From: <mail@nodoa.me>
To: <ffmpeg-devel@ffmpeg.org>
Subject: Re: [FFmpeg-devel] [PATCH] lavfi/vf_decimate: add mixed option to process input only partially to be decimated
Date: Wed, 9 Nov 2022 21:08:47 +0900
Message-ID: <001401d8f434$06dcf3d0$1496db70$@nodoa.me> (raw)
The purpose of this new option is to enable processing of mixed content such
as TV recordings or even movies which have some cuts in telecined 24fps and
others in 30p.
Enabling it (mixed=1) will calculate a common timebase between decimated and
non-decimated content and set frame duration according to whether the
current cycle contains a frame deemed to be a duplicate or not.
The default is disabled (mixed=0) and keeping it disabled will keep the PTS
as before (verified using ffprobe).
Regarding setting frame->pts, I had to adjust this part a bit as it is no
longer possible to assume all frames counted by frame_count_in have the same
duration.
As for outlink->frame_rate, I have removed the assignment in the case of
mixed content as the output will be of variable frame rate. Please tell me
in case this is not sufficient to signalize VFR content.
An example for verifying the result is
http://samples.ffmpeg.org/HDTV/Hellboy.ts
ffmpeg -i Hellboy.ts -map 0:v -c:v libx264 -vf
fps=fps=30000/1001,fieldmatch,decimate=mixed=1,fps=fps=120000/1001 -preset
veryfast -crf 10 Hellboy.mp4
The source has a frame rate of 30000/1001 -> timebase 1001/30000 which with
a decimation cycle of 5 results in a decimated timebase of 24000/1001 and a
common timebase of 1001/120000.
The source contains 24fps interlaced content which will result in a duration
of 5 frames at the output frame rate of 120000/1001.
The source also contains 30p content which in the output will have a
duration of 4 frames.
This particular source requires the frame rate to be set to constant
30000/1001. I haven't looked into why but I have verified this to also be
required if not applying this patch.
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
next reply other threads:[~2022-11-09 12:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-09 12:08 mail [this message]
2022-12-19 15:27 ` Paul B Mahol
-- strict thread matches above, loose matches on Subject: below --
2022-11-09 12:07 mail
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='001401d8f434$06dcf3d0$1496db70$@nodoa.me' \
--to=mail@nodoa.me \
--cc=ffmpeg-devel@ffmpeg.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
This inbox may be cloned and mirrored by anyone:
git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git
# If you have public-inbox 1.1+ installed, you may
# initialize and index your mirror using the following commands:
public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \
ffmpegdev@gitmailbox.com
public-inbox-index ffmpegdev
Example config snippet for mirrors.
AGPL code for this site: git clone https://public-inbox.org/public-inbox.git