June 2015 - ffmpeg-user - lists.ffmpeg.org

Is it possible to speed up merging-speed from HD to LAN?
by Christoph Gerstbauer 09 Jul '15

09 Jul '15

Hello I am working with ffmpeg over LAN. I want to MERGE 2 files. 1 AVI with huffyuv and 1 WAV with pcm_s24le to one file (AVI) with a video and a audio stream. If I do this from HardDisk to LANshare it takes more time than a simple filecopy of both files to the same target. 1GBIT LAN: Filecopy: 80 percent LAN speed Merging: 25 percent LAN speed https://cerebrum.noa-audio.com/noacloud/public.php?service=files&t=7b6808d2… On the left side you can see the filecopy- and on the right side the merging-lanload. Is it possible to speed the merging up in any way? Does the ffmpeg merger has an internal bottleneck (?) command line: ffmpeg -i inputfile.avi -i inputfile.wav -acodec copy -vcodec copy -map 0:0 -map 1:0 \\lanshare\folder\targetfile.avi Best Regards Christoph

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Re: [FFmpeg-user] How to make partially transparent png image
by compname＠verizon.net 06 Jul '15

06 Jul '15

At 6/28/2015 02:09 AM, you wrote: > > Since ffmpeg is a video processing tool, even if it could I wouldn't >recommend it. I used another free tool: IrfanView. I believe you can load >an image into it & tell it to make a certain color/range of colors >transparent. > >IrfanView is not free Well, OK for commercial use it's not free. But just about any business (that's planning on staying in business anyway) isn't going to quibble over the $12 reg. fee. And for us individuals/educators/etc. it is free. > and ffmpeg have already tools to make certain >color/range of colors transparent. I've recently used the geq filter to do just that. But I never considered FFmpeg to be a (still) image editor/converter, even though it does work nicely as such (-i in.bmp -vf [image filters] -c:v png out.png).

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Silence Removal
by sk8f 06 Jul '15

06 Jul '15

I have an audio file which has the following specifications. Codec: MPEG AAC Audio (mp4a) Channels: Stereo Sample rate: 44100 Hz Bitrate: 253 kbps It has both leading and trailing silence. I want to remove the silences AND keep the quality intact. So far I've tried ffmpeg -i 1.m4a -af silenceremove=1:0.5:0:1:0.5:0 2.m4a This is supposed to remove both the leading and trailing silences. But for some reason it doesn't remove the trailing silence. There is a similar thread on this mailing list that has the same problem. Also, it reduces the bitrate to 128kbps. This I could fix by adding the -ab 253k and making the command: ffmpeg -i 1.m4a -af silenceremove=1:0.5:0:1:0.5:0 *-ab 253k* 3.m4a Now the problem is that the trailing silence isn't removed and when I want to process a batch of files I can't use the same bitrate (like 253kbps ) for every file. Any help will be appreciated. Thanks. -- View this message in context: http://ffmpeg-users.933282.n4.nabble.com/Silence-Removal-tp4671207.html Sent from the FFmpeg-users mailing list archive at Nabble.com.

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Is possible to capture a frame and convert a video file in the same ffmpeg command?
by Dani A 06 Jul '15

06 Jul '15

Is it possible to use one ffmpeg command to capture a frame and convert a video file to another format?

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Need more detailed description of the behaviour of the "-ac <channelcount>" option
by Christoph Gerstbauer 03 Jul '15

03 Jul '15

Hello I need to know how -ac <channelcount> is exactly working. In the documenetation following is mentioned: -ac[:stream_specifier]channels(/input/output,per-stream/) "Set the number of audio channels. For output streams it is set by default to the number of input audio channels. For input streams this option only makes sense for audio grabbing devices and raw demuxers and is mapped to the corresponding demuxer options." But there is nothing descriped for these usecases: Inputfile has 2 channels (1stream) -> outputfile setting -ac 8 (8channels, 1 stream) Inputfile has 8 channels (1stream) -> outputfile setting -ac 2 (2channels, 1 stream) I tested a Stereo file to encode into IMX50 with 16bit audio an 8ch. The stereo pair was correctly placed at ch1 and ch2. The other 6 channels were silent (correct). Is this behaviour standard for -ac ? Or is there any mixing made in some cases? (8ch -> 2ch?) I just want to prevent surprises when using -ac ;) So is -ac just + cutting of or + adding silent channels? Best Regards Christoph Gertsbauer

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Converting .mov files playable on html5 players..but very slow
by Dani A 01 Jul '15

01 Jul '15

I am using the below command to covert the .mov files to play html5, but it takes so much time..Is there another way to convert those files so they can play on html5 players but fast to convert... ffmpeg -i input.MOV -vf scale=720x406,setdar=16:9 -c:v libx264 -profile:v main -crf 20 -movflags faststart output.MOV Is there a faster codec to use compared to the libx264?

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ffplay at half size by means of a math function
by Jim Shupert, Jr. 01 Jul '15

01 Jul '15

Friends, I wish to be able to play a file with ffplay but have it play at 1/2 the real size with -x NUM -y NUM I can control play size with ffplay -x 640 -y 360 -i dog.avi this works as hoped but what I would really like to do is do some math on the file and scale it down with something like ffplay -vf=scale=iw/2:ih/2 -i /media/data/zzz-s/NASA_logo.mov my Goal is to have a means of scaling down 1080p to a size that fits nicely on my vga ffplay -vf=scale=iw/2:ih/2 -i /media/data/zzz-s/NASA_logo.mov ffplay version git-2013-10-16-586b8ea Copyright (c) 2003-2013 the FFmpeg developers built on Oct 16 2013 13:38:00 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration: --prefix=/home/j/ffmpeg_build --extra-cflags=-I/home/j/ffmpeg_build/include --extra-ldflags=-L/home/j/ffmpeg_build/lib --bindir=/home/j/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-libx264 --enable-nonfree --enable-x11grab libavutil 52. 46.101 / 52. 46.101 libavcodec 55. 37.100 / 55. 37.100 libavformat 55. 19.102 / 55. 19.102 libavdevice 55. 4.100 / 55. 4.100 libavfilter 3. 88.101 / 3. 88.101 libswscale 2. 5.101 / 2. 5.101 libswresample 0. 17.103 / 0. 17.103 libpostproc 52. 3.100 / 52. 3.100 Failed to set value '-i' for option 'vf=scale=iw/2:ih/2': Option not found with video_size ffplay -video_size 320x240-i /media/data/zzz-s/NASA_logo.mov ffplay version git-2013-10-16-586b8ea Copyright (c) 2003-2013 the FFmpeg developers built on Oct 16 2013 13:38:00 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration: --prefix=/home/j/ffmpeg_build --extra-cflags=-I/home/j/ffmpeg_build/include --extra-ldflags=-L/home/j/ffmpeg_build/lib --bindir=/home/j/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-libx264 --enable-nonfree --enable-x11grab libavutil 52. 46.101 / 52. 46.101 libavcodec 55. 37.100 / 55. 37.100 libavformat 55. 19.102 / 55. 19.102 libavdevice 55. 4.100 / 55. 4.100 libavfilter 3. 88.101 / 3. 88.101 libswscale 2. 5.101 / 2. 5.101 libswresample 0. 17.103 / 0. 17.103 libpostproc 52. 3.100 / 52. 3.100 Option video_size not found.aq= 0KB vq= 0KB sq= 0B f=0/0 Thanks jim S

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How to output video with only specific Y/U/V bit planes
by Kieran O'Leary 30 Jun '15

30 Jun '15

Hello, I have been playing around with the bit plane filter in QCTools. More info here: http://htmlpreview.github.io/?https://github.com/bavc/qctools/blob/master/S… >From what I understand, QCtools is using ffmpeg to generate all these filters. Is it possible to harness this bit plane filter via ffmpeg.exe and export a video with it? For example, enable bit 1 of Y, bit 4 of U, bit 5 of V? Is there another way of doing this? I've tried to find information on this but I've been coming up short. Best regards, Kieran. ------ This email has been scanned for spam and malware by The Email Laundry.

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what does "is_slowmedia" filed in AVIOContext mean
by 我是科学家 30 Jun '15

30 Jun '15

what does "is_slowmedia" filed in AVIOContext mean? Does it mean local file?

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HAP encoding?
by Jesper Taxbøl 30 Jun '15

30 Jun '15

Hi Guys, I need to HAP Q encode my videos, to be able to use video in an realtime video application. >From what I can read HAP is not supported in FFmpeg yet and the only client I have found that can do it is relying on GUI which breaks my workflow. http://vdmx.vidvox.net/tutorials/using-the-hap-video-codec I would therefore ask if anyone is aware if there is an ffmpeg initiative in that direction? I dont feel confident to be able to do that myself, but I would like to support it if I can. Kind regards Jesper

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