int x264_vbv_max_bitrate = -1; // In kilobits. 0 = no limit, -1 = same as <x264_bitrate> (CBR).
int x264_vbv_buffer_size = -1; // In kilobits. 0 = one-frame VBV, -1 = same as <x264_bitrate> (one-second VBV).
std::vector<std::string> x264_extra_param; // In “key[,value]” format.
+ std::string v4l_output_device; // Empty if none.
bool enable_alsa_output = true;
std::map<int, int> default_stream_mapping;
bool multichannel_mapping_mode = false; // Implicitly true if input_mapping_filename is nonempty.