[Ffmpeg-devel-irc] ffmpeg.log.20160814

Mon Aug 15 03:05:01 EEST 2016

[00:32:51 CEST] <fa0> I followed the example for changing volume here;
[00:32:54 CEST] <fa0> https://trac.ffmpeg.org/wiki/How%20to%20change%20audio%20volume%20up-down%20with%20FFmpeg
[00:33:37 CEST] <fa0> But the original video says;
[00:33:39 CEST] <fa0> Stream #0:0(eng): Audio: aac (HE-AAC), 48000 Hz, stereo, fltp (default)
[00:33:51 CEST] <fa0> Volume changed;
[00:34:02 CEST] <fa0>  Stream #0:1(eng): Audio: vorbis, 48000 Hz, stereo, fltp (default)
[00:34:17 CEST] <furq> what did you expect
[00:34:18 CEST] <fa0> I thought the cmd is only to boost volume not change the codec?
[00:34:27 CEST] <furq> you can't change the volume without reencoding
[00:34:35 CEST] <furq> evidently you didn't specify a codec and it picked vorbis
[00:34:48 CEST] <fa0> ahhh ok, I thought it would just copy the audio
[00:35:29 CEST] <fa0> or just use the default, is there an option to have it keep the default, or you have to pick/add in?
[00:35:49 CEST] <furq> the defaults are for the container you picked
[00:35:59 CEST] <furq> i'm guessing you're using mkv
[00:36:05 CEST] <fa0> yea
[00:36:17 CEST] <furq> you could maybe try aacgain if you want to raise the volume losslessly
[00:36:33 CEST] <fa0> actually I did; -vcodec copy -af "volume=10dB"
[00:36:40 CEST] <furq> yeah you can't do it with ffmpeg
[00:36:50 CEST] <furq> http://aacgain.altosdesign.com/
[00:37:23 CEST] <fa0> sorry can't do what with ffmpeg, have it just use the default audio, have it detect and use that?
[00:37:37 CEST] <furq> you can't change the audio volume without reencoding with ffmpeg
[00:38:06 CEST] <fa0> ok thanks
[00:38:07 CEST] <furq> and reencoding will incur some quality loss
[00:39:00 CEST] <fa0> why the url of aacgain?
[00:39:14 CEST] <furq> because that can do it without reencoding
[00:39:51 CEST] <furq> you can either use -af volume=10db -c:a libfdk_aac -profile:a aac_he_v2 out.mkv
[00:39:57 CEST] <furq> or demux the audio, use aacgain and then remux it
[00:41:12 CEST] <furq> the second one shouldn't lose any quality
[00:42:56 CEST] <fa0> the first is for ffmpeg?
[00:43:01 CEST] <furq> yeah
[00:44:16 CEST] <fa0> Hmm I'm using 3.1.2 and I tried running it and nothing happens, ffmpeg doesn't open
[00:44:59 CEST] <fa0> I actually have it in a bash script;
[00:45:02 CEST] <fa0> for i in *.*; do
[00:45:10 CEST] <fa0> urxvt -g 173x40 -e ffmpeg -i "$i" -vcodec copy -af volume=10db -c:a libfdk_aac -profile:a aac_he_v2 "$OUTPUT/${i%.*}.mkv"
[00:45:12 CEST] <fa0> done
[00:47:55 CEST] <fa0> I don't see anything in 'man ffmpeg' about -profile
[00:57:26 CEST] <fa0> furq: can I re-encode the audio and boost it at the same time, or I have to re-encode it, then boost it a second time?
[00:58:31 CEST] <fa0> err that doesn't make sense, then I'm back to where I started, wasn't thinking about that
[00:58:50 CEST] <fa0> errr I don't get this, I can't figure out how to run this with increasing the vol. too
[01:02:36 CEST] <DHE> fa0: the 'profile' option is codec-specific. while it's a generic option, each codec has different options it will accept.
[01:05:33 CEST] <fa0> ok
[01:05:42 CEST] <fa0> I'm looking at the Wiki; https://trac.ffmpeg.org/wiki/Encode/AAC
[01:06:34 CEST] <fa0> just trying to figure how to make this HE-AAC version 2 work with volume=10db
[01:07:07 CEST] <fa0> and copy the video as I pasted my example above...
[01:07:55 CEST] <fa0> ffmpeg -i input.mkv -vcodec copy -af volume=10db -c:a libfdk_aac -profile:a aac_he_v2 output.mkv"
[01:08:28 CEST] <DHE> I don't see anything wrong with your above command. beyond inconsistency in the parameters (mixing -vcodec with -c:a)
[01:09:15 CEST] <furq> i'm guessing you don't have libfdk_aac
[01:09:45 CEST] <fa0> what libfdk_aac support in ffmpeg?
[01:09:49 CEST] <furq> yeah
[01:09:51 CEST] <fa0> I do
[01:09:55 CEST] <furq> oh
[01:09:57 CEST] <furq> that should work then
[01:09:59 CEST] <DHE> the docs say dB (captital  B) for the volume parameter...
[01:10:10 CEST] <DHE> that's the only thing that stands out, and it might not matter...
[01:10:15 CEST] <furq> that would be really dumb if that broke it
[01:10:26 CEST] <fa0> hmm ok
[01:10:39 CEST] <DHE> well, it says invalid inputs are simply ignored... which is kinda stupid all by itself.
[01:11:30 CEST] <fa0> I don't get it, it's running now with db
[01:13:52 CEST] <fa0> I have an ouput directory and if there's a copy in that dir then it runs, if I delete it, then it doesn't run
[01:13:55 CEST] <fa0> hmm
[01:14:16 CEST] <fa0> Maybe I have the order wrong...
[01:14:35 CEST] <fa0> This
[01:14:38 CEST] <fa0> ffmpeg -i "$i" -vcodec copy -c:a libfdk_aac -profile:a aac_he_v2 -af "volume=10db" "$OUTPUT/${i%.*}.mkv"
[01:14:39 CEST] <fa0> Or
[01:15:39 CEST] <fa0> fmpeg -i "$i" -vcodec copy -af "volume=18dB" -c:a libfdk_aac -profile:a aac_he_v2 -af "$OUTPUT/${i%.*}.mkv"
[01:15:56 CEST] <furq> you've got an extra -af there
[01:16:13 CEST] <furq> the order of output options makes no difference though
[01:16:15 CEST] <fa0> err
[01:16:18 CEST] <fa0> ok
[01:17:34 CEST] <fa0> Ahh yes it needed dB :) LOL
[01:20:26 CEST] <fa0> if I do ffprobe -i will it tell me if it's HE-AAC v1 or v2?
[01:20:32 CEST] <fa0> All I see is;
[01:20:39 CEST] <fa0> Stream #0:0(eng): Audio: aac (HE-AAC), 48000 Hz, stereo, fltp (default)
[01:21:08 CEST] <furq> you have to reencode anyway so it makes no difference
[01:22:39 CEST] <fa0> No, I mean, was wondering if ffprobe is telling the version, and then just re-encode to that version is all...
[01:23:12 CEST] <fa0> I guess I'm assuming v2 newer better...
[01:28:36 CEST] <fa0> furq: I noticed you didn't show the cmds with either -b:a or -vbr, so if neither is used, in the cmds I have, how is this working?
[01:28:46 CEST] <fa0> some default assumed, based off the default?
[01:34:14 CEST] <furq> -b:a and -vbr are mutually exclusive
[01:34:20 CEST] <furq> i assume it defaults to -b:a 64k
[01:35:37 CEST] <fa0> I assume, or ffmpeg?
[01:35:55 CEST] <fa0> oh ok...
[01:41:52 CEST] <fa0> Hmm is ffmpeg -i or ffprobe -i suppose to show the bitrate? I only see a sampling rate, or I've overlooking it...
[01:44:25 CEST] <agrathwohl> fa0 it should, look for the ` Stream #0:0 ` line in the output
[01:44:25 CEST] <fa0> Ok in a .mp4 I see;
[01:44:28 CEST] <fa0>  Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 159 kb/s (default)
[01:44:46 CEST] <fa0> Hmm 159 is the bitrate? that seems an odd number...
[01:45:06 CEST] <agrathwohl> fa0 it may be VBR
[01:45:18 CEST] <fa0> ok
[01:45:19 CEST] <agrathwohl> but yes, that is the bitrate as reported by ffmpeg
[01:45:30 CEST] <agrathwohl> of that stream in your MP4 container
[01:46:09 CEST] <fa0> Now in this mkv it only reports this;
[01:46:11 CEST] <fa0> Stream #0:0(eng): Audio: aac (HE-AAC), 48000 Hz, stereo, fltp (default)
[01:46:18 CEST] <fa0> why on bitrate reported?
[01:46:24 CEST] <fa0> why on/no...
[01:46:33 CEST] <furq> mkv doesn't store the bitrate in the metadata
[01:46:39 CEST] <fa0> ahh ok
[01:46:55 CEST] <furq> mediainfo will sometimes report it
[01:47:53 CEST] <agrathwohl> in ffprobe you can get bitrate at the stream level of an MKV, see for instance this section of the FFprobe Tips wiki https://trac.ffmpeg.org/wiki/FFprobeTips#FrameRate
[01:48:12 CEST] <agrathwohl> substitute the `avg_frame_rate` key with `bit_rate`
[01:50:05 CEST] <fa0> Ok I got; 19001/634
[01:51:55 CEST] <fa0> ffprobe -v error -show_format -show_streams
[01:52:12 CEST] <fa0> I was looking at the bottom of the page...
[01:52:15 CEST] Action: fa0 checks
[01:53:37 CEST] <agrathwohl> fa0 do instead `stream=bit_rate`
[01:53:45 CEST] <fa0> avg_frame_rate=19001/634
[01:56:47 CEST] <fa0> sorry not following, that's a flag for ffprobe -v ?
[02:01:19 CEST] <fa0> Under [FORMAT] it gave me; bit_rate=1073639
[06:40:47 CEST] <jookiyaya> what is better quality  720p or 1080i ?
[08:19:00 CEST] Last message repeated 1 time(s).
[09:19:12 CEST] <friki> jookiyaya: interlaced sucks. I'm not a video expert but I hate interlaced
[09:19:38 CEST] <jookiyaya> friki yeah but i am sure you prefer 1080i  over  480p
[09:19:55 CEST] <friki> it depends
[09:20:08 CEST] <friki> what's on the screen? a movie?
[09:20:19 CEST] <jookiyaya> anything
[09:20:41 CEST] <jookiyaya> from a movie to sports to blackandwhite
[09:20:47 CEST] <friki> and what about bitrates? it's losless?
[09:21:07 CEST] <jookiyaya> nothing is lossless
[09:21:10 CEST] <friki> and the playback? is requiered to deinterlace?
[09:21:19 CEST] <jookiyaya> friki yes
[09:23:41 CEST] <friki> i think i can't do a general recomendation
[09:24:38 CEST] <friki> motorsport, golf, tennis, sitcom, pr0n, conference, cartoon...  are too different
[09:27:05 CEST] <jookiyaya> are you serious
[09:27:08 CEST] <jookiyaya> how different can it be
[09:27:40 CEST] <jookiyaya> no way you prefer 480p over 1080i
[09:27:46 CEST] <jookiyaya> or any content
[09:27:49 CEST] <jookiyaya> on*
[09:28:42 CEST] <friki> try to see golf or tennis on a lo framerate
[09:28:59 CEST] <friki> usualy "p" have half frame rate
[09:30:37 CEST] <friki> btw, why are you asking about this?
[09:47:13 CEST] <jookiyaya> because i didn't know where else i could ask
[09:51:26 CEST] <dl2s40> i prefer 480p on my small netbook screen
[09:53:08 CEST] <dl2s40> and if it is a crappy quality 1080 I would probably prefer high quality 480p even on my larger screens
[09:55:59 CEST] <jookiyaya> such a liar
[09:56:18 CEST] <jookiyaya> i am calling you out
[09:59:45 CEST] <dl2s40> *shrug*
[10:00:30 CEST] <jookiyaya> wow, that's it
[10:00:40 CEST] <jookiyaya> i called you a liar
[10:00:46 CEST] <jookiyaya> and that's all you can say
[10:01:04 CEST] <dl2s40> you cant even say what is better quality.. because quality has nothing to do with resolution
[10:01:43 CEST] <jookiyaya> no way you prefer 480p over 1080i (of exact same content)  there happy?
[10:05:06 CEST] <dl2s40> i could make an encode of the same content in 480p and one in 1080i just set those 1080i settings so bad that everything is blurred, and just set settings on the 480p encode so it leads in a nice transparent encode, pretty sure you would prefer the 480p
[10:05:37 CEST] <jookiyaya> are you serious
[10:05:55 CEST] <jookiyaya> i am sure you could  but  that's won't be fair comparison
[10:07:48 CEST] <mrelcee_> it all depends on whether the person doing the encodes has a clue.   Ill take a good 720p over 1080 that's been squished too much..    cant' say I see much 1080i except from cheap camcorders...
[10:10:06 CEST] <dl2s40> well just compare 1080p and 720p on netflix e.g. and you know what i mean. yeah cant say much about 1080i too i guess it is on some, rare but some blu-rays or from tv broadcast. i only want to say that resolution has nothing to do with quality
[10:14:57 CEST] <Mavrik> Pretty much all broadcast TV is 1080i
[10:15:15 CEST] <Mavrik> But yeah, bitrate and encoder quality trumps resolution mostly :)
[10:24:32 CEST] <mrelcee_> my top gun blu-ray has so much film noise, it's a shitty film transfer..  with little or no processing that I can tell..     it didn't do well until I cranked up the resulting file size..
[11:05:31 CEST] <Mavrik> That's pretty obvious
[11:05:39 CEST] <Mavrik> Noise is hard to compress so you need bitrate to store it
[11:05:50 CEST] <Mavrik> Running a denoise filter first would help
[14:44:35 CEST] <sfan5> what's the best way to cut multiple clips from a single source file and encode them into one "coherent" video?
[14:47:37 CEST] <bencc> sfan5: do you want to re-encode?
[14:48:14 CEST] <bencc> if you need to cut at arbitrary places (not keyframes) without re-encoding, you'll need something like
[14:48:15 CEST] <bencc> https://github.com/anyc/avcut
[14:48:25 CEST] <sfan5> yes i want to re-encode
[14:48:32 CEST] <bencc> ok, re-encoding is easier
[14:49:13 CEST] <bencc> so create multiple small clips with something like
[14:49:25 CEST] <sfan5> can't i avoid that?
[14:49:33 CEST] <bencc> ffmpeg -ss 00:00:10 -t 00:00:20 -i input.mp4 ...
[14:49:36 CEST] <bencc> avoid re-encoding?
[14:49:46 CEST] <sfan5> avoid creating multiple small clips first
[14:50:13 CEST] <bencc> maybe you can but isn't it easier to 1. create several clips. 2. combine them into one long movie?
[14:51:04 CEST] <sfan5> that's easier indeed
[14:52:04 CEST] <bencc> ffmpeg -f concat -i clips.txt -c copy -movflags +faststart output.mp4
[14:52:11 CEST] <bencc> that's how you combine several clips
[14:52:29 CEST] <bencc> https://trac.ffmpeg.org/wiki/Concatenate
[14:52:34 CEST] <sfan5> oh and then use "inpoint" and "outpoint"?
[14:52:40 CEST] <sfan5> http://ffmpeg.org/ffmpeg-formats.html#concat-1
[14:52:51 CEST] <bencc> 1. create several clips
[14:52:54 CEST] <bencc> 2. concat
[14:53:26 CEST] <sfan5> it looks like concat can also handle seeking
[14:53:31 CEST] <bencc> yes, you can probably use inpoint and outpoint. I wasn't familiar with this
[14:53:31 CEST] <sfan5> i'll try that first
[14:53:38 CEST] <sfan5> i didn't know that it could do that either
[14:53:40 CEST] <furq> sfan5: -filter_complex "[0:v]trim=10:20,setpts=PTS-STARTPTS[out1];[0:v]trim=30:40,setpts=PTS-STARTPTS[out2];[out1][out2]concat[out]" -map [out] out.mkv
[14:54:13 CEST] <sfan5> that might work but gets more complex the more cuts i have
[14:54:15 CEST] <sfan5> thanks anyway
[14:54:29 CEST] <furq> it's easy enough to script
[14:54:40 CEST] <furq> any solution gets more complex the more cuts you have
[15:10:24 CEST] <furq> sfan5: http://sprunge.us/agaG
[15:14:20 CEST] <sfan5> hm concat format doesn't seem to work
[15:15:08 CEST] <sfan5> i have this input file http://sprunge.us/CKWP
[15:15:19 CEST] <sfan5> ffmpeg instantly finishes and doesn't encode even a single frame
[15:37:27 CEST] <sfan5> o.O
[15:37:32 CEST] <sfan5> furq: same result with your script
[15:37:45 CEST] <sfan5> nvm my fault
[15:38:24 CEST] <sfan5> seems like it's actually doing something
[15:38:33 CEST] <sfan5> this doens't feel like the ideal solution though...
[15:41:18 CEST] <sfan5> my script now: http://sprunge.us/QJND?sh
[15:46:59 CEST] <basisbit> hey, about half a year ago there was a page in the doxygen on what api parts you need to call to get from the video file to the finished frame for showing. I can't currently find that. Does anyne of you know where that could be found?
[16:27:17 CEST] <Threads> furq found out how to mux subtitles into mkv with ffmpeg and have them turned off
[16:27:22 CEST] <Threads> im using -map 0:0 -disposition:v:0 1 -map 1:0 -disposition:a:0 1 -map 2:0 -disposition:s:0 0
[16:27:36 CEST] <Threads> seems like you have to map it
[16:59:30 CEST] <lavalike> does anyone know of a way to use ffmpeg to grab two '.m4u8's, one for video, one for audio, and pipe it to a chromecast?
[17:29:09 CEST] <Threads> lavalike does the m38u's one contains video and one contains audio ?
[17:30:20 CEST] <lavalike> Threads: yes exactly
[17:31:57 CEST] <lavalike> I am fiddling with a tiny ffserver conf, plus ffmpeg -i &.m3u8 -i &.m3u8 -map 0:x -map 1:y -c:v copy -c:a copy http://localhost:8090/input.ffm but I am not being very successful
[17:37:04 CEST] <Threads> ffmpeg -i video.m38u -i audio.m38u -map 0:0 -map 1:0 -c copy outputfile.mkv
[17:37:52 CEST] <Threads> something like that maybe so you get them mapped properly and change the last one to what you need
[17:49:56 CEST] <Mandevil> Hm, does ffmpeg support avisynth files?
[17:50:12 CEST] <furq> it does if you build with --enable-avisynth
[17:50:34 CEST] <furq> and have avisynth.dll somewhere appropriate
[17:51:23 CEST] <Mandevil> I have --enable-avisynth....
[17:51:30 CEST] <Mandevil> Complains of error.
[17:51:44 CEST] <Mandevil> AviSynth of course present and working on my system.
[17:52:15 CEST] <furq> are you using 32-bit ffmpeg
[17:52:23 CEST] <furq> (or 64-bit avisynth)
[17:52:30 CEST] <furq> they both need to be the same
[17:52:44 CEST] <Mandevil> How do I know what ffmpeg I have?
[17:52:52 CEST] <Mandevil> I have 32-bit avisynth that's for sure.
[17:53:14 CEST] <furq> `ffmpeg -version` might have a clue
[17:53:22 CEST] <furq> otherwise check in task manager
[17:53:36 CEST] <furq> i don't think the zeranoe builds mention it
[17:55:03 CEST] <Mandevil> Hm, I think it's 64-bit ffmpeg.
[17:55:05 CEST] <Mandevil> Welp.
[17:56:26 CEST] <Mandevil> Is there any significant advantage to 64-bit ffmpeg?
[17:56:33 CEST] <Mandevil> Otherwise I might just switch to 32-bit...?
[17:56:41 CEST] <furq> none that i know of
[17:57:12 CEST] <furq> 64-bit might be slightly faster but if you're using avisynth you're probably not overly concerned about that
[17:57:31 CEST] <Mandevil> I'm not doing that much heavy-lifting anyway.
[17:57:42 CEST] <Mandevil> And few seconds here and there makes no difference.
[17:58:38 CEST] <furq> i just used 32-bit ffmpeg before i switched to vapoursynth
[17:59:20 CEST] <Mandevil> Heard about this vapoursynth thing...
[17:59:59 CEST] <furq> i only switched because avisynthmt likes crashing so much
[18:00:20 CEST] <furq> vapoursynth is slower and there are fewer plugins available, but the multithreading actually works reliably
[18:00:21 CEST] <Mandevil> Not using -mt.
[18:00:32 CEST] <furq> probably no reason to switch then
[18:01:10 CEST] <Mandevil> BTW, can ffmpeg alter metadata like fps in video?
[18:01:23 CEST] <furq> it can't change fps without reencoding
[18:01:32 CEST] <furq> some dedicated muxers can do that with certain codecs
[18:01:41 CEST] <Mandevil> That's one thing I use AviSynth for...
[18:01:46 CEST] <Mandevil> ..to change FPS.
[18:01:52 CEST] <Mandevil> (not the only one, of course).
[18:02:04 CEST] <furq> if you mean while reencoding then use -vf fps
[18:02:09 CEST] <Mandevil> No.
[18:02:33 CEST] <Mandevil> Well, actually, yes :)
[18:03:04 CEST] <Mandevil> I used to use lagarith, where I would pass it through AviSynth to change framerate.
[18:03:26 CEST] <Mandevil> I had to switch to ProRes/DNxHD.
[18:04:14 CEST] <furq> https://ffmpeg.org/ffmpeg-filters.html#fps-1
[18:04:45 CEST] <Mandevil> Yes, 32-bit works fine with avisynth, thanks for the hint.
[18:05:34 CEST] <lavalike> Threads: it kind of works, it screws up the audio by doing aac->ac3 on its own volition, instead of doing what -c:a copy says, weird! [ Stream #0:2 -> #0:0 (aac (native) -> ac3 (native)) ]
[18:07:25 CEST] <lavalike> it also says  Stream #0:1 -> #0:1 (h264 (native) -> h264 (libx264))  which I wonder if it is due to ffm being the output container, that doesn't seem to be respecting -c:v copy either
[18:09:56 CEST] <Mandevil> Tried "ffplay -vf fps=fps=25" and it doesn't seem to do anything...?
[18:10:50 CEST] <Mandevil> I mean, it plays the video at original framerate.
[18:19:54 CEST] <durandal_1707> which is?
[18:22:31 CEST] <Mandevil> 239.76 fps
[18:24:13 CEST] <furq> it works for me
[18:25:05 CEST] <Mandevil> furq: The commandline is: ffplay -vf fps=fps=25 GOPR0940.MP4
[18:25:32 CEST] <furq> if you want it to speed up the video then use -vf setpts
[18:25:44 CEST] <Mandevil> I want to play it at 25 fps.
[18:25:55 CEST] <Mandevil> Since playing it at 240 fps makes no sense.
[18:26:40 CEST] <furq> shrug
[18:26:47 CEST] <furq> `-vf fps=1` works for me
[18:27:20 CEST] <durandal_1707> Mandevil: what version?
[18:27:36 CEST] <Mandevil> furq: Yes, that work for me too!
[18:27:52 CEST] <Mandevil> furq: 1 fps ok, 25 ... not ok.
[18:28:05 CEST] <Mandevil> durandal_1707: ffplay version N-81338-g6612d04
[18:29:18 CEST] <Mandevil> Wait.
[18:29:23 CEST] <Mandevil> I'm using the wrong file.
[18:29:32 CEST] <Mandevil> No, I'm not.
[18:29:34 CEST] <Mandevil> Hm.
[18:29:39 CEST] <Mandevil> Don't get it.
[20:17:23 CEST] <bulletfreak> so I was trying to compile ffmpeg on Slackware and for some bizarre reason it requires Samba. The build fails with this error: ERROR: smbclient not found
[20:18:25 CEST] <Hans_> Hi, i need --enable-pthreads during compiling(linux) for using threads during encoding? In the documentation i found nothing about this.
[20:20:15 CEST] <c_14> Hans_: if your system has support for pthreads it should be enabled by default
[20:20:36 CEST] <c_14> You can check the output of ./configure --help to check if it's enabled or disabled by default and whether it does autodetection
[20:21:19 CEST] <Hans_> ah ok thanks
[20:21:23 CEST] <Hans_> And --enable-postproc what is? i can found a list of all these config options somewhere?
[20:23:25 CEST] <BtbN> --help
[20:24:37 CEST] <durandal_1707> no such command
[22:17:01 CEST] <drathir> guys im wonder if -vf scale=0:0 skip option or will slowdown processing?
[00:00:00 CEST] --- Mon Aug 15 2016