[Ffmpeg-devel-irc] ffmpeg.log.20181223

[burek]

[03:53:33 CET] <kode54> is there an easy way to probe whether an HEVC video is either 8 or 10 bit?
[03:59:08 CET] <kode54> ah, it says "Main" not "Main10"
[06:03:27 CET] <fengshaun> I have transcoded an mp4/h264/aac file with ffmpeg libav api, but the resulting video has fps of 12 (transcoded) instead of 24 (original video), I haven't changed any parameters between the decoding and encoding context
[06:04:03 CET] <fengshaun> except height, width, simple_aspect_ratio, time_base, and pix_fmt
[06:04:28 CET] <fengshaun> time_base = av_inv_q(decoding_context->framerate)
[06:04:54 CET] <fengshaun> what am I missing as far as fps is concerned?
[06:05:00 CET] <fengshaun> I'd like to keep the original fps
[06:06:55 CET] <fengshaun> as far as I understand, time_base is reciprocal of framerate, so in this case, the framerates of encoding_context and decoding_context (AVCodecContext *) should be the same
[06:23:56 CET] <fengshaun> hmm looks like I can just set the encoding and decoding AVCodecContexts' time_bases the same and the resulting transcoded file seems to play fine
[06:24:37 CET] <fengshaun> not sure if there is a reason to set the encoder's time_base to inverse of decoder's framerate instead of setting the encoder's time_base to that of decoder's time_base
[07:52:53 CET] <mixfix41> 5~
[12:14:43 CET] <Alina-malina> after using amix and adelay the sound become so so bad, bearly can hear it, is there a way to make sound volume up?
[12:16:49 CET] <durandal_1707> Alina-malina: full uncut console ffmpeg output missing
[12:17:20 CET] <durandal_1707> you can use volume filter....
[12:17:28 CET] <Alina-malina> ok just a moment let me show you
[12:18:16 CET] <Alina-malina> durandal_1707, https://pastebin.com/raw/vASLuVyP  i know i should add the volume parameter, but i am not sure where
[12:20:39 CET] <durandal_1707> Alina-malina: what are you attempting to do with so many adelay filters?
[12:21:01 CET] <Alina-malina> mixing specific sound to that times
[12:21:03 CET] <Alina-malina> why?
[12:21:28 CET] <Alina-malina> special effects
[12:21:29 CET] <Alina-malina> lol
[12:22:11 CET] <durandal_1707> wrong approach, amix will reduce volume even when there is silence in most of inputs
[12:22:49 CET] <Alina-malina> well thats from yesterday discussion
[12:23:00 CET] <Alina-malina> what is the right approach then?
[12:23:14 CET] <Alina-malina> i mean both mp3 files i can barely hear
[12:23:25 CET] <Alina-malina> not 1 but both are bad very bad
[12:23:48 CET] <durandal_1707> are you concating and fading or looping them or doing some special mixing?
[12:24:27 CET] <Alina-malina> well the kaching.mp3 file is a 1 second sound of money
[12:24:34 CET] <Alina-malina> the first mp3 file is a music background
[12:24:45 CET] <Alina-malina> so i am applying that sounds to my game
[12:24:53 CET] <Alina-malina> game is soundless
[12:25:01 CET] <Alina-malina> so i am adding sound effects to game
[12:25:30 CET] <Alina-malina> so game.mp4    sound background.mp3   and kaching.mp3 when get achievement
[12:25:37 CET] <durandal_1707> you better use some specific library inside game directly
[12:25:49 CET] <Alina-malina> well ye, that might work too
[12:25:54 CET] <Alina-malina> i can write that
[12:25:57 CET] <Alina-malina> but still
[12:26:01 CET] <Alina-malina> need this first
[12:26:09 CET] <durandal_1707> openal comes to mind
[12:27:55 CET] <Alina-malina> do i need to add volume=0.2 to after each adelay? or i can do that in the very end of that string?
[12:28:32 CET] <durandal_1707> volume=0.2 will make it even more silent
[12:29:31 CET] <durandal_1707> you can use volumedetect filter first to measure output volume
[12:30:10 CET] <durandal_1707> and after measuring replace volumedetect filter with volume filter to get final output
[12:30:59 CET] <Alina-malina> i am not sure where to apply that volume filter, i am getting error when i try to add it
[12:31:12 CET] <durandal_1707> at end
[12:31:45 CET] <durandal_1707> before [aout]
[12:32:09 CET] <durandal_1707> ... amix=inputs=51:duration=first:dropout_transition=32,volume=50[aout]"
[12:32:34 CET] <Alina-malina> ok let me try that
[12:33:17 CET] <Alina-malina> ye nice nice it works!!
[12:33:20 CET] <Alina-malina> finaly
[12:33:21 CET] <Alina-malina> lol
[12:33:26 CET] <Alina-malina> thanks durandal_1707  <3 <3 <3
[13:59:39 CET] <__gh0st> Hi, how can I get the pict_type of a frame(access unit) from h.264 bitstream using ffmpeg api? Currently I am using av_read_frame to read packets into AVPacket struct and I need to get the pict_type of the frame, without decoding it.
[14:00:26 CET] <__gh0st> Are there any facilities that ffmpeg api has to derive such information from AVPacket struct?
[14:01:51 CET] <__gh0st> Or I need to manually look for pict_type using some offset from AVPacket.pos to look for pict_type in the stream?
[14:06:28 CET] <__gh0st> There is a h.264 parse in ffmpeg, but I not entirely sure how to use it in my case.
[15:21:49 CET] <Alina-malina> durandal_1707, https://www.youtube.com/watch?v=AvtCyRshAdk&feature=youtu.be in case if you interested what i was making bro, anyways its beginner steps, dont expect pro video there lol
[18:20:50 CET] <oxek> this video plays horribly choppy https://send.firefox.com/download/42e7d21f5f/#J-JyN3vEvb6SVbj2yZKGxA
[18:27:23 CET] <poutine> good to know
[18:27:59 CET] <analogical> how do I use FFmpeg to trim a couple of seconds from a video file without re-encoding the video?
[18:29:19 CET] <poutine> analogical, ffmpeg -ss 00:00:03 -i file -c copy out.mp4, potentially -t for duration based on where you're trimming it from, timing will be inexact will only cut on i-frames afaik
[18:29:49 CET] <pink_mist> yeah, if you need more exact than i-frames, you need to re-encode I believe
[22:36:39 CET] <Bertl_oO> greetings! I'm currently trying to record an RTSP stream as MP4 or MKV container
[22:37:10 CET] <Bertl_oO> now the stream contains a data stream besides the video/audio streams and everything works fine if I drop the data with -dn
[22:37:50 CET] <Bertl_oO> the question is, can I somehow store the data stream in the MP4 or MKV container as well, and if so, how?
[23:07:03 CET] <kode54> looks like oxek's video is indeo 4.1
[23:07:13 CET] <kode54> good luck fixing that, ffmpeg
[23:07:40 CET] <kode54> it appears to be arranging the frames in the wrong order
[00:00:00 CET] --- Mon Dec 24 2018