From Wang Rui, "additional FFmpegParameters class in the ffmpeg plugin for setting parameters before opening the video file, which benefits from getPluginStringData() as shown in the ReaderWriter implementation.

Now we can use ffmpeg to render webcam video (using the vfwcap device) under Windows:

osgmovie 0 -e ffmpeg -O "format=vfwcap frame_rate=25"

The number 0 just indicates a default device number in ffmpeg.

I think this can work under Linux, too, and should be a bit better than comparing the filename with a '/dev/' string. Just type:

./osgmovie /dev/yourcam -e ffmpeg -O "format=video4linux2 frame_rate=30 size=320x240""

src/osgPlugins/ffmpeg/FFmpegParameters.cpp

@@ -0,0 +1,79 @@
+
+#include "FFmpegParameters.hpp"
+
+#include <string>
+#include <iostream>
+#include <sstream>
+
+
+
+namespace osgFFmpeg {
+
+
+
+FFmpegParameters::FFmpegParameters() :
+    m_format(0)
+{
+    memset(&m_parameters, 0, sizeof(m_parameters));
+}
+
+
+FFmpegParameters::~FFmpegParameters()
+{}
+
+
+void FFmpegParameters::parse(const std::string& name, const std::string& value)
+{
+    if (value.empty())
+    {
+        return;
+    }
+    else if (name == "format")
+    {
+        avdevice_register_all();
+        m_format = av_find_input_format(value.c_str());
+        if (!m_format)
+            OSG_NOTICE<<"Failed to apply input video format: "<<value.c_str()<<std::endl;
+    }
+    else if (name == "pixel_format")
+    {
+        m_parameters.pix_fmt = avcodec_get_pix_fmt(value.c_str());
+    }
+    else if (name == "frame_size")
+    {
+        int frame_width = 0, frame_height = 0;
+        if (av_parse_video_frame_size(&frame_width, &frame_height, value.c_str()) < 0)
+        {
+            OSG_NOTICE<<"Failed to apply frame size: "<<value.c_str()<<std::endl;
+            return;
+        }
+        if ((frame_width % 2) != 0 || (frame_height % 2) != 0)
+        {
+            OSG_NOTICE<<"Frame size must be a multiple of 2: "<<frame_width<<"x"<<frame_height<<std::endl;
+            return;
+        }
+        m_parameters.width = frame_width;
+        m_parameters.height = frame_height;
+    }
+    else if (name == "frame_rate")
+    {
+        AVRational frame_rate;
+        if (av_parse_video_frame_rate(&frame_rate, value.c_str()) < 0)
+        {
+            OSG_NOTICE<<"Failed to apply frame rate: "<<value.c_str()<<std::endl;
+            return;
+        }
+        m_parameters.time_base.den = frame_rate.num;
+        m_parameters.time_base.num = frame_rate.den;
+    }
+    else if (name == "audio_sample_rate")
+    {
+        int audio_sample_rate = 44100;
+        std::stringstream ss(value); ss >> audio_sample_rate;
+        m_parameters.sample_rate = audio_sample_rate;
+    }
+}
+
+
+
+} // namespace osgFFmpeg