Converting script into standalone C application#

It is easy to convert a well written LoomShell script into a standalone C application using the following steps :

Convert the shell script comments into C - style inline comments and keep them inside main() function
Use “amdovx-modules/utils/loom_shell/loom_shell_util.h” for wrapper utility functions, such as, loadBuffer()
Add “amdovx-modules/utils/loom_shell/loom_shell_util.cpp” to project for wrapper utility function implementations

Below is the C code generated from script in Example#3.

#include "loom_shell_util.h"
int main()
{
    // create context, configure, and initialize
    ls_context context;
    context = lsCreateContext();
    lsSetOutputConfig(context, VX_DF_IMAGE_RGB, 3840, 1920);
    lsSetCameraConfig(context, 16, 1, VX_DF_IMAGE_RGB, 1920, 1080 * 16);
    lsImportConfiguration(context, "pts", "myrig.pts");
    lsSetCameraModule(context, "vx_loomio_bm", "com.amd.loomio_bm.capture", "30,0,0,16");
    lsSetOutputModule(context, "vx_loomio_bm", "com.amd.loomio_bm.display", "30,0,0");
    lsInitialize(context);

    // process live from camera until aborted by input capture plug-in
    run(context, 0);

    // release the context
    lsReleaseContext(&context);

    return 0;
}