Menu
▾
▴
#42 "man 5 yuv4mpeg" is incomplete
As well as I know "man 5 yuv4mpeg" is THE official spec of yuv4mpeg2 format. So, I consult it when I try to read and write y4m in my own tools.
The man says: "420jpeg - 4:2:0 with JPEG/MPEG-1 siting (default). 420mpeg2 - 4:2:0 with MPEG-2 siting. 420paldv - 4:2:0 with PAL-DV siting".
First of all, I think there is a typo: "sitting" should be. But I am not native English speaker, so think before changing this.
Then, there is no any info about what this siting means. I tried to websearch "JPEG/MPEG-1 siting", but found nothing. So, please put here some link where I can learn what this siting means or at least change the description to something websearchable.
Finally, please add all details needed to write and read y4m. This is THE SPEC, and so I should be complete. Or add a link to a more complete info. Or state explicitly, that there is no more info, and the reader invited to read the source.
All this applies to current subversion revision, i. e. 3429
Hallo
siting is no typo. The word is based on the word site which means position or location (https://www.merriam-webster.com/dictionary/siting)
In the video world you the definition of 'co-sited': http://www.yourdictionary.com/co-sited (it means sampled at the same time). Also check the link to "See chroma subsampling" with a discussion showing what co-sited (or co-siting) looks like http://www.yourdictionary.com/chroma-subsampling#computer
The program need's to know the difference between MPEG-2 and PAL-DV chroma sampling the relevant standards or textbooks should be able to explain the differences. My point is that the mjpegtools should not add that text again, because there are sources available.
What about changing docs/yuv4mpeg.5 file part "FRAMING" to say something like "for more details about reading and writing yuv4mpeg files read the sources - there are many utility programs, some simple, some complex that can serve as guides."
I change the manpage, and close the ticket.