Merge pull request #1479 from jmargeta:fix-record-command-docs

PiperOrigin-RevId: 613927858
Change-Id: I8fe30db8677811c98ed4f881b51a0f430d93dd3b

doc/programming/samples.rst

@@ -150,21 +150,60 @@ This code sample simulates the passive dynamics of a given model, renders it off
 values, and saves them into a raw data file that can then be converted into a movie file with tools such as ffmpeg. The
 rendering is simplified compared to :ref:`simulate.cc <saSimulate>` because there is no user interaction, visualization
 options or timing; instead we simply render with the default settings as fast as possible. The dimensions and number of
-multi-samples for the offscreen buffer are specified in the MuJoCo model, while the simulation duration, frames-per-
+multi-samples for the offscreen buffer are specified in the MuJoCo model with the visual/global/{`offwidth
-second to be rendered (usually much less than the physics simulation rate), and output file name are specified as
+<https://mujoco.readthedocs.io/en/stable/XMLreference.html#visual-global-offwidth>`__, `offheight
-command-line arguments. For example, a 5 second animation at 60 frames per second is created with:
+<https://mujoco.readthedocs.io/en/stable/XMLreference.html#visual-global-offheight>`__} and visual/quality/`offsamples
+<https://mujoco.readthedocs.io/en/stable/XMLreference.html#visual-quality-offsamples>`_ attributes, while the simulation
+duration, frames-per-second to be rendered (usually much less than the physics simulation rate), and output file name
+are specified as command-line arguments.
 
 .. code-block:: Shell
 
-     render humanoid.xml 5 60 rgb.out
+   record modelfile duration fps rgbfile [adddepth]
 
-The default humanoid.xml model specifies offscreen rendering with 800x800 resolution. With this information in hand, we
+Where the command line arguments are
-can compress the (large) raw date file into a playable movie file:
+
+.. list-table::
+   :width: 95%
+   :align: left
+   :widths: 1 1 5
+   :header-rows: 1
+
+   * - Argument
+     - Default
+     - Meaning
+   * - ``modelfile``
+     - (required)
+     - path to model
+   * - ``duration``
+     - (required)
+     - duration of the recording in seconds
+   * - ``fps``
+     - (required)
+     - number of frames per second
+   * - ``rgbfile``
+     - (required)
+     - path to raw recording file
+   * - ``adddepth``
+     - 1
+     - overlay depth image in the lower left corner (0: none)
+
+For example, a 5 second animation at 60 frames per second is created with:
 
 .. code-block:: Shell
 
-     ffmpeg -f rawvideo -pixel_format rgb24 -video_size 800x800
+   record humanoid.xml 5 60 rgb.out
-       -framerate 60 -i rgb.out -vf "vflip" video.mp4
+
+The default `humanoid.xml <https://github.com/google-deepmind/mujoco/blob/main/model/humanoid/humanoid.xml>`__ model
+specifies offscreen rendering with 2560x1440 resolution. With this information in hand, we can compress the (large) raw
+data file into a playable movie file:
+
+.. code-block:: Shell
+
+   ffmpeg -f rawvideo -pixel_format rgb24 -video_size 2560x1440
+          -framerate 60 -i rgb.out -vf "vflip,format=yuv420p" video.mp4
+
+Note that the offscreen rendering resolution of the model and ffmpeg's video_size must be the identical.
 
 This sample can be compiled in three ways which differ in how the OpenGL context is created: using GLFW with an
 invisible window, using OSMesa, or using EGL. The latter two options are only available on Linux and are envoked by

sample/record.cc

@@ -217,8 +217,8 @@ void closeOpenGL(void) {
 
 int main(int argc, const char** argv) {
   // check command-line arguments
-  if (argc!=5) {
+  if (argc < 5 || argc > 6) {
-    std::printf(" USAGE:  record modelfile duration fps rgbfile\n");
+    std::printf(" USAGE:  record modelfile duration fps rgbfile [adddepth]\n");
     return 0;
   }
 
@@ -255,6 +255,11 @@ int main(int argc, const char** argv) {
     mju_error("Could not open rgbfile for writing");
   }
 
+  int adddepth = 1;
+  if (argc > 5 && std::sscanf(argv[5], "%d", &adddepth) != 1) {
+    mju_error("Invalid adddepth argument");
+  }
+
   // main loop
   double frametime = 0;
   int framecount = 0;
@@ -276,12 +281,15 @@ int main(int argc, const char** argv) {
       mjr_readPixels(rgb, depth, viewport, &con);
 
       // insert subsampled depth image in lower-left corner of rgb image
-      const int NS = 3;           // depth image sub-sampling
+      if (adddepth) {
-      for (int r=0; r<H; r+=NS)
+        const int NS = 3;           // depth image sub-sampling
-        for (int c=0; c<W; c+=NS) {
+        for (int r=0; r<H; r+=NS) {
-          int adr = (r/NS)*W + c/NS;
+          for (int c=0; c<W; c+=NS) {
-          rgb[3*adr] = rgb[3*adr+1] = rgb[3*adr+2] = (unsigned char)((1.0f-depth[r*W+c])*255.0f);
+            int adr = (r/NS)*W + c/NS;
+            rgb[3*adr] = rgb[3*adr+1] = rgb[3*adr+2] = (unsigned char)((1.0f-depth[r*W+c])*255.0f);
+          }
         }
+      }
 
       // write rgb image to file
       std::fwrite(rgb, 3, W*H, fp);