Using the PowerVR SDK to Optimize your...

© Imagination Technologies p1 www.imgtec.com

March, 2013

Using the PowerVR SDK to Optimize your Renderer


First, an Introduction

© Imagination Technologies p3

Who are we?

Who?

Joe Davis, Developer Technology Engineer

Bob Gardner, Developer Technology Engineer

Both from Imagination Technologies


Who are Imagination?

Leading silicon, software & cloud IP supplier

Multimedia: graphics; GPU compute; video; vision

Communications: demodulation; connectivity; sensors

Processors: applications CPUs; embedded MCUs

Cloud: device and user management; services

Targeting high volume, high growth markets

Top semis and OEMs for mobile, connected home consumer

automotive and more

Pure: our strategic product division

Digital radio, internet connected audio, home automation

Established technology powerhouse

Founded 1985; London FTSE 250 (IMG.L); ~1,500 employees

UK HQ; global operations

Comprehensive IP

portfolio for SoCs

& cloud connectivity

IP business pathfinder

Market maker/driver


What’s the Focus?


The Focus

Optimisation Tools Stability, functionality and GUI of PVRTune and PVRTrace

+

A Live Demo of the new features


The Focus

But First…


What is the PowerVR SDK?


What is the PowerVR Insider SDK?

Asset creation Development Debugging and profiling

+ PVRTexTool

PVRGeoPOD

+ PVRVFrame

PVRShaman

PVRShaderEditor

+ PVRTune

PVRTrace

PVRScope


What is the PowerVR Insider SDK?

Assists in rapid application development, debugging, and performance analysis

Educational resource for embedded graphics techniques

Develop on…

Develop for…

Windows OSX Linux

Windows OSX Linux BB10 iOS Android


Asset Optimization

Utilities


PVRGeoPOD

Geometry exporter and optimizer

Provided as…

Plug-in (Blender, Maya and 3D Studio)

Standalone GUI

Standalone command-line tool

Features

Triangle sorting

Vertex sorting

Data stripping


What is POD?

POD is the PowerVR Object Data format

Optimized deployment format for 3D geometry and animation with a public specification

De facto standard format used in successful AAA mobile games

Minigore 2: Zombies Bike Baron


Shout out to Mountain

Sheep for the awesome

screenshots


PVRTexTool

Texture compressor and converter

Provided as…

Stand-alone GUI & Command-line tool

PVRTexLib

Photoshop plugin

Features

Support for all core file formats for OpenGL

ES 1.x/2.0/3.0 as well as DirectX 9/10/11

Primary tool for converting to PVRTC


What is PVRTC?

What is PVRTC?

High quality, high ratio texture compression format,

designed for PowerVR hardware

Lowest, widely available, bitrate of any texture

compression format

Two variations

4 bits and 2bits per pixel

Both variations support alpha channels

Stored in .PVR files by default

Public file format specification


Development

Utilities


PVRShaderEditor

Syntax highlighted shader & kernel editor

Also useful for shader verification and profiling

Provided as…

Stand-alone GUI

Features

Error output for PowerVR hardware

Profiling with overall and per line cycle counts for

GLSL ES


GLSL Profiling Compilers

Provided as…

Command-line tool

Exposes GLSL ES shader profiling information

Estimated per-line & total cycle counts

Compiler provided for every family of PowerVR GPU

Note: Profiling compilers don’t generate binaries

Disassembly compilers available under NDA

Built in to PVRShaderEditor


PVRShaman

Shader Development Environment

Provided as…

Stand-alone GUI

Features

Integrated PVRShaderEditor & Profiler

Works with POD scenes and can import Collada

files

Immediate scene visualisation

Support for OpenGL and OpenGL ES graphics

APIs.


PVRVFrame

PowerVR OpenGL ES emulator

Supports ES 1.1, 2.0, 3.0

Provided as…

Dynamic library, with control GUI

Features

IMG extensions

Hardware profiles

Debugging output


Debugging and Profiling

Utilities


PVRTrace

OpenGL ES API Tracer

Provided as…

Analysis GUI with Recording Libraries and Control

APK

Features:

Records GL Calls, data, and render state for any

number of frames

Playback whole traces, frames, ranges of calls, or

single calls

Edit traces, and playback the newly edited traces on

device


PVRTune

PowerVR GPU Performance Analyser

Provided as…

Analysis GUI with Server on device

Features:

Real-time hardware data using hardware level

registers and counter

Negligible impact on performance

Counters are enabled by default on most devices

No special builds of application required to do

performance analysis


PVRScope

Interface to the performance analysis stats

found in PowerVR hardware

Provided as…

Static library

Features

Provides access in any application to

PVRTunes statistics

OR:

Can be used to send custom counters &

custom markers to PVRTune


Source Code


PVRShell

Graphics-focused OS abstraction framework

Allows application development without worrying

about the platform underneath

Enables quick and easy application porting with

a consistent implementation across each API

and OS

Supports all PowerVR platform configurations


PVRTools

Tackles common functionality required during

graphics development

Texture, model and shader runtimes

Vector, matrix, and Quaternion maths

3D text display functions

Extension retrieval

Etc.

Cross platform tools library

Tested to work on all PowerVR platforms

Consistent implementation across APIs


Examples

Step by step guide from the basics of computer

graphics to advanced effects tailored for mobile

devices

PVRShell and PVRTools used consistently

across all the examples

Same examples across all APIs (OpenGL,

OGLES 1.1, 2.0 and 3.0)


Documentation

Wide range of documentation to support

development

Architecture Guide

Performance recommendations

User Manuals

Etc.

Whitepapers for specific technologies &

techniques

Water effects

UI Render

Etc.


What’s New in SDK 3.1


Just A Reminder

Focus on Optimisation Tools Stability, functionality and GUI of PVRTune and PVRTrace


PVRTune


Initial Rogue Support

Initial Series6 support

Series6 specific counters

Series6 specific timing data

Timing data colouration coming soon

Also includes better compute support


Render State Override

PVRTune now includes render state

override capability

See the effect on performance, in real

time of disabling and changing various

states.

Makes it much easier to test hypotheses

quickly

Even more so if you’re using PVRScope to

remotely edit your app


Improved GUI

SDK 3.0 ported all our applications to Qt

SDK 3.1 includes considerable GUI improvements

Improved counter description panel

Improved group selection

Improved state saving

Many more


Improved Counter Descriptions

… they will tell you:

What the counter represents

What a high value of the counter means

How you can try to solve the problem


PVRTrace


OpenGL ES 3.0 Tracing

SDK 3.0 allowed ES 3.0 recording but

could only display the call list

SDK 3.1 now includes full functionality

for ES 3.0

…and any IMG extensions


Pixel Picker

User can select a pixel from the Image

Analysis panel

See what shaders affected that pixel

Double click a shader to open it in the

shaders tab

…then edit it…more on this later


Shader Analysis

Displays the following for the current frame:

Fragment Cost

Num. times shader is ran * cycle count of shader returned by profiling compiler

Fragment Count

Num. times shader is ran

Fragment Texture Reads

Num. times shader is ran * num. texture reads


Editing & Splitting

Trace files can be edited & saved

Shaders changed

Calls disabled

Quickly see if something fixes a bug

before committing a change

Trace files can be split

Save sub-sections of traces

Useful for repeatedly playing back or

examining traces


Playback

Play a trace file, even one that has been edited

Record calls on one platform, play them back on another

Change things in the PVRTrace GUI, play them back on platform

Identify problems, find solutions, test them, all without having to touch your code

First public iteration

Find it in the PVRTrace package in the SDK


Time for a demo

Let’s see how it all works


Using PVRTune – A Practical Approach


What is PVRTune?

PowerVR GPU Performance Analyser

Provided as…

Analysis GUI with Server on device

Features:

Real-time hardware data using hardware level

registers and counter

Negligible impact in performance

Counters are enabled by default on most devices

No special builds of application required to do

performance analysis


Installing & Running PVRTune

Install the PVRPerfServer

adb install

PVRPerfServerDeveloper.apk

Using ADB on Android

Forward the 6520 port

adb forward tcp:6520 tcp:6520

Run PVRTune

Connect to ‘localhost’


The PVRTune GUI What does it all mean?

Counter List

Renderstate

Override

Counter

Description

Remote

Editor

Active Counter List

Counter Graphs

Timing Data


The Five Basic Bottlenecks

Reading PVRTune


Identifying Bottlenecks

Bottlenecks usually fall into one of five categories:

CPU limited,

Vertex limited,

V-Sync limited,

Fragment limited, or

Bandwidth limited.

We’ll show you how to spot these

For everything else…

A.K.A. Why is my application running so slow?



…read the counter descriptions…




… they will tell you:

What the counter represents

What a high value of the counter means

How you can try to solve the problem



CPU Limited

Gaps between TA & 3D Blocks

Gaps in the USSE Load

One or more

CPUs at max

load


Vertex Limited

High TA Load

Very little gap between TA Tasks

Gaps between

3D tasks

High USSE Load: Vertex


Fragment Limited

High USSE Load: Pixel

Very large gaps between TA Tasks

No gaps

between 3D

tasks

High USSE clock cycles per pixel


Bandwidth Limited

No direct way for PVRTune to show bandwidth information

Will often appear as other bottlenecks but with illogical data

There are two main giveaways that you are bandwidth limited:

‘TA/3D’ shows the application to be fragment limited but the ‘USSE Load: Pixel’ is low

‘TA/3D’ shows the application to be vertex limited but the ‘USSE Load: Vertex’ and ‘TA load’

are low

As a rule of thumb, whenever possible, optimise for bandwidth usage


V-Sync Limited

Easy to determine…you’ll probably have turned it on

If you haven’t, look out for the following:

GPU goes to sleep intermittently

Frame rate hovers around a set number

Turn it off to profile, or it’ll add noise to your readings


Using PVRTrace – A Practical Approach


What is PVRTrace?

OpenGL ES API Tracer

Provided as…

Analysis GUI with Recording Libraries and Control

APK

Features:

Records GL Calls, data, and render state for any

number of frames

Playback whole traces, frames, ranges of calls, or

single calls

Edit traces, and playback the newly edited traces on

device


Installing & Running PVRTrace

Install the PVRTrace Installer

adb install PVRTraceApp.apk

Using ADB on Android on a rooted device

Install the recording libraries

Set up the recording libraries

Trace the application


The PVRTune GUI What does it all mean?

Call Summary &

Frame Summary

Trace modification

information, search

output, emulator

output

Render state

information Pixel Analysis

Texture Viewer

and Shader

Viewer

Image Analysis

& Playback

Function Call List

Frame Scrubber


Using PVRTrace – Without Root


Tracing without Root on Android

It is possible to run PVRTrace without rooting the device

1. Tell the Native Activity to

load the recording libraries

2. Tell the Android.mk to point

to the correct libraries

3. Perform an NDK Build then copy the recording libraries to

‘<build_output>/libs/armeabi-v7a/’


Tracing without Root on Android

4. Install your application

5. Create ‘pvrtrace.cfg’ in the root of /sdcard

6. Make sure ‘pvrtrace.cfg’ points to the Android

‘shim’ drivers, not the actual drivers

7. Run the application, and analyse the trace

pvrtrace.cfg example:


March, 2013

Getting the SDK


Download it now! How to get it?

http://bit.ly/PVR_SDK

Download the installer

Next, next, next…

Done!

Or grab a DVD

Booth 512

We also have T-Shirts


PowerVR Insider

http://bit.ly/PVR_SDK

Benefits of being a PowerVR Insider

PowerVR Insider SDK downloads

Open developer forums

Email support from our Dev. Tech. team

[email protected]

Documentation & FAQs

Training (web based, our site, or your site)

Early access

NDA only tools (on request)

mailto:[email protected]


March, 2013

What’s New in SDK 3.1

Using the PowerVR SDK to Optimize your...

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