The Export panel (also File > Export Video…) is used to create a new video or audio file from your project because File > Save saves a project file. Think of this like a photo editor that saves its own format (e.g. .psd or .xcf) versus saving a JPEG or a word processor that saves to its own format (e.g. .doc or .odt) versus a PDF.
The most important thing to know is to click Export File to export your project as a new video file. It opens the standard save file dialog for your operating system where you must choose a folder and give it a name.
Here are the other things to know about the Export panel in its basic mode:
Click Advanced to show many more controls and options. However, by clicking Advanced you should understand that Shotcut expects you to be advanced and know what you are doing. There are simply too many combinations of settings and options that Shotcut’s advanced export mode lets you create invalid combinations and does not protect you from yourself.
The Reset button is used in advanced mode to reset all the options and settings to their default values.
The list of many things on the side are Presets. There are many presets provided by Shotcut in the Stock category, and you can add your own that will be shown under the Custom category. The + and - buttons at the bottom of the list are used to add and delete custom presets. NOTE: It is not necessary to choose a preset! Shotcut comes with default values that creates a high quality H.264 MP4 file at a reasonable size and speed that automatically adapts to the resolution, frame rate, and visual complexity of your project. Clicking Reset or the preset named Default restores the panel to its default values.
The From field lets you choose what to export. You can export more than just the timeline. In fact, you do not even need to use the Timeline in Shotcut! You can export a single clip that has been trimmed and filtered in the Source player. You can also add that clip to the Playlist, add more clips, and export the playlist as a single, sequential file or a separate file for each item.
Use hardware encoder is option to use the hardware-accelerated encoder in your NVIDIA or AMD GPU or CPU (Intel Quick Sync on most processors since 2012, but it may depend on your motherboard as well). You will need to tell Shotcut which you have, but if it has not been configured Shotcut tries to automatically detect it when you click the checkbox to turn it on. Pay attention to the status message area just below the player controls for several seconds after clicking the checkbox to see what it reports. This feature currently only supports the H.264 (aka AVC) and HEVC (aka H.265) codecs.
Configure… opens a dialog for the configuration of the hardware encoder. This is useful in case there was a problem with automatic detection, you want to see what automatic detection found, or you want to change it if you have more than one available on your system.
Next, you might need to understand some basic, fundamental concepts of video and audio compression to understand why it takes long or why the file size is not what you expected. Please see this article
would like to understand some basic export settings more deeply.
I mostly use h.264 (mpeg4) export setting and often use the Youtube option, but i adjust the quality from 55% to 64%. I dont see much difference honestly but the video file is approx. 30-40% larger.
As i understand it if i re-encode the same video again and again, the quality will drop with each encoding process (unless i use 100% quality - right?).
If i only want to adjust music/audio but the same video track unchanged how can i achieve a re-encoding without loosing video quality?
What does the quality option mean in general and how does it compare to file size? Does 100% mean lossless? What export settings would be the best with resp. to quality/file size relation?
They have a direct relationship, but it is not necessarily linear. There is no way to answer the what quality means without fully explaining video compression, which is very complex and depends on the codec. At a high level “quality” speaks for itself. Look up the meaning in a dictionary if you need to. Higher means better and bigger size; lower means less and smaller size.
Whether 100% quality means lossless depends on the codec. For non-hardware H.264 in Shotcut, it does mean lossless, but that is a rare thing. Most codecs are either lossless or not or require explicit lossless mode option.
What export settings would be the best with resp. to quality/file size relation?
This is impossible to answer because it is subjective and depends on the context and usage, but I tried to give you something that I think most people want in this ratio with the default options (aka Default preset) with H.264 quality 55%.
If i only want to adjust music/audio but the same video track unchanged how can i achieve a re-encoding without loosing video quality?
The only true way to avoid losing quality is to use one of the intermediate (visually lossless) or lossless presets. However, most people do not need true or nearly lossless. Start with the defaults, and adjust from there. It also depends on what you are doing with the files and their value.
Just one more question: are there video codecs that dont mix video and audio track in the compression process? If so, would it be possible to use these codecs for audio adjustments without touching the video track in the re-encoding process - thus resulting in lossless video-reencoding?
The background to these questions are the following: I do a lot of image sequence (3d rendering from 3d animations or google earth e.g.) with many thousands of pictures so i have to encode them in smaller pieces otherwise the data handling would be too complex for SC and my system. Later on i put these video pieces together to form the final video. I want to minimize quality losses for each process and sometimes i have to adjust small parts or audio tracks even afterwards in a third encoding process.
Codec copy is not supported. The closest thing available to that is Properties > menu > Extract sub-clip, which uses the in and out points of a trimmed clip. Shotcut is not primarily a ffmpeg command line front end, but that particular function is.
I have done a short test to compare and understand the quality factor in h.264 export. I actually used 54 sec. of video footage in FHD h.264 as a basis with some audio and exported this in different quality settings starting from 10% up to 100%. I used the YT-preset with unchanged parameters beside the quality (in the advanced - codec settings).
Here are my results:
Quality___ encoding time____file size__ artefacts
10%______38 s______________9.3 k__very massive artefacts, blocking, color flickering, loss of detail
20%______44 s_____________13.8 k__lots of visible blocking, color flickering
30%______49 s_____________24.8k__less visible artefacts, but still obvious
40%______53 s ____________ 44.3k__slightly visible artefacts
50%______58 s_____________85.8k__hardly visible to no artefacts
60%______78 s____________196.3k__no visible artefacts (for me on laptop screen)
70%______83 s____________372.2k__no visible artefacts
80%______95 s____________598 k___no visible artefacts
90%_____112 s____________921 k___no visible artefacts
100%____116 s___________1585 k___no artefacts
Best quality to file size ratio is somewhere between 50…60% i would assume. For me, already at 40% there are hardly any visible obvious artefacts. Over 50% you can be quite sure you wont see any artefacts unless you have an eagle’s eyes
More than 70% quality is a disk space waste unless you absolutely need 100% quality (for a later re-encoding e.g.)
As a rule of thumb (except for the extreme ends) you can approx. say 10% more quality means a doubling in file size.
Note: all measurement were done on a Thinkpad P50 laptop with render preset=“fast”. You can set the render preset on the EXPORT - ADVANCED - OTHER tab. “fast” was the default here, you can set it also to “veryfast” (or “medium”) which decreases render times about 30% on the cost of output quality (at the same quality setting).
Agreed. I frequently mention 68% quality on the forum, but that’s because people specifically ask for the highest quality settings. Had they asked for reasonable quality settings, I would have quoted closer to 55%. To be worthy of the 68% level, a video needs to be exquisitely captured, beautifully color graded, shown on a giant screen, and serve the dual purpose of transcoding copies into other formats. Some members here can actually pull that off, so if they ask for highest quality settings, I’ll tell them what it is without a lot of questions.
