[Ffmpeg-devel-irc] ffmpeg.log.20131028

burek burek021 at gmail.com
Tue Oct 29 02:05:01 CET 2013


[00:53] <Samizdat> evenin
[00:54] <Samizdat> If anyone who has hefty resources, a few GB of RAM, a feg GHz clock speed, good bandwidth, etc. and wishes to help me test a YouTube live stream download, I'd appreciate it.
[00:54] <Samizdat> Just let me know, and I'll give you a download URL customized to your IP (which you'll need to supply me).
[00:55] <Samizdat> Vienna via Brooklyn - the Delphi Chamber Orchestra at 720p (I'll even provide the 1080p live download link, if you think you can handle it)
[01:01] <Samizdat> Here, I'll make it simple for you -- suspicion runs high these days, and I understand this, as mine does too -- http://shoutkey.com/pasture+ will show you the download link -- but you'll have to change the YOUR-IP-HERE part to, well, you know.
[01:02] <sacarasc> What is this for?
[01:04] <Samizdat> Take your modified URL, get yourself a shoutkey 24-hour URL, and further modify it thusly: http://coblitz.codeen.org/shoutkey.com/YOUR-MODIFIED-SHOUTKEY-HERE -- what this will do is avail you of Princeton's Large File Transfer Service, further enhancing speed.
[01:06] <Samizdat> sacarasc: I don't have the resources to perform a decent 640p capture, let alone a 720p, but I wish to know if YouTube can supply one.
[01:08] <Samizdat> oh, one last thing -- you Linux bugs probably have something even niftier than my lowly Windows Net Transport, which provides 2-threaded downloading.  WXDownload Fast provides at least 5-threaded, but I've had bad results with that particular program.
[01:10] <Samizdat> Hmm, that last post was a mistake.  ffmpeg can handle the (properly modified) URL above, using the following command line: ffmpeg -i "http://shoutkey.com/YOUR-MODIFIED-SHOUTKEY-HERE" -v 0 yourfile.ts
[01:12] <Samizdat> You can leave out the -v 0 part, but you'll have a very verbose output in your Command Prompt (or terminal).
[01:14] <Samizdat> The live YouTube concert in question is at http://www.youtube.com/watch?v=0csF4V944Os , and two hours gone, so I don't know how much time you'll have, but it won't be forever.
[01:17] <Samizdat> Corrected command line: ffmpeg -i "http://coblitz.codeen.org/shoutkey.com/YOUR-MODIFIED-SHOUTKEY-HERE -v 0 yourfile.ts
[01:17] <Samizdat> Whew.
[01:18] <Samizdat> I'll probably never see any feedback on this, but there it is, something new (perhaps) you didn't know before.
[01:22] <Samizdat> P.S. -- with VLC version 2.1.0 Rincewind, simply play the YouTube watch URL, switch to playlist view (if you don't use playlist view by default), select (highlight) the playing item, right-click, sroll to "Information," left-click, and copy the Location URL, the one ffmpeg will use to make a .ts file from a number of segments.
[01:22] <Samizdat> Alrighty then.
[01:22] <Samizdat> Enjoy!
[01:22] <Samizdat> Hopefully the Cards are either ahead, or tied at zero.
[01:22] <Samizdat> I do dislike the Sox.
[01:23] <Samizdat> Adios
[03:28] <buu> So uh, if I compile ffmpeg then run make install, I get libavutil.a; but how do I get libavutil.so?
[03:28] <buu> Or is it hiding someplace?
[03:39] <Guest12270> Hi, can someone help me with direct show screencast command line commands
[04:13] <buu> Ok seriously
[04:13] <buu> How do I get .so files out of this thing?
[04:55] <Plorkyeran> --enable-shared when running configure
[04:56] <Plorkyeran> but that's usually the default...
[06:08] <pzich> anyone have recommendations to get good, compact webm videos? I'm pretty happy with the profiles for libx264, but am not familiar with what's available for webm
[15:11] <ThinkTank> Hi guys/girls. I'm working on a hobby project to create a simple CCTV application to show multiple 1080p camera streams on a flat screen tv. My problem is that i'm getting frame dropping when I have 5< streams. Any suggestions? CPU dosen't seem to be working that hard 50-60%
[15:12] <durandal_1707> ThinkTank: what library you use?
[15:13] <ThinkTank> Haven't chosen one yet. Just trying ffplay x 8
[15:13] <durandal_1707> ffplay is not library
[15:14] <durandal_1707> ffplay is toy
[15:16] <ThinkTank> I thought it was just bare metal on top of ffmpeg
[15:16] <durandal_1707> ffplay use libsdl
[15:17] <ThinkTank> ah
[15:17] <ThinkTank> I thought it used opengl to render the video
[15:17] <ThinkTank> my mistake
[15:18] <Jimx-> question - I'm writing a project that will depend upon ffmpeg libraries.  my project is multi-platform, and admittedly I am inexperienced with how dependencies such as this are handled on non-windows systems.  should I use ffmpeg as a git submodule/etc?
[15:19] <Plorkyeran> on linux people will want to use the copy of ffmpeg packaged by their distro
[15:20] <Plorkyeran> on other platforms I'm a fan of git submodules for ffmpeg due to the general lack of API stability
[15:20] <Jimx-> that's what I figured, I wouldn't want them to build it if they can just get it through a package manager, though I don't know quite how to handle includes and such
[15:20] <Plorkyeran> as it makes pinning to a specific rev pretty useful
[15:21] <Plorkyeran> whatever build system you're using should support using pkg-config to get all of the information you need to include/link the libs
[15:21] <Plorkyeran> if it doesn't, use a better build system~
[15:22] <ThinkTank> durandal_1707: What do you suggest that I use for testing performance?
[15:22] <Jimx-> ah, yea.  like I said I'm a windows developer normally so my experience with proper tools is severely lacking.  a slight bit in the dark, I'm glad I ended up asking
[15:23] <Jimx-> thank you for the info
[15:29] <plm> Hi all
[16:16] <dreamhawk> Hello
[16:17] <dreamhawk> quick question, how can i combine output-dir + seq%04d.ts ? like /tmp/stream/seq%04d.ts
[16:17] <dreamhawk> Hope you understand what i want to do :)
[16:18] <spaam> output-dir/seq%04d.ts
[16:18] <spaam> done
[16:19] <spaam> can you tell us what do you mean?
[16:19] <dreamhawk> Nope, i get 1 file named seq%04d.ts, i want files like seq0000.ts, seq0001.ts, seq0002.ts etc
[16:24] <dreamhawk> saste: im just trying to do 1 ffmpeg cmd :) . "ffmpeg -y -i stream -vcodec copy -acodec copy -b:v 800k -flags -global_header -map 0:1 -map 0:2 -hls_list_size 20 -hls_time 10 -hls_wrap 8 -segment_list /tmp/hls/stream.m3u8 /tmp/hls/files/seq%04d.ts"
[16:24] <dreamhawk> without the "" .
[16:26] <saste> dreamhawk, -f hls
[16:26] <saste> ?
[16:26] <saste> and trust me when i say !pb dreamhawk
[16:27] <dreamhawk> saste: that is the line i am executing. no other script behind.
[16:29] <saste> this team read the text, or no one can help
[16:29] <saste> *time
[16:30] <dreamhawk> saste: don't see colors on irssi ;). I will save the output.
[19:05] <Guest12270> Can someone help me with directshow screencasting commands?
[19:10] <llogan> durandal_1707: do you have an answer for this guy? http://ffmpeg.org/pipermail/ffmpeg-user/2013-October/018182.html
[19:11] <llogan> Guest12270: https://trac.ffmpeg.org/wiki/How%20to%20grab%20the%20desktop%20%28screen%29%20with%20FFmpeg
[19:11] <Guest12270> I already seen that
[19:12] <Guest12270> not enough information to make it happen to my liking
[19:12] <llogan> not enough information to make answer
[19:14] <Hydrant> hi everyone, I'm attempting to do a screencast and figure out what I record isn't very sharp (the text gets fuzzy after a second or two)... I am recording 1280x720 and would expect that playback on my own system will look as sharp as the original screen rather than blurry
[19:14] <Hydrant> ffmpeg -video_size 1280x720 -framerate 25 -f x11grab -i :0 output.flv
[19:14] <Hydrant> that is the command I'm using on this first attempt
[19:15] <durandal_1707> llogan: tell him to look at code if he does not want to pay for consulting
[19:16] <llogan> durandal_1707: you can provide an answer
[19:17] <durandal_1707> llogan: certainly, i can, but do I want?
[19:19] <llogan> i did it for you
[19:19] <llogan> with a shitty worthless answer
[19:19] <Guest12270> What I need is to set directshow video source option to 30 FPS, audio codec to True audio(TTA), and output to mkv
[19:20] <Guest12270> So far my guesses is: ffmpeg -f dshow -r 30 -i video="UScreenCapture":audio="Stereo Mix" -vcodec libx264 -crf 0 -preset slow -acodec tta -ac 8 -ar 192000 -ab 36864000 out.mkv
[19:20] <durandal_1707> llogan: sorry, but answer is far from trivial, as question
[19:22] <llogan> ok
[19:23] <Guest12270> also have additional question about stereo mix and pixel formats
[19:52] <llogan> Guest12270: what are your questions? where is the ffmpeg console output?
[20:08] <Guest12270> My question is correct commands for screencasting by setting directshow video source to 30 frames per second, video codec to lossless h.264, audio source as stereo mix, audio codec as true audio(TTA) at 8 channel, 192000Hz, bitrate at 8*192000*24, and finally output to mkv
[20:10] <Guest12270> and additional question include what pixel format provides best quality and how many channels of audio stereo mix provides
[20:12] <Guest12270> and no console output since I didn't believe my guesses were correct in audio codec area
[20:16] <pzich> do I need to blow away the 2pass log if I'm batch 2-passing files, or does it take care of that?
[20:22] <llogan> Guest12270: the default pixel format will provide best quality. i can't answer anything else without console output
[20:22] <llogan> pzich: you don't need to do anything
[20:23] <pzich> llogan: cool, that's what I thought, but it's good to hear confirmed
[20:31] <Guest12270> what console output do you want?
[20:31] <Guest12270> options for the direct show devices?
[20:32] <Guest12270> or list of direct show devices?
[20:32] <llogan> you haven't tried your command yet?
[20:35] <Guest12270> nope
[20:36] <Guest12270> I only tried listing directshow devices and their options
[20:41] <Guest12270> I think UScreenCapture and Stereo Mix as directshow devices are all that's required to answer my questions.
[20:41] <Guest12270> and I can't copy and paste command prompt for some reason
[20:46] <Guest12270> http://tinypic.com/view.php?pic=2h36hvm&s=5#.Um6_EhCFfjs
[20:46] <Guest12270> is that what you wanted?
[21:13] <llogan> it at least shows that you're using ffmpeg
[21:40] <FunnyLookinHat> Anyone here done webm / libvpx encoding?  I can't get it to output a nice-looking 1080p video for the life of me... -vcodec libvpx -s 1920x1080 -crf 10 looks like crap
[21:42] <sacarasc> I thought -crf was libx264 only? *shrug*
[21:42] <JEEB> I think they mapped it into something random for libvpx?
[21:42] <FunnyLookinHat> Ah great.
[21:42] <FunnyLookinHat> heh
[21:42] <JEEB> and naturally the range of values is completely different
[21:42] <FunnyLookinHat> This list crf but yeah... no go: http://trac.ffmpeg.org/wiki/vpxEncodingGuide
[21:43] <JEEB> I think they added a kind-of-similar-to-CRF mode for vp9 into libvpx finally
[21:43] <JEEB> but yeah, most probably it's the range of values that's different
[21:43] <JEEB> so if it looks bad, push it lower?
[21:44] <FunnyLookinHat> Yeah - I'll do that... :0
[21:45] <FunnyLookinHat> Thanks JEEB !
[21:45] <JEEB> vp8 will probably not have that really CRF-like mode tho
[21:45] <JEEB> and the one for vp9 is two-pass it seems
[21:45] <JEEB> so it first checks the whole clip, and then encodes it with the selected parameter
[21:46] <FunnyLookinHat> Yeah - well I got something somewhat useful by just setting an extremely high bitrate...  I'll try to match up to whatever h264 has in terms of bitrate and call it a day :)
[21:47] <JEEB> sounds good enough I guess
[21:48] <FunnyLookinHat> For testing and such it is :)
[21:49] <JEEB> FunnyLookinHat, I guess you'll want to use 2pass bit rate based encoding for libvpx then :)
[21:49] <FunnyLookinHat> Yeah definitely
[21:49] <JEEB> libvpx stuff for vp9 kind of looks interesting, smarter got some kind of AQ done and such
[21:49] <JEEB> and the constant quality mode kind of interests, too
[21:55] <llogan> i don't think anyone knows how to encoder for VP8
[21:55] <llogan> *encode
[21:56] <JEEB> and I'm not learning, mostly because it's clear that libvpx will be mostly pushing vp9 now, which at least isn't years late into the race
[21:57] <JEEB> I'm also keeping an eye on the HEVC side's common suspects as far as encoders go
[21:57] <llogan> ja ja ja
[00:00] --- Tue Oct 29 2013


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