[Ffmpeg-devel-irc] ffmpeg.log.20160704

[burek]

[03:01:11 CEST] <HSKW> hello! a question, AAC-LC and AAC-Main profile are too different??
[03:03:12 CEST] <klaxa> yes
[03:03:41 CEST] <klaxa> also what is your actual question?
[03:03:45 CEST] <klaxa> this one is quite vague
[03:05:25 CEST] <gonzafirewall> Hi people I am using ffmpeg 2.1 and I use with streaming rtmp but i need to know i have some api to calcular the bitrate or some snippet or help about that. Thanks.
[03:05:54 CEST] <HSKW> klaxa: i've a trouble with it... if i run in AAC-Main profile some SetTopBox can't decode it... problem is the CPU broadcom
[03:06:18 CEST] <HSKW> i must use an special software decodind to run this AAC-Mail
[03:06:28 CEST] <HSKW> if i encode in AAC-LC no problem
[03:06:35 CEST] <furq> does ffmpeg even have a main profile encoder
[03:06:35 CEST] <klaxa> well use AAC-LC then
[03:06:42 CEST] <furq> i don't think i've ever seen it in use
[03:07:14 CEST] <HSKW> klaxa: not simple, for now i would study the difference
[03:07:25 CEST] <furq> HSKW: https://wiki.multimedia.cx/index.php?title=Advanced_Audio_Coding#Common_AAC_Flavors
[03:08:27 CEST] <HSKW> what are  Hulu streams??
[03:08:35 CEST] <furq> hulu.com
[03:09:55 CEST] <HSKW> i need to transcode it with ffmpeg, is the only solution atm... need patch the physical encoder
[09:25:22 CEST] <ossifrage> Everytime I use ffmpeg "-vf" I am amazed by how much you can do with it
[09:28:13 CEST] <Threads> -vf is like the karma sutra too much todo use and do
[09:32:33 CEST] <ossifrage> I still don't understand why my text is bouncing around by 1 line every few frames, the positioning should be based on the baseline
[09:57:33 CEST] <ossifrage> Is there an option to get ffplay to play frames as fast as they are available from the input (a pipe from x265 via recon-y4m-exec)
[11:14:12 CEST] <HSKW> what difference are between H264 Main 3.0 and Main 3.1 ??
[11:14:41 CEST] <furq> HSKW: https://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels
[11:15:49 CEST] <HSKW> well only Major Luma sample/macroblock and higher bitrate support?
[11:16:05 CEST] <furq> higher bitrate and frame size
[11:16:37 CEST] <HSKW> well an Baseline 3.1 is better than an Main 3.0?
[11:17:00 CEST] <furq> define better
[11:17:24 CEST] <HSKW> better quality at the same bitrate
[11:17:36 CEST] <furq> probably not if main is using cabac
[11:18:11 CEST] <furq> level is only meaningful with regard to constrained decoders
[11:18:21 CEST] <furq> if you don't need to play something back on an old phone or something then you can just ignore it
[11:19:49 CEST] <HSKW> did you mean level: base main high or leve 3.0, 3.1?
[11:20:00 CEST] <furq> base/main/high are profiles, not levels
[11:20:07 CEST] <HSKW> ok thanks
[11:20:21 CEST] <HSKW> another question, minQp and maxQp parameter
[11:21:13 CEST] <HSKW> what are?
[11:21:24 CEST] <furq> https://en.wikibooks.org/wiki/MeGUI/x264_Settings#qpmin
[11:21:39 CEST] <furq> in general you shouldn't touch them
[11:23:13 CEST] <HSKW> i've minQp:4 maxQp:45
[11:23:31 CEST] <HSKW> encodinc at 30fps and keyframe at 60
[11:23:41 CEST] <HSKW> *key interval 60
[11:24:40 CEST] <HSKW> furq: what do you think about this parameter setted for an 640x360 VBR streaming?
[11:26:04 CEST] <furq> if it looks good at a good bitrate then use it
[11:26:12 CEST] <furq> those qp settings probably aren't doing anything though
[11:27:13 CEST] <HSKW> i've an 1Mbps upload speed... Max bitrate are setted at 700kbps
[11:27:44 CEST] <HSKW> i this is the best that i can obtain with this upload speed?
[11:28:30 CEST] <furq> i have no idea
[11:28:39 CEST] <furq> you haven't mentioned any settings which affect quality other than the bitrate
[11:29:07 CEST] <furq> if you want higher quality at the same bitrate then use a slower preset
[11:29:59 CEST] <HSKW> Use High at 3.0 is the only that i can support
[11:30:13 CEST] <furq> that's a profile, not a preset
[11:30:38 CEST] <furq> http://dev.beandog.org/x264_preset_reference.html
[11:30:41 CEST] <HSKW> preset is 9 levels right?
[11:30:48 CEST] <furq> ^
[11:32:07 CEST] <HSKW> a question veryslow profile require a lot cpu encoding... also in decoding require a lot of cpu???
[11:32:15 CEST] <furq> it makes no difference to decoding
[11:33:06 CEST] <HSKW> Very Good Thanks!
[11:33:19 CEST] <furq> except ultrafast which will decode faster because it doesn't use cabac
[11:33:28 CEST] <furq> but ultrafast is garbage anyway
[11:34:34 CEST] <HSKW> well in decoder side only the profile and levels, right?
[11:36:09 CEST] <furq> if the decoder supports high profile then any preset should be fine
[11:36:53 CEST] <furq> you might need to lower -refs though
[11:38:05 CEST] <HSKW> i dont understand -refs
[11:38:57 CEST] <furq> https://en.wikibooks.org/wiki/MeGUI/x264_Settings#ref
[11:39:21 CEST] <furq> some hardware decoders don't like high -refs and -bframes values
[11:39:29 CEST] <furq> i doubt it'll be a problem though
[11:39:49 CEST] <JEEB> ffmpeg cli nowadays limits refs et al in case you have set -level with x264
[11:39:57 CEST] <JEEB> like level 30 for 3.0
[11:40:00 CEST] <furq> oh neat
[11:40:28 CEST] <furq> just use the slowest profile that your cpu will tolerate then
[11:40:34 CEST] <furq> er
[11:40:38 CEST] <furq> slowest preset
[11:41:53 CEST] <HSKW> furq: ok in encoding side most slowset preset that i can tolerate on cpu clock... on decoder side the max profile that he can tolerate
[11:42:56 CEST] <viric> by "your cpu will tolerate" you mean "your patience will tolerate"
[11:43:10 CEST] <furq> it's streaming so i assume it's realtime
[11:43:37 CEST] <furq> any decent cpu should be able to do 360p in realtime at veryslow
[11:45:05 CEST] <HSKW> furq: yes but if i use an I7 2th generation and a very slow profile the cpu goes at 99% load, with i7 6th generation, in the same setting cpu only 30%load
[11:47:15 CEST] <viric> isn't there a preset for realtime?
[11:51:33 CEST] <HSKW> yes but ex. i7 2th generation i cant down over medium preset...cpu in overload... with i7 6th generation i can use the veryslow preset and cpu remain at 30% load
[11:53:24 CEST] <viric> won't the realtime preset pick the best that still provides realtime?
[11:55:06 CEST] <HSKW> viric: for me better to have more quality at low bitrate instead some milliseconds of the realtime...
[11:56:27 CEST] <viric> ah
[14:44:12 CEST] <asimas> Hi. A general question: is it possible to determine if this is the original wav file or was decoded from an mp3? E.g. if I convert from mp3 to wav back and forward multiple times I will lose quality. But is there a way to determine whether this has happened?
[14:44:58 CEST] <bencoh> .48
[14:44:59 CEST] <bencoh> woops
[14:45:23 CEST] <bencoh> you could compare the result to the original (psnr maybe?)
[15:12:10 CEST] <sole_> i am trying to use a video encoded using libav with the codecs aac and libx264 in <video tag
[15:12:22 CEST] <sole_> when i do it live it doesnt work , when i simply use
[15:12:48 CEST] <sole_> ffmpgeg -i http://10.0.0.1/hdmi out.mp4
[15:12:58 CEST] <sole_> and then use the filename in the video tag it works
[15:13:19 CEST] <sole_> what could it be?
[15:36:36 CEST] <BtbN> sole_, "do it live"?
[15:36:58 CEST] <BtbN> you can't play an mp4 file before it's finished.
[15:52:44 CEST] <Guest20950> sure you can, with -movflags faststart
[15:53:05 CEST] <sole_> BtbN: like hls
[15:53:45 CEST] <DHE> mp4 requires the full file be written out first before it's streamable
[15:53:46 CEST] <BtbN> Guest20950, that moves the moov atom the the beginning of the file.
[15:53:51 CEST] <BtbN> After it's written.
[15:54:30 CEST] <BtbN> sole_, well, you'll have to use HLS or DASH then.
[15:54:43 CEST] <sole_> so whats mpeg4-ts?
[15:54:54 CEST] <sole_> ie
[15:55:15 CEST] <DHE> mpeg-ts is a true streamable format. it's what's used in broadcast transmissions on cable, satellite, antenna, etc
[15:55:16 CEST] <sole_> ffmpeg -i http://10.1.1.1/hdmi vid.m3u8
[15:55:20 CEST] <DHE> that's HLS
[15:55:56 CEST] <sole_> ok and the .ts inside that file is mpeg4-ts?
[15:56:00 CEST] <sole_> or am i mixing stuff?
[15:56:22 CEST] <DHE> technically it's called mpge2 transport stream, or just mpegts for short
[15:56:32 CEST] <DHE> (obvious typo is obvious)
[15:56:44 CEST] <sole_> yeah
[15:56:45 CEST] <sole_> mpeg2
[15:57:53 CEST] <BtbN> Most Browsers can't play mpeg-ts though.
[16:10:14 CEST] <mechahop> anyone seen any good ways to record a rtmp stream but if it breaks keep recording?
[16:10:26 CEST] <mechahop> need to use a loop or sometbhing
[16:38:57 CEST] <ayum> hello everyone
[16:39:04 CEST] <ayum> I have a problem when try to save AVFrame to png files
[16:39:11 CEST] <ayum> here is the source code: http://p.fdzh.org/8g8arXRZ
[16:39:20 CEST] <ayum> and here is the result picture: https://s32.postimg.org/ldlw79ct1/222.png
[16:39:30 CEST] <ayum> my original idea is to get the true color png file, but I found the color of picture is very strange, it's gray, and been split to 2 parts
[16:39:46 CEST] <ayum> is it the problem of my code?  please help me
[17:08:13 CEST] <Mavrik> ayum, that looks like you didn't do pixel format conversion
[17:08:19 CEST] <Mavrik> Video files aren't in RGB :)
[17:09:12 CEST] <ayum> I am test with .ts file
[17:09:32 CEST] <ayum> I'll using some video file test again
[17:13:05 CEST] <DHE> video files might produce 4:2:0 colourspaces, so, yeah...
[17:58:53 CEST] <asimas> It is said that converting from a lossy format (e.g. mp3) to another lossy format (e.g. ogg) will decrease the quality. Is this change noticeable by human ear?
[18:01:16 CEST] <yagiza> asimas, usually no
[18:01:20 CEST] <DHE> depends on the quality settings/bitrates and codecs involved
[18:01:42 CEST] <ln-> not to mention the quality of speakers/headphones/other equipment
[18:02:14 CEST] <yagiza> Especially if bitrate is high enough.
[18:03:01 CEST] <asimas> The bitrate's ~140kb/s
[18:04:52 CEST] <DHE> that's usually fine. one transcode isn't going to destroy it
[18:06:38 CEST] <asimas> Alright. Thanks a lot guys.
[18:09:20 CEST] <ChocolateArmpits> This might be unrelated but is AOM codec testable? Can anything be encoded at the state it's currently on?
[18:09:27 CEST] <ChocolateArmpits> in*
[20:08:53 CEST] <Guiri> Hey, saw the Openmax support for RPi in the release notes.  How can I test this?
[20:09:59 CEST] <Guiri> I didn't see it on the HWAccelIntro wiki
[20:14:03 CEST] <jkqxz> Guiri:  Build with --enable-omx-rpi, use encoder h264_omx.
[20:14:15 CEST] <Guiri> ty, jkqxz.
[20:15:34 CEST] <Guiri> Ah, do'h: https://github.com/FFmpeg/FFmpeg/blob/a590d344e3164f5616d0fe85daee45dd834c4841/libavcodec/omx.c#L919
[20:46:11 CEST] <furq> oh cool
[20:46:16 CEST] <furq> it's about time omx showed up
[21:29:54 CEST] <BtbN> Isn't OMX deprecated in favor of some new API on the Pi?
[00:00:00 CEST] --- Tue Jul  5 2016