Archive:Kdenlive/Manual/Project Menu/Render: Difference between revisions

    From KDE UserBase Wiki
    (section name change)
    (Marked this version for translation)
    (97 intermediate revisions by 11 users not shown)
    Line 1: Line 1:
     
    <languages/>
    {{:Kdenlive/Templates/ContentTodo|
    {{:Kdenlive/Templates/ContentTodo|
    * How to choose the correct output format and bit rate?
    * How to choose the correct output format and bit rate?
    * What to do for rendering lossless, for an iPhone, or whatever? (Dropdown containing targets like lossless/HQ/player)
    * What to do for rendering lossless, for an iPhone, or whatever? (Dropdown containing targets like lossless/HQ/player)
    }}
    }}
    <translate>
    ==== Rendering ==== <!--T:1-->


    <!--T:2-->
    Rendering is the process where the edited clips are saved into a single complete video clip. During the rendering process the video can be compressed and converted to a number of different video formats (aka codecs).


    == Rendering ==
    <!--T:3-->
    The rendering dialog is brought up from the render button {{Icon1|Kdenlive Render button.png}}, from selecting <menuchoice>Render</menuchoice> in the [[Special:myLanguage/Kdenlive/Manual/Project_Menu|Project Menu]]  or by the <keycap>Ctrl + Enter</keycap> shortcut.


    Rendering is the process where the edited clips are saved into a single complete video clip. Durring the rendering process the video can be compressed and converted to a number of different video formats (AKA codecs).
    ===== Rendering Dialog Ver 17.04 =====  <!--T:84-->
    [[File:Kdenlive Render dialog 17 04.png|frame|left|File rendering dialog - ver 17.04]]
    <br clear=all>


    The rendering dialog is brought up from the render button [[File:Kdenlive Render button.png]], from selecting render in the [[Special:myLanguage/Kdenlive/Manual/Project_Menu|Project Menu]] or by the <ctl><enter> shortcut.
    ===== Rendering Profile Categories ===== <!--T:4-->
    [[File:Kdenlive Render dialog 17 04 categories expanded.png|frame|left|File rendering categories- ver 17.04]]
    <br clear=all>


    === Rendering Profile Categories ===
    <!--T:85-->
    Kdenlive offers many different pre-set rendering profiles to choose from. The rendering profiles are grouped into categories. See pic.  
    '''Kdenlive''' offers many different preset rendering profiles to choose from. The rendering profiles are grouped into categories. See picture Above.  


    <!--T:6-->
    [[File:Kdenlive Rendering options2.png]]
    [[File:Kdenlive Rendering options2.png]]


    === File Rendering ===
    </translate><span id="File Rendering"></span><translate>
     
    ====== File Rendering - earlier Versions ====== <!--T:7-->
     
    <!--T:70-->
    The following figures show the render dialog when the <menuchoice>Destination</menuchoice> category is '''File Rendering'''. The first two figures show the layout of the dialog under ver 0.9.10 of '''Kdenlive''' and the third figure shows how the dialog appears in ver 0.9.8 of '''Kdenlive'''.
     
    <!--T:71-->
    Version 0.9.10 of '''Kdenlive''' changes the render dialog significantly because it implements a method where you can choose to render the project with either a variable video bitrate (VBR) or a constant video bitrate (CBR)
     
    ====== Variable Bit Rate  - earlier Versions  ====== <!--T:72-->
     
    <!--T:73-->
    [[File:Kdenlive Render dialog vbr 0.9.10.png |frame|left|File rendering dialog Variable Bit Rate - ver 0.9.10]]
    <br clear=all>
    When a variable bitrate profile is selected, the <menuchoice>File Size</menuchoice> section displays a drop down for choosing the '''Video quality''' you want. This quality figure is a codec-dependent number representing the quality of the video that will be rendered. Generally, lower numbers mean higher quality video and larger file sizes (e.g. x264, MPEG2, VPx), but some codecs use opposite order (e.g. Theora). Profiles provided with '''Kdenlive''' offer these numbers ordered from best quality (almost lossless) to lower quality (still not degrading too much).  The exact file size that is produced can not be predicted when using the VBR method.  The idea behind this is that you specify a certain quality of video that you want through the entire video and the encoding optimizes bitrate to give you that constant quality, lowering data size for low action scenes and using more bits for high action scenes.
     
    <!--T:74-->
    Example: 1min 55 seconds of 720 x 576 H.264 iPhone footage rendered at quality 15 with the H.264/AAC High Profile would produce a file size of 186 Mb. Whereas rendering the same footage at quality quality 20 produced an 83Mb file.
     
    ====== Constant Bit Rate  - earlier Versions ====== <!--T:75-->
     
    <!--T:76-->
    [[File:Kdenlive Render dialog cbr 0.9.10.png  |frame|left|File rendering dialog Constant Bit Rate - ver 0.9.10]]
    <br clear=all>
    When a constant bitrate (CBR) profile is selected, the <menuchoice>File Size</menuchoice> section displays a drop down for choosing the '''Video bitrate''' you want. This is similar to the ver <=0.9.8 behaviour of '''Kdenlive'''. You select the video bitrate you want and the video is encoded at that video bitrate across its entire length.
    [[File:Kdenlive Render dialog 0.9.8.png|frame|left|File rendering dialog - ver 0.9.8]]
    <br clear=all>


    [[File:Kdenlive File rendering.png]]
    ====== DVD Rendering  - earlier Versions  ====== <!--T:9-->


    === DVD Rendering ===
    <!--T:10-->
    DVD Rendering produces files that are compatible with DVD authoring software.  MPEG2 files created from [[Special:myLanguage/Kdenlive/Manual/Project_Menu/Render#File_Rendering|file rendering]] profiles are less likely to be compatible with DVD software.  For quality settings see [[#Variable Bit Rate|Variable Bit Rate]] and [[#Constant Bit Rate|Constant Bit Rate]]. For DVD VBR lower <menuchoice>Video quality</menuchoice> setting number means better quality.


    DVD Rendering produces files that are compatible with DVD authoring software.  MPEG2 files created from [[Kdenlive/Manual/Project_Menu/Render#File_Rendering|file rendering]] profiles are less likely to be compatible with DVD software.   
    <!--T:11-->
    Note that this rendering does not create a DVD file system. It merely creates DVD-compatible MPEG2 files that can be used by DVD authoring software.  If you check the <menuchoice>Open DVD Wizard after Rendering</menuchoice> check box, then the [[Special:myLanguage/Kdenlive/Manual/File Menu/DVD Wizard|DVD Wizard]] will open and you can use it to create a DVD file system (in .ISO format).  The DVD Wizard is also available from the [[Special:myLanguage/Kdenlive/Manual/File Menu|File Menu]].   


    Note that this option does not create a DVD file system. It mearly creates DVD compatible MPEG2 files that can be used by DVD authoring software. If you check the ''Open DVD Wizard after Rendering'' check box then the [[Kdenlive/Manual/File Menu/DVD Wizard|DVD Wizard]] will open and you can use this to create a DVD file system (in .ISO format). The DVD Wizard is also available from the [[Kdenlive/Manual/File Menu|File Menu]].
    <!--T:12-->
    <menuchoice>Create chapter file based on guides</menuchoice> enables chapter markings on your DVD. Chapters work with the "next" and "previous" buttons on the DVD player and can populate scene selection menus. In order to create chapters this way you need to have marked chapters with [[Special:myLanguage/Kdenlive/Manual/Timeline/Guides|guides]] on timeline. DVD wizard enables marking of chapters also during DVD creation step.


    <!--T:69-->
    [[File:Kdenlive DVD rendering.png]]
    [[File:Kdenlive DVD rendering.png]]


    === Websites ===
    ====== Websites - earlier Versions ====== <!--T:13-->
     
    <!--T:14-->
    [[File:Kdenlive WebSites rendering.png]]
    [[File:Kdenlive WebSites rendering.png]]


    === Mobile Devices ===
    ====== Mobile Devices - earlier Versions ====== <!--T:15-->


    <!--T:16-->
    [[File:Kdenlive Mobile devices.png]]
    [[File:Kdenlive Mobile devices.png]]


    === Create Custom Render Profiles ===
    ===== Create Custom Render Profiles ===== <!--T:17-->
    You can create your own custom render profiles by clicking the button highlighted in the screen shot below
     
    [[File:Custom render profiles.png]]
    <!--T:18-->
    You can create your own custom render profiles by clicking the button highlighted in the screenshot below.
     
    <!--T:32-->
    [[File:Custom render profiles.png|350px]]
     
    <!--T:19-->
    This will open the '''Save Profile''' dialog (also shown in the above screenshot) and the <menuchoice>Parameters</menuchoice> section will be filled in with the render parameters of the profile that you had selected when you clicked the {{Icon|document-new}} button. You can edit values in the parameters and save your own custom render profile.
     
    <!--T:20-->
    The parameters in the rendering profile are ''melt'' parameters. For an explanation of their meaning, check the ''melt'' [http://www.mltframework.org/bin/view/MLT/Documentation documentation] or type <code>melt -help</code> in a command prompt.
     
    <!--T:65-->
    The above screenshot shows the '''Save Profile''' dialog as it appears in vers <=0.9.4 of '''Kdenlive'''.
     
    <!--T:66-->
    In version >=0.9.5 there is an improved version of the '''Save Profile''' dialog (see below) which allows you to customize the bitrates that are offered in the render profile.
     
    <!--T:67-->
    [[File:Kdenlive Custom render profile 0.9.5.png|350px]]
     
    <!--T:21-->
    See also [[Special:myLanguage/Kdenlive/Manual/Project_Menu/Render/Render_Profile_Parameters|Render Profile Parameters - How to read them]]
     
    ===== Rendering In Batch mode ===== <!--T:22-->
     
    <!--T:23-->
    If you have a lot of rendering jobs to do, you can use '''Kdenlive''' to create rendering scripts which you can accumulate and then execute in batch mode overnight. See [[Special:myLanguage/Kdenlive/Manual/Rendering|Rendering Using Rendering Scripts]].
     
    <!--T:24-->
    Alternatively, once you have submitted a rendering job on a project and it is up and running in the '''Job Queue''', you can drag the render window out of the way and edit the project some more or load a new project and render that one too. The second render job submitted will go into the '''Job Queue'''. Editing the project after a render job is submitted will not change the settings on that job.
     
    <!--T:25-->
    [[File:Kdenlive Rendering job queue.png|500px]]
     
    ===== Rendering Using the Guide Zone Option ===== <!--T:26-->
     
    <!--T:27-->
    This makes use of [[Special:MyLanguage/Kdenlive/Manual/Timeline/Guides|Guides]] to define a region of the project that is to be rendered. See [[Special:myLanguage/Kdenlive/Manual/Rendering|Rendering Using Rendering Scripts]].</translate>
    <span id="Rendering Using the Selected Zone Option"></span>
    <translate>
    ===== Rendering Using the Selected Zone Option ===== <!--T:28-->
     
    <!--T:29-->
    If you select the <menuchoice>Selected Zone</menuchoice> radio button from the bottom of the render dialog, '''Kdenlive''' will only render that portion of the project which has a selected zone created for it. See [[Special:myLanguage/Kdenlive/Manual/Monitors#Creating_Zones_in_Project_Monitor|Creating Zones in Project Monitor]]
     
    ===== Render Overlay ===== <!--T:33-->
     
    <!--T:34-->
    [[File:Kdenlive Render overlay.png ]]
     
    <!--T:35-->
    This option overlays a time code or frame count over the rendered video.  This will put the overlay over the entire rendered project.  Alternatively you can use the [[Special:MyLanguage/Kdenlive/Manual/Effects/Misc/Dynamic_Text|Dynamic Text]] effect to overlay selected regions of the video.
     
    <!--T:68-->
    [[File:Kdenlive Render overlay result eg.png|150px|frame|left|render overlay result]]
    <br clear=all>
     
    ===== Export Metadata ===== <!--T:36-->
    Check this to have the metadata which has been entered under <menuchoice>Project Settings- ></menuchoice> [[Special:MyLanguage/Kdenlive/Manual/Projects_and_Files/Project_Settings#Metadata_Tab|Metadata]] placed into the metadata of the rendered file.
     
    <!--T:37-->
    In version 0.9.6 for Linux, you have to double-click the data area of a metadata field line to make the field available for input.
     
    <!--T:83-->
    This image shows metadata settings for a project:
    [[File:Kdenlive project settings metadata.png]]
     
    <!--T:38-->
    And this is the metadata on the resulting clip (rendered with <menuchoice>Export Metadata</menuchoice> checked).
    [[File:Kdenlive Clip properties metadata res.png]]
     
     
    <!--T:39-->
    {{Input|1=$ ffprobe dog_rotated_meta_data.mp4}}
     
    <!--T:40-->
    {{Output|1=
        Metadata:
        major_brand    : isom
        minor_version  : 512
        compatible_brands: isomiso2avc1mp41
        title          : Bailey
        encoder        : Lavf53.21.1
        copyright      : VSF
    }}
     
    <!--T:30-->
    This reveals a bug in ver 0.9.4 of '''Kdenlive''' - the full title is not placed in the metadata - it is truncated at the first space. This has been fixed in 0.9.5 of '''Kdenlive''' as Mantis number [http://www.kdenlive.org/mantis/view.php?id=2996 2996].
     
    ===== Export Audio Checkbox===== <!--T:77-->
     
    <!--T:78-->
    This is an unusual one. Instead of a normal on/off checkbox toggle, the <menuchoice>Export Audio</menuchoice> checkbox cycles among three choices.
     
    <!--T:42-->
    [[File:Kdenlive Export audio check box crop.png ]]
    [[File:kdenlive export audio checked ubuntu.png ]]
    [[File:kdenlive export audio unchecked ubuntu.png ]]
    <br clear=all>
     
    <!--T:79-->
    As if that weren't confusing enough, the ''Export audio (automatic)'' option may appear different depending on your combination of distribution, desktop environment and theme.  See three examples below:
    <br clear=all>
    [[File:Kdenlive Export audio check box crop.png ]]
    [[File:kdenlive export audio automatic dashed.png ]]
    [[File:kdenlive export audio automatic nocheck.png ]]
     
    <!--T:80-->
    Regardless of how the checkbox on the ''Export audio (automatic)'' option may appear on your installation, rest assured that when that option is showing, it is enabled.
     
    <!--T:44-->
    So what do the three options mean?
     
    <!--T:45-->
    ''Export audio (automatic)'' means detect if an audio track is present and write the audio track if found
     
    <!--T:46-->
    ''Export audio'', when checked, means write an audio track in the rendered file even if there is no audio track to write.
     
    <!--T:81-->
    ''Export audio'', when unchecked, means do not write an audio track in the rendered file.
     
    <!--T:47-->
    The difference in behavior between enabling ''Export audio'' versus ''Export audio (automatic)'' can be seen in the situation where you have a video on the timeline but there is no audio track on the timeline and the video in the video track also does not have an audio track. An example of such a situation is shown in the screenshot below.
     
    <!--T:48-->
    [[File:Kdenlive Video with no audio.png]]
     
    <!--T:49-->
    In this situation, if you render with ''Enable audio (automatic)'', the rendered file will not have an audio track (Result 1 on screenshot below). But if you render with ''Export Audio'' checked, then the rendered file will contain an audio track &mdash; the track will however be empty  (Result 2 on screenshot below).
     
    <!--T:50-->
    [[File:Kdenlive Render export audio auto vs just checked2.png ]]
     
    <!--T:51-->
    FFprobe on file generated from an audio-less track using ''Export audio (automatic)''. Note only one stream &mdash; Stream #0.0 &mdash; a video stream. '''Kdenlive''' automatically detected there was not an audio track and so it did not write one.
     
    <!--T:52-->
    {{Input|1=$ ffprobe dog_rotated_exp_audio_auto.mp4}}
    {{Output|1=  Metadata:
        major_brand    : isom
        minor_version  : 512
        compatible_brands: isomiso2avc1mp41
        encoder        : Lavf53.21.1
    Duration: 00:00:03.62, start: 0.000000, bitrate: 12592 kb/s
    Stream #0.0(und): Video: h264 (High), yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 12587 kb/s, 27.83 fps, 27.83 tbr, 30k tbn, 55.66 tbc
    }}
     
    <!--T:53-->
    FFprobe on file generated from an audio-less track using ''Export audio'' checked. Note two streams &mdash; Stream #0.0 and Stream #0.1 &mdash; the latter being an aac audio track.  We forced '''Kdenlive''' to write an audio track even though there was not any source audio to write.
     
    <!--T:54-->
    {{Input|1=$ ffprobe dog_rotated_exp_audio.mp4}}
    {{Output|1=
      Metadata:
        major_brand    : isom
        minor_version  : 512
        compatible_brands: isomiso2avc1mp41
        encoder        : Lavf53.21.1
      Duration: 00:00:03.62, start: 0.000000, bitrate: 12598 kb/s
     
    <!--T:55-->
    Stream #0.0(und): Video: h264 (High), yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 12587 kb/s, 27.83 fps, 27.83 tbr, 30k tbn, 55.66 tbc
    Stream #0.1(und): Audio: aac, 48000 Hz, stereo, s16, 2 kb/s
    }}
     
    <!--T:56-->
    In cases where there is an audio track ...
    [[File:Kdenlive Video plus Audio in seperate tracks.png]]
     
    <!--T:57-->
    Rendering with ''Export audio'' unchecked will produce a file with no audio track &mdash; result 4 in the screenshot above.
    Rendering with ''Export audio (automatic)''  (result 3  in the screenshot above) or with  ''Export audio'' checked will produce files with Audio tracks.
     
    ===== Encoder Threads ===== <!--T:58-->
     
    <!--T:59-->
    [[File:Kdenlive Encoder threads.png]]
     
    <!--T:82-->
    Determines the value of ''Encoding threads'' passed to melt.  For encoding to certain codecs, namely MPEG-2, MPEG-4, H.264, and VP8, kdenlive can use more than one thread and thus make use of multiple cores. Increase this number to take advantage of this feature on multi-core machines.  See [http://www.mltframework.org/bin/view/MLT/ConsumerAvformat#threads melt doco - threads] and [http://www.mltframework.org/bin/view/MLT/Questions#Does_MLT_take_advantage_of_multi melt FAQ] on multi-threading.


    Ths will open the Save Proile dialog shown above and the Parameter section will be filled in with the render parameters of the profile that you had selected when you clicked the add new profile button. You can edit values in the parameters and save your own custom render profile.
    ===== Scanning Dropdown ===== <!--T:60-->


    === Rendering In Batch mode ===
    <!--T:61-->
    [[File:Kdenlive Render scanning.png]]


    If you have a lot of rendering jobs to do you can use kdenlive to create rendering scripts which you can accumulate and then execute in a batch mode overnight. See [[Kdenlive/Manual/Rendering|Rendering Using Rendering Scripts]].
    <!--T:62-->
    This option controls the frame scanning setting the rendered file will have.
    Options are ''Force Progressive'', ''Force Interlaced'' and ''Auto''.  


    Alternatively, once you have submitted a rendering job on a project and it is up and running in the Job Queue you can drag the render window out of the way and edit the project some more or load a new project and render that one too. The second submitted render job will go into the Job Queue. Editing the project after a render job is submitted will not change the settings on that job.
    <!--T:63-->
    ''Auto'' causes the rendered file to to take the scanning settings that are defined in the [[Special:MyLanguage/Kdenlive/Manual/Projects_and_Files/Project_Settings#Project_Settings_Tab|project settings]]. Use the other options to override the setting defined in the project settings.


    === Rendering Using the Guide Zone Option ===
    <!--T:64-->
    {{Prevnext2
    | prevpage=Special:MyLanguage/Kdenlive/Manual/Settings_Menu | nextpage=Special:MyLanguage/Kdenlive/Manual/Rendering
    | prevtext=Settings Menu | nexttext=Using Guides and Scripts
    | index=Special:MyLanguage/Kdenlive/Manual | indextext=Back to menu
    }}


    See  See [[Kdenlive/Manual/Rendering|Rendering Using Rendering Scripts]].
    <!--T:31-->
    [[Category:Kdenlive]]
    </translate>

    Revision as of 14:33, 13 September 2017

    Information

    • How to choose the correct output format and bit rate?
    • What to do for rendering lossless, for an iPhone, or whatever? (Dropdown containing targets like lossless/HQ/player)

    Rendering

    Rendering is the process where the edited clips are saved into a single complete video clip. During the rendering process the video can be compressed and converted to a number of different video formats (aka codecs).

    The rendering dialog is brought up from the render button , from selecting Render in the Project Menu or by the Ctrl + Enter shortcut.

    Rendering Dialog Ver 17.04
    File rendering dialog - ver 17.04


    Rendering Profile Categories
    File rendering categories- ver 17.04


    Kdenlive offers many different preset rendering profiles to choose from. The rendering profiles are grouped into categories. See picture Above.

    File Rendering - earlier Versions

    The following figures show the render dialog when the Destination category is File Rendering. The first two figures show the layout of the dialog under ver 0.9.10 of Kdenlive and the third figure shows how the dialog appears in ver 0.9.8 of Kdenlive.

    Version 0.9.10 of Kdenlive changes the render dialog significantly because it implements a method where you can choose to render the project with either a variable video bitrate (VBR) or a constant video bitrate (CBR)

    Variable Bit Rate - earlier Versions
    File rendering dialog Variable Bit Rate - ver 0.9.10


    When a variable bitrate profile is selected, the File Size section displays a drop down for choosing the Video quality you want. This quality figure is a codec-dependent number representing the quality of the video that will be rendered. Generally, lower numbers mean higher quality video and larger file sizes (e.g. x264, MPEG2, VPx), but some codecs use opposite order (e.g. Theora). Profiles provided with Kdenlive offer these numbers ordered from best quality (almost lossless) to lower quality (still not degrading too much). The exact file size that is produced can not be predicted when using the VBR method. The idea behind this is that you specify a certain quality of video that you want through the entire video and the encoding optimizes bitrate to give you that constant quality, lowering data size for low action scenes and using more bits for high action scenes.

    Example: 1min 55 seconds of 720 x 576 H.264 iPhone footage rendered at quality 15 with the H.264/AAC High Profile would produce a file size of 186 Mb. Whereas rendering the same footage at quality quality 20 produced an 83Mb file.

    Constant Bit Rate - earlier Versions
    File rendering dialog Constant Bit Rate - ver 0.9.10


    When a constant bitrate (CBR) profile is selected, the File Size section displays a drop down for choosing the Video bitrate you want. This is similar to the ver <=0.9.8 behaviour of Kdenlive. You select the video bitrate you want and the video is encoded at that video bitrate across its entire length.

    File rendering dialog - ver 0.9.8


    DVD Rendering - earlier Versions

    DVD Rendering produces files that are compatible with DVD authoring software. MPEG2 files created from file rendering profiles are less likely to be compatible with DVD software. For quality settings see Variable Bit Rate and Constant Bit Rate. For DVD VBR lower Video quality setting number means better quality.

    Note that this rendering does not create a DVD file system. It merely creates DVD-compatible MPEG2 files that can be used by DVD authoring software. If you check the Open DVD Wizard after Rendering check box, then the DVD Wizard will open and you can use it to create a DVD file system (in .ISO format). The DVD Wizard is also available from the File Menu.

    Create chapter file based on guides enables chapter markings on your DVD. Chapters work with the "next" and "previous" buttons on the DVD player and can populate scene selection menus. In order to create chapters this way you need to have marked chapters with guides on timeline. DVD wizard enables marking of chapters also during DVD creation step.

    Websites - earlier Versions

    Mobile Devices - earlier Versions

    Create Custom Render Profiles

    You can create your own custom render profiles by clicking the button highlighted in the screenshot below.

    This will open the Save Profile dialog (also shown in the above screenshot) and the Parameters section will be filled in with the render parameters of the profile that you had selected when you clicked the button. You can edit values in the parameters and save your own custom render profile.

    The parameters in the rendering profile are melt parameters. For an explanation of their meaning, check the melt documentation or type melt -help in a command prompt.

    The above screenshot shows the Save Profile dialog as it appears in vers <=0.9.4 of Kdenlive.

    In version >=0.9.5 there is an improved version of the Save Profile dialog (see below) which allows you to customize the bitrates that are offered in the render profile.

    See also Render Profile Parameters - How to read them

    Rendering In Batch mode

    If you have a lot of rendering jobs to do, you can use Kdenlive to create rendering scripts which you can accumulate and then execute in batch mode overnight. See Rendering Using Rendering Scripts.

    Alternatively, once you have submitted a rendering job on a project and it is up and running in the Job Queue, you can drag the render window out of the way and edit the project some more or load a new project and render that one too. The second render job submitted will go into the Job Queue. Editing the project after a render job is submitted will not change the settings on that job.

    Rendering Using the Guide Zone Option

    This makes use of Guides to define a region of the project that is to be rendered. See Rendering Using Rendering Scripts.

    Rendering Using the Selected Zone Option

    If you select the Selected Zone radio button from the bottom of the render dialog, Kdenlive will only render that portion of the project which has a selected zone created for it. See Creating Zones in Project Monitor

    Render Overlay

    This option overlays a time code or frame count over the rendered video. This will put the overlay over the entire rendered project. Alternatively you can use the Dynamic Text effect to overlay selected regions of the video.

    render overlay result


    Export Metadata

    Check this to have the metadata which has been entered under Project Settings- > Metadata placed into the metadata of the rendered file.

    In version 0.9.6 for Linux, you have to double-click the data area of a metadata field line to make the field available for input.

    This image shows metadata settings for a project:

    And this is the metadata on the resulting clip (rendered with Export Metadata checked).


    $ ffprobe dog_rotated_meta_data.mp4
    Metadata:
        major_brand     : isom
        minor_version   : 512
        compatible_brands: isomiso2avc1mp41
        title           : Bailey
        encoder         : Lavf53.21.1
        copyright       : VSF

    This reveals a bug in ver 0.9.4 of Kdenlive - the full title is not placed in the metadata - it is truncated at the first space. This has been fixed in 0.9.5 of Kdenlive as Mantis number 2996.

    Export Audio Checkbox

    This is an unusual one. Instead of a normal on/off checkbox toggle, the Export Audio checkbox cycles among three choices.


    As if that weren't confusing enough, the Export audio (automatic) option may appear different depending on your combination of distribution, desktop environment and theme. See three examples below:

    Regardless of how the checkbox on the Export audio (automatic) option may appear on your installation, rest assured that when that option is showing, it is enabled.

    So what do the three options mean?

    Export audio (automatic) means detect if an audio track is present and write the audio track if found

    Export audio, when checked, means write an audio track in the rendered file even if there is no audio track to write.

    Export audio, when unchecked, means do not write an audio track in the rendered file.

    The difference in behavior between enabling Export audio versus Export audio (automatic) can be seen in the situation where you have a video on the timeline but there is no audio track on the timeline and the video in the video track also does not have an audio track. An example of such a situation is shown in the screenshot below.

    In this situation, if you render with Enable audio (automatic), the rendered file will not have an audio track (Result 1 on screenshot below). But if you render with Export Audio checked, then the rendered file will contain an audio track — the track will however be empty (Result 2 on screenshot below).

    FFprobe on file generated from an audio-less track using Export audio (automatic). Note only one stream — Stream #0.0 — a video stream. Kdenlive automatically detected there was not an audio track and so it did not write one.

    $ ffprobe dog_rotated_exp_audio_auto.mp4
    Metadata:
        major_brand     : isom
        minor_version   : 512
        compatible_brands: isomiso2avc1mp41
        encoder         : Lavf53.21.1
    Duration: 00:00:03.62, start: 0.000000, bitrate: 12592 kb/s
    Stream #0.0(und): Video: h264 (High), yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 12587 kb/s, 27.83 fps, 27.83 tbr, 30k tbn, 55.66 tbc

    FFprobe on file generated from an audio-less track using Export audio checked. Note two streams — Stream #0.0 and Stream #0.1 — the latter being an aac audio track. We forced Kdenlive to write an audio track even though there was not any source audio to write.

    $ ffprobe dog_rotated_exp_audio.mp4
    Metadata:
        major_brand     : isom
        minor_version   : 512
        compatible_brands: isomiso2avc1mp41
        encoder         : Lavf53.21.1
      Duration: 00:00:03.62, start: 0.000000, bitrate: 12598 kb/s
    
    Stream #0.0(und): Video: h264 (High), yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 12587 kb/s, 27.83 fps, 27.83 tbr, 30k tbn, 55.66 tbc
    Stream #0.1(und): Audio: aac, 48000 Hz, stereo, s16, 2 kb/s

    In cases where there is an audio track ...

    Rendering with Export audio unchecked will produce a file with no audio track — result 4 in the screenshot above. Rendering with Export audio (automatic) (result 3 in the screenshot above) or with Export audio checked will produce files with Audio tracks.

    Encoder Threads

    Determines the value of Encoding threads passed to melt. For encoding to certain codecs, namely MPEG-2, MPEG-4, H.264, and VP8, kdenlive can use more than one thread and thus make use of multiple cores. Increase this number to take advantage of this feature on multi-core machines. See melt doco - threads and melt FAQ on multi-threading.

    Scanning Dropdown

    This option controls the frame scanning setting the rendered file will have. Options are Force Progressive, Force Interlaced and Auto.

    Auto causes the rendered file to to take the scanning settings that are defined in the project settings. Use the other options to override the setting defined in the project settings.