August 2019 - ffmpeg-user - lists.ffmpeg.org

How to use global_sidx
by kumar vikram 20 Aug '19

20 Aug '19

Hi, I need to generate DASH segments with sidx box embedded in fragments. Is "global_sidx " in movenc is the one which we need to use in my commands? If yes please share a sample command? if no, please suggest a way ow i can add sidx box in my MP4 segments? Regards, Vikram

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OpenSSL overhead
by Simon Brown 19 Aug '19

19 Aug '19

Hi, further to my question the other day about getting FFMpeg built with openssl, I was wondering what the overhead is on generating an rtmps stream from a normal TS, rather than an rtmp stream. When I streamed to Facebook live using FFmpeg and an rtmps stream the live video had significant breakup on it, yet the ffmpeg output showed no warnings or errors about broken macro blocks or concealing errors, etc. My command line is: ffmpeg -re -i udp://@:65224 -codec copy -bsf:a aac_adtstoasc -f flv -fflags nobuffer rtmps://facebookliveurl This was running ffmpeg as compiled from the git head last week. The stream coming in on the udp port is a local stream - ie no network issues. Cheers, Simon

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Extracting opus frames from webm/mkv
by Dziku 19 Aug '19

19 Aug '19

Hello, I have webm files with only opus encoded audio track that I'm streaming through a voice chat that requires opus encoded packets as input. So far I've been using ffmpeg to convert the webms with opus audio to ogg containers and then use my own code to extract opus packets from ogg, which is obviously inefficient, because webms already contain the very same opus packets. I would like to extract opus encoded packets so that I can directly serve them to the voice chat. Is it possible to achieve with ffmpeg cli or any of its C libraries? Best regards, Adam Nowak

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h264_v4l2m2m encoder separate header mode usage
by JooAun Saw 19 Aug '19

19 Aug '19

Hi all, I'm trying to use the h264_v4l2m2m encoder. By following the "doc/examples/encode_video.c" example, I managed to send NV21 format images to it, and receive encoded packets from it. All good until here. The encoder sends out the stream header as a separate packet because "ffmpeg/libavcodec/v4l2_m2m_enc.c" hardcoded the header mode to HEADER_MODE_SEPARATE. I currently use av_write_frame function to write the received packet to my mp4 file, but ffprobe & other players complain of missing keyframe at timestamp 0. I think media players expect the first frame to be a keyframe. Question is, what is the correct way to write this header packet to my output mp4 file? Regards, jasaw

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FFprobe should not return a duration if the file is a JPEG picture
by August Johansson 18 Aug '19

18 Aug '19

Hi, I am a writing a software that scripts against the FFprobe binary. My software expects that FFprobe returns N/A as a duration for picture files and the duration if the file actually is video or audio file. However I have recently found that when FFprobe is on a JPEG picture file, it returns 00:00:00.04 as a duration. I consider this a bug and something that should be fixed. Thanks for reading

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ffplay, display subtitles
by Michael Castellon 17 Aug '19

17 Aug '19

Hello, my name is Michael Castellón. I'm writing from Managua, Nicaragua. I'm new in linux, and I'm interested to use your vast suite of libraries open source and ffplay for media player. Compile and run ffplay work very well, but it don't display the subtitles of the file mkv. It's possible display subtitles of an mkv in ffplay? Linux information Distro: Debian 10 kernel: 4.19.0-5-amd64 Libraries: libxv-dev/stable,now 2:1.0.11-1 amd64 [installed] -- X11 Video extension library (development headers) libsdl2-dev/stable,now 2.0.9+dfsg1-1 amd64 [installed] -- Simple DirectMedia Layer development files libvdpau-dev/stable,now 1.1.1-10 amd64 [installed] -- Video Decode and Presentation API for Unix (development files) libva-dev/stable,now 2.4.0-1 amd64 [installed] -- Video Acceleration (VA) API for Linux -- development files libfreetype6-dev/stablibvdpau-dev/stable,now 1.1.1-10 amd64 [installed] -- FreeType 2 font engine, development files Sorry for my english, is not very good. Thank you, very much. Michael. Regards.

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Book with examples
by Michael Koch 17 Aug '19

17 Aug '19

Hello all, this is not a question. During the last few years I've tested many things with FFmpeg, and now I've written it all in this document: http://www.astro-electronic.de/FFmpeg_Book.pdf It contains many examples for FFmpeg and a few other programs, also for audio processing, color grading and fulldome video production. Please feel free to use all examples as a starting point for your own projects. If you find errors, please let me know. This is a work in progress, so the chapter numbers will change when I add new chapters in future. For the FFmpeg programming experts, there is a chapter "FFmpeg: Suggestions for improvement". Michael

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ffmpeg capture on Android lags
by Channagiri Jagadish 16 Aug '19

16 Aug '19

We currently run video capture on Android Samsung S9 and few other Android devices, FFmpeg version 4.0.1, Javacversion 1.4.2, Android minSdkVersion 21, and compileSdkVersion 28. After 30 minutes or so, between the range 33 - 36 minutes, the audio lags video. I really do not understand why this happens. Any ideas or suggestions would be highly appreciated.

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Combining clipping and add an overlay
by Darrin Smith 16 Aug '19

16 Aug '19

I have a master video I wish to take a clip out of and on that clip place an overlay (mostly transparent png file). Does this need to be a two step process, first creating the clip, then reading it in and adding the overlay, or can it be combined into one step to save time? To create the clip I have successfully used this command (in Kotlin): val cmd = "-ss $start -t $duration -accurate_seek -i $inputFile -codec copy -avoid_negative_ts 1 $outputFile" val command = cmd.split(" ".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray() FFmpeg.getInstance(context).execute(command, object : ExecuteBinaryResponseHandler() {...} For the overlay, I know I need to do something like this: val cmd2 = "-y -i $sourceMp4 -i overlayImage.png -filter_complex \"[1]format=bgra,colorchannelmixer=aa=1,rotate=0:c=black@0:ow=rotw(0):oh=roth(0)[overlayImage];[0][overlayImage]overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2\" $outputFileMp4" Can those two be commands be combined? Thanks.

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hstack a video with a delayed version of itself
by Michael Koch 14 Aug '19

14 Aug '19

Hello all, I want to hstack a video with a delayed version of itself. First test: ffmpeg -f lavfi -i testsrc2=size=600x400:duration=10 -y test1.mp4 This produces a video of 10 seconds length. The clock is running from 0 to 10, as expected. Second test: ffmpeg -f lavfi -i testsrc2=size=600x400:duration=10 -vf trim=start=4 -y test2.mp4 This produces a video of 6 seconds length. The clock is running from 4 to 10, as expected. Third test: ffmpeg -f lavfi -i testsrc2=size=600x400:duration=10 -filter_complex split[1][2];[2]trim=start=4,setpts=PTS-4[3];[1][3]hstack=shortest=1 -y test3.mp4 This produces a video of 6 seconds length. But both clocks are running synchronously from 4 to 10. I would have expected that one clock runs from 0 to 6 and the other from 4 to 10. The console output for the third test is copied below. Michael F:\Perseiden_2019>c://ffmpeg/ffmpeg -f lavfi -i testsrc2=size=600x400:duration=1 0 -filter_complex split[1][2];[2]trim=start=4,setpts=PTS-4[3];[1][3]hstack=short est=1 -y test3.mp4 ffmpeg version N-94455-g01994c93db Copyright (c) 2000-2019 the FFmpeg developers built with gcc 9.1.1 (GCC) 20190716 configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfi g --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libb luray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enab le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --e nable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable -libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 - -enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enab le-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --en able-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --en able-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --e nable-dxva2 --enable-avisynth --enable-libopenmpt libavutil 56. 33.100 / 56. 33.100 libavcodec 58. 55.100 / 58. 55.100 libavformat 58. 30.100 / 58. 30.100 libavdevice 58. 9.100 / 58. 9.100 libavfilter 7. 58.100 / 7. 58.100 libswscale 5. 6.100 / 5. 6.100 libswresample 3. 6.100 / 3. 6.100 libpostproc 55. 6.100 / 55. 6.100 Input #0, lavfi, from 'testsrc2=size=600x400:duration=10': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 600x400 [SAR 1:1 DAR 3:2], 25 tbr, 25 tbn, 25 tbc Stream mapping: Stream #0:0 (rawvideo) -> split hstack -> Stream #0:0 (libx264) Press [q] to stop, [?] for help [libx264 @ 000000000056afc0] using SAR=1/1 [libx264 @ 000000000056afc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2 [libx264 @ 000000000056afc0] profile High, level 3.1, 4:2:0, 8-bit [libx264 @ 000000000056afc0] 264 - core 158 r2984 3759fcb - H.264/MPEG-4 AVC cod ec - Copyleft 2003-2019 - http://www.videolan.org/x264.html - options: cabac=1 r ef=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed _ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pski p=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 deci mate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_ adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=2 5 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.6 0 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'test3.mp4': Metadata: encoder : Lavf58.30.100 Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1200x400 [S AR 1:1 DAR 3:1], q=-1--1, 25 fps, 12800 tbn, 25 tbc Metadata: encoder : Lavc58.55.100 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1 frame= 71 fps=0.0 q=28.0 size= 0kB time=00:00:04.56 bitrate= 0.1kbits/ frame= 136 fps=133 q=28.0 size= 512kB time=00:00:07.16 bitrate= 585.8kbits/ [Parsed_testsrc2_0 @ 00000000004f48c0] EOF timestamp not reliable frame= 150 fps=104 q=-1.0 Lsize= 1103kB time=00:00:09.72 bitrate= 930.0kbits /s speed=6.77x video:1101kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.232055% [libx264 @ 000000000056afc0] frame I:1 Avg QP:16.81 size: 20849 [libx264 @ 000000000056afc0] frame P:48 Avg QP:25.84 size: 10446 [libx264 @ 000000000056afc0] frame B:101 Avg QP:30.53 size: 5984 [libx264 @ 000000000056afc0] consecutive B-frames: 1.3% 21.3% 16.0% 61.3% [libx264 @ 000000000056afc0] mb I I16..4: 50.9% 33.1% 16.1% [libx264 @ 000000000056afc0] mb P I16..4: 2.0% 5.7% 2.0% P16..4: 9.9% 5.2 % 3.6% 0.0% 0.0% skip:71.6% [libx264 @ 000000000056afc0] mb B I16..4: 0.2% 0.2% 0.1% B16..8: 15.1% 3.9 % 1.3% direct: 2.0% skip:77.3% L0:48.8% L1:43.6% BI: 7.6% [libx264 @ 000000000056afc0] 8x8 transform intra:52.8% inter:34.4% [libx264 @ 000000000056afc0] coded y,uvDC,uvAC intra: 14.2% 27.5% 26.1% inter: 4 .5% 9.7% 8.7% [libx264 @ 000000000056afc0] i16 v,h,dc,p: 77% 21% 2% 0% [libx264 @ 000000000056afc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 8% 9% 82% 0% 0% 0% 0% 0% 1% [libx264 @ 000000000056afc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 33% 22% 37% 1% 1% 1% 1% 1% 3% [libx264 @ 000000000056afc0] i8c dc,h,v,p: 61% 16% 20% 3% [libx264 @ 000000000056afc0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 000000000056afc0] ref P L0: 47.2% 7.1% 26.8% 19.0% [libx264 @ 000000000056afc0] ref B L0: 77.1% 18.7% 4.2% [libx264 @ 000000000056afc0] ref B L1: 94.9% 5.1% [libx264 @ 000000000056afc0] kb/s:1502.18

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