Viewing media and media metadata

Proxies and thumbnails

A clip can have different types of media representation: small thumbnail images, the original movie or media file, and a low-resolution proxy movie. A clip in CatDV contains a reference to its media, not the media itself, so all these types of media can be shared by more than one clip. (This also applies when you create subclips. Subclips refer to parts of a media file, specified by a time offset from the start of the file, and don't involve creating new files or modifying your original files.)

Thumbnails

Thumbnails are stored in the catalog along with the clips (so they remain available even when the media file is offline).
Thumbnail images are created when you import a movie or still image into a catalog, typically for the first, last and middle frame of each movie or scene, though there is a Preference option to control how many thumbnails are created (or even to turn off automatic thumbnail generation altogether).
You can select the size of thumbnails in Preferences. (Note that larger thumbnails increase the size of catalog files and the time to open them.)
Thumbnails are automatically shared. All the thumbnails in a catalog with the same tape name and whose timecode lies between the "in" and "out" point of a clip are available for display with that clip.
Use the Build Thumbnails command to rebuild the poster thumbnails of selected clips (after changing the thumbnail size for example). You can also create additional thumbnails, for example one every 10 seconds. Again, please note that creating extra thumbnails increases memory requirements, and the time to save and load the catalog.
You can create an additional thumbnail manually, and set that as the poster for a clip, by going to the frame you want in the "movie" tab and pressing the Set Poster button.
Conversely, you can delete an unwanted thumbnail using the Delete Thumbnail button. You can also switch to a thumbnail view and delete unwanted "thumbnail clips" there.

Original media

The original movie or source media files can be played if they are online, i.e. accessible on the computer's hard drive or a mounted network volume. Clips can also be offline, if the file was moved or deleted or a removable volume is offline, or if the file has been archived and purged from local disk.
Use the Attach Media command if you have recaptured the source media, or to attach a media file to a clip that didn't previously have one (eg. because the clip definition was imported from an EDL or batch list).
Use Update Media Location if you have simply renamed or moved the source media files to a new location. Usually you only need to select the new location for the first file - other files in the same directory are reattached automatically if they still have the same name and file size.
Adding the original and new location as equivalent media directories (see below) allows CatDV to locate similarly moved media files automatically without asking you.

Proxies

CatDV supports the use of low-resolutions proxy movies (also known as "preview movies") to use if the original media is offline. In a networked environment the online media might only be accessible to the edit suites while desktop computers might use the previews for logging and to decides whether clips are suitable for inclusion in a project.

Use the Build Proxy Movies command to build a proxy movie of the selected clips.
Proxy movies are stored on disk in a common proxy directory and are shared between catalogs. Once created they are available even when the original source movie is deleted.
Specify the directory for proxies and choose their size and quality in CatDV's Preferences. You can also choose whether to burn in timecode or a watermark image into the proxy file.
CatDV uses the media path to automatically look up the proxy (see below). The older tape-based proxy mechanism for legacy workflows is no longer supported.
You can have more than one proxy directory. The first directory is where new proxies will be created but all the directories are searched in turn when looking for a proxy movie.
To create proxy files automatically as part of a complex networked workflow consider using the separate CatDV Worker Node product.

Locating media

CatDV performs path-based lookup (of original media or low-res proxies) using the Media Path field.

For most workflows, such as if you are cataloging existing files on disk, then CatDV will locate media based on a file path. A media file may move, however, or it may have different paths depending on which machine you access the media from (eg. M:\ProjectX\File1.mov and /Volumes/Media/ProjectX/File1.mov may be the same file). CatDV therefore uses a search path with file mapping rules to look for any files which it can't find in their original location.
For example, if CatDV knows that M:\ is mapped to /Volumes/Media then CatDV on a Mac would be able to find the media file even if the catalog was saved on a Windows machine.
You can edit path mappings in the Media Search Paths section of Preferences. You should normally enter both the original (what is stored i the catalog) and new location (where the files are now).
If you omit the original location CatDV will search every combination of paths for the file. This will generally work but is less efficient and may find erroneous matches. For example, if the file was originally at "/Capture Scratch/Project X/Good Clips/Clip1.mov" and you add "/Volumes/Archive" to the search path then it will search all the following locations in turn:
/Volumes/Archive/Capture Scratch/Project X/Good Clips/Clip1.mov

/Volumes/Archive/Project X/Good Clips/Clip1.mov

/Volumes/Archive/Good Clips/Clip1.mov

/Volumes/Archive/Clip1.mov
If you try to play a file (using the Play Media command) and it's offline (not at the location where the catalog says it is), CatDV will prompt you to locate it. If you successfully locate the file at a new location CatDV will offer to add the mapping from old to new location to media search path for you.
As well as searching for the original full-resolution media files which may have moved, you can also enable path-based proxy movies. These use the same search path mechanism to map original location to proxy location but unlike with full-quality media the proxies don't need to have the same size and filename as the original file. For example, you might set "/Volumes/Proxies" as a path-based proxy location and have a proxy file "/Volumes/Proxies/Project X/Good Clips/Clip1.mp4".

Legacy Tape-based lookup is no longer supported.

Media dialog

Often it's convenient to play the movie for a clip so it's scaled to fit within the clip details panel at the top of the main window, but you can also play media in a separate window. The media dialog is resizable and offers additional features, such as full screen playback or slide show operation:

Use the Play Media (Windowed) menu command (or toolbar button) to play the selected clip in its own window. (You can also use the keyboard shortcut Cmd/Ctrl-P, or define a double click action of Media Preview in Preferences and then double click a clip to play its media).
Use the Pay Media (Full Screen), or full screen button in the controls below the media panel player, to play the selected clip full screen.
Use the Run Slide Show command to present the selected clips as a slide show of individual clips (this is mainly intended for stills).

All these options use the media dialog to show the media, either in a window or full screen. Double click or press Escape to close the media dialog. See below for various other keyboard shortcuts you can use to control the media as it's playing. For a description of the movie controller that is used when playing movies see the clip details panel.

There are also a number of Preferences options that control how media is played, for example the slide show delay. The Present Movie and Run Slide Show commands are only available if you turn on advanced menus.

Keyboard shortcuts

The following keyboard shortcuts can be used to control the media presentation and mark the clip that is playing and also control movie playback in the clip details panel. (Some keys are only relevant to the separate Media Dialog window or in the embedded Clip Details panel, but most are common to both.)

Space bar	play or pause a movie
Up, Down	move to previous or next clip in the catalog
Escape (or Cmd-W)	close the media dialog
F	toggle into full screen mode. Double click to return to normal mode.
Tab (or R)	start or pause slide show mode
Enter	close a slide show
+, -	increase or decrease the audio volume (certain players only)
[, ]	rotate image 90 degrees left or right
D	double the playback size of the movie or image
Shift-D	restore playback to normal size
Ctrl-R	refresh the display, re-centering the window on the screen
0-9	adjust speed of slide show (when slide show is running)
Alt-0 - Alt-5	set star rating of the clip
C	toggle showing/hiding the movie controller
G/H	slow motion playback (see below)
J/K/L/;	jog-shuttle controls (see below)
Shift-L	toggle looping playback mode
Cmd/Ctrl-M	toggle the mark flag for the clip
Cmd/Ctrl-Shift-M	clear the mark flag for the clip
M	insert a timecode event marker
I, O	set start/end of a selection (in2/out2)
P	play the selection from start to end (in2 to out2)
Shift P	Set the clip's poster thumbnail to the current frame
T, Y	move to start/end of a selection (in2/out2)
S, E	play start/end of a selection (in2/out2)
Ctrl-J (or Cmd-I)	display clip details dialog
A	Toggle audio waveform display (if available)
Cmd/Ctrl +/-	Zoom in and out of the audio waveform display

JKL controls

The behaviour of the JKL jog-shuttle controls depends on the Preferences setting:

In shuttle mode 'J' plays in reverse and 'L' plays forward. Successive presses will speed up playback to 1x, 1.5x, 2x, 3x, or 4x normal rate. Press 'K' to stop the movie, and hold down 'K' at the same time as pressing 'J' or 'L' to step one frame at a time. (Professional Edition only)
Press 'H' to play back at half the normal rate (and again to play at a quarter of the normal rate). Press 'G' to play backwards in slow motion.
In jog mode 'J' and 'K' step backwards by 0.5s or one frame respectively, while 'L' and ';' step forwards by the corresponding amount.

Additionally, the numeric keypad can be used as follows:

-, +	step back or forwards by one frame
1, 3	step back or forwards by 0.25s
4, 6	step back or forwards by 1s
7, 9	step back or forwards by 5s
2, 8	play backwards or forwards
5	toggle playback
/, *	setstart/end of a selection (in2/out2)

These keys apply in the media dialog, in the Movie and Proxy tab of the clip details dialog, and when playing movies full screen.

This page summarises all the menu command shortcuts in one place. Press Cmd (Mac OS X) or Ctrl (Windows) together with one of the following keys:

A / Shift A	Select All / Deselect All
B / Shift B	Bulk Edit / Search & Replace
C / Shift C	Copy Clips / Timecode Calculator
D / Shift D	Toggle Details Panel / Import Directory
E / Shift E	Export Movie / Export Still
F / Shift F	Find Clip / Remote Query
G / Shift G	Find Next / Toggle Grouping
H / Shift H	(Reserved by Mac OS X) / (Unused)
I / Shift I	Clip Details / HTML Summary
J / Shift J	File Details / Catalog Summary
K / Shift K	Connect to Server / Server Admin
L / Shift L	Launch In Default App / New Empty Clip
M / Shift M	Mark Clip / Insert Marker
N / Shift N	New Catalog / New View
O / Shift O	Open/Import File / Programmable Import
P / Shift P	Play Media / Play Media (Windowed)
Q / Shift Q	Quit / (Reserved by Mac OS X)
R / Shift R	Run Slide Show / (Unused)
S / Shift S	Save Catalog / Toggle Summary Mode
T / Shift T	Toggle Tree Navigator / Toggle Toolbar
U / Shift U	New Subclip / Find Master/Subclips
V / Shift V	Paste Clips / Verbatim Logger
W / Shift W	Close Window / Convert Markers to Subclips
X / Shift X	Cut Clips / Programmable Export
Z / Shift Z	Undo / Redo
- / =	Select Reviewed / Select Marked
\	Automatic Column Widths
1..5	Switch between Media and Details Panel Tabs
Up, Down	Previous/Next Clip
[, ]	Rotate Left or Right
F5	Refresh Window
/	Help

Media playback options

There are many different formats of media file in existence and CatDV supports a number of different mechanisms for playing and working with these files. Which player is used depends on the file type and the options selected in Preferences. (A coloured letter in the movie controller indicates which player is being used, and you can click on this letter to jump to the appropriate section of preferences if you need to make any changes.)

Available players

Advanced player

With QuickTime becoming obsolete, CatDV has shifted its focus to the native Advanced player, which combines the functionality of all of the previously used individual codecs in one native player. First introduced in CatDV 11, the native helper process plays common media files, making use of a number of codec libraries, including FFmpeg, RED, and Tin Man libraries. Most formats can be played natively, including QuickTime movies, AVI, MPEG, AVCHD, R3D, XAVC, P2, and XDCAM files.

Image sequences (DPX, EXR and JPG)

Pegasus includes a special native image sequence player that supports image sequences in JPEG, TIFF and PNG formats, as well as DPX and EXR images.

FFmpeg & RED players

Originally introduced as extra codec libraries for the native player, both the open-source FFmpeg library and the RED decode library (the latter is only available in Pegasus and Enterprise) are included in the Advanced player for playback. You can manually choose a specific player if required for diagnostic purposes.

Other players

CatDV has built-in support for displaying common still image formats, including JPEG, PSD, PNG, BMP, TIFF, and many camera RAW files (including CR2, NEF, DNG, ORF, PEF, ARW, and MOS, though some only at low resolution). It also has a built-in player for certain types of OMFI files.

Even if no player is available to play or view a raw media file from within CatDV, you can still use CatDV to catalog and tag such files, and double click on the clip (or use the Cmd/Ctrl-L menu shortcut) to open the file in its default application. You can also use an external application to create a proxy for such files and configure CatDV to play the proxy instead.

Obsolete players

A number of old players are now obsolete and have been removed with the move to 64-bit only architecture:

As of CatDV 13, both QuickTime for Java player (dark blue 'Q') and the QuickTime element of the native player have been obsoleted by Apple, necessitating the move to the self-contained Advanced player.
The old 'protected player' (green 'P') has been superseded by the new native player, which provides similar protection against the possibility of corrupt files or third party codecs causing the CatDV application to crash.
The old DirectShow player (magenta 'D') remains as a 32-bit legacy feature in earlier versions of CatDV, but has been removed with the move to 64-bit only in CatDV 13.
The Java Media Framework player (red 'J') has also been removed.
The old Xuggle player (yellow 'X') was superseded by the FFmpeg player.

Configuring the media player

In most cases the correct player is chosen automatically but sometimes more than one player can open a particular file and it may be desirable to override the default player. If you right-click on the media panel a popup menu letting you manually choose a specific player is shown.

You can also configure which player to use. On the Media Playback tab of Preferences you can specify a series of rules as to which player to use based on the file extension or other criteria. One or more rules can be specified, one per line, and the first one which matches the clip and successfully opens the file is used:

The simplest rules consist of one or more filename extensions followed by the player to try, eg. "jpg png gif cr2 = JAVA"
More complex rules have the form tag:value where tag is one of 'ext', 'type', 'audio', 'video', 'importer', 'os', 'path' to check the file extension, clip type, audio and video format, importer used, operating system (mac, win) and file path respectively, eg. "video:ProRes = QT" to match any clip that includes ProRes in the video format. You can also match on arbitrary clip fields including user defined fields, eg. "U12:true = FFMPEG".
Conditions can be combined with '&' (AND), space (OR) and '!' (NOT), eg. "ext:mov&!video:ProRes ext:mxf&audio" to match .MOV files except ProRes files, and MXF files with audio.
The following players are available: 'JIMG' (built-in still image viewer using Java Image I/O), 'QT' (native QuickTime player), 'RED' (native RED player), 'FFMPEG' (native FFmpeg player), 'IMSEQ' (image sequence player for DPX, EXR and JPG image sequences), 'IMSEQ_FF' (image sequence player using FFmpeg), 'JFX' (JavaFX player), 'AVF' (Mac AVFoundation player), and 'WMF' (Windows Media Foundation player). A number of additional legacy players are available if you use the 32-bit version of the application: 'QTJ' (old QuickTime for Java player), 'DSJ (old DirectShow player), 'XUGGLE' (old Xuggle player), and 'JMF' (old Java Media Framework player). You can provide a comma-separated list of one of more players to try if that rule matches.
The special pattern '*' is a default rule that matches any clip for which a player hasn't yet been found, and the special player value 'NONE' means stop matching rules and don't try opening the clip with any other players.
Normally the same player is used for playback and for building thumbnails/exporting still images. If necessary you can specify different rules in each case by adding mode:playback or mode:stills to the conditions, or by appending a suffix to the player name such as QT.playback or XUGGLE.stills.
Normally the same player is used when opening original full quality files or proxies but you can specify different players by adding mode:original or mode:proxy.
There is an additional image decoder with player name 'FFCMD' to indicate use the FFmpeg command line interface to extract stills. This may be useful if you have installed your own version of FFmpeg with additional decode codecs.

In normal use just leave the default box checked and the correct player will be chosen automatically.

FFmpeg transcoding

You can export movies using any FFmpeg export codec. CatDV includes a copy of the open source FFmpeg application, invoked through the command line interface, which it uses for transcoding.

FFmpeg is free, open source software. The source code for the version FFmpeg that CatDV uses is available on request or you can download the latest source code from www.ffmpeg.org and compile it yourself, for example to get access to additional codecs and filters or the latest bug fixes.

CatDV provides a graphical user interface to configure the FFmpeg export settings, together with a number of presets. In the export settings dialog you can choose the container format (such as .MOV or .MP4) then the video and audio codec to use, the video frame size, the target bit rate to use, and whether to change the frame rate or audio sample rate. Note that not all video and audio codecs are compatible with all container formats and if you choose an incompatible combination you will get an error when you perform the export. Note also that ffmpeg includes a large number of old and obscure codecs in its list of options and in most cases it is best simply to ignore codecs you are not familiar with.

You can add burnt in text or a watermark into the exported movie. As well as fixed text such as a copyright notice you can include CatDV variables such as ${NM1} for the clip name or tick the option for burnt in timecode. You can also burn in a watermark image by specifying the filename for a transparent PNG or GIF image. This image will be scaled to fill the frame so you would typically place a logo in one corner and leave the rest of the image transparent.

If you check the 'Advanced' option you will see additional export options, including the ability to set the quality level (FFmpeg -qscale option) and control which audio track is used. Note that you can specify either the quality or the target bit rate, not both, and also that some codecs don't use the -qscale setting (for example, the x264 codec is configured using -crf or -qp instead).

You can also directly specify ffmpeg command line options. Detailing these is well beyond the scope of this article and you should refer to online FFmpeg documentation. Certain words in the options list have special processing when building the ffmpeg command line:

Use -vcodec or -acodec to override the selected video and audio codec.
Use -vf to add another filter to the video filter chain CatDV creates.
Use s/old/new/ to apply regular expression rewriting of the command line.
Use fontfile=xxx, fontcolor=xxx, fontsize=xxx, textx=xxx, texty=xxx to override the appearance of burnt in text and timecode.

Press the 'Test' button to preview the ffmpeg command line that will be used.

Media file metadata

CatDV provides detailed information about virtually any kind of media file that you import into a catalog, including stills, audio files, and other formats, not just movies.

All the metadata (ie. information about the file, as opposed to the media content of the file itself) that CatDV reads from a file is extracted at the time of import and stored in the CatDV catalog. It is displayed in special properties against each clip, and is cached in the catalog so is available even if the media file is offline.

This information can be very useful when searching for clips, when grouping similar clips together, or when diagnosing problems with particular files. A wide variety of metadata fields are available, though which are shown depends on the type of file.

General metadata

The following properties are potentially applicable to any type of media file:

Video	A summary of the format of the visual track, including the codec, frame size and frame rate. (If there are several video tracks the overall frame size of the movie is shown.)
Audio	A summary of the format of the audio track, including codec and sample rate.
Importer	Details of which importer was used to read the file
Format	A concise summary of the container format and codec, based on the Importer, Video and Audio fields.
Tracks	A list of all the tracks in the file. When using the QuickTime importer the 4 character type and subtype codes are shown, eg. "vide/jpeg" is a JPEG video track, while "soun/musi" is a MIDI music track. The size in pixels (Width x Height), the number of samples, and the duration of the track are shown also.
Metadata	Any QuickTime user data or Windows Media metadata, such as movie title or copyright annotations, that might be stored in the file is shown here in concatenated form. This field also shows metadata such as JPEG comments, ID3 tags from MP3 files such as artist and track, and Exif tags. (See below).
Underlying Type	The clip type icon indicates whether a clip is a DV clip, a still, an audio clip, an interactive file (eg. Flash or QuickTime VR), or other movie.
Aspect Ratio	The aspect ratio of the visual frame. In the case of DV the intended display size (4:3 or 16:9) is shown, taking into account the non-square pixel size, even though this won't match the ratio of the frame size.
Frame rate	The frame rate of the visual track, if known, or an indication if this file is a still.
Frame size	The normal display size of the movie in pixels, after any transformation matrix has been applied. (By contrast, the unscaled size of each track is shown in the Encoded Dimension field if it's different.)
Audio Rate	The audio sample rate (this is extracted from the Audio column and made available separately so it can be used for grouping).
Import Notes	If anything unusual about the file is detected, such as audio and video tracks that differ in length or don't seem to relate correctly to the number of media samples, or if there are problems with the timecode, then a warning message may be displayed here.
Duration	The duration of the media file. The timecode format used depends on the file.
In (and Out)	If the file has a timecode track then the in and out points use this timecode information, otherwise each media file is assumed to start at 0:00:00
Media path	The last known location on disk of the source media file.
Media date	The modification time of the source media file (typically the time the file was captured or digitized, as opposed to the original record date.)
Media size	The physical size of the source media file in kilobytes or MB. (This is the size of the media file as a whole, not the size for a particular scene.)
Data rate	The average data rate of the media. You can choose which units are used for displaying data rates in Preferences.

Exif metadata

The following fields have special meaning for JPEG and TIFF files with Exif metadata:

Exposure	A summary of the Exif exposure details (if present). The EV (exposure value) number combines the aperture and exposure times and gives an approximate indication of the overall light intensity in the scene, assuming the shot was exposed correctly and the camera has equivalent sensitivity to ISO100 film. (Typically EV0 would correspond to almost complete darkness, while EV18 might be a pure white object in very bright sunshine.)
Metadata	This lists all the Exif tags commonly recorded by a digital camera, such as camera make and model, exposure time, whether flash was used, etc. combined into one field
GPS Coordinates	If the image contains geotag information it is extracted and indicated by a blue globe icon on the Summary tab of clip details. Clicking on the icon will display the location in Google Maps.
Record Date	If the Exif data has a DateTimeOriginal or CreationDate tag then this value is extracted and stored in the Rec Date field.

DV metadata

The following fields have special meaning for legacy DV and DVCam/DVCPro clips:

Aux T/C	Additional user-settable or time of day timecode supported by some cameras. (Professional Edition only)
DV T/C	The timecode value at the start of each clip as stored in the DV data itself (this may be different from the QuickTime timecode track).
Exposure	Camera exposure details recorded in the DV data at the time of recording by some camera models.
Format	A summary of the format, such as whether PAL or NTSC, widescreen or normal, and locked or unlocked audio. In the case of DV this field is based on the DV data itself, not on what QuickTime reports. For example, if a captured movie file has been conformed by rendering a new audio track then the Format field might report that the original recording was at 32kHz even though the Audio field reports that the movie has a 48kHz audio track.
Record Date	The original date and time of recording, stored in the DV data (assuming the clock on the camera was set correctly at the time of recording).

Metadata columns

Depending on the files you import, all kinds of other metadata may be read and are stored in generic metadata columns. The possible field names are not predefined and new metadata columns may be added as required. They can include:

Title, Album, Artist, AlbumArtist, Genre, Track and Year for MP3 and iTunes audio files.
Name, Copyright, Producer, Software and similar annotations for QuickTime movies
Make, Model, ExposureTime, ExposureProgram, FocalLength etc. for Exif images
Title, Copyright, Information, Language for WMV or WMA files
Manufacturer, Software, Camera Serial No., UMID (unique media id) for MXF files
Additional user-defined metadata read from an XML sidecar files at the time of import

The "Metadata (media)" field shows all the QuickTime user data (and other textual annotations that's read from a file) together in concatenated form in one field. As well as displaying the metadata fields in concatenated form, you can expand each metadata field as a separate column by checking the Enable metadata columns box in Preferences. You can then choose whether particular columns are shown or not, and also whether they are used for grouping. (This only affects how the columns are displayed, not how they're stored, so these options are safe to change at any time.)

Supported file formats

CatDV natively supports a wide range of common media file types using the FFmpeg media library and its own built-in support. CatDV will play back and export files in formats including:

QuickTime .MOV files, with most common codecs
AVI and WMV files
MPEG-4 files, with various codecs (H.264, H.265/HEVC, MPEG-4 Video, 3GP, etc)
MPEG transport streams
Raw DV streams
Still image formats (including JPEG, GIF, TIFF, BMP, PNG, JPEG 2000, and PSD)
Audio formats (including MP3, WAV, AU, AIFF)

Camera RAW images

CatDV has built-in support for reading many common camera RAW still image formats, including 3FR, ARW, CR2, DCR, DNG, ERF, FFF, K25, KDC, MOS, NEF, ORF, PEF, RAW, RW2, RWL, SR2, SRF, MPO and RAF. In most cases the files contains a preview thumbnail that can be displayed and CatDV will extract camera metadata such as exposure and white balance information and other Exif data (including camera maker notes). Some formats can be viewed in CatDV but in most cases to view the full resolution version of the image or to make adjustments you will need to open the image in an external application such as Photoshop.

Native importers

CatDV includes its own importers to process MP4, MOV, MPEG, WMV, OMF, MXF, TIFF, and PDF files, amongst others. These importers are designed to allow you to catalog the catalogs and extract metadata from the files (including movie duration, audio and video format, timecode, title or copyright information, GPS coordinates and so on, depending on what the file format supports) whether or not the generic FFmpeg or QuickTime importers support that metadata.

Other file formats

CatDV understands several file formats that can contain clip information, such as batch logs, Final Cut Pro XML files and EDLs. When you import one of these recognised formats a clip is created for each entry in the file.

With CatDV Pegasus Client or the Professional Edition you have access to additional media formats including MXF, R3D, DPX, EXR etc., as well as the option to import arbitrary non-media files, such as text files, Word documents, spreadsheets, project files, and so on.

Import warnings

When importing movies several consistency checks are applied and a warning message may be displayed in the Import Notes column under various circumstances. The most common messages and their meanings are shown below. (These warnings are fairly technical in nature and can usually be ignored.)

Timecode jump

This indicates that the DV timecode in the captured movie is not strictly continuous, either because the original source tape has a timecode discontinuity, because frames were dropped during capture, or possibly because data corruption occurred or the movie was edited or rendered by computer. If the 'strictly base clips on captured DV media' import option is on each continuous segment is processed separately during import into CatDV.

Dropped frame(s) between ? and ? Repeated frame(s) between ? and ?

These indicate shorter timecode errors of just a few frames. CatDV treats these differently and does not automatically create a new clip at each point.

Timecode differs (DV/QT=?)

There are two ways to determine the timecode for a particular DV frame: either based on the QuickTime 'timecode' track or on the digital data stored in the DV stream itself. Usually these will give the same result but if you have dropped frames or other anomalies occurred during capture the results may be different and CatDV displays a warning during import. If you have set the 'strict' import option then CatDV will always try to use the DV timecode and generate new clips whenever it detects a jump, otherwise it uses QuickTime's concept of the timecode (which may agree more with what other applications use) and displays the DV timecode for reference in the DV T/C field.

Incorrect length (? short of ?)

This means the length of the media in the movie does not match the overall length reported by QuickTime for the movie as a whole. This can occur if frames were dropped during capture but other frames are stretched out to maintain the overall movie length. Sometimes the movie is reported as being longer than it really is and the last frame appears as one long frozen still, stretching out to give the movie its overall length. In this case the length that QuickTime thinks the movie is is shown in the message but the clip in CatDV will be shorter and reflect the media that is actually present.

Audio sample rate mismatch

If a DV movie has a separate audio track this message indicates that the sample rate of the audio track doesn't agree with that originally recorded in the DV stream. This can happen if the audio was resampled during capture, or if you capture a clip where the audio sample rate changes mid way through, in which case QuickTime can sometimes get confused about the sample rate and create an unplayable audio track.

Unstable frame at start Skipping unstable frame(s) at ?

When the camcorder starts recording a new scene the tape may not have stabilised fully and the DV data in the first frame or two may not have a valid timecode or date/timestamp. Where possible, the unstable data is ignored and the first valid date or timecode is used instead.

Video and Audio differ by ? seconds

This means the audio track is shorter than the video track by the amount shown. This may indicate dropped frames or some other capture problem, but it could also mean that the movie was edited or rendered, or that the camcorder doesn't precisely lock audio and video samples.

? fps invalid for PAL/NTSC DV

This indicates that the frame rate is not exactly 25 or 29.97/30 fps for PAL or NTSC respectively, perhaps because the movie was rendered by computer rather than captured with a camera, or because frames were dropped during capture.

Average ? doesn't match nominal ? fps

The average frame rate (total number of frames divided by movie duration) doesn't match the typical frame rate (this could mean the movie has some dropped frames).

Many of these messages only apply to the clip representing the movie as a whole, which is hidden by default. You should therefore show hidden clips if you are trying to diagnose capture or import problems. You can also use the Media Information dialog to display more details about a media file.

Controlling how movies are imported

Use the 'Strictly base clips on captured DV media' preferences option (which is on by default) to:

produce a log that precisely matches the DV data, even if there are dropped frames or timecode discontinuities which might mean there are gaps in the captured media;
ignore any QuickTime timecode track and read the timecode from the DV stream instead;
ignore the movie length as reported by QuickTime and use the length of the media itself instead (bypassing an issue affecting some capture applications where the movie may be reported as being longer than it really is).

Turn off the 'strict' option:

if you are unlikely to batch recapture the material from DV tape and it's more important to reflect the file in its currently captured state;
for improved compatibility with other applications which are likely just to use the QuickTime information;
if you don't want each timecode sequence to result in a separate clip.

If you get a warning about average and nominal fps not matching and the clip appears to have wrong timecode format try toggling the "Timecode format" advanced preference option. For DV files CatDV can determine the correct format easily but for other files it can base it on the average frame rate or the nominal frame rate (time scale / nominal frame duration).

You should not normally use the "Ignore DV timecode" option but if you do then CatDV will treat DV files as ordinary QuickTime files.