[Ffmpeg-devel-irc] ffmpeg-devel.log.20170304

[burek]

[02:29:03 CET] <cone-470> ffmpeg 03Steven Liu 07master:4507f29e4a6a: avformat/hlsenc: move the segment files handler close to before temp flags process
[03:06:52 CET] <cone-470> ffmpeg 03Michael Niedermayer 07master:2ce4f2843162: avcodec/vp56: Require a correctly decoded frame before using vp56_conceal_mb()
[03:06:53 CET] <cone-470> ffmpeg 03Michael Niedermayer 07master:eb41956636fc: avcodec/mpeg4videodec: Improve the overflow checks in mpeg4_decode_sprite_trajectory()
[09:17:17 CET] <paras2052> Hello Everyone ! I am paras chadha, 3rd year Undergraduate in Btech CSE. I am interested in the FITS image decoder and encoder project for GSOC 2017.
[09:18:42 CET] <paras2052> I am new to FFmpeg and i want to work on the qualification task but i need some advice as where to begin
[09:48:13 CET] <durandal_1707> paras2052: write decoder, there is also already xpm patch on mailing list by me which needs only some changes
[09:52:25 CET] <paras2052> durandal_1707: Okay, I am working on it.
[10:10:43 CET] <durandal_1707> paras2052: have you found patch?
[10:12:50 CET] <paras2052> durandal_1707: yes, i have found it in the archives
[10:38:19 CET] <durandal_1707>  
[13:23:58 CET] <michaelni> atana, if you need help/more details on how to use ff_generate_window_func() say so and ill explain how its exactly used
[16:28:01 CET] <dev_123> @omerjerk I'm interested in the project "MPEG-4 ALS codec improvements". Kindly guide where to begin from.
[16:45:42 CET] <dev_123> @BBB I'm interested in the project  "MPEG-4 ALS codec improvements". Can you guide me about where to start ?
[16:46:05 CET] <BBB> Im not in charge of that project, sorrt
[17:11:00 CET] <dev_123> @BBB Where can I contact the mentor of this project, which I can see from the project ideas list is Omerjerk. But he is not present here.
[17:28:05 CET] <nevcairiel> the primary mentor has an email listed, try that
[17:28:16 CET] <adeel_> durandal_1707: did you take a look at the diff file I shared yesturday?
[17:30:29 CET] <durandal_1707> adeel_: nope
[17:30:46 CET] <durandal_1707> adeel_: did you got decoding working?
[17:31:55 CET] <adeel_> durandal_1707: the problem was with the XPM file. You told me to add code for removing C comments. But, then there was another issue and you mentioned somthing about probing.
[17:32:22 CET] <adeel_> durandal_1707: here the latest diff: https://gist.github.com/adl1995/5b3f681ba2c710915cc6cf567d3cdb83
[17:34:05 CET] <durandal_1707> adeel_: still lot of stuff missing
[17:34:20 CET] <adeel_> durandal_1707: :/ like what?
[17:34:41 CET] <durandal_1707> adeel_: have you followed xbmdec logic regarding ff get buffer?
[17:35:05 CET] <durandal_1707> you just commented bunch of code
[17:35:50 CET] <durandal_1707> follow xbmdec logic to get decoded output
[17:40:22 CET] <adeel_> durandal_1707: I think I already did. Let me check again
[17:40:46 CET] <durandal_1707> adeel_: you put it commented in wrong place
[17:41:15 CET] <adeel_> durandal_1707: okay, checking
[17:41:25 CET] <durandal_1707> do you have any idea how simple intra only decoders work?
[17:42:28 CET] <durandal_1707> you just call ff get buffer before you need to play with output pointers
[17:57:18 CET] <adeel_> durandal_1707: Is there a method names "ff_get_vbuffer" or did I just make a typo?
[17:57:23 CET] <adeel_> named*
[17:57:35 CET] <durandal_1707> yes typo
[17:58:20 CET] <adeel_> durandal_1707: alright, going through the compilation process again
[18:06:09 CET] <adeel_> durandal_1707: after issuing these commands './configure', 'make install', and 'ffplay  /test.xpm'. I'm getting this error "/test.xpm: Invalid data found when processing input"
[18:06:30 CET] <adeel_> durandal_1707: probably something wrong in xpmdec.c
[18:07:21 CET] <durandal_1707> adeel_: make sure decode frame is being called
[18:07:48 CET] <cone-806> ffmpeg 03Michael Niedermayer 07master:d23727e0420b: avcodec/adxdec: Fix runtime error: left shift of negative value -1
[18:07:48 CET] <cone-806> ffmpeg 03Michael Niedermayer 07master:ab998f4c7faf: avcodec/h264_mvpred: Fix multiple runtime error: left shift of negative value
[18:07:48 CET] <cone-806> ffmpeg 03Michael Niedermayer 07master:d757ddbaab8f: avcodec/mpeg12dec: Fix runtime error: left shift of negative value -13
[18:07:53 CET] <adeel_> durandal_1707: okay, will output something
[18:08:30 CET] <adeel_> No, it isn't being called. I added 'printf("Testing XPM decoder");' at the beginning
[18:13:19 CET] <durandal_1707> adeel_: try different xpm file
[18:19:07 CET] <adeel_> durandal_1707: using this:https://github.com/ifwe/wx/blob/8ef3ca2eff1acc6de1c40d1ccc2112c1f5cddf95/art/htmoptns.xpm still getting the same " Invalid data found when processing input" error though
[18:25:02 CET] <durandal_1707> adeel_: can you push you branch to your repo on github?
[18:25:53 CET] <adeel_> yes
[18:30:59 CET] <adeel_> durandal_1707: please take a look: https://github.com/adl1995/FFmpeg/tree/new_branch
[18:31:55 CET] <adeel_> durandal_1707: only last two commits are relevant
[18:34:04 CET] <durandal_1707> adeel_: is ffplay build shared?
[18:59:43 CET] <atana> michaelni, updated repo. How do I initialize window_func_lut ?
[19:02:18 CET] <adeeln2> durandal_1707: sorry for the late reply. Not sure what you mean why ffplay build. Do you mean the ffplay.c file?
[19:03:25 CET] <durandal_1707> adeeln2: i mean if its shared you need to install itt
[19:04:25 CET] <adeeln2> durandal_1707: oh yes it is installed. I'm currently using this command: 'ffplay  ~/test1.xpm'
[19:05:29 CET] <durandal_1707> adeeln2: does ffmpeg -decoders list xpm?
[19:07:12 CET] <adeeln2> nope
[19:08:57 CET] <michaelni> atana, the 2nd parameter to the function is the number of samples in the window, so the first parameter which is the window needs to be allocated to that size times sizeof(float)
[19:10:17 CET] <atana> ok
[19:11:06 CET] <durandal_1707> adeeln2: so you need to run make install
[19:17:59 CET] <adeeln2> durandal_1707: I just did. But, it's still not showing. Maybe it's somehow pointing to the old build?
[19:23:13 CET] <durandal_1707> adeeln2: whats not showing?
[19:24:00 CET] <adeeln2> durandal_1707: On issuing 'ffmpeg -decoders', I don't see XPM in the list. 
[19:24:34 CET] <atana> michaelni, do you mean window_func_lut = av_realloc_f(window_func_lut, m, m*sizeof(float)) ?
[19:25:10 CET] <durandal_1707> adeeln2: then find where is ffmpeg being installed
[19:25:28 CET] <durandal_1707> if its installed at all
[19:28:25 CET] <durandal_1707> adeeln2: does ffplay now works?
[19:29:38 CET] <adeeln2> durandal_1707: accessing from same directory using './' after issuing './ffplay  ~/test1.xpm' I now get " 28586 segmentation fault (core dumped) "
[19:30:08 CET] <durandal_1707> adeeln2: thats because your code is wrong
[19:30:21 CET] <michaelni> atana, no that would multiply by m twice but av_malloc_array() is better
[19:30:32 CET] <durandal_1707> you need to call get buffer before using pointers
[19:30:38 CET] <adeeln2> durandal_1707: should I try to replicated xbmdec.c?
[19:30:48 CET] <durandal_1707> adeeln2: no
[19:31:05 CET] <durandal_1707> adeeln2: just learn to work with pointers
[19:31:30 CET] <durandal_1707> adeeln2: move ff get buffer above its too low
[19:31:39 CET] <michaelni> atana,  and the window should be stored in the context not calculated repeatly
[19:31:40 CET] <adeeln2> durandal_1707: okay
[19:31:59 CET] <durandal_1707> seriously im helping you too much
[19:32:04 CET] <atana> ok
[19:32:41 CET] <michaelni> the window never changes so theres no need to calculate it more than once
[19:38:22 CET] <durandal_1707> adeeln2: you dont have xpm listed in -decoders because libavcodec/codec_desc.c is missing xpm 
[19:38:49 CET] <durandal_1707> adeeln2: also please remove uneeded files from your code
[19:39:12 CET] <durandal_1707> like txt patch and similar you put there
[19:40:07 CET] <adeeln2> okay
[19:44:05 CET] <nightlingo> hi
[19:44:29 CET] <durandal_1707> hi
[19:47:32 CET] <adeeln2> durandal_1707: please review: https://github.com/adl1995/FFmpeg/commit/de437d43cf634b077c797264472d003aae70b907
[19:48:06 CET] <atana> michaelni, repo updated
[19:48:14 CET] <adeeln2> now getting this: Testing XPM decoder[xpm @ 0x7f4798007480] [IMGUTILS @ 0x7f479e71b6f0] Picture size 0x0 is invalid [xpm @ 0x7f4798007480] video_get_buffer: image parameters invalid [xpm @ 0x7f4798007480] get_buffer() failed [image2 @ 0x7f47980008c0] decoding for stream 0 failed [image2 @ 0x7f47980008c0] Could not find codec parameters for stream 0 (Video: xpm, none): unspecified size Consider increasing the value for the 'ana
[19:48:29 CET] <adeeln2> decoder function is now being called
[19:49:30 CET] <durandal_1707> adeeln2: good, guess it is missing parsing and ignoring " in comments
[19:50:25 CET] <nightlingo> I want split a small portion of a .mp4 video using ffmpeg, without re-encoding it and get the output sent to stdout. I reallized that ffmpeg doesn't support outputting an .mp4 video to stdout because the MP4 muxer needs the ability to seek back in a stream. Then I tried outputting a fragmented mp4 video, which worked for stdout, but it turns out it is not supported by several players like Windows 7 Media Player. Any other suggesti
[19:50:25 CET] <nightlingo> please?
[19:51:18 CET] <nightlingo> *to
[20:00:48 CET] <adeeln2> durandal_1707: alright. Would I have to replicate with from xbmdec or write my own?
[20:02:25 CET] <durandal_1707> adeeln2: looks like it works fine without it
[20:03:41 CET] <durandal_1707> adeeln2: the  xpm you linked works fine here
[20:04:25 CET] <durandal_1707> nightlingo: use mkv
[20:05:05 CET] <adeeln2> durandal_1707: oh, cool. what's next?
[20:07:48 CET] <durandal_1707> adeeln2: fix it so it works for you to and add >256 color support
[20:08:16 CET] <adeeln2> durandal_1707: okay, will get on it tomorrow. thanks!
[20:08:38 CET] <michaelni> atana, ok, next you need to apply the window on the data before the FFT
[20:10:20 CET] <michaelni> atana, that is the samples are multiplied by the values from the window befor the fft
[20:15:35 CET] <nightlingo> durandal_1707: or, avi, right?
[20:16:11 CET] <durandal_1707> maybe
[20:18:59 CET] <nightlingo> durandal_1707: thank you, I will try it
[20:37:15 CET] <nightlingo> durandal_1707: unfortunately neither .mkv nor .avi files produced using stdout are playable by Windows Media Player 7
[20:38:48 CET] <nightlingo> Im wondering, maybe there is a way to simply copy the portion of the mp4 Im interested in and then re-calculate the MOOV atom and attach it to the end of the new file?
[20:47:50 CET] <BtbN> use mpeg-ts if you want to freely cut and copy without the need to seek
[20:50:00 CET] <nightlingo> BtbN: this is a .mts file suffix?
[20:53:13 CET] <nightlingo> BtbN: ffmpeg says: Requested output format 'mts' is not a suitable output format
[20:53:14 CET] <nightlingo> pipe:1: Invalid argument
[20:53:30 CET] <kierank> ts
[20:53:32 CET] <kierank> or m2ts
[20:58:41 CET] <nightlingo> I tried both , it says that they are not a suitable format
[20:58:43 CET] <nightlingo> I run it as:
[20:58:53 CET] <nightlingo> ffmpeg -ss 00:00:10 -t 00:00:20 -i inputfile.mp4 -f m2ts pipe:1 >  out.mp4
[20:59:56 CET] <unholy_me> hello devs!
[20:59:58 CET] <kierank> mpegts
[21:00:26 CET] <unholy_me> something I want to clear about decoders
[21:01:10 CET] <unholy_me> Is a square decoder a type of Regular Polygon decoders?
[21:02:07 CET] <durandal_1707> unholy_me: yes
[21:02:35 CET] <durandal_1707> its mentioned in wikipedia entry
[21:02:53 CET] <unholy_me> Ya I just saw that
[21:03:24 CET] <unholy_me> However the formula given is for 3 channels only
[21:03:53 CET] <unholy_me> How do I calculate for 4 channels (ambisonic sound)
[21:03:58 CET] <durandal_1707> unholy_me: because z is not used
[21:04:21 CET] <durandal_1707> unholy_me: formula is in wikipedia
[21:04:33 CET] <durandal_1707> you just need to copy it
[21:05:44 CET] <unholy_me> okay....
[21:05:52 CET] <BtbN> building with -j16 is fun
[21:06:01 CET] <unholy_me> Why is z not used.. if I may?
[21:06:41 CET] <nightlingo> kierank: thanks, its working now!
[21:06:42 CET] <durandal_1707> unholy_me: because all speakers are on same plane
[21:07:22 CET] <unholy_me> Okay! z is the height constraint...ok
[21:07:25 CET] <nightlingo> Do you think its safe to save the mpegts file with a .mp4 suffix? it seems to be playing on VLC and Windows Media Player, but maybe there would be any other implications Im not aware of?
[21:08:34 CET] <unholy_me> In Ambisonic Sound: " It covers sound sources above and below the listener "
[21:08:53 CET] <unholy_me> Why is it given like this
[21:08:54 CET] <unholy_me> ?
[21:10:14 CET] <unholy_me> Sorry, I found the right material, ignore the questions
[21:28:42 CET] <paras2052> durandal_1707: hi, thank you for reviewing the code. Is there any documentation of the new API that shows the changes made to the old API. Currently i am looking at the definitions of structs to see which functions and variables have been removed.
[21:30:28 CET] <durandal_1707> there was no docs just flag that its deprecated
[21:30:44 CET] <durandal_1707> just remove commented code out
[21:30:59 CET] <durandal_1707> and make sure it decodes files
[21:31:12 CET] <paras2052> okay, yes doing that
[21:41:34 CET] <wm4> read doc/APIchanges to see what changed
[21:42:46 CET] <paras2052> wm4: okay, thanks. let me see
[22:33:34 CET] <madguy02_> hii,i wanted to know how to start contributing towards ffmpeg and learn more about developing on it
[00:00:00 CET] --- Sun Mar  5 2017