[Ffmpeg-devel-irc] ffmpeg.log.20141021

[burek]

[00:41] <swair> any guide on how to use libavfilter to apply filter on frames?
[00:42] <swair> tutorials/docs anything works
[01:05] <tolmark12> newbie question: I need to convert some files to M2V for play on an old system. When I try converting a .MOV to M2V, the M2V file is really pixelated. Is there a way to maintain the high quality of the original file?
[01:05] <tolmark12> command : https://gist.github.com/Tolmark12/8070ceb5f12d9c776e97
[01:05] <c_14> Throw more bitrate at it.
[01:06] <PovAddict> tolmark12: if you don't set a bitrate, the default is 200kb/s, which is stupidly low
[01:06] <tolmark12> ah
[01:06] <tolmark12> what's a good bitrate?
[01:07] <tolmark12> looking at docs : ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
[01:07] <tolmark12> is that fairly standard?
[01:07] <PovAddict> 64k is even lower :P
[01:07] <c_14> You do know that 64k < 200k, right?
[01:07] <c_14> Your input is around 222376 kb/s, aim for that ballpark
[01:07] <PovAddict> lol
[01:07] <PovAddict> the input is RLE though
[01:07] <tolmark12> cool, let me give that a shot
[01:08] <tolmark12> perfect, thanks for the help!
[01:57] <Cin_> So, if anyone's around, I have a hopefully quick, if potentially stupid question (and feel free to route me elsewhere if this is the wrong place to ask)
[01:57] <Cin_> Does the MP4 container support independant stream metadata titles? Because I kept thinking the script I was working on was screwing up and dropping them, but I'm now questioning if my entire premise is flawed and it's an issue with the container >.>
[01:58] <Cin_> crap, wrong channel
[01:58] <Cin_> lol
[01:58] <Cin_> ignore that, I'm apparently too tired to pay attention tonight @_@
[01:58] <Cin_> wait, right channel
[01:59] <Cin_> I'm more tired than I thought...
[03:05] <llogan> Cin_: i'm not sure about the specifications, but ffmpeg doesn't seem to show anything for an output made with -metadata:s:v:0 title="stream title"
[03:14] <Cin_> llogan: hmmm, it seems to work with language, just not title
[03:18] <Cin_> so if I run the following
[03:18] <Cin_> -metadata:s:a:1 language=jpn -metadata:s:a:1 title="DTS Core 5.1 @ 1.5 Mbps"
[03:19] <Cin_> the language will override the 2nd audio stream's default language (english) perfectly fine
[03:19] <Cin_> but it won't have a title
[03:19] <llogan> does the input show a per stream title?
[03:19] <Cin_> and just running with -metadata:s:a:1 title="DTS Core 5.1 @ 1.5 Mbps" and no language reference does nothing :/
[03:20] <relaxed> maybe it depends on the container
[03:20] <Cin_> that's what's so weird! Both Input and Output of ffmpeg are showing stream title metadata
[03:20] <Cin_> it's just not in the final file
[03:21] <Cin_> relaxed: my original question was basically, is this even a thing that the mp4 container can do, or is it an issue with ffmpeg, or is it an issue with my script :P
[03:24] <relaxed> I'm not sure, see if it works with matroska
[04:17] <Cin_> relaxed: so I massively slimmed down my ffmpeg command string so that I'm only modifying the video and no longer saying anything about the audio or subtitles. When converting to mkv, it drops everything but audio track 1, subtitle track 1, and the video, but audio track one has its correct metadata title. Converting to mp4, which the same command and just changing the file extension of the output file, it drops all subtitles and the au
[04:18] <Cin_> so even by default, there seems to be different handling of mkv and mp4 containers and it seems to be making some assumptions without my direction
[04:19] <Cin_> don't suppose anyone knows where I can find a canonical answer to whether mp4, as a container, supports stream metadata?
[04:26] <ognugs> Greetings.  I am using ubuntu to stream a .flv file to rtmp destination.  I cannot seem to stop pixelation (blocking) on high motion scenes.
[04:26] <ognugs> I do not think output bitrate is too low, as I can screen capture and output at a similar rate and have a sharp image.   Here is my command line, perhaps I am missing something or a setting is too low?  http://pastebin.com/SAHxvJQs    Thanks for your support. :)
[05:05] <PovAddict> I want to turn a 16:9 video into 4:3, putting half the difference into black bars on top and bottom, and half into cropping the sides, any suggestions on how to do that?
[06:19] <ac_slater> hey all. Does anyone have any hints for using libavformat and creating an mpegts output stream? I'm interesting in both video and arbitrary data (for which I'm making an mux/demux enc/dec pairs for.
[08:27] <deivor> Hi, I'm trying to cross compile ffmpeg for raspbian with libfdk-aac. I've built libfdk-aac correctly and I'm getting "ERROR: libfdk_aac not found" when running ./configure  on ffmpeg source dir. config.log shows the error "/home/david/built_ffmpeg/lib/libfdk-aac.a: could not read symbols: File format not recognized".
[08:29] <deivor> I have built ffmpeg successfully without fdk_aac, which means my environment variables are most likely OK. This are my configure flags: http://pastebin.com/tcth9c2F
[08:35] <rcombs> deivor: could you pastebin your entire config.log?
[08:38] <deivor> Yes: http://pastebin.com/fUK4jT8i
[08:49] <relaxed> deivor: remove --enable-libfdk-aac from ffmpeg's configure and see if it fails on the next lib.
[08:50] <deivor> Runs OK without fdk-aac (I do get this : WARNING: /opt/tools/arm-bcm2708/arm-bcm2708hardfp-linux-gnueabi/bin/arm-bcm2708hardfp-linux-gnueabi-pkg-config not found, library detection may fail.
[08:50] <deivor> )
[08:56] <relaxed> maybe that's the issue
[08:57] <deivor> Well, it does build OK (without fdk-aac), I've been using the internal aac encoder for now
[09:06] <relaxed> you may have better luck building in a VM
[09:24] <K4T> how I can list all capture card in ffmpeg on Linux?
[09:29] <relaxed> K4T: https://trac.ffmpeg.org/wiki/Capture/Webcam
[10:11] <Akagi201> When I cross-compile a program with ffmpeg's lib, I got these link errors. https://gist.github.com/Akagi201/912891ccb22b085e5d32
[10:11] <Akagi201> Any help is very nice.
[11:31] <kevmitch> are there any opinons on this: https://github.com/mpv-player/mpv/issues/1205
[11:32] <JEEBsv> you should probably prod #ffmpeg-devel about this ;)
[11:33] <JEEBsv> since this is mostly a user-oriented channel, and not many of the developers linger here
[11:33] <kevmitch> will do
[13:29] <pikovit> hi guys... I have a problem encoding a video to ismv format with different streams not being aligned
[13:30] <pikovit> I narrowed it down to the fact that one of the output ismv files does not start on timestamp 0
[13:30] <pikovit> but I'm having trouble figuring it out, why exactly that happens
[13:49] <pikovit> anyhwow --- I figured out the problems were bframes in x264, but I don't know why
[13:51] <pikovit> check the outputs: http://pastebin.com/4eF6wm5Y (no bframes, I set the wrong title of pastebin) vs http://pastebin.com/8yXm3NAS (WITH bframes)
[13:51] <pikovit> is this expected behaviour ?
[13:52] <pikovit> I can provide sample of input and output if needed, let me know
[13:58] <pikovit> another interesting thing to note - changing the output format to mp4 instead of ismv, it works OK, see http://pastebin.com/4unNCmXG
[14:07] <t4nk856> hello, guys. Could anyone in a few words explain when avformat-54.dll is built and when avformat-55.dll and what does indexes mean?
[14:21] <t4nk856> hello?
[14:22] <kepstin-laptop> t4nk856: you get avformat-55 if you build ffmpeg version 2.0-2.3 and avformat-54 for 0.11-1.1
[14:22] <kepstin-laptop> it's just a version number indicating incompatible changes
[14:22] <t4nk856> kepstin-laptop: really??
[14:22] <t4nk856> hell
[14:23] <kepstin-laptop> the versions of the libraries in each version are shown on the releases page: http://ffmpeg.org/download.html#releases
[14:25] <t4nk856> kepstin-laptop: thank you very much
[14:25] <pikovit> anyone any thoughts on the ismv issue above? :)
[14:54] <edoardo>  [video4linux2,v4l2 @ 0x1d4e520] The v4l2 frame is 40588 bytes, but 614400 bytes are expected.
[14:54] <edoardo> can i solve this?
[15:21] <termos> how I can properly set the bufsize of the encoding i libffmpeg? Right now I'm setting it with av_dict_set(&codec_options, "bufsize", "4000000", 0)
[15:27] <termos> it does not look like it is being honored by the encoder
[16:05] <active8> is the format / container (flv, mp4, 3gp, etc. ) that can be sent via RTMP limited by the RTMP protocol or the player?
[16:05] <active8> i.e., the player on the viewing end.
[16:11] <zenny> HI: if one has to trim a video timewise, -ss and -t values works. Is there any way to trim frames, not duration using ffmpeg?
[16:19] <Ney> hi, i have a .ts file that ffmpeg (latest zeranoe buiild) reports a wrong duration on, with "-i input -f null" flags, could anyone explain to me either what I do wrong, or what i can do to get ffmpeg to report a more correction duration, or if i can troubleshoot what is wrong with the file
[16:20] <termos> a follow up to what I asked earlier: seems that vbv-bufsize if the correct thing to set, not bufsize
[16:21] <termos> hm nope
[16:30] <Sunghost> hello - i have installed ffmpeg from squeeze packages and read that a newer one is available in unstable - how can i install that -from backports?
[16:42] <pomaranc> hi, is there any way for ffplay to play a file from the middle - without the header? h264 and any container
[16:42] <kepstin-laptop> i.e. you have actually chopped off part of the file?
[16:43] <pomaranc> yes
[16:43] <kepstin-laptop> it depends on the container format; some will be unplayable, some (like mpeg-ts) might work.
[16:43] <edoardo> hi!
[16:43] <edoardo> cracking sound with alsa: how can i solve that?
[16:43] <edoardo> it also says "alsa buffer xrun"
[16:52] <zenny> Is there a way to remove a few frames in the beginning or end of a video with ffmpeg? Similar to -ss and -t options for time and duration.
[16:59] <relaxed> Sunghost: That's more of a #debian question, or you can you a static build http://johnvansickle.com/ffmpeg/
[17:02] <Sunghost> ok thanks thought someone had same questions
[17:11] <c_14> zenny: you can use the trim filter with the start_frame and end_frame arguments
[17:34] <zenny> c_14: thanks. when I read https://ffmpeg.org/ffmpeg-filters.html#trim it states start_frame is the number of the first frame that should be passed to the output and end_frame is the number of the first frame that should be dropped. A bit confusing how the syntax works. Let's assume that a 5m video needs to be trimmed 5 frames from the beginning and 6 frames at the end. How does the syntax looks like, any clue?
[17:35] <bencc> how can I check if mp4 has the metadata at the end of the file or at the start?
[17:35] <bencc> I can ensure it's at the start with "-movflags +faststart"
[17:35] <bencc> but first I want to check
[17:40] <ChocolateArmpits> bencc, that pushes the atom to the beggining, but not the metadata
[17:41] <bencc> ChocolateArmpits: what should I use to make the file load fast in the browser?
[17:41] <ChocolateArmpits> Exactly that
[17:41] <bencc> cool
[17:42] <bencc> how can I check if a file has the atom at the start or end?
[17:42] <ChocolateArmpits> atomparsley
[17:42] <ChocolateArmpits> Excuse me, AtomicParsley
[17:42] <bencc> I'll look for ubuntu package. thanks
[17:42] <ChocolateArmpits> It's a cli application, it can print file structure
[17:43] <ChocolateArmpits> If you used the flag moov_atom should be at the start
[17:43] <bencc> ChocolateArmpits: I'm using the flag for my files
[17:44] <bencc> now I'm trying to see if a file from another source has it
[17:44] <c_14> zenny: should be -vf trim=start_frame=6:end_frame=6 , that should drop the first five and last 6 frames
[17:45] <ChocolateArmpits> bencc: You can also try setting the atom with mp4box. As I understand it can interleave moov_atom over amount of time so the initial amount of data to download before playback should be at around 40% lower than compared to ffmpeg's faststart
[17:46] <ChocolateArmpits> The rest of it is downloaded over amount of time specified
[17:48] <bencc> ChocolateArmpits:  http://dpaste.com/33WZA7V
[17:48] <bencc> looks like the moov atom is close to the start?
[17:49] <ChocolateArmpits> Is the size of the file 9 mbytes?
[17:50] <bencc> 72MB
[17:50] <bencc> AtomicParsley input.mp4 -T | sed -n 2p | grep -q "moov" && echo "yup" || echo "nope"
[17:50] <bencc> this gives me "nope"
[17:52] <ChocolateArmpits> Ok, it's at the end
[17:52] <ChocolateArmpits> It needs to preceed Atom mdat
[17:53] <bencc> good
[17:53] <bencc> that might explain why it takes a long time for the video to start playing
[17:53] <bencc> thanks
[17:58] <feklee> Just checked out master, but cannot find the -tile-columns option for streaming WebM/VP9.
[17:58] <feklee> Is there another branch which contains these?
[17:59] <feklee> Or does master support WebM streaming?
[18:21] <PovAddict> how big is the tv-safe area? :/
[18:23] <ChocolateArmpits> PovAddict: Depends on suggestions
[18:23] <ChocolateArmpits> https://tech.ebu.ch/docs/r/r095.pdf
[18:24] <PovAddict> I'm targeting a 4:3 CRT TV
[18:28] <ChocolateArmpits> In general 80% of total width and maybe around 84% of height can be allowed for title area
[18:28] <ChocolateArmpits> Actually those would be very safe
[18:39] <PovAddict> got my menu to fit with some trial and error
[18:57] <Cin_> Hey, wondering if anyone can help answer whether I'm seeing an issue in FFMPEG or with the MP4 container
[18:57] <Cin_> if I run the following:
[18:57] <Cin_> -metadata:s:a:1 language=jpn
[18:58] <Cin_> it overrides the original track's language just fine, so no syntax issue there
[18:58] <Cin_> but if I run:
[18:58] <Cin_> -metadata:s:a:1 title="DTS Core 5.1 @ 1.5 Mbps"
[18:58] <Cin_> nothing happens
[18:58] <Cin_> the track gets no title
[18:58] <Cin_> anyone else tried that before?
[20:28] <dcoffey> Greetings!  I have a question -- I just compiled and installed ffmpeg 2.4.2 from source.  When I use ffprobe or ffmpeg on a file, the entire contents of the XMP data are printed before encoding starts.  Is it possible to disable parsing the XMP data entirely?
[20:28] <c_14> What part do you want?
[20:29] <c_14> You can try ffprobe -show_streams
[20:29] <dcoffey> I would like to skip the read altogether, it takes about a minute to print the entire data to the screen.  If I use -v quiet, it still hangs while parsing the dta
[20:29] <dcoffey> s/dta/data/
[20:30] <c_14> Can you ffprobe your complete command and console output?
[20:30] <c_14> what
[20:30] <c_14> eh
[20:30] <c_14> s/ffprobe/pastebin
[20:30] <PovAddict> lol
[20:30] <dcoffey> sure, hang on
[20:30] <PovAddict> c_14: need to ship a ffpaste
[20:30] <PovAddict> :P
[20:38] <dcoffey> ok sorry for the delay, here is the pastebin of the xmp issue I am having http://pastebin.com/khztXyGC
[20:39] <dcoffey> i truncated it as the log was a 27MB file
[20:46] <dcoffey> the xmp data is 300,000+ lines long, so takes minutes to print before encoding starts
[20:55] <c_14> I'm not sure there's an option to skip reading or to skip parsing of that information. If the problem is that your terminal can't print fast enough, you can try redirecting stderr somewhere else.
[21:01] <feklee> The option `-an` gives: "Undefined constant or missing '(' in 'an'"
[21:04] <feklee> Well, here it is: http://pastebin.com/fYc2Lggf
[21:05] <c_14> There's something wrong with ${VP9_DASH_PARAMS}
[21:05] <feklee> I try to convert to WebM for DASH streaming. I've compiled the latest master branch: "./configure --enable-libvpx --enable-libvorbis --enable-libx264 --enable-avresample --enable-gpl"
[21:05] <c_14> Hint the: [libvpx-vp9 encoder @ 0x1a9dde0] Error setting option frame-parallel to value -an.
[21:07] <feklee> @c_14: `$VP9_DASH_PARAMS`: "-tile-columns 4 -frame-parallel"
[21:07] <c_14> >  -frame-parallel    <int>        E..V.... Enable frame parallel decodability features (from -1 to 1) (default -1)
[21:08] <c_14> -frame-parallel takes an int
[21:08] <feklee> Phew, basically copied from here: http://wiki.webmproject.org/adaptive-streaming/instructions-to-playback-adaptive-webm-using-dash
[21:08] <feklee> Don't even know what `-frame-parallel` does.
[21:08] <c_14> try with -frame-parallel 1
[21:09] <feklee> @c_14: Thanks, that seems to work - it's converting!
[21:10] <feklee> The path to WebM/DASH streaming is full of obstacles...
[21:14] <dcoffey> anyone know which line in libavformat/dump.c I'd need to modify to stop from printing the XMP metadata altogether from http://pastebin.com/khztXyGC while preserving all other output?
[21:32] <dcoffey> found it, line 136 I added this to stop dumping xmp if anyone is curious: http://pastebin.com/puh6SRZx
[21:32] <dcoffey> that's libavformat/dump.c
[21:36] <bofh> Hi all! can somebody please suggest how can I decrease volume from 100% to 80% for a input file, starting at position of second 5 to position of second 8 in the file (so the volume would go down at that range)?
[21:36] <bofh> linear
[21:49] <zenny> c_14: used -vf start_frame=6:end_frame=6, but the output video froze at frame 6 while audio seems to be okay.
[21:49] <c_14> That's not a correct filter...
[21:50] <c_14> eh
[21:50] <c_14> wait
[21:51] <c_14> Right, first of all, it should be -vf trim=[foobar], second you're going to need the total number of frames and then use end_frame=[num_frames]-6
[21:52] <c_14> And no, ffmpeg itself can not get the total number of frames within a filter (than I know of) you'll have to get at that programatically
[21:54] <zenny> c_14: Thanks. Is there a specific programmatic way of ffmpeg to get the total number of frames?
[21:56] <c_14> If it's cfr, it's fps * time_in_seconds, if not you can do `ffmpeg -i file -c copy -f null /dev/null' and then grab the frame= part
[22:00] <ChocolateArmpits> Would it be faster via ffprobe's select_entry as you wouldn't have to parse the text ?
[22:03] <c_14> It might, if used together with -count_frames
[22:05] <zenny> c_14: Thanks for the pointer. But ffmpeg seems to reencode the entire file once again and taking a long time to produce the output video.
[22:06] <c_14> Shouldn't with -c copy, but you can try ffprobe -count_frames -show_streams and then look at the nb_frames of the video stream. It still needs to decode/demux the entire file though.
[23:14] <bencc> is there something in this video that is not optimzied for web browsers?
[23:14] <bencc> http://dpaste.com/15C93YG
[23:14] <bencc> how can I know the codec profile?
[23:16] <bencc> it says "Constrained Baseline"
[23:24] <Nosomy> in x264 settings: --profile baseline
[23:25] <Mavrik> bencc, is that direct dump from some camera?
[23:25] <Nosomy> this video is youtube shit?
[23:25] <Mavrik> it looks fine from here except that the bitrate is kinda large
[23:26] <Mavrik> Nosomy, since when does youtube use constrained baseline profile?
[23:26] <Nosomy> some videos youtube use baseline profile.
[23:27] <Mavrik> mhm, but I highly doubt anyone at Google would ever get so drunk as to serve a 854x480 H.264 video at 3Mbit/s :P
[23:29] <Nosomy> Mavrik, youtube Follow a Standard, 5Mbit/s for 720p  (or 3Mbit/s if is new young account)
[23:30] <bencc> Nosomy: I think it is youtube reencoded with some text on top of it
[23:30] <Mavrik> huh.
[23:30] <Nosomy> Youtube Standard is funny
[23:30] <Mavrik> why.
[23:30] <Mavrik> we serve 720p video at 2Mbits
[23:30] <Mavrik> silly.
[23:30] <bencc> it's not the original video
[23:30] <bencc> probably edited with windows movie editor
[23:31] <Mavrik> bencc, anyway, if you reencoded it you probably have to move the MOOV atom to the start
[23:31] <Mavrik> using qt-faststart or some tusch
[23:31] <bencc> Mavrik: if the html5 video element with preload="auto" is on the page
[23:31] <bencc> the browser will preload the video in the background, right?
[23:32] <bencc> the video size is 70MB
[23:32] <bencc> and users waited 10 mintues before playing it
[23:32] <Mavrik> No idea what all 15 browsers out there will do sadly
[23:32] <Mavrik> I'm not a web dev.
[23:32] <bencc> only Chrome
[23:32] <bencc> some of the users saw the video. some saw only black
[23:32] <Mavrik> bencc, if users had to wait before playing it, you certanly have a MOOV atom with file index at the end of file
[23:33] <Mavrik> do a faststart.
[23:33] <bencc> yes, I have the MOOV atom at the end
[23:33] <bencc> and moving it to the start is the first thing I'm going to do
[23:33] <bencc> but I wonder if there are other issues that I need to avoid
[23:34] <bencc> I don't have a machine that reproduces it but got complains from remote users
[23:34] <Mavrik> well first of all, 3Mbit is a huge file
[23:35] <Mavrik> meaning people need a stable, clean, working 3Mbit+ DSL or cable to stream it
[23:35] <Mavrik> and that pretty much kills all your mobile market
[23:35] <Mavrik> so getting that down to 1Mbit or even less (which is achievable at your resolution) should be a first priority
[23:35] <Mavrik> switching to Main or High profile should help with that
[23:36] <bencc> 3Mbit what?
[23:36] <bencc> I don't see it in the ffprobe output
[23:37] <Mavrik> bitrate: 2699 kb/s
[23:37] <Mavrik> each second of your video is 2.7Mbit large
[23:37] <bofh> I'm trying to merge 2-8 seconds of file 1.mp3, delayed with 1 second, with 2 seconds of file 2.mp3
[23:37] <bofh> ffmpeg -i 1.mp3 -i 2.mp3 -filter_complex "[0]atrim=2:10,adelay=1000|1000[0:o];[1]atrim=0:2[1:o];[0:o][1:o]amerge=inputs=2" 3.mp3
[23:38] <bofh> but the result is 2 seconds
[23:39] <bencc> Mavrik: what is a reasonale bitrate? 1000 kb/s?
[23:39] <Mavrik> depends on your content
[23:39] <bencc> if the client has time to buffer, won't it be fine?
[23:39] <Mavrik> bencc, how would it be fine?
[23:39] <Mavrik> if each second of your video needs more bandwidth that client has available
[23:39] <Mavrik> the buffer is just empty
[23:40] <Mavrik> *will just empty making people wait for next buffer
[23:40] <bencc> Mavrik: can't the client preload?
[23:40] <Mavrik> but WHY
[23:40] <Mavrik> 854x480 video has no business being 3Mbit :P
[23:41] <Mavrik> we serve PAL (720x576) at 1Mbit, 720p at 3Mbit and 1080p at 8Mbit
[23:42] <Mavrik> if you want to deliver that to people over internet reencode it to 1-1.5Mbit or so (depending on visual quality) in Main profile with medium or slow x264 preset
[23:42] <bencc> I need the video for an online virtual class
[23:42] <bencc> so I can compromise about quality
[23:44] <bencc> Mavrik: thanks. I'll try it
[23:46] <brontosaurusrex> any plans to add cineform decoder in near future?
[23:47] <Nosomy> for me is x264 CRF 20, trade-off between quality and size.
[23:49] <bencc> Nosomy: what is CRF 20?
[23:50] <bencc> I thought that a mobile client can preload 70MB video file and just play it no matter the bitrate
[23:50] <bencc> if I have enough time, why does the bitrate matters?
[23:52] <Mavrik> ...
[23:52] <Nosomy> crf is "quality metric" ratecontrol of x264, and after so many tests, i saw crf 20 is enough to make sure it is good, and quite good filesize.
[23:52] <bencc> will it still load the video in real time?
[23:52] <Mavrik> Nosomy, CRF needs vbv control added for good web experience
[23:53] <Mavrik> but otherwise it's ok yeah
[23:53] <Cin_> anyone know if the MP4 container supports stream specific metadata titles?
[23:54] <Cin_> like naming audio track 2 as "Commentary" etc?
[23:54] <Nosomy> yes, for this, web videostream is a problem.
[23:54] <bencc> Mavrik: I don't think the mobile client need to load the video in real time
[23:55] <bencc> <video preload="auto"> will let it cashe the file so the bitrate won't be an issue
[23:55] <Mavrik> bencc, which part of "making people wait because your video is ass is bad experience" don't you understand?
[23:55] <Cin_> bencc: keep in mind that on mobile, there's also the issue of data caps in some countries
[23:56] <Mavrik> bencc, you'll be burning 70MB of data for a person and making him wait for your video
[23:56] <bencc> I agree with you that I should reduce the bitrate (filesize)
[23:56] <Mavrik> instead of using 25MB and him being able to view it instantly because you can't be bothered to set proper video parameters?
[23:56] <brontosaurusrex> bencc: perhaps bitrate matters due to AVC levels
[23:56] <bencc> but trying to understand if that what causes some of the users to see black video even after preloading for several mintues
[23:56] <Mavrik> that too, but most devices will carry Level 5.1 and High profile with no problem lately
[23:57] <Mavrik> bencc, some versions of Chrome refused to play MP4s with MOOV at the end for me
[23:57] <bencc> so for web I need faststart and crf 20?
[23:57] <bencc> Mavrik: that's interesting
[23:57] <Cin_> The crf level depends on your needs
[23:57] <Cin_> but 20 is usually fine
[23:58] <Cin_> and the default for a lot
[23:58] <Mavrik> bencc, https://trac.ffmpeg.org/wiki/Encode/H.264#AdditionalInformationTips
[23:58] <bencc> Cin_ do I need other settings?
[23:58] <Mavrik> bencc, see CRF with maximum bit rate
[23:58] <bencc> thanks
[23:58] <Mavrik> add -profile main -preset medium
[23:58] <Mavrik> if you won't add -maxrate/-bufsize CRF might spike too much
[23:58] <bencc> isn't it safer to use baseline profile?
[00:00] --- Wed Oct 22 2014