How to use ProRes format correctly

No matter what projects you have been involved in these years, you must have used ProRes or other intermediate decoders when shooting, editing or archiving. Apple ProRes format can bring a variety of frame sizes, frame rates, bit depths and color sampling rates.

However, people still doubt what kind of procedures should be used in a project. At present, there are six versions of ProRes: ProRes Proxy, ProRes 422 LT, ProRes 422, ProRes 422 HQ, ProRes 4444 and ProRes 4444 XQ, and each ProRes uses different situations and shooting environments. According to his personal experience and investigation, Larry Jordan made a statistical study on these different project workflows.

How to use ProRes format correctly

For example, ProRes Proxy is designed for efficient editing, and is generally used in old computers, but the hard disk of old computers runs slowly and the system performance is poor. This ProRes format is also suitable for multi-shot editing, and its main advantage is performance rather than image quality. ProRes Proxy is used as a proxy workflow, which requires full-resolution video with low data rate. The resolution is 1920 x 1080, 29.97 fps, and the target data rate of Apple ProRes 422 Proxy is about 45 Mbps.

How to use ProRes format correctly

Compared with the ProRes Proxy, the overall picture quality of the ProRes LT is higher, because the ProRes LT contains every pixel in the picture, and its code rate is twice that of the ProRes Proxy. The resolution is 1920 x 1080, the frame rate is 29.97 fps, and the target data rate of Apple ProRes 422 LT is about 102 Mbps. In the past, Bian Xiao used this codec to edit the 2007 version of Macbook Pro, and its performance was excellent. Even if FCP's multi-segment viewer loaded 12 segments, it had no effect.

How to use ProRes format correctly

In Final Cut Pro X, ProRes 422 is the default format of all optimized media, which can well balance the image quality and editing efficiency, and is also the first choice for most DSLR users. The resolution of Apple ProRes 422 is 1920 x 1080, the frame rate is 29.97 fps, and the target data rate is about 102 Mbps, which makes ProRes 422 the best choice for most 8-bit video formats such as H.264, AVCHD, MPEG-4 and DVCPro.

To be sure, ProRes HQ is the most popular category of ProRes, which has a high adoption rate in later works. It supports a full-frame 4: 2: 2 video source with pixel depth of 10 bit, and through several generations of decoding and re-encoding, almost no loss can be seen visually. This is the ideal format for GH4. For example, it supports 10 bit 4: 2: 2 color sub-sampling. The resolution is 1920 x 1080, the frame rate is 29.97 fps, and the target data rate of Apple ProRes HQ is about 220 Mbps. But now GH4 can only be realized with ATOMOS recorder.

ProRes 4444 supports full resolution and performs well in 4: 4: 4: 4 RGBA color and visual reproduction. Because it provides color sampling for each pixel, it is no different from the original material in perception.

How to use ProRes format correctly

Apple ProRes 4444 is high resolution, which is used for the storage, exchange and synthesis of dynamic images. The alpha channel is lossless up to 16 bits. It is almost very suitable for VFX operation, chroma keying and color re-matching operation. When the resolution is 1920 x 1080, the frame rate is 29.97 fps and the data source is 444, the target data rate of Apple ProRes 4444 is about 330Mbps.

For example, if you want to save a lot of hard disk space and save the highest image quality and color reproduction by transcoding BMCC Raw in ProRes 4444, then ProRes 4444 is a wise choice. According to experience, ProRes 4444 is the best choice for videos, which originated from computers, such as screen shots, dynamic projects, post-effect projects, Photoshop sequences or videos requiring alpha channels.

Prores 4444 XQ is the newest member of the Prores family. Is a very professional and high-quality format, which is specially designed for high-end post-workflow and equipment. For example, the standard Apple ProRes 4444 codec supports 12 bits per picture channel and 16 bits per alpha channel. When the resolution is 1920 x 1080, the frame rate is 29.97 fps and the data source is 444, the target data rate of Apple ProRes 4444 XQ is about 500 Mbps. This codec cannot be used in general projects, such as an ordinary DSLR photographer working for a small independent production project. At least there is a shooting project in a studio in Hollywood, which should be used when shooting with the latest Arri Alexa XT, and this project will be a member of the big production team later.