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diff --git a/doc/visualization.html b/doc/visualization.html index 6ad44dd..207d3a5 100644 --- a/doc/visualization.html +++ b/doc/visualization.html @@ -69,7 +69,7 @@ <li>Enable VSync: Enable vertical synchronization.</li> <li>Save Viewport: Restore last camera configuration when the visualization is started.</li> <li>Window Width/Height: Change the window size. If the size equals to your screen size, the visualization will start in fullscreen mode.</li> - <li>FPS: FPS limit of the visualization.</li> + <li>Target FPS: FPS limit of the visualization.</li> <li>Supersampling: Supersample anti-aliasing for the 3D visualization scene. 1 means no SSAA.</li> <li>Multisampling: Multisample anti-aliasing for the 3D visualization scene. 0 means no MSAA.</li> <li>FOV: Field of view.</li> @@ -87,6 +87,122 @@ </ul> </li> </ul> + <h2>Visualization Renderer</h2> + The visualization plugin comes with a standalone application that generates high quality rendering of a midi file. + <h3>Command line usage</h3> + <pre style="font-variant-ligatures:none;"> +Usage: ./qmpvisrender [options] file +Renderer a visualization of a midi file. + +Options: + -h, --help Displays help on commandline options. + --help-all Displays help including Qt specific options. + -v, --version Displays version information. + -f, --output-file <filename> File name of the output file. + --receiver <command> Specify a program and its arguments to + process the rendered frames. Supports + parameter substitution. See documentation for + details. + -e, --receiver-execution <mode> Execution mode of the receiver command. + Valid options are 'one-shot' and 'per-frame' + -s, --show-window Do not hide the visualization window. + -c, --config <qmprc file> Load options from the configuration file. + -o, --option <key-value pair> Set option for the visualization module. + --list-options Show a list of recognized options. + +Arguments: + file MIDI file to render + </pre> + <h3>Basic usage</h3> + You will most likely to load your QMidiPlayer configuration file so that + you can get the exact same results as viewed in QMidiPlayer. + You should also make sure ffmpeg is ready to use. Then you can run + <code>qmpvisrender -c <path-to-configuration-file> <MIDI file to render></code> + and wait for the results. The output file is named output.mp4 and will be found + in the current work directory. + <h3>Supplementary materials for commandline options</h3> + <p> + When specifying a value for an option under the "Visualization" category, the category part + in the key may be omitted, so "-o Visualization/wwidth=1920" would become "-o wwidth=1920". + </p> + <p> + The renderer performs parameter substitution before invoking the receiver command line. + </p> + <table> + <style> + td,th{ + padding-top:0.5em; + padding-bottom:0.5em; + } + </style> + <tr><th>Placeholder</th><th>Substituted with</th><th>Remarks</th></tr> + <tr><td><code>%w</code></td><td>width of an output frame in pixels</td><td></td></tr> + <tr><td><code>%h</code></td><td>height of an output frame in pixels</td><td></td></tr> + <tr><td><code>%r</code></td><td>framerate which the output frames should be played at</td><td></td></tr> + <tr><td><code>%i</code></td><td>input format specification for ffmpeg</td><td>shorthand for "-f rawvideo -pixel_format rgba -video_size %wx%h -framerate %r -i pipe:"</td></tr> + <tr><td><code>%o</code></td><td>output file name specified by the --output-file option</td><td>If the receiver execution mode is "per-frame", "%f" in the output file name will also be replaced.</td></tr> + <tr><td><code>%f</code></td><td>a six-digit frame number</td><td>only works if the receiver execution mode is "per-frame".</td></tr> + </table> + <p> + To add a literal space in the receiver command, put a single backslash before the space. + To add a percent sign, either put two consecutive percent signs or use a backslash followed + by a percent sign. + </p> + <p> + The default receiver command is <code>ffmpeg %i -vf vflip -pix_fmt yuv420p -c:v libx264 -preset slow -crf 22 %o</code>. + In case the output quality doesn't satisfy your needs, consider lowering the number after '-crf' or selecting a even slower + profile ('slower' or 'veryslow'). + </p> + <h3>How it works</h3> + <p> + Notice: you don't have to understand anything under this section to use this tool. + You may try out the examples below or simply adhere to the basic usage shown above even this + section makes zero sense to you. + </p> + <p> + The renderer feeds a sequence of images into one command or a series of commands that process + the images through a pipe. That's it! + </p> + <p> + The data is an stream of raw RGBA values, where each color takes one byte in every pixel. The frame + size is the same as used by the visualization module, and the frames should be played back at a fixed + frame rate. The pixel data starts from the bottom-left of a frame and follows row-major ordering (so + you may want to flip the frame when using the frame with some applications). + </p> + <p> + The renderer supports two modes of receiver program operation. If the mode is set to 'one-shot', + the receiver is only started once and gets all rendered frames. If it is set to 'per-frame', + the receiver will be started every time a frame is rendered, and will only get one frame to process. + </p> + <h3>Examples</h3> + <p> + If you wish to try these examples, make sure you have the required receiver program ready to run. + </p> + <ol> + <li>Render to a vp9 encoded webm video.</li> + <pre style="white-space:pre-wrap;"> +qmpvisrender -c ~/.config/qmprc --output-file test.webm --receiver 'ffmpeg %i -vf vflip -c:v libvpx-vp9 -crf 30 -b:v 0 %o' <midi file> + </pre> + <li>Render to a h264 encoded mp4 video with hardware encoding acceleration using VA-API.</li> + <pre style="white-space:pre-wrap;"> +qmpvisrender -c ~/.config/qmprc --output-file test.mp4 --receiver 'ffmpeg -vaapi_device /dev/dri/renderD128 %i -vf vflip,format=nv12,hwupload -c:v h264_vaapi -b:v 5M %o' <midi file> + </pre> + <li>Render the frames into png files using imagemagick.</li> + <pre style="white-space:pre-wrap;"> +qmpvisrender -c ~/.config/qmprc --receiver-execution per-frame --receiver 'convert -size %wx%h -depth 8 RGBA:- -flip pngout/%f.png' <midi file> + </pre> + <li>Show the visualization window. Discard all rendered frames.</li> + <pre style="white-space:pre-wrap;"> +qmpvisrender -c ~/.config/qmprc -s --receiver 'dd of=/dev/null bs=24M' <midi file> + </pre> + <li>Save the raw frame data.</li> + <pre style="white-space:pre-wrap;"> +qmpvisrender -c ~/.config/qmprc --receiver-execution per-frame --receiver 'tee rawoutput/%f.raw' <midi file> + </pre> + </ol> + <h3>Useful stuff to refer to</h3> + <a target="_blank" href="https://www.ffmpeg.org/ffmpeg.html">ffmpeg documentation</a> + and <a target="_blank" href="https://www.ffmpeg.org/ffmpeg-codecs.html">ffmpeg codecs documentation</a>, if you want to tweak the ffmpeg encoder. </div> </body> </html> |