User:Massimo

FOREWORD

All the Kdenlive features not treated in this document (as for eg. Keyframes implementation) are already completed or near to be.

SUMMARY

KEYBOARD SHORTCUTS

ADVANCED TRIMMING TOOLS

INSERT EXTRACT OVERWRITE AND LIFT OPERATIONS (Just improved)

AUDIO WORKFLOW

CLIP SPEED (Just implemented)

TRANSITIONS

MULTICAM EDITING

TITLER (Just improved)

PHOTOGRAPHIC LAYERS IMPORT

GENERATORS (Just implemented)

MATCH FRAME (Just implemented)

PREVIEW RENDERING

NESTING (Just improved)

EXTERNAL MONITOR

COLOR CORRECTION (Just improved)

FILTERS

ALPHA CHANNEL MANAGEMENT

SUGGESTIONS

CONCLUSIONS

KEYBOARD SHORTCUTS

During the first Kdenlive café we talked about to open a page about keyboard shortcuts. Someone said that professionals won't use Kdenlive because without the right shortcuts the job isn't fast enough. I'm a professional video editor who wants to sustain Kdenlive development so I studied the problem but, as I wrote in the chat during the Café, we don't miss the shortcuts but the functions (insert and extract with IN OUT point as references, a good trimming window and all the 4 different kinds of trimming functions.) As a first step, I checked again how the main professional systems I used in the past (AVID, Premiere and FCP) are mapped. For the moment, my first list for basi functions is this one:

IN: I

OUT: O

Go to IN: Q

Go to OUT: W

PREVIOUS EDIT: A

NEXT EDIT: S

Go at the beginning of the timeline or of a clip: HOME

Go at the end of the timeline or of a clip: END

Next Frame: RIGHT ARROW

Previous Frame: LEFT ARROW

Delete IN: D

Delete OUT: F

Delete IN and OUT: G

Play Pause: Space

Stop Pause: K

Play: L (for multispeed press more times L, for 50% slow motion press Shift+L)

Play backward: J (for multispeed press more times J, for 50% slow motion press Shift+J)

INSERT: V

OVERWRITE: B

LIFT from IN to OUT point: Z (this function still miss)

EXTRACT from IN to OUT point: X (this function still miss and in FCP and Premiere X is used for cutting at the editline position)

Standard video or audio TRANSITION: Shift+D (you have to be with the edit line between two clips and we need single track video and audio transition function)

ZOOM IN: T

ZOOM OUT: R

RENDER: ENTER

NEW BIN: N

Menu Acess: Alt+letter for the menu (but you never use menu during editing. You use it for preparing the project and for managing the editor program)

MATCH FRAME: M

AVID

Premiere Pro

FCP

ADVANCED TRIMMING TOOLS

ROLLING

A rolling action trims adjacent OUT and IN points at the same time by an equal number of frames. When you perform this action you move the edit point between clips, keeping the position of the clips on the track and preserving the total duration of the sequence.

RIPPLE

A ripple action trims a clip and shifts following clips in the track by the number of frames you trim. When you shorten a clip by this action all clips that follow the cut shift back in time, contrariwise, when you extend a clip the clips after the cut shift forward in time. If an empty space is on the track it behaves as a clip and it shifts in time as a standard clip would be.

SLIP

A slip action shifts, in a single operation, the IN and OUT points of a clip forward or backward by the same number of frames by keeping the original duration and without affecting adjacent clips.

SLIDE

A slide action shifts a clip in time and trims adjacent clips for compensating the move. When you perform this action the IN and OUT points and the duration of the clip that you move remain unchanged while the OUT point of the previous clip and the IN point of the following clip are trimmed by the number of frames you shift the clip.

All these operations are possible in AVID, FCP and Premiere by using the keyboard. A trimming window is useful for checking how the new in out point match with the previous and following edit cuts. I know that in Flowblade ROLLING, RIPPLE and SLIP trimming functions are already implemented. I don't know if it can be useful because Flowblade and Kdenlive are both based on MLT but Flowblade is written in Python and not in C++ as Kdenlive is. Anyway here you can find the code that Flowblade uses for these trimming operations:

https://github.com/jliljebl/flowblade/blob/master/flowblade-trunk/Flowblade/trimmodes.py

TRIM WINDOW AND TRIM PREVIEWS

In all major video editing systems, we can find a trim window or a trim mode where the clip window and the program become the trim interface. These tools are very useful for these reasons:

1. It gives you access to control the trim by keyboard (frame by frame control, 5 or more frames control, depending on the software, and jog function in both directions).

2. It allows switching between different modalities (rolling, ripple, slip and slide)

3. In rolling and ripple modes you can watch simultaneously the new IN and OUT point of both clips so you can decide where is the best point for the new cut.

4. In slip and slide modes you can watch the OUT point of the previous clip, the IN and the OUT points of the clip you are trimming and the IN point of the following clip. (Slip mode it's very useful for news and documentary editing on speech or interview)

INSERT EXTRACT OVERWRITE AND LIFT OPERATIONS

Even if I'm pretty sure everybody knows the differences between these operations I'll try to make a short recap:

- INSERT: in AVID is called also Splice-in operation. It is when you insert marked source material into the timeline without replacing material already in the sequence. Existing material moves beyond the spliced material, lengthening the overall duration of the sequence or of a track.

- EXTRACT: is the opposite operation. You remove selected material from a track in the timeline and automatically close the gap. When you extract material, you shorten the duration of the track or sequence.

- OVERWRITE: replaces a section in the timeline with the selected source material. An overwrite edit replaces existing material and does not lengthen the overall duration of the sequence unless the material used to overwrite goes beyond the end of the sequence.

- LIFT: removes selected material from a track in the timeline and leaves a gap.

Each software has different ways to perform these operations. The first difference is the way they set target tracks. In AVID, you have a panel on the timeline head with buttons which represent the source (1 video button and a number of audio buttons equal to the number of the audio channels) you have to move near the target tracks. Then you have to activate/deactivate (arm the tracks) the tracks you want to work on.

On Premiere and FCP (even if in the latest version Premiere works same as AVID) you have source buttons too to align to target tracks but instead of to activate or deactivate tracks you have to lock or unlock them. The operation you perform act on all tracks except the ones you locked.

I guess this can be the way Kdenlive could work because its development is already in this direction. At today, you can select a target track and you can lock tracks. The problem is that the action is performed only on the target track and you can't control the audio. (About the audio workflow I'll express my opinions later)

When you perform an INSERT or an EXTRACT operation you have to decide not only the target tracks but also other tracks you want to cut, for inserting materials or a blank space, or, if you perform an extract, where to remove the gap. For eg: if you want to insert a small part of an interview in the middle of a scene edited by 1 video track, 2 video tracks with graphics and 4 audio tracks (environmental sounds, sounds efx and music) you have to open a gap on all tracks. If you don't want to stop the music you have to create a gap on all tracks except the one where music is. And so on.

During an OVERWRITE or a LIFT operation, you can overwrite video and audio and also remove materials in other tracks by overwriting them with a blank space. For eg: I want to substitute a video clip, an audio track and I want to delete audio efx or music which correspond to the previously edited scene. Or I want to remove, by leaving a gap in the timeline, all the materials which correspond to a previously edited scene and that they are on several different tracks.

For selecting the time position where to perform the actions, we have two ways: the first is to use the IN and OUT point on the timeline so we can remove, or fill, or replace, or let a blank area where indicated. The second way is to start from the point where the edit line is: in this second situation we can only perform an INSERT or an OVERWRITE operation. The clip length is determined by the selected area of the clip in the source window.

NOTE: now we have 2 new functions: Extract and Lift which work on all unlocked tracks very well. The Insert and Overwrite functions finally have a super easy 3 Point Edit approach. Insert/Overwrite functions work as well on all unlocked tracks and they put the clip on the target track. When you use the audio video separation now you can set both the target tracks for video and audio. You can do it by selecting the track you want to use and by pressing the Shift+T shortcut for enabling and disabling it as the target. If just the video or the audio target is selected you will put only the video or the audio on the timeline. If no target is selected you'll create an empty space on the timeline. If a track is set as the target the Led indicator will turn green. If the track is locked the Led will turn Red. If some of the mute options (mute video or mute audio) are turned on the Led will turn yellow. More, by pushing the Shift+Ctrl+L you can "Un/Lock all but current" track.

- 3 POINT EDITING Three-point editing is a way to insert or overwrite a clip from the source window into a destination track in the timeline. To perform it you have to set three edit points: you can set the IN and OUT points of the clip in the source window and the IN point on the timeline which indicates where to insert/overwrite the clip or the IN and OUT points in the timeline that the clip will fit into and the IN point in the source window which indicates the starting point of the clip to insert/overwrite.

3 point edit in Final Cut Pro

NOTE: now you can choose if you want to insert the clip zone you selected in the clip monitor or if you want to fill the zone you selected on the timeline. You just have to toggle, by a simple button on the timeline head, the "Use Timeline zone for insert" feature. When it's disabled you insert/overwrite the selected clip zone at the edit line position otherwise you fill the selected timeline zone.

AUDIO WORKFLOW

In professional workflows, audio is always produced inside the video editor application except only for high budget fiction products (where you edit the live audio in the video editor and you use applications as ProTools for adding music and efx and creating the final 5.1 surround master). In tv stations when the editor ends the job he delivers the content with a peak between -20db and -10db then, during broadcasting, the audio track passes through a compressor before to be normalized. For this reason, every professional video editing system has a strong and complete audio workflow integrated. Then by the fact that today even small company can provide DCP contents to movie theaters (mostly are advertisements but not only), video editor apps integrate also 5.1 surround panners.

The audio workflow it's based on two main tools: the timeline and the audio mixer. On the timeline, the editor sets the volume automations, places transitions and uses filters for some minor effects. By the mixer, he sets the volume, the pan and the filters for each track and he premixes some tracks by using busses (or submixes as they are called in Premiere).

TIMELINE WORKFLOW - Automations: in my experience the best way to creates automations in video editor apps is to cut the audio track where you have to make an automation, then you put a crossfade audio transition (which in all professional applications you can use on single track) and lift up or down the gain of the clip you have to modify. This technique is the fastest way to create automations on the timeline. It's true that you can use keyframes (and sometimes they are very useful) but this way it's slower mostly if you have to later modify. By using transitions you can move the automation point by using a standard rolling operation, you can refine the length of the automation by change the duration of the transition, you can change the start and the end point of the automaton by sliding the transition. For changing the gain of the clip you have to modify we have different approaches: on AVID you select the clip on the timeline and you modify the gain by the mixer (the mixer acts on the clip when selected and on all the track when nothing is selected). On Premiere, you have the gain menu in the contextual (right-click) menu and in FCP, you have the volume of the clip in the effects stack (I think that the FCP approach is probably the best one).

Audio crossfades in AVID

- Filters are not generally used on the timeline except for managing audio channels or to fix some main issue of a specific clip. You can use filters on the timeline also when you have to create some specific special effect (eg: echo bounce, distortions, etc) on short clips.

- On Kdenlive and other FLOSS video editors based on MLT, we have audio embedded on video clips as it is on iMovie or in Windows MovieMaker. No professional tools use this approach because it creates some issues: you find all the video tracks on the audio mixer, you can't create audio splits (audio splits is when audio and video cuts have different times. eg: audio anticipate the video cut or the opposite), if you dissolve video you do the same with audio, etc. In my personal opinion, I think that this feature can be preserved for a simplified layout (which Kdenlive could have for helping newbies and amateurs) but I believe that when you select the automatic audio/video separation button (as I done) the option to put audio clips on the video tracks must be disable .

Audio split in Premiere

I also see that video track are numbered reversed as all other video editor applications. Generally, the approach is to start from the center with video and audio tracks numbered as 1 (as you can see on the "timeline heads" picture in the section above) On the different professional video editor applications the audio is managed these way:

on AVID, you have only mono tracks, so if you have a stereo signal you'll have two mono tracks to pan one on the right and the other one on the left. The tracks are not linked to anything (not to the video not each other). If they move out of sync you have the number of frames reported on the video track and on the audio track which is out of sync.

On Premiere, you have to choose which kind of track you want to create on the timeline (mono, stereo, 5.1) and then you can put in the specified track only audio which matches the track setting. You can change the way the software interprets the audio format by a special menu. Once on the timeline, audio and video are linked but you can separate them by using the command in the contextual menu (as it is for Kdenlive) or by using the mouse while you keep pressed the alt key (in this situation you can manage the audio as you want. Then, when you complete the operation the audio is still linked to the video in the new position but the video and the audio clip report, as it is in AVID, the number of frames they are out of sync).

On FCP, even if you can create a stereo pair track, you always use single channel tracks by default. The audio and the video are linked but you can use the linked selection button on the right upper corner of the timeline to turn linked selection on and off. When you move audio out of sync you see, as for the others systems, the number of the frames reported on the clips.

As in AVID, Premiere and FCP you can't put audio clips in video tracks as you can't put video clips in audio tracks you set targets (read the "About INSERT EXTRACT OVERWRITE and LIFT operations" section) for separating audio from the video. For eg. if you want to insert only the video part of the clip and not the audio you set only the video target track. Or if you want insert only the audio part of the clip you just set the audio target track but not the video target track.

- Audio functions on the timeline that still miss in Kdenlive are: slow-motion playback (by using JKL + Shift keys), audio speed* (same as the speed effect for video - with or without keeping the pitch) and audio reverse at all speeds, slow and fast (it's very important to have the chance to manage the clip speed and keep its audio synchronized at the new speed) *For more information about speed features please read the CLIP SPEED section.

MIXER WORKFLOW - By the mixer, you can control volume and pan for each track. In Premiere, you can also record automations in realtime but I always thought that this tool creates more problems than the ones it is supposed to fix (it creates too many keyframes - handles - so if you later want to modify you'll risk an headache and to spend a lot of time)

- You have a filters stack which acts on the whole track so you need no more to copy and paste effects on all clips in the track.

- You have busses (submixes). These are virtual channels. You can create one or more of these. You can decide, by selecting on the channel list of the track, to send the output signal of each audio track straight to the final master or to pass, before, trough a bus. The busses can premix all the input channels they receive, so you can put common filters on more track together and then send them to the master for the final mix. For eg you can have some tracks with different filter treatments which pass in a bus for be treated with a common reverb and then which are mixed to a music track in the final master.

- You have voiceover recording tools. (mic input selection, volume control, target track selection)

AVID Media Composer 7 Audio Mixer

Premiere Pro Audio Mixer

- I don't know if my proposal to watch at the qtractor code is good because this software has midi channels, which Kdenlive doesn't need, and I guess it's based on Jack.

QTractor Audio Mixer

MONO, STEREO AND MULTICHANNEL AUDIO At today there is no way to create and mix a 5.1 surround audio track from scratch by using FLOSS software except for Cinelerra and Ardour. In my opinion Cinelerra has a lot of problems in stability and usability. Ardour misses working panners and the ambisonic workaround is not a good workflow for usability and for the lack of features.

Kdenlives already accepts all kind of multichannel tracks. I tried to put mono, stereo and 5.1 clips on the timeline and it accepts all formats without any problems. I think that this is pretty good and simple. The problem is that I can't find a way for changing the number of channel of the output master and a way to map it. By this function and 5.1 panners, with a LFE send, I guess it's possible to give to Kdenlive the ability to create, mix and edit a multichannels audio track.

CLIP SPEED

The speed effect which is in the effects library works pretty well because it changes the length of the clip in real time and you can use it even for filling gaps as it is for Premiere "rate stretch tool" or for the FCP "Fit to fill" tool. The missing feature for this filter is that it doesn't work on audio so you can't keep the audio sync and that you can't use it for reversing the clip (negative values). As it was already indicated on the audio section it's very useful that the audio can change speed to match the video (in Premiere you can even select for keeping the audio pitch if you need it)

Right-click contextual menu for clip speed from clip on the timeline in Premiere Pro. You can change speed, reverse it and manage the audio for keeping it in sync

The way you can reverse the clip on Kdenlive is pretty rigid. You can't choose at which speed to reverse the clip and you loose the audio too. I found a workaround to slow down the reversed clip by opening the mlt script into a text editor and by changing the framerate value: higher is the number slower is the play speed. It doesn't work for speeding it up by lowering the framerate value. The fact you can't reverse only a portion of a clip straight on the timeline makes near impossible to create a "come and go loop" which sometimes is pretty useful.

NOTE: this feature was just implemented. Now the speed effect which is in the effects library is able also to reverse the clip at all speed and to keep the audio at the new speed in both directions in sync. It is not yet possible to change the speed to an audio-only clip.

TRANSITIONS

In Kdenlive what are called transitions are actually blending methods which work pretty well also for creating video transitions. These blending features are very well implemented and useful but in the standard professional video editor apps (where this excellent approach on layer blending we can find in Kdenlive is missing) transitions are a different thing. They are crossfades, wipes, 3D effects (as page curl, cubes, etc.) and all the way to pass from an image to another (or to crossfade two audio clips) and they works only on edit cuts. At today on all the main video editor apps you can apply the transition effect on a single track (this is made mostly for using the keyboard) and you have a panel for fine tune the parameters.

Transitions panels in AVID Premiere and FCP

I suggest to change the name to the current transitions in something like "Compositing and Transitions" and "Fast transitions" to the standard way to apply transitions when it will be implemented.

Transitions in AVID

Transitions in Premiere Pro

Transitions in FCPX

MULTICAM EDITING

This is a very useful feature that we can find in all major professional video editing apps. AVID multicam workflow

Multicam workspace in AVID

Multicam workspace in Premiere Pro

Multicam window in FCP

Multicam workspace in FCPX

On FLOSS the only app that has this feature totally implemented is Blender in which is actually working pretty well. At today on Kdenlive, there is a part of a workflow already that looks like on the right way. To complete it still misses 2 main features: buttons for selecting which video is on the program window and an automatic way to overwrite with a blank space the tracks which are not selected while you're playing for editing. Once these 2 features are implemented the basic workflow it'll be complete. My suggestions are:

1. Create a new window on purpose for this task.

2. Use the program window for monitoring the result.

3. Decide a way for controlling the edit (I guess that buttons on the multicam window which you can control by number keys on the keyboard, it can be a practical approach)

4. As a final step, I guess that update the multitrack view up to 9 tracks (3 row for 3 columns) can satisfy all needs.

Possible Kdenlive multicam workflow

TITLER The Kdenlive titler is already a good tool. I read in the roadmap that developers want to migrate to a new code by using what is called the Webfx library. I guess that this option is mostly motivated by the wish to have a titler which creates animations. I can say that in professional video editing applications usually titler has, except for rolling and crawling titles, few or no animation tools. Generally, you create the graphics and then you animate them on the timeline so you can sync keyframes directly with other objects (audio and video events) My suggestions is that the present titler is pretty good and it only misses some minor features as:

1. Drop shadow (as workaround is possible to double the object which has to project the shadow, turn it to the color you want for the shadow, set it as a lower layer, blur it and then move it to the needed position) 2. Inner and outer glow (you can use a similar workaround as the one for the drop shadow) 2. Kerning 3. Slant 4. Baseline shift 5. Leading 6. Small caps 7. More shapes (circle, triangle, etc.) 8. Text distribution

If it's possible it could be great that Kdenlive allows putting vector graphics on the timeline so you can manage them without losses. (No professional video editor applications can do it) 'NOTE: Drop shadow, kerning, leading, and gradients were just added to the titler making it a more complete tool.'

PHOTOGRAPHIC LAYERS IMPORT This feature, implemented in Premiere and FCP, is very useful when you create an image by graphics layers with an alpha channel you want to import into the video editor application for creating animations. Generally, you can import only the Photoshop psd format but, as Kdenlive is a FLOSS application, I suggest to make it possible also with xcf (Gimp) and kra (Krita) file formats. When you import a multi-layers image in Premiere and FCP they create a folder in the project window with all the layers as a single image. In Premiere, you can also choose to open it as a sequence so you can find all your resources already placed in the timeline in the right order ready for the animation (for more details read the NESTING section). The workaround I'm using at today is to export each layer from the Gimp (I use it) as a single image in png or tga format and then I import all files in Kdenlive. Then I place them manually on the timeline in the right order. What could be useful is a feature which allows you to import not only files but also folders (this not only for this task) and a way to place all layers automatically on the timeline in the right order. Of course, the feature which allows you to import xcf, kra and psd file is the best solution.

GENERATORS Standard generators that we can find in all main professional software are:

1. Color and black image 2. Countdown 3. Bars and tone

The adding to Kdenlive of bars and tone and a standard SMPTE countdown could be enough. 'NOTE: these features were just implemented. The new counter, bars and white noise are very good. I just think that a 1 kHz sine wave tone inside the bars (as in standard SMPTE bars) could be useful. Anyway, at today, you can import it from the Freesound Audio Library menu. https://en.wikipedia.org/wiki/SMPTE_color_bars Then the SMPTE countdown generally goes to black at 2 seconds and then we have a white mark with a 1 kHz beep at 1 second this for keeping the counter hidden during the last 2 seconds. This is useful for connecting the begin of the video exactly at the frame 0 after the end of the countdown. This for helping people who have to broadcast videos from tape. At today, as files are usually used instead of tapes, the countdown is mostly requested for video presentation as in professional field there is still this legacy. https://www.youtube.com/watch?v=GfAnyT9QitU I know that these small issues are due to the MLT generators which at now are able to produce only this kind of objects.'

MATCH FRAME Match frame is a feature that allows you to put your editline on a clip in the Timeline and find that exact same frame from the original clip in the source monitor. In AVID, you have a button on the GUI and a shortcut on the keyboard. In Premiere, you have to press the M key on the keyboard and in FCP you have to use the right-click contextual menu. In Kdenlive I cut the clip (Shift+R) on the frame I need to match, then I open the properties panel of the clip in the timeline and I copy the in point timecode. Then, after I pressed ctrl+z to delete the cut I created by the shit+R command, I look for the original clip in the project window by using the shortcut on the right-click contextual menu, I open it in the source monitor and I paste the previously copied timecode for matching the frame. A short way to achieve it could be really comfortable. 'NOTE: this feature was just implemented. It is available in the timeline clip context menu under "Show clip in project bin". It will switch to the Clip monitor, and seek to current timeline position in the original clip.'

PREVIEW RENDERING It's very important while you are editing to be able to review the timeline in a smooth way without any frame dropping and at full resolution. For this reason, all the professional video editor applications have the option for rendering effects on the timeline. In Lightworks timeline rendering is one of the features you have to pay! Even if it is supposed that Kdenlive works in realtime, when you creates complex effects it's not able (it depends, of course, on the hardware you have) to play the edited sequence without dropping frames. The proxy clips feature can help but you can't use compressed clips for colors correction or for keying. In avid and FCP you can turn ON / OFF an RT feature. When the button is turned on the app works as Kdenlive is working at today. When RT is turned OFF you have to render all the part of the timeline the hardware is not able to playback without dropping frames. Cinelerra has, since more than 10 years, an interesting feature called "background rendering" which was recently introduced in AVID media composer 8.2 and in FCPX. It renders automatically all the areas you need to calculate while you're working. In all these applications there is a red line on top of the timeline which remarks the areas you have to render. By using the render bar you can indicate which part of the timeline you want to render. When you modify something on the timeline you have to render again only that section so you can always watch smoothly all your work without exporting it every time you change something.