[Ffmpeg-devel-irc] ffmpeg.log.20190808

[burek]

[01:40:19 CEST] <goel> Hi I am not sure if this is possible or not but I am currently fiddling around with AVPackets in libavcodec. Is it possible to re-order or insert AVPackets from a video file?
[01:41:04 CEST] <goel> Say I wanted to insert an AVPacket into the middle of a video file, is this actually possible or would I have to expose some internal function?
[01:42:13 CEST] <goel> Maybe I am asking in the wrong way, I am guessing I need to decode the frames and then re-order? Is that possible?
[05:05:07 CEST] <Henry151> https://termbin.com/bzjb
[05:12:14 CEST] <relaxed> Henry151: what's the problem?
[05:23:11 CEST] <Henry151> hi relaxed , no problems :) just wanted to run it by you first, mostly to see if i put the -c:a copy -movflags +faststart in the right place
[05:23:46 CEST] <Henry151> https://termbin.com/y68b
[05:23:54 CEST] <Henry151> this is where i imagine they go
[05:24:06 CEST] <another> nope
[05:24:32 CEST] <another> those are supposed to be output options
[05:24:48 CEST] <another> the need to go after the input and before the output
[05:25:58 CEST] <Henry151> https://termbin.com/6ujm how's this look?
[05:27:32 CEST] <another> better
[05:29:15 CEST] <Henry151> anything else i should change on this for turning a bunch of .mkv of varying sizes into mp4 with the subtitles burnt in? I want to get this right because i'm going unleash it on a fairly large selection of videos
[05:36:18 CEST] <another> i see nothing wrong there
[05:37:12 CEST] <another> altough if your audio is dts or ac3 it might get problematic to play those files in the browser
[05:37:49 CEST] <Henry151> i see... so perhaps i could leave out the -c:a and let it re-encode the audio for each of them
[05:40:13 CEST] <another> e.g.
[05:40:32 CEST] <another> also, you should probably take a look at this https://trac.ffmpeg.org/wiki/Encode/H.264
[05:46:55 CEST] <Henry151> another: so, if I want to set something like, say, set the preset to "slower", where do i put that option? between input and output again?
[05:50:15 CEST] <Henry151> ah i'm reading more now sorry for dumb question.
[12:21:47 CEST] <DHE> Henry151: yeah, ffmpeg syntax is:   ffmpeg [input1 options] -i input1 [[input2 options] -i input2]...   [output1 options] output1 [[output2 options] output2]...
[12:22:23 CEST] <DHE> and some global options like -filter_complex can go anywhere, but usually put between the last input and first output for style reasons
[16:56:35 CEST] <goel> Hello, does 1 AVPacket from av_read_frame() only contain 1 AVFrame?
[16:56:55 CEST] <JEEB> not necessarily
[16:57:12 CEST] <JEEB> https://www.ffmpeg.org/doxygen/trunk/group__lavc__encdec.html
[16:57:17 CEST] <JEEB> recommended reading from the docs
[16:58:24 CEST] <goel> Ok thank you
[16:59:33 CEST] <goel> I am trying to read packets from an mp4 file and write them into another mp4 file. I do not want to call avcodec_decode_video2() and decode each frame. I just want to write the packet.
[16:59:56 CEST] <goel> I tried calling avio_write with the packet data but it is incorrect? I have called av_write_header and av_write_trailer afterwards.
[17:07:53 CEST] <DHE> goel: you want the badly named av_write_frame (or the interlaced version if you have multiple streams that aren't synced properly)
[17:08:42 CEST] <DHE> avio_write is a raw file IO function, allowing you to do things like treat an HTTP URL or a local file name identically for IO purposes for example
[17:30:59 CEST] <goel> DHE I have av_write_frame within a loop which reads the frames from the format context: e.g.
[17:31:23 CEST] <goel> while (av_read_frame(fileFormatContext, &packet) >= 0)
[17:31:43 CEST] <goel> av_write_frame(outputFileContext, &packet);
[17:32:06 CEST] <goel> It ends up only writing the header/trailer of the file.
[17:32:16 CEST] <goel> The content of the packet does not seem to be written.
[17:33:05 CEST] <DHE> might want to check the return code of av_write_frame then. lacking details I'd guess that you didn't set up the streams in the output file properly before writing the header?
[17:35:20 CEST] <zerodefect> I have an MXF file where MediaInfo reports a timecode (the same timcode) for both the source and material packages of the file. Now when I do "ffprobe -i TTY9001051.mxf -print_format json -show_streams -show_format" and examine the json output, I can see the same timecode as a tag in the 'format' section. Using the C-API, is it possible to get to the Tc while demuxing MXF? Presumably,
[17:35:20 CEST] <zerodefect> 'AV_FRAME_DATA_GOP_TIMECODE' would give me the Tc from the video essence?
[17:38:15 CEST] <goel> DHE I just tried it and the return code was 0 indicating it was a success but the output file does not open.
[17:40:35 CEST] <goel> I have created a new video stream by using avformat_new_stream
[17:44:03 CEST] <goel> I am wondering why the video does not play. I have only 1 packet inside that video and it is a single frame.
[17:44:14 CEST] <goel> The file size seems correct but it does not want to play.
[22:37:49 CEST] <ChrisJW> Does anyone understand the licensing for H265/HEVC?
[22:38:04 CEST] <ChrisJW> My best understanding is that it is free to decode up to 100k devices
[22:38:21 CEST] <ChrisJW> Any idea on how wrong I am?
[22:46:53 CEST] <jkqxz> In answer to your first question, no.  There are multiple different patent groups, and you may need separate licences from each one.
[23:08:01 CEST] <pzy> technical answer: lol licensing
[23:08:51 CEST] <vejetaryenvampir> What's the quivalent of `-f pulse -ac 2 -i "$(pactl list sinks | awk '/Monitor Source:/{print $3}')"` in alsa?
[23:09:03 CEST] <vejetaryenvampir> equivalent*
[23:09:16 CEST] <vejetaryenvampir> I can't find it.
[23:09:30 CEST] <vejetaryenvampir> -f alsa -i hw:0 doesn't work.
[00:00:00 CEST] --- Fri Aug  9 2019