# Secrets of Cinelerra: Configuration

Because of the variety of uses, Cinelerra can not be run optimally without some intimate configuration for your specific needs. Very few parameters are adjustible at compile time. Runtime configuration is the only option for most configuration because of the multitude of parameters.

Go to settings->preferences and run through the options.

# PLAYBACK

AUDIO OUT:

> These determine what happens when you play sound from the timeline.

> SAMPLES TO READ FROM DISK: Cinelerra uses a pipeline for rendering audio. The first stage is reading large chunks of audio from disk, the samples to read from disk. This is followed by processing small fragments in a virtual console.

> SAMPLES TO SEND TO CONSOLE: - The second stage is rendering small fragments through the virtual console to the sound driver. A larger value here causes more latency when you change mixing parameters but gives more reliable playback.

> Some sound drivers don't allow changing of the console fragment so latency is unchanged no matter what this value is.

> VIEW FOLLOWS PLAYBACK: - Causes the timeline window to scroll when the playback cursor moves out of view. This can bog down the X Server.

> USE SOFTWARE FOR POSITIONING INFORMATION: - Most soundcards and sound drivers don't give reliable information on the number of samples the card has played. When playing video you need this information for synchronization. This option causes the sound driver to be ignored and a software timer to be used for synchronization.

> AUDIO PLAYBACK IN REALTIME: - Back in the days when 150Mhz was the maximum, this allowed uninterrupted playback on heavy loads. Now you'll probably only need it for playing video and audio when the load is to high for uninterrupted audio.

> AUDIO DRIVER: - There are many sound drivers for Linux. This allows selecting one and setting parameters specific to it. Some of the common parameters for a sound driver are

> > DEVICE PATH: - Usually a file in the /dev/ directory which controls the device.

> > BITS: - The number of bits of precision Cinelerra should set the device for. This sometimes has a figuritive meaning. Some sound drivers need to be set to 32 bits to perform 24 bit playback and won't play anything when set to 24 bits. Some sound drivers need to be set to 24 bits for 24 bit playback.

> > CHANNELS: - The number of channels Cinelerra should set the device for. Regardless of the number of channels in the project, the number of channels set here will be written to the device. When this is set to 2 and the project has 1 channel you'll hear sound through the left speaker and not centered as expected for a monaural project. When this is set to 1 and the project has 2 channels you'll hear the left channel centered and not 2 channels mixed together.

VIDEO OUT

> These determine what happens when you play video from the timeline.

> FRAMERATE ACHIEVED: - The number of frames per second being displayed during playback.

> SCALING EQUATION: - The algorithm used in all video resizing in the virtual console. This doesn't affect scaling to the size of the compositor window.

> > NEAREST NEIGHBOR ENLARGE AND REDUCE: - lowest but fastest quality. Produces jagged edges and uneven motion.

> > BICUBIC ENLARGE AND BILINEAR REDUCE: - highest but slowest quality. For enlarging a bicubic interpolation is used, which blurs slightly but doesn't reveal stair steps. For reduction a bilinear interpolation is used, which produces very sharp images and reduces noise. The bilinear reduced images can be sharpened with a sharpen effect with less noise than a normal sized image.

> > BILINEAR ENLARGE AND BILINEAR REDUCE: - when slight enlargement is needed a bilinear enlargement looks better than a bicubic enlargement.

> PRELOAD BUFFER FOR QUICKTIME: - The Quicktime/AVI decoder can handle CDROM sources better when this is around 1000000. This reduces the amount of seeking. For normal use this should be 0.

> VIDEO DRIVER: - Normally video on the timeline goes to the compositor window during continuous playback and when the insertion point is repositioned. Instead of sending video to the Compositor window the video driver can be set to send video to another output device during continuous playback. This doesn't affect where video goes when the insertion point is repositioned, however.

> Various parameters are given for Video Driver depending on the driver.

> > DISPLAY: - The is intended for dual monitor displays. Depending on the value of Display, the Compositor window will appear on a different monitor from the rest of the windows.

> > DEVICE PATH: - Usually a file in the /dev/ directory which controls the device.

> > SWAP FIELDS: - Make the even lines odd and the odd lines even when sending to the device. On an NTSC or 1080i monitor the fields may need to be swapped to prevent jittery motion.

> > OUTPUT CHANNEL: - Devices with multiple outputs may need a specific connector to send video on.

> > PORT: - The IEEE1394 standard specifies something known as the port. This is probably the firewire card number in the system to use.

> > CHANNEL: - The IEEE1394 standard specifies something known as the channel. For DV cameras it's always 63.

# RECORDING

AUDIO IN:

These determine what happens when you record audio.

> RECORD DRIVER: - This is used for recording audio in the Record window. It may be shared with the Record Driver for video if the audio and video are wrapped in the same stream. It takes variable parameters depending on the driver. The parameters have the same meaning as they do for playback.

> > DEVICE PATH: - Usually a file in the /dev/ directory which controls the device.

> > BITS: - The number of bits of precision Cinelerra should set the device for. This sometimes has a figuritive meaning. Some sound drivers need to be set to 32 bits to perform 24 bit recording and won't record anything when set to 24 bits. Some sound drivers need to be set to 24 bits for 24 bit recording.

> > CHANNELS: - The number of channels Cinelerra should set the device for. Regardless of the number of channels in the record operation, the number of channels set here will be read from the device. When this is set to 2 and the record operation has 1 channel you'll record the left speaker and not a mix of the left and right speakers as expected for a monaural project. When this is set to 1 and the project has 2 channels you'll record the left and right channels mixed into the left speaker and not 1 channel spead across two speakers.

> SAMPLES TO WRITE AT A TIME: - Audio is first read in small fragments from the device. Many small fragments are combined into a large fragment before writing to disk. The disk writing process is done in a different thread. The value here determines how large the combination of fragments is for each disk write.

> SAMPLE RATE FOR RECORDING: - Regardless of what the project settings are. This is the sample rate used for recording. This should be the highest the audio device supports.

VIDEO IN:

These determine what happens when you record video.

> RECORD DRIVER: - This is used for recording video in the Record window. It may be shared with the Record Driver for audio if the audio and video are wrapped in the same stream. It takes variable parameters depending on the driver. The parameters have the same meaning as they do for playback.

> FRAMES TO RECORD TO DISK AT A TIME: - Frames are recorded in a pipeline. First frames are buffered in the device. Then they're read into a larger buffer for writing to disk. The disk writing is done in a different thread as the device reading. For certain codecs the disk writing uses multiple processors. This value determines how many frames are written to disk at a time.

> FRAMES TO BUFFER IN DEVICE: - The number of frames to store in the device before reading. This determines how much latency there can be in the system before frames are dropped.

> USE SOFTWARE FOR POSITIONING INFORMATION: - Video uses audio for synchronization but most soundcards don't give accurate position information. This calculates an estimation of audio position in software instead of the hardware for synchronization.

> SYNC DRIVES AUTOMATICALLY: - For high bitrate recording the drives may be fast enough to store the data but Linux may wait several minutes and stall as it writes several minutes of data at a time. This forces Linux to flush its buffers every second instead of every few minutes and produce slightly better realtime behavior.

> SIZE OF CAPTURED FRAME: - This is the size of the frames recorded. It is independant of the project frame size because most video devices only record a fixed frame size. If the frame size given here isn't supported by the device it might crash Cinelerra.

> FRAME RATE FOR RECORDING: - The frame rate recorded is different from the project settings. This sets the recorded frame rate.

# PERFORMANCE

You'll spend most of your time configuring this section.

> INDEX FILES GO HERE: - Back in the days when 4 MB/sec was unearthly speed for a hard drive, index files were introduced to speed up drawing the audio tracks. This option determines where index files are placed on the hard drive.

> SIZE OF INDEX FILE: - Determines the size of an index file. Larger index sizes allow smaller files to be drawn faster while slowing down the drawing of large files. Smaller index sizes allow large files to be drawn faster while slowing down small files.

> NUMBER OF INDEX FILES TO KEEP: - To keep the index directory from becoming unruly, old index files are deleted. This determines the maximum number of index files to keep in the directory.

> DELETE ALL INDEXES: - When you change the index size or you want to clean out excessive index files, this deletes all the index files.

> CACHE ITEMS: - To speed up rendering, several assets are kept open simultaneously. This determines how many are kept open. A number too large may exhaust your memory pretty fast and result in a crash. A number too small may result in slow playback as assets need to be reopened more frequently.

> SECONDS TO PREROLL RENDERS: - Some effects need a certain amount of time to settle in. This sets a number of seconds to render without writing to disk before the selected region is rendered. When using the renderfarm you'll sometimes need to preroll to get seemless transitions between the jobs. Every job in a renderfarm is prerolled by this value.

> FORCE SINGLE PROCESSOR USE: - Cinelerra tries to use all processors on the system by default but sometimes you'll only want to use one processor, like in a renderfarm client. This forces only one processer to be used. The operating system, however, usually uses the second processor anyway for disk access so this option is really a 1.25 processor mode.

> RENDER FARM:

> To use the renderfarm set these options. Ignore them for a standalone system.

> > USE RENDER FARM FOR RENDERING: - When selected, all the file->render operations use the renderfarm.

> > NODES: - Displays all the nodes on the renderfarm and which ones are active. Select the ON column to activate and deactivate nodes. Select the HOSTNAME and PORT columns to edit a node. Computer freaks may be better off editing the ~/.bcast/.Cinelerra_rc file than this if they have hundreds of nodes.

> > HOSTNAME: - Edit the hostname of an existing node or enter the hostname of a new node here.

> > PORT: - Edit the port of an existing node or enter the port of a new node here.

> > REPLACE NODE: - When editing an existing node, hit this to commit the changes to HOSTNAME and PORT. The changes won't be committed if you don't hit this buttoin.

> > ADD NODE: - Create a new node with the HOSTNAME and PORT settings.

> > DELETE NODE: - Deletes whatever node is highlighted in the NODES list.

> > SORT NODES: - Sorts the NODES list based on the hostname.

> > FILESYSTEM PREFIX ON REMOTE NODES: - Sets the relative location of all the assets on the nodes. If the assets are in /mov on the master and the master filesystem is mounted under /mnt on the nodes, the filesystem prefix should be /mnt. Ideally the assets should appear under the same directory on the nodes as the master. In this case the filesystem prefix can be /.

> > TOTAL JOBS TO CREATE: - Determines the number of jobs to dispatch to the renderfarm. The more jobs you create, the more finely balanced the renderfarm becomes.

# INTERFACE

These parameters affect purely how the user interface works.

USE HOURS:MINUTES:SECONDS.XXXVarious representations of time are given. Select the most convenient one. The time representation can also be changed by CTRL clicking on the time ruler.

USE THUMBNAILS: - The Resource Window displays thumbnails of assets by default. This can take a long time to set up. This option disables the thumbnails.

CLICKING IN/OUT POINTS DOES WHAT: - Cinelerra not only allows you to perform editing by dragging in/out points but also defines three seperate operations which occur when you drag an in/out point. For each mouse button you select the behavior in this window. The usage of each editing mode is described in editing.

MIN DB FOR METER: - Some sound sources have a lower noise threshold than others. Everything below the noise threshold is meaningless. This option sets the meters to clip below a certain level. Consumer soundcards usually bottom out at -65. Professional soundcards bottom out at -90.

FORMAT FOR METER: - This option allows you to select the format for all the VU meters. If you're a CS major select percentage and if you're a EE major select DB.

THEME: - Cinelerra supports variable themes. Select one here and restart Cinelerra to see it.