[Ffmpeg-devel-irc] ffmpeg.log.20181112

burek burek021 at gmail.com
Tue Nov 13 03:05:02 EET 2018

[00:55:07 CET] <foo> I'm wanting to convert an MP3 to FLAC (first 30 seconds) only. I can A) transcribe with ffmpeg on filesystem, store as flac, use file, then delete or B) I can do this all in memory somehow and never actually write the file to disk. Anyone happen to know which might be preferred? I know I can do A) really easy... but converting + deleting file sounds unnecessary if I can do it all in memory... although doing it all in memory may use more memory... ...
[00:55:13 CET] <foo> ... originating mp3 file can be < 100MB
[01:00:41 CET] <hololeap> foo: if you are in linux you could mount a tmpfs to the filesystem and get the best of both worlds
[01:01:26 CET] <iive> why -t 30 is not working for your case?
[01:01:57 CET] <foo> hololeap: I'm doing this in python, FWIW. I'll delete the resulting file afterwards
[01:02:16 CET] <foo> iive: oh, ffmpeg -t 10 -i Jared.mp3 Jared.flac works fine
[01:02:29 CET] <foo> I'm wanting to do this on the fly, use file once, then delete it... debating doing this in memory or on FS
[01:03:10 CET] <hololeap> depending on your distro, a tmpfs (basically a RAM filesystem) may be mounted at /tmp, so if you store it there temporarily, it may never touch your disks
[01:04:33 CET] <foo> hololeap: oh, interesting, I may not be familiar with this
[01:04:47 CET] <foo> yeah, since I'm ultimately wanting to tie it into this... with io.open(file_name, 'rb') as audio_file: content = audio_file.read() ...
[01:04:54 CET] <foo> I believe with python-flask I could do this too
[01:04:56 CET] Action: foo investigates
[01:07:37 CET] <somy> hi there, anybody has any experience using  hwdec in the libs... I'm totally lost... it's half working I get all the frames in decode order that would be ok if the pts where not equals to the dts...
[01:09:00 CET] <foo> hmm, anyone see what I'm doing wrong? https://paste.ofcode.org/tTgRrgUfwVrsNwgTNu5b6Z
[01:09:07 CET] <foo> I may have to explicitly pass conversion from mp3 to flac
[01:13:59 CET] <foo> ah, nevermind
[01:15:27 CET] <foo> ]trim=duration=10[s0] matches no streams
[01:15:49 CET] <foo> I see the filter here https://github.com/kkroening/ffmpeg-python/blob/master/ffmpeg/_filters.py
[01:17:07 CET] <foo> .filter('trim', duration=10) looks right too. /me scratches head
[01:22:17 CET] <foo> .filter('trim', start=0, end=10) still throws Stream specifier '' in filtergraph description [0]trim=end=10:start=0[s0] matches no streams.
[01:22:20 CET] <foo> huh
[01:27:19 CET] <foo> aha, got it
[02:10:56 CET] <Buliarous> hey so i want to break a movie up into pieces using segments or something such that each piece is no larger than 128mb (maybe 120mb to be safe) is there an easy way to do this?
[02:19:42 CET] <relaxed> Buliarous: I recommend mkvmerge for this: https://mkvtoolnix.download/doc/mkvmerge.html#mkvmerge.description.split
[02:20:23 CET] <relaxed> if matroska is an ok output container
[02:20:59 CET] <Buliarous> must be avi unfortunately ... but that is good to keep in mind for the future
[02:23:29 CET] <relaxed> https://ffmpeg.org/ffmpeg-formats.html#segment_002c-stream_005fsegment_002c-ssegment
[02:25:49 CET] <k-man> hi
[02:26:57 CET] <relaxed> Buliarous: might be easier to use mkvmerge and then remux to avi with ffmpeg
[02:32:42 CET] <Buliarous> relaxed: thanks! i usually work with mkv so definitely will be keeping that in mind for later. I found this to work for my purposes: https://superuser.com/questions/712893/how-to-split-a-video-file-by-size-with-ffmpeg#714749  The split-video.sh script works really well and you can do something like ./split-video.sh myMovie\ transcode.avi 120000000 "-vcodec copy -acodec copy" to split into pieces of
[02:32:48 CET] <Buliarous> 120mb and keep the video and audio codecs, which is pretty great
[02:34:10 CET] <relaxed> that looks pretty hacky
[02:34:25 CET] <Buliarous> kudos to LukeLR whoever you are
[02:41:27 CET] <Buliarous> relaxed: sure is
[16:10:07 CET] <th3_v0ice> For UDP input, is FFmpeg automatically setting cicrular buffer or some other parameters? I am getting "Input/Output Error" while reading UDP with av_read_frame(). Circular buffer overflow is shown above it.
[17:07:38 CET] <JEEB> th3_v0ice: that just sounds like you're running out of buffer because you're not processing stuff quickly enough
[17:07:54 CET] <JEEB> if you need more buffer you can configure that
[21:21:20 CET] <th3_v0ice> JEEB: Ok, thanks. Other things point out that that seems to be the case.
[00:00:00 CET] --- Tue Nov 13 2018

More information about the Ffmpeg-devel-irc mailing list