[FFmpeg-user] FFmpeg-user] VOB, DV, AVI, TS...

[Toerless Eckert]

On Sun, Dec 04, 2016 at 10:00:24AM +0100, Carl Eugen Hoyos wrote:
> 2016-12-04 5:15 GMT+01:00 Toerless Eckert <tte at cs.fau.de>:
> > I am trying to encode TV recordings into the "best" container format,
> > where "best" means that the video has changing aspect ratio, eg:
> > some segments 16:3 then 4:3, then back to 16:9.
> 
> Then simply keep your ts recordings, they are for sure the "best"
> recordings by all means.

> > TS plays back correctly with all players - ffplay, kodi, vlic, mplayer,
> > but TS has aout 10% overhead over all the other containers in
> > my experience.
> 
> Of course, it is meant for lossy transmission.

hmm.. Is it really redundancy or just the ability to quickly sync to a channel
after channel changing in a broadcast system ? 

How about a nerd knob in ffmpeg "encode TS with any form of redundancy redundancy
minimized. Aka: drop from encoding anything that could also drop in transmission
without visual experience loss.

> (TS and MPEG2 TS are the same.)
> This seems to imply that you know of other formats supporting
> aspect change that are not supported by FFmpeg.

No, just PS/TS/AVI and i've tried to figure out if mp4/mkv support it,
and the seeming asnwer is "no".

> > Only mplayer can correctly play back aspect changes with AVI,
> > kodi, ffplay, vlc all just play back with the initial aspect ratio.
> 
> The reason may be that aspect ratio change in avi is not well
> specified.

Yeah.... how do i compare a badly documented Microsoft format that
does support what i want with a probably much better specified
open source format (matroska) that seemingly does not do what i want ;-))

> > The PS files created with "-f vob" or "-f dvd" in ffmpeg have about
> > the same size as avi and are correctly played back with AR changes
> > by ffplay, vlc, kodi. The versions of mplayer i tried only plays back
> > mpeg2 video in PS, not h264. Alas, i have some important apps that
> > leverage mplayer.
> 
> This should work with -demuxer lavf but it seems that the usual h264
> timestamp problem hits us.

http://grouper.ieee.org/groups/1722/contributions/2015/IEEE1722_H264_Timestamps.pdf 
?

> >   - how "standards" compliant is it actually to encode h264 into vob/PS
> >     files. As in: i'd feel a lot safer if i'd know that my encoding
> >     was standard compliant and mplayer has a bug than if mplayer is
> >     right, and all the other players are just very forgiving.
> >     After all, h264 seems to only exist in Blu Ray and those seem to
> >     use TS, not PS...
> 
> This question makes no sense imo (you already forgot dvdhd) but
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> in any case, keep your recordings.

Sorry, trying to parse. was my question confusingly written ?

Forget standards: companies that build media players will make them try to
play back whatever the feel is sufficiently often used that enough customers
would want to use it. I am not aware that any commercial media creates
h264 inside MPEG-2 PS as their file format. If DVD-HD was doing that, that
would be interesting, but alas not very relevant today.

Cheers
    Toerless

> 
> Carl Eugen
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-- 
---
tte at cs.fau.de