Radeon LoomShell

Radeon LoomShell#

DESCRIPTION#

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 3 1080p cameras with Circular FishEye lenses. The below example demonstrates how to stitch images from these cameras into a 4K Equirectangular 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 16 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 below 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 :

  1. Convert the shell script comments into C - style inline comments and keep them inside main() function

  2. Use “amdovx-modules/utils/loom_shell/loom_shell_util.h” for wrapper utility functions, such as, loadBuffer()

  3. 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;
}
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