Whether you are working with Ffmepg, Avidemux or Olive Video Editor, you should be wondering what parameters to use to final render a video montage. Here are my choices for some specific purpose.

There is no standardized meaning for high-definition, generally the minimum standard is 720p, a progressive HD signal where each frame is sized 1280×720 pixels. Many mid-sized TV sets produced in the early 2000s, known as HD Ready, were capable of 1280×720, 1360×768 or 1366×768. The next evolution step, called Full HD or 1080p, have a frame size of 1920×1080 is common in interlaced or progressive mode.

At first we aimed to produce videos for the entry level High Definition Video, so we choosed a target resolution of 1366×768 pixel. After all, we have a 32-inch television capable only of 1366×768 pixels.

Our main source of videos is the Xiaomi Yi action camera, which records full HD videos 1920×1080 pixels at a variable bitrate of 12.0 Mb/s. So we re-encode the final montage with the following settings:

We can use Avidemux to make the final rendering (re-encoding). For a command line only solution you can consider ffmpeg to perfomr the re-encoding and to make the merge (mux) all into a Matroska container.

#!/bin/sh
TITLE="Balcani, maggio 2022"
ffmpeg \
    -i "video-high-quality.mkv" \
    -i 'audio-music.ogg' -i 'audio-live.ogg' \
    -map '0:v:0' -map '1:a:0' -map '2:a:0' \
    -metadata title="$TITLE" -metadata:s:v:0 title="$TITLE" \
    -metadata:s:a:0 title="Accompagnamento musicale" \
    -metadata:s:a:1 title="Audio in presa diretta" \
    -filter:v "scale=1366x768" -aspect "16:9" \
    -vcodec 'libx264' -pix_fmt 'yuvj420p' -preset 'veryslow' -tune 'film' -profile:v 'high' -level:v 5 \
    -acodec copy \
    "2022-05_balcani.mkv"

We used the yuvj420p pixel format. What does it means?

First of all consider the 420 code; this means tat for each matrix of 4×2 pixels the stream encode all the values for the luminance, only 2 values for the chrominance on the X axis and zero values for the chrominance on the Y axis. This figure explains clearly the 4:4:4, 4:2:2 and 4:2:0 subsampling methods:

Is file size is not a concern, we might ask ourselves whether a pixel format with less loss of chroma information would be preferable. Obviously is useless to add more chroma information if the final rendering has the same resolution of the original video, but if we are scaling down the video resolution we may retain chroma information using a different pixel format.

The fact is that in movies 4:2:0 is almost lossless visually, which is why it can be found used in Blu-ray discs and a lot of modern video cameras. There is virtually no advantage to using 4:4:4 for consuming video content.

Furthermore, it may happen that some players (software or hardware) are not compatible with pixel formats other than 4:2:0.

How to get the piexel format:

ffprobe -loglevel error \
    -show_entries stream=pix_fmt \
    -select_streams v YDXJ4050.mp4

How to get the bits per raw sample:

ffprobe -loglevel panic \
    -show_entries stream=bits_per_raw_sample \
    -select_streams v YDXJ4050.mp4 

• Which pixel format for web mp4 video?
• Using ffmpeg or ffprobe to get the pixel bit depth of a video
• Chroma Subsampling
• YCbCr