[Ffmpeg-devel-irc] ffmpeg.log.20190108

[burek]

[00:53:11 CET] <Neoflash> I keep getting a bunch of "error while deconding MB" errors, what do they mean?
[01:23:31 CET] <iive> Neoflash, that's usually result of damaged bitstream
[01:26:04 CET] <Neoflash> I have change the settings according to some article that I have found on the internet and it helped, I've got the stream going but the video is lagging about 10 seconds behind the camera. What would normally cause that?
[01:57:35 CET] <DHE> buffering in the player is a normal thing, and some codecs do internal buffering as well. I think x264 buffers a couple of seconds unless you use -tune:v zerolatency (at your own risk)
[01:57:41 CET] <DHE> oh he's gone...
[08:00:04 CET] <jimgray> hey, guys. I have downloaded a dash audio with webm format, how to convert it to mp3?
[08:00:21 CET] <jimgray> also i'd like to keep the quality as best
[12:21:29 CET] <lavaflow> I'm playing around with the showspectrum filter and noticed that when I reduce the vertical dimension, the spectrogram scrolls faster
[12:22:02 CET] <lavaflow> is this because it's faster to generate for a smaller vertical resolution?   and what if I want it to stay slow?
[12:22:14 CET] <lavaflow> the fps option doesn't help
[12:22:27 CET] <lavaflow> command I'm testing with: ffplay -f lavfi 'amovie=in.mp3,asplit=2[out1][a]; [a]showspectrum=color=rainbow:scale=cbrt:slide=scroll:orientation=vertical:overlap=1:s=1366x700[out0]'
[12:23:38 CET] <lavaflow> if I knock that s=1366x700 down to s=1366x100 or something like that, it scrolls really fast.   Ideally I'd like to say "use the 1366 width to show N seconds"
[14:03:04 CET] <durandal_1707> lavaflow: there is fps option, try adjust that one
[14:17:46 CET] <fred1807> I found this line as an example how to stream a video with ffmpeg: ffmpeg -re -i video.mov -vcodec copy -f avi -an udp://239.0.1.23:1234       , please explain like I am five... Should I set the udp ip number to the ip number of my machine?  Or I can leave this number from the example (and this ip will be "created" out of thin air) ? I know this may be a really dumb question...
[14:22:21 CET] <kepstin> lavaflow: different height means it has to change the window size on the fft, which means each column corresponds to more/less time.
[14:22:41 CET] <BtbN> 239.0.0.0/8 is multicast. And why would you use avi for that? Is that even streamable?
[14:22:52 CET] <kepstin> lavaflow: you can always pick a size that results in a speed you like then just scale the height.
[14:27:26 CET] <fred1807> BtbN: well that was the example I found... I dont know why it has -f avi....
[15:02:22 CET] <fred1807> I have this strange video format: Width: 608 pixels Height : 1 080 pixels Rotation: 270°. Locally, mpv plays it like it should, using the full screen.   When I streaming this with ffmpeg -i video.mov -vcodec copy -f mpegts udp://239.0.1.23:123, the playing mpv rotates the video...
[15:08:45 CET] <fred1807> maybe solution would be to encode the rotation, instead of using only a metadata?
[15:11:02 CET] <BtbN> You'll need to copy the rotation metadata. I doubt mpegts supports it though.
[15:36:24 CET] <fred1807> BtbN: Any suggestion?
[15:39:44 CET] <DHE> a quick source code search suggests that only MP4/MOV supports rotation metadata, at least in ffmpeg
[16:04:43 CET] <fred1807> -f mp4 results in error.. How can I stream in mp4 ?
[16:15:28 CET] <DHE> mp4 isn't streaming-friendly, except that a finished mp4 with the right options can be played over "streaming" protocols like HTTP
[16:25:55 CET] <Mavrik> Rotate the video and stream it like that, there's bunch of players that don't properly support the rotation flag anyway.
[20:06:15 CET] <lavaflow> kepstin: ah good call, thanks
[00:00:00 CET] --- Wed Jan  9 2019