To use the proxy in a classic way, i.e. as a scaling, select \texttt{Settings $\rightarrow$ Proxy settings} and change the Scale factor from Original size to your downsized choice. You can choose ffmpeg as the File Format \index{file format} and a choice of various codecs associated with that. A good choice is the default of mpeg which can usually be quite fast. In addition, to modify values for that codec, click on the wrench icon.
-We can use the \textit{Proxy 1:1} in two ways: setting "1" as \textit{Scale factor}, or check the \textit{Rescaled to project size (FFMPEG only)} button. In this mode we don't have scaling, i.e. downsize, but only variations of the codec parameters that allow to maintain the original resolution. The advantage is that you can use filters that require the original size to work well. Please note that if we set any scaling, by activating the \textit{Rescaled to project size (FFMPEG only)} button we automatically lose scaling and enter Proxy 1:1 mode.
+We can use the \textit{Proxy 1:1} in two ways: setting "1" as \textit{Scale factor}, or check the \textit{Rescaled to project size (FFMPEG only)} button. In this mode we don't have scaling, i.e. downsize, but only variations of the codec parameters that allow to maintain the original resolution. The advantage is that you can use filters that require the original size to work well. Please note that if we set any scaling, by activating the \textit{Rescaled to project size (FFMPEG only)} button we automatically lose scaling and enter Proxy 1:1 mode. The size of your video is scaled down of the \textit{Scale factor} but, then, it is rescaled up to the project format. For example, your format project is $1920x1080$ and Proxy's Scale factor is $\frac{1}{4}$, then your videos will be scaled down to $480x270$ and then up-scaled to $1920x1080$. For an old computer, this option is not recommended.
When you have completed your choices, just click OK, and then the video tracks will be rendered. This may take some time, but previous proxy renders will be reused.
You will get an error message if you already have a transcoded file in the selected format with the same suffix name and try to transcode it again with a different selection made -- you will have to delete that file first. An example would be
an already converted file that has both video and audio and now you request video only.
-The BIGGEST gain from using this is if you have media that is not \textit{seekable} \index{seek}, that is, you can play it from the beginning but can not move to another spot and have the audio or video play correctly. A video file with no keyframes makes seeking next to impossible, but then a Transcode generally adds these keyframes. This is particularly useful for the \texttt{mkv} container, which often has seek problems.
+The BIGGEST gain from using this is if you have media that is not \textit{seekable} \index{seek}, that is, you can play it from the beginning but can not move to another spot and have the audio or video play correctly. A video file with no keyframes makes seeking next to impossible, but then a Transcode generally adds these keyframes. This is particularly useful for the \texttt{mkv} container, which often has seek problems. For more details on mkv container see \ref{ssub:note_mkv_container}
Another important function of Transcode is being able to convert the project's media into a high-quality \textit{mezzanine} codec \index{mezzanine codec} (sometimes also called \textit{intermediate} codec \index{digital intermediate}), which makes timeline work lighter and more efficient. In fact such codecs (ffv1, ProRes, DNxHD, OpenEXR, huffyuv, etc) are generally little or not at all compressed; the type of compression is intraframe --more suitable for editing, and the image quality (4:2:2 up; 10-bit color up; floating point; etc) is suitable for \textit{Color Correction}, \textit{Chroma Key} and \textit{Rotoscoping}. The use of mezzanine codecs leads to very large files, so you need to make sure you have enough storage space.
projects / goodguy / cin-manual-latex.git / blobdiff