[Ffmpeg-devel-irc] ffmpeg.log.20190308

[burek]

[01:37:26 CET] <ricemuffinball> what is more noticable to human eye?   4:2:0 vs 4:4:4  or  8bit color vs 10bit color
[01:57:42 CET] <c3r1c3-Win> I would say it depends on the content.
[01:57:53 CET] <c3r1c3-Win> And the display the person is viewing it on.
[01:58:15 CET] <c3r1c3-Win> And how the person views/weights things.
[02:00:19 CET] <ricemuffinball> picture of a human
[02:00:53 CET] <ricemuffinball> on a 10 bit color monitor
[02:01:39 CET] <ricemuffinball> c3r1c3-Lin there
[02:03:07 CET] <ricemuffinball> .red
[02:03:51 CET] <c3r1c3-Win> Hmm...then it would depend on the brightness of said monitor. If it's say... 1,000 nits+ that would weigh in favor of the 10-bit
[02:04:26 CET] <c3r1c3-Win> BUT if it's a still then the 420 will be noticeable than if it's video, esp. video with a lot of motion.
[02:04:38 CET] <c3r1c3-Win> *be MOR noticeable
[02:04:42 CET] <c3r1c3-Win> **MORE
[02:04:59 CET] <ricemuffinball> okay, what if it's video not a still "or human being"
[02:05:01 CET] <ricemuffinball> of*
[02:05:25 CET] <pink_mist> (why not both, though?)
[02:05:38 CET] <pink_mist> 4:4:4 10bit
[02:06:00 CET] <ricemuffinball> pink_mist because that's not my question
[02:20:08 CET] <c3r1c3-Win> In general I would go for the 10-bit stuff, esp. on a 'true' HDR display.
[02:20:58 CET] <Sauraus> Hello
[02:21:31 CET] <Sauraus> Can anyone tell how I can suppress messages like these [hls,applehttp @ 0x19f6fc0]
[02:21:44 CET] <c3r1c3-Win> It not only expands the luminance range, but also the color range as well, and since 420 is fairly pervasive (and most people don't notice it that much) I think that the extra contrast/brightness/nuance would be better appreciated.
[02:22:47 CET] <c3r1c3-Win> BUT...if one has lots of solid colors in a limited range, then 444 will "win" because you're content is playing to it's strength.
[02:23:04 CET] <c3r1c3-Win> *solid=solid/bold
[02:38:41 CET] <ricemuffinball> every video i have seems to use:   Color space: --------> YUV   . is it possible to have a video file use other than YUV ?
[02:39:26 CET] <pzy> YUV is a color encoding system, so it can also be RGB
[02:40:21 CET] <ricemuffinball> pzy why is it that i never acrossed a video file that use RGB then
[02:41:22 CET] <pzy> beats me! you could convert it to RGB with ffmpeg though probably haha
[02:41:45 CET] <ricemuffinball> okay let me try: how do i do that
[02:42:08 CET] <pzy> -pix_fmt rgb24
[02:44:14 CET] <ricemuffinball> pzy is YUV and rGB are only "color space" options out there
[02:45:17 CET] <pzy> I'm not really an expert on that, but yeah I think it's just those two, with some modifications for HD video and such
[02:46:09 CET] <pink_mist> try ffmpeg -pix_fmts
[02:46:16 CET] <pink_mist> for me it lists loads of others
[02:46:53 CET] <pzy> pixel formats are different than color space
[02:46:56 CET] <pzy> but also similar
[02:47:02 CET] <pink_mist> oh
[02:47:07 CET] <pzy> it's all very complicated and you can blame 1960s TV engineers
[02:48:05 CET] <iive> yuv is more efficient for encoding video, because human eye is more sensitive to light, than color
[02:48:33 CET] <pzy> and it originally had something to do with getting a coherent black and white picture out of the single Y signal
[02:48:41 CET] <pzy> rather than RGB which wouldn't look great in a single channel
[02:48:55 CET] <ricemuffinball> -pix_fmt rgb24 resulted in:  -pix_fmt rgb24   (High 4:4:4 Predictive), yuv444p(progressive)
[02:49:02 CET] <ricemuffinball> it's still YUV but 4:4:4
[02:49:22 CET] <iive> so the Y channel is the luminosity (gray or b&w). and uv contain color information
[02:50:04 CET] <iive> since the color is less important, yuv420 uses U and V channels with reduced resolution
[02:50:06 CET] <pzy> you might have to process it as raw video ricemuffinball? not sure
[02:50:11 CET] <pzy> see this load of technical stuff: https://forum.videohelp.com/threads/349890-YUV-4-2-0-to-RGB
[02:50:29 CET] <ricemuffinball> i still yet to see a RGB video
[02:50:56 CET] <iive> huffman should support it :)
[02:53:33 CET] <ricemuffinball> since YUV is more popular, is it safe to say YUV is better than RGB ?
[02:54:39 CET] <pzy> you'll never get anyone in a video engineering position to tell you something is better, unless they work for the company that sells it or spent way too much money implementing it :P
[02:55:18 CET] <ricemuffinball> i still yet to see a RGB video
[02:56:11 CET] <pzy> check archive.org
[02:58:40 CET] <ricemuffinball> pzy i still cannot produce rgb video using ffmpeg
[02:58:59 CET] <pzy> I really don't know enough about it
[02:59:17 CET] <ricemuffinball> pzy but your command/option produced 4:4:4 video
[14:54:17 CET] <sazawal> Hello. I want to convert a video clip into png images and get the associated timestamp. I tried this command, "ffmpeg -i input.mkv -vf "showinfo" -vsync 0 $framepath%04d.png -hide_banner >& output.txt". But sometimes the number of frames generated are more than the number of timestamps I get. How do I solve this?
[14:57:39 CET] <durandal_1707> sazawal: put -vsync 0 before -i
[15:01:03 CET] <sazawal> durandal_1707, Hi. It didn't solve the problem. Let me explain more, maybe I am doing some other mistake.
[15:02:35 CET] <sazawal> I have split a video at every keyframe, and from this step I got many clips. When I use this command on the first clip, I get the same no. of frames and timestamps. But clip-1 and clip-2, I am getting one timestamp less than the number of frames.
[17:44:43 CET] <famer> hi room
[17:45:28 CET] <famer> I'm trying to continue interrupted encoding
[17:45:53 CET] <famer> I'm using -ss to start from last seen timestamp in log
[17:46:25 CET] <famer> do I have to skip header somehow, since I have it in first part
[17:46:32 CET] <famer> I plan to join them later
[17:53:40 CET] <AppAraat> hi, I'm trying to rotate a file (ffmpeg -i input.avi -c copy -metadata:s:v:0 rotate=180 output.avi) but it doesn't seem to apply that: https://bpaste.net/show/8dd5b4767556
[17:54:53 CET] <furq> i don't think avi supports rotate metadata
[17:55:12 CET] <famer> AppAraat, it rotates only in a metadata(if command is correct) so your player have to support it, if I'm not wrong
[17:56:40 CET] <AppAraat> yeah I'm aware that it only changes metadata (which is good since I don't want to re-encode) but mpv should be able to see the metadata and act accordingly. But yeah if avi doesn't support rotating metadata then my efforts are futile in terms of that ¯\_(Ä)_/¯
[17:57:04 CET] <furq> it's rawvideo so you might as well just use -vf rotate anyway
[17:57:21 CET] <AppAraat> a more verbose output of me loading the rotating video for those interested: https://bpaste.net/show/7f6345613ae2
[17:57:28 CET] <AppAraat> oh hmm, yeah I might do that
[17:57:55 CET] <furq> -c:v rawvideo -vf rotate=PI
[17:59:01 CET] <AppAraat> is rotate=PI equivalent to rotate=180 ?
[17:59:15 CET] <famer> so guys, anyway to skip header metadata in mp4? like ti does for junks in global_header?
[17:59:22 CET] <furq> pi radians = 180 degrees
[17:59:31 CET] <famer> AppAraat, you have to rotate in radians
[17:59:53 CET] <AppAraat> oh I see, thanks.
[18:00:09 CET] <furq> famer: you don't need to skip the header, the concat demuxer demuxes the streams before concatenating them
[18:00:09 CET] <famer> clockwise_degreese*PI/180
[18:00:23 CET] <famer> furq
[18:00:25 CET] <famer> thanks
[18:01:37 CET] <AppAraat> [avi @ 0x559981399f00] yuv444p rawvideo cannot be written to avi, output file will be unreadable - oops :p
[18:02:02 CET] <AppAraat> I'm just gonna see if mpv is going to be able to read it lol
[18:04:25 CET] <durandal_1707> use NUT format
[18:05:07 CET] <AppAraat> lol it somehow tripled he image
[18:05:31 CET] <AppAraat> https://i.imgur.com/scrsL58.jpg
[18:06:34 CET] <AppAraat> but it did flip it, this is the original: https://i.imgur.com/LTuPwwP.jpg
[18:07:26 CET] <furq> i guess you need to convert it back to yuv422p
[18:09:29 CET] <AppAraat> I'm reading about the NUT format but I have no clue how to convert it. I should specify using "-f fifo -fifo_format nut" ?
[18:09:43 CET] <AppAraat> I'll take a look at flipping the image in Kdenlive if possible
[18:09:51 CET] <AppAraat> (since I'm going to edit the video anyways)
[18:12:08 CET] <durandal_1707> AppAraat: dont be clueless, just use .nut extension
[18:12:44 CET] <AppAraat> oh it's an actualy extension. First time I'm hearing about it.
[18:16:10 CET] <AppAraat> yeah that worked! yay :D
[18:16:14 CET] <AppAraat> thanks :)
[18:19:24 CET] <AppAraat> hmm, Kdenlive apparently can't import .nut files
[18:22:21 CET] <durandal_1707> kdenlive is shit
[18:23:25 CET] <AppAraat> they're supposedly refactoring entire codebase tho
[18:23:35 CET] <AppAraat> but what video editor do you suggest otherwise?
[18:27:34 CET] <furq> AppAraat: shotcut is apparently pretty good
[18:29:19 CET] <AppAraat> heh, the same thing I've heard from durandal_1707 about kdenlive I heard about shotcut, but regardless I'll give it a try since I've never done so before.
[18:29:44 CET] <furq> i've never tried either but shotcut should at least import nut since it uses libavformat
[18:30:01 CET] <furq> you could also just try using mkv or converting the video back to yuv422p
[19:36:28 CET] <AppAraat> furq: yeah I'll give shotcut a try because otherwise I'll have to convert first to .nut and then back again. Though the webcam recording I'll probably make in the future will be mjpeg anyway since I can get 30fps that way.
[22:21:58 CET] <AlexP11223> I have mp4 with 2 audio tracks, how to replace them with different tracks from wav files (the same length)?
[22:21:58 CET] <AlexP11223> I tried ffmpeg -i 1.mp4 -i a1.wav -i a2.wav -map 0:v:0 -map 0:a:1 -map 1:a:2 -c copy new.mp4
[22:21:58 CET] <AlexP11223> but got error Stream map '1:a:2' matches no streams.
[22:21:58 CET] <AlexP11223> https://gist.github.com/AlexP11223/97215dd2331c0a0dc72c8093f7bae2ca
[22:26:32 CET] <Ariyasu> isn't it 1:a:1
[22:29:14 CET] <relaxed> 1:a or 1:a:0
[22:29:30 CET] <relaxed> stream count starts at zero
[22:31:21 CET] <AlexP11223> 2 is supposed to be input number
[22:31:21 CET] <AlexP11223> before that I tried
[22:31:21 CET] <AlexP11223> ffmpeg -i 1.mp4 -i a1.wav -i a2.wav -map 0:v:0 -map 1:a:0 -map 2:a:1 -c copy new.mp4
[22:31:40 CET] <relaxed> hmm, wait.  ffmpeg -i 1.mp4 -i a1.wav -i a2.wav -map 0:v -map 1:a -map 2:a -c copy new.mp4
[22:33:01 CET] <AlexP11223> hm, got this now: [mp4 @ 000001f92d6d3540] Could not find tag for codec pcm_s16le in stream #1, codec not currently supported in container
[22:34:21 CET] <relaxed> encode the audio to aac
[22:35:07 CET] <relaxed> alac would be lossless, but it may not be supported on some playback devices
[00:00:00 CET] --- Sat Mar  9 2019