4 **apitrace** consists of a set of tools to:
6 * trace OpenGL, OpenGL ES, Direct3D, and DirectDraw APIs calls to a file;
8 * replay OpenGL and OpenGL ES calls from a file;
10 * inspect OpenGL state at any call while retracing;
12 * visualize and edit trace files.
14 See the [apitrace homepage](http://apitrace.github.io/) for more details.
17 Obtaining **apitrace**
18 ======================
20 To obtain apitrace either [download the latest
21 binaries](http://apitrace.github.io/#download) for your platform if
22 available, or follow the instructions in INSTALL.markdown to build it yourself.
23 On 64bits Linux and Windows platforms you'll need apitrace binaries that match
24 the architecture (32bits or 64bits) of the application being traced.
30 Run the application you want to trace as
32 apitrace trace --api API /path/to/application [args...]
34 and it will generate a trace named `application.trace` in the current
35 directory. You can specify the written trace filename by passing the
36 `--output` command line option.
38 Problems while tracing (e.g, if the application uses calls/parameters
39 unsupported by apitrace) will be reported via stderr output on Unices. On
40 Windows you'll need to run
41 [DebugView](http://technet.microsoft.com/en-us/sysinternals/bb896647) to view
44 Follow the "Tracing manually" instructions below if you cannot obtain a trace.
48 apitrace dump application.trace
50 Replay an OpenGL trace with
52 apitrace replay application.trace
54 Pass the `--sb` option to use a single buffered visual. Pass `--help` to
55 `apitrace replay` for more options.
63 qapitrace application.trace
65 You can also tell the GUI to go directly to a specific call
67 qapitrace application.trace 12345
70 Advanced command line usage
71 ===========================
77 Several tools take `CALLSET` arguments, e.g:
79 apitrace dump --calls=CALLSET foo.trace
80 apitrace dump-images --calls=CALLSET foo.trace
82 The call syntax is very flexible. Here are a few examples:
86 * `0,2,4,5` set of calls
88 * `"0 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
90 * `0-100/2` calls 1, 3, 5, ..., 99
92 * `0-1000/draw` all draw calls between 0 and 1000
94 * `0-1000/fbo` all fbo changes between calls 0 and 1000
96 * `frame` all calls at end of frames
98 * `@foo.txt` read call numbers from `foo.txt`, using the same syntax as above
107 On 64 bits systems, you'll need to determine whether the application is 64 bits
108 or 32 bits. This can be done by doing
110 file /path/to/application
112 But beware of wrapper shell scripts -- what matters is the architecture of the
115 Run the GLX application you want to trace as
117 LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
119 and it will generate a trace named `application.trace` in the current
120 directory. You can specify the written trace filename by setting the
121 `TRACE_FILE` environment variable before running.
123 For EGL applications you will need to use `egltrace.so` instead of
126 The `LD_PRELOAD` mechanism should work with the majority applications. There
127 are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
128 have global function pointers with the same name as OpenGL entrypoints, living in a
129 shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
130 those global function pointers get overwritten with the address to our wrapper
131 library, and the application will segfault when trying to write to them. For
132 these applications it is possible to trace by using `glxtrace.so` as an
133 ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
135 ln -s glxtrace.so wrappers/libGL.so
136 ln -s glxtrace.so wrappers/libGL.so.1
137 ln -s glxtrace.so wrappers/libGL.so.1.2
138 export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
139 export TRACE_LIBGL=/path/to/real/libGL.so.1
142 If you are an application developer, you can avoid this either by linking with
143 `-Bsymbolic` flag, or by using some unique prefix for your function pointers.
145 See the `ld.so` man page for more information about `LD_PRELOAD` and
146 `LD_LIBRARY_PATH` environment flags.
150 To trace standalone native OpenGL ES applications, use
151 `LD_PRELOAD=/path/to/egltrace.so /path/to/application` as described in the
152 previous section. To trace Java applications, refer to Dalvik.markdown.
156 Run the application you want to trace as
158 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
160 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
161 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
162 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
163 page for more details about these environment flags.
167 When tracing third-party applications, you can identify the target
168 application's main executable, either by:
170 * right clicking on the application's icon in the _Start Menu_, choose
171 _Properties_, and see the _Target_ field;
173 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
174 click on the application name in the _Applications_ tab, choose _Go To Process_,
175 note the highlighted _Image Name_, and search it on `C:\Program Files` or
176 `C:\Program Files (x86)`.
178 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
179 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
180 column of the _Processes_ tab of _Windows Task Manager_ window.
182 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
183 wrappers directory to the directory with the application you want to trace.
184 Then run the application as usual.
186 You can specify the written trace filename by setting the `TRACE_FILE`
187 environment variable before running.
189 For D3D10 and higher you really must use `apitrace trace -a DXGI ...`. This is
190 because D3D10-11 API span many DLLs which depend on each other, and once a DLL
191 with a given name is loaded Windows will reuse it for LoadLibrary calls of the
192 same name, causing internal calls to be traced erroneously. `apitrace trace`
193 solves this issue by injecting a DLL `dxgitrace.dll` and patching all modules
194 to hook only the APIs of interest.
197 Emitting annotations to the trace
198 ---------------------------------
200 From whitin OpenGL applications you can embed annotations in the trace file
201 through the following extensions:
203 * [`GL_KHR_debug`](http://www.opengl.org/registry/specs/KHR/debug.txt)
205 * [`GL_ARB_debug_output`](http://www.opengl.org/registry/specs/ARB/debug_output.txt)
207 * [`GL_AMD_debug_output`](http://www.opengl.org/registry/specs/AMD/debug_output.txt)
209 * [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
211 * [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
213 **apitrace** will advertise and intercept these OpenGL extensions regardless
214 of whether the OpenGL implementation supports them or not. So all you have
215 to do is to use these extensions when available, and you can be sure they
216 will be available when tracing inside **apitrace**.
218 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
219 detect and use OpenGL extensions, you could easily accomplish this by doing:
223 if (GLEW_KHR_debug) {
224 glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, __FUNCTION__);
229 if (GLEW_KHR_debug) {
230 glDebugMessageInsert(GL_DEBUG_SOURCE_APPLICATION, GL_DEBUG_TYPE_OTHER,
231 0, GL_DEBUG_SEVERITY_MEDIUM, -1, "bla bla");
236 if (GLEW_KHR_debug) {
242 This has the added advantage of working equally well with other OpenGL debugging tools.
244 Also, provided that the OpenGL implementation supports `GL_KHR_debug`, labels
245 defined via glObjectLabel() , and the labels of several objects (textures,
246 framebuffers, samplers, etc. ) will appear in the GUI state dumps, in the
250 For OpenGL ES applications you can embed annotations in the trace file through the
251 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
255 For Direct3D applications you can follow the standard procedure for
256 [adding user defined events to Visual Studio Graphics Debugger / PIX](http://msdn.microsoft.com/en-us/library/vstudio/hh873200.aspx):
258 - `D3DPERF_BeginEvent`, `D3DPERF_EndEvent`, and `D3DPERF_SetMarker` for D3D9 applications.
260 - `ID3DUserDefinedAnnotation::BeginEvent`,
261 `ID3DUserDefinedAnnotation::EndEvent`, and
262 `ID3DUserDefinedAnnotation::SetMarker` for D3D11.1 applications.
265 Dump OpenGL state at a particular call
266 ----------------------------------
268 You can get a dump of the bound OpenGL state at call 12345 by doing:
270 apitrace replay -D 12345 application.trace > 12345.json
272 This is precisely the mechanism the GUI uses to obtain its own state.
274 You can compare two state dumps by doing:
276 apitrace diff-state 12345.json 67890.json
279 Comparing two traces side by side
280 ---------------------------------
282 apitrace diff trace1.trace trace2.trace
284 This works only on Unices, and it will truncate the traces due to performance
288 Recording a video with FFmpeg/Libav
289 -----------------------------------
291 You can make a video of the output with FFmpeg by doing
293 apitrace dump-images -o - application.trace \
294 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
296 or Libav (which replaces FFmpeg on recent Debian/Ubuntu distros) doing
298 apitrace dump-images -o - application.trace \
299 | avconv -r 30 -f image2pipe -vcodec ppm -i - -vcodec mpeg4 -y output.mp4
301 Recording a video with gstreamer
302 --------------------------------------
304 You can make a video of the output with gstreamer by doing
306 glretrace --snapshot-format=RGB -s - smokinguns.trace | gst-launch-0.10 fdsrc blocksize=409600 ! queue \
307 ! videoparse format=rgb width=1920 height=1080 ! queue ! ffmpegcolorspace ! queue \
308 ! vaapiupload direct-rendering=0 ! queue ! vaapiencodeh264 ! filesink location=xxx.264
313 You can truncate a trace by doing:
315 apitrace trim --exact --calls 0-12345 -o trimed.trace application.trace
317 If you need precise control over which calls to trim you can specify the
318 individual call numbers in a plain text file, as described in the 'Call sets'
321 There is also experimental support for automatically trimming the calls
322 necessary for a given frame or call:
324 apitrace trim --auto --calls=12345 -o trimed.trace application.trace
325 apitrace trim --auto --frames=12345 -o trimed.trace application.trace
331 You can perform gpu and cpu profiling with the command line options:
333 * `--pgpu` record gpu times for frames and draw calls.
335 * `--pcpu` record cpu times for frames and draw calls.
337 * `--ppd` record pixels drawn for each draw call.
339 The results from these can then be read by hand or analyzed with a script.
341 `scripts/profileshader.py` will read the profile results and format them into a
342 table which displays profiling results per shader.
344 For example, to record all profiling data and utilise the per shader script:
346 apitrace replay --pgpu --pcpu --ppd foo.trace | ./scripts/profileshader.py
349 Advanced usage for OpenGL implementors
350 ======================================
352 There are several advanced usage examples meant for OpenGL implementors.
358 These are the steps to create a regression test-suite around **apitrace**:
362 * obtain reference snapshots, by doing on a reference system:
364 mkdir /path/to/reference/snapshots/
365 apitrace dump-images -o /path/to/reference/snapshots/ application.trace
367 * prune the snapshots which are not interesting
369 * to do a regression test, use `apitrace diff-images`:
371 apitrace dump-images -o /path/to/test/snapshots/ application.trace
372 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
375 Automated git-bisection
376 -----------------------
378 With tracecheck.py it is possible to automate git bisect and pinpoint the
379 commit responsible for a regression.
381 Below is an example of using tracecheck.py to bisect a regression in the
382 Mesa-based Intel 965 driver. But the procedure could be applied to any OpenGL
383 driver hosted on a git repository.
385 First, create a build script, named build-script.sh, containing:
389 export PATH=/usr/lib/ccache:$PATH
392 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
396 It is important that builds are both robust, and efficient. Due to broken
397 dependency discovery in Mesa's makefile system, it was necessary to invoke `make
398 clean` in every iteration step. `ccache` should be installed to avoid
399 recompiling unchanged source files.
404 export LIBGL_DEBUG=verbose
405 export LD_LIBRARY_PATH=$PWD/lib
406 export LIBGL_DRIVERS_DIR=$PWD/lib
408 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
409 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
410 git bisect run /path/to/tracecheck.py \
411 --precision-threshold 8.0 \
412 --build /path/to/build-script.sh \
413 --gl-renderer '.*Mesa.*Intel.*' \
414 --retrace=/path/to/glretrace \
415 -c /path/to/reference/snapshots/ \
416 topogun-1.06-orc-84k.trace
418 The trace-check.py script will skip automatically when there are build
421 The `--gl-renderer` option will also cause a commit to be skipped if the
422 `GL_RENDERER` is unexpected (e.g., when a software renderer or another OpenGL
423 driver is unintentionally loaded due to a missing symbol in the DRI driver, or
424 another runtime fault).
427 Side by side retracing
428 ----------------------
430 In order to determine which draw call a regression first manifests one could
431 generate snapshots for every draw call, using the `-S` option. That is, however,
432 very inefficient for big traces with many draw calls.
434 A faster approach is to run both the bad and a good OpenGL driver side-by-side.
435 The latter can be either a previously known good build of the OpenGL driver, or a
436 reference software renderer.
438 This can be achieved with retracediff.py script, which invokes glretrace with
439 different environments, allowing to choose the desired OpenGL driver by
440 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
443 For example, on Linux:
445 ./scripts/retracediff.py \
446 --ref-env LD_LIBRARY_PATH=/path/to/reference/OpenGL/implementation \
447 --retrace /path/to/glretrace \
448 --diff-prefix=/path/to/output/diffs \
453 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
459 qapitrace has rudimentary support for replaying traces on a remote
460 target device. This can be useful, for example, when developing for an
461 embedded system. The primary GUI will run on the local host, while any
462 replays will be performed on the target device.
464 In order to target a remote device, use the command-line:
466 qapitrace --remote-target <HOST> <trace-file>
468 In order for this to work, the following must be available in the
469 system configuration:
471 1. It must be possible for the current user to initiate an ssh session
472 that has access to the target's window system. The command to be
473 exectuted by qapitrace will be:
477 For example, if the target device is using the X window system, one
478 can test whether an ssh session has access to the target X server
483 If this command fails with something like "cannot open display"
484 then the user will have to configure the target to set the DISPLAY
485 environment variable, (for example, setting DISPLAY=:0 in the
486 .bashrc file on the target or similar).
488 Also, note that if the ssh session requires a custom username, then
489 this must be configured on the host side so that ssh can be
490 initiated without a username.
492 For example, if you normally connect with `ssh user@192.168.0.2`
493 you could configure ~/.ssh/config on the host with a block such as:
499 And after this you should be able to connect with `ssh target` so
500 that you can also use `qapitrace --remote-target target`.
502 2. The target host must have a functional glretrace binary available
504 3. The target host must have access to <trace-file> at the same path
505 in the filesystem as the <trace-file> path on the host system being
506 passed to the qapitrace command line.
509 [![githalytics.com alpha](https://cruel-carlota.pagodabox.com/c1062ad633aa7a458e9d7520021307e4 "githalytics.com")](http://githalytics.com/apitrace/apitrace)