December 2017 - ffmpeg-user - lists.ffmpeg.org

compile ffmpeg for software OpenMeetings
by Андрей Прицепов 15 Dec '17

15 Dec '17

Greetings. I use this instruction http://www.thingsiuse.org/2014/06/building-ffmpeg-for-h264-and-aac.html to compile ffmpeg. The instruction is old so I need new. How can I compile current ffmpeg 3.4.1 for OpenMeetings? I talked with OpenMeetings developers they told that problem to view video in OpenMeetings because of ffmpeg. How can I compile ffmpeg 3.4.1, when I use those instruction? I have problem when I do this command: CPPFLAGS="$CPPFLAGS -I/usr/local/x86_64-w64-mingw32/include" ./configure --extra-ldflags='-L/usr/local/x86_64-w64-mingw32/lib' --prefix=/usr/local/x86_64-w64-mingw32 --cross-prefix=x86_64-w64-mingw32- --target-os=mingw32 --enable-w32threads --enable-memalign-hack --arch=x86_64 --enable-runtime-cpudetect --disable-debug --enable-static --disable-shared --disable-ffplay --disable-ffserver --enable-gpl --enable-version3 --enable-nonfree --enable-libmp3lame --enable-libfdk-aac --enable-libx264 I have error on this step: Unknown option "--enable-memalign-hack". See ./configure --help for available options. Do you have advice for me what version of ffmpeg I can use for OpenMeetings? ------------------- С уважением, Андрей Прицепов "Лаборатория Форт Крым"

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Need a little clarification
by JD 14 Dec '17

14 Dec '17

I ran ffprobe on a file to see what the audio bitrate was. The line showing audio info says: Stream #0:1: Audio: vorbis, 44100 Hz, stereo, fltp (default) So, what is the 'ab' rate? Thanx!

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Exporting FFV1 from Premiere Pro
by Dima Ballin 14 Dec '17

14 Dec '17

Greetings all, I am new to ffmpeg. I've read about how to export H.264 files from Premiere Pro via ffmpeg, but I was wondering if it's also possible to export a movie as FFV1? Basically, I am trying to create an archival master file for a 2-hour movie which is currently in our Premiere Pro timeline. From what I gather, I can export an uncompressed intermediary file and then encode the FFV1 from that, but I was wondering if it's possible to skip the intermediary step? If this is not possible, what would be the best intermediary uncompressed file format to export to, for encoding an FFV1? We are working in Windows. Thanks so much. D

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remove all I Frames from a video
by KE 14 Dec '17

14 Dec '17

hey i would love to cut out all the i frames from a video. and most importantly have NO new i frames added to the output file. i know this will break the video. but thats exactly what i want. what i tried so far: ffmpeg -y -i input.mp4 -filter:v "select='not(eq(pict_type\,PICT_TYPE_I))'" -v:c output.mp4 ffmpeg -y -i input.mp4 -filter:v "select='not(eq(pict_type\,PICT_TYPE_I))'" -keyint_min 999999 output.mp4 but somehow i still get i frames in the output video :( i suspect its because ffmpeg is too smart and adds them right back in after removing them because it thinks i want them. is there an option to get the raw video before i frames are added again? or maybe a different approach to get a video without i frames? cheers

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Error running ./configure
by Lucas Coehlo 13 Dec '17

13 Dec '17

Hello I'm unable to configure FFMPEG I did copy gas-preprocessor.pl to my PATH. Not sure if that is enough. Thanks for your help

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Trying to get he example prorgam decode_encode.c to run
by Peadar Ó'Colmáin 13 Dec '17

13 Dec '17

Hello all, I am looking at the demonstration code decode_encode.c which I received with ffMpeg when I downloaded it. I want to get this code to run as it is before doing anything else with it. I have the part that uses avcodec_encode_audio2 to encode into mp2 format. This program opens just one file, the one it writes to so I am taking it that I am supposed to give it its source sound. I am using Windows and Visual C++. I recorded my voice with Audacity and saved it as a WAV file. Then I opened that WAV file with a fopen command and I put the following 'fread' line into the example program. av_init_packet(&pkt); pkt.data = NULL; // packet data will be allocated by the encoder pkt.size = 0; BytesRead = fread(samples, 1, buffer_size, InFilePtr); // from my WAV file for (j = 0; j < c->frame_size; j++) { samples[2*j] = (int)(sin(t) * 10000); for (k = 1; k < c->channels; k++) samples[2*j + k] = samples[2*j]; t += tincr; } It runs and writes to the file ok but the output file in MP2 format just makes a whirring noise. Has anyone managed to get his program to run and to process a source file into MP2?. Am I misunderstanding something? Is WAV the correct format to start with? Any help much appreciated Peadar --- This email has been checked for viruses by AVG. http://www.avg.com

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Proxying ffserver behind nginx?
by Alec Taylor 12 Dec '17

12 Dec '17

What's the trick to proxying ffserver behind nginx? My attempt: location /stream0 { proxy_pass http://localhost:8086; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; } Currently I'm just serving some webm feeds from different cameras. This is the ffserver conf I am using: https://www.acmesystems.it/ffmpeg PS: I've compiled nginx-rtmp-module in, but I think that ffserver would be more reliable + feature rich, so would prefer that. Thanks for all suggestions

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Problematic Hikvision video file for conversion ffmpeg
by George Andguladze 12 Dec '17

12 Dec '17

Greetings to all, I have a video file acquired from Hikvision's NVR connected to IP cameras. The method used to download this video was Hikvision NVR's internal API that produced a flawed video file in several ways: 1. Duration of the video file is wrong (as seen in Mediainfo or VLC). My guess is this happens due to NVR storing video files in chunks and when attempting to download video by supplying specific start time and end time to NVR's API the software just creates a new video file in memory by extracting the needed parts from stored video and attaching the original video file's duration to the newly created one. 2. Audio cannot be played in most media players including VLC. I have tried converting the video file using ffmpeg with different settings to try and fix these issues but the output video still has the same problems. What's interesting is that ffmpeg's ffplay is able to play the video file perfectly with sound and no disruptions. Therefore I figured there must be a way to convert the video file to normalize it for other players as well. Mediainfo output of the video file in question: https://pastebin.com/zNTpPi79 Output of ffmpeg: https://pastebin.com/vAZZV9CT Video file itself: https://www.dropbox.com/s/9ccptsuiqk2ntsv/1.zip?dl=0 Any help is greatly appreciated, Regards, George A.

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Extraction of timebase/frame rate for timecodes of audio files
by Robert Krüger 12 Dec '17

12 Dec '17

Hi, is there a way to extract the information about the timebase of a timecode in an audio file, like you can find in the wild e.g. in MXF or in Mov files? I can see that ffmpeg apis and thus ffprobe expose the timecode as a string-valued tag (e.g. TAG:timecode=00:00:00:00) but the information what timebase the timecode uses, which IIRC is encoded in MXF or Mov is not exposed or am I missing something? When the file contains a video stream a workaround is to use the frame rate of the video stream to guess what the timebase of the timecode probably is but for audio files I fail to see a possibility to extract the correct timecode. Is this a limitation or am I in fact missing something? Thanks, Robert

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Recording video and audio together with options
by gomi odabaşıoğlu 12 Dec '17

12 Dec '17

Hello, I want to record video and audio on Windows. I am using this command now. "C:\Users\gomid_000\Desktop\ffmpeg.exe -f gdigrab -show_region 1 -framerate 60 -video_size cif -i desktop C:\Users\gomid_000\Desktop\out.mp4" Is gdigrab supporting h264 codec and audio recording ? (If that is what should I do ?) My issue is I want to record my video with h264 (I will use intel quick sync video or h264 cpu) codec at 60 fps and with 80 / 100 quality at mp4 format. Audio will be AAC codec - 192bitrate - srereo 48000hz. I will compare the result with bandicam program. I really want to achieve this but I do not know which way should I follow. Then, can I do this with gdigrab, then which one should I pick to record video and auido together in same file ? Can you help me ?

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