December 2009 - ffmpeg-user - lists.ffmpeg.org

Flip in sws_scale
by romulo.fernandes＠gmail.com 11 Mar '16

11 Mar '16

Hello, I'm using libswscale to scale and convert pixel format from frames that I capture from the screen. In my windows build the frames that I capture are in DIB format. I'm using FFMPEG SVN rev 16437. Calling sws_scale normally I get the image correctly, except that it's vertically flipped. If I change the srcSliceY from 0 to srcHeight and srcSliceH from srcHeight to 0, I get a grey image (with correct dimensions). If I keep the srcSliceY in 0 and change srcSliceH from srcHeight to -srcHeight, I also get that grey image. Is there a way to make sws_scale flip the image for me ?

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Howto compile ffplay.c in seperate directory with my own svn-version of ffmpeg
by tps＠netmaster.dk 23 Feb '16

23 Feb '16

Dear All I have compiled svn-version of ffmpeg. I only do configure and make. I do not do make install because I don't want this svn-version of ffmpeg to overwrite the 'official' Ubuntu version of ffpeg that is also on the host. Now I want to compile my own version of ffplay.c so I create a directory ffplay at the same level as the svn ffmpeg-directory. I copy ffplay.c from ffmpeg to ffplay. Now what gcc options should I use to compile ffplay.c? I tried with this but got tons of errors: gcc -o ffplay ffplay.c -I../ffmpeg -L../ffmpeg/libavcodec -L../ffmpeg/libavformt -L../ffmpeg/libswscale -L../ffmpeg/libavutil -lavcodec -lavformat -lswscale -lavutil -lmp3lame -lx264 `sdl-config --cflags --libs` I note that when I do the make in the svn ffmpeg-directory there are a lot of options on the gcc command. I hardly know any of the options. Thanks in advance

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axis mpeg4 stream w/ aac audio
by danielp＠choma.hu 30 May '14

30 May '14

Hello, i've an Axis 247s video server which provides mpeg4 stream w/ aac audio, and i would like to get an flv stream from this. i've compiled ffmpeg/ffserver with --enable-libmp3lame --enable- shared --enable-libamr-nb --enable-nonfree --enable-gpl --enable- libfaad --enable-libfaac i can get the stream work with ffserver without audio, but not with audio. my ffserver.conf: Port 8090 BindAddress 0.0.0.0 MaxClients 1000 MaxBandwidth 1000 CustomLog - NoDaemon <Feed feed1.ffm> File /tmp/feed1.ffm FileMaxSize 1G ACL allow 127.0.0.1 </Feed> <Stream test.flv> # the source feed Feed feed1.ffm # the output stream format - FLV = FLash Video Format flv VideoCodec flv # this must match the ffmpeg -r argument VideoFrameRate 25 # generally leave this is a large number VideoBufferSize 80000 # another quality tweak VideoBitRate 500 # quality ranges - 1-31 (1 = best, 31 = worst) VideoQMin 1 VideoQMax 5 VideoSize 640x480 # this sets how many seconds in past to start PreRoll 0 AudioBitRate 64 AudioChannels 1 AudioSampleRate 44100 AudioCodec mp3 </Stream> i've tried several things like: openRTSP -b 80000 -y -c -4 -f 25 -w 640 -h 480 -t rtsp://xxx.hu:554/mpeg4/1/media.amp | \ ffmpeg -v 9 -vcodec mpeg4 -acodec mpeg4aac -ab 32k -i - -acodec libmp3lame -ar 44100 -ab 64k -ac 1 -vcodec mpeg4 http://localhost:8090/ or: mencoder \ -rtsp-stream-over-tcp rtsp://xxx.hu:554/mpeg4/1/media.amp \ -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=500:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 \ -oac mp3lame -lameopts abr:br=64:q=1:mode=3 \ -o - | \ ffmpeg \ -ab 32 -acodec mp3 -ar 44100 -ac 1 -f mpeg -r 25 -i - \ -r 25 -ab 32 -acodec mp3 -ar 44100 -ac 1 http://localhost:8090/ and tons of switches, but nothing worked. can you please help me somehow? thx, -- dp

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Extracting MXF Metadata
by hsomob1999＠yahoo.com 02 Sep '13

02 Sep '13

Hello, Is it possible to retrieve MXF metadata with ffmpeg? Is there way to extract metadata from any format? I see that there is a -metadata flag but this only allows one to set metadata. Thanks

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iMovie created variable frame rates cause a/v sync problems
by jdrukman＠gmail.com 22 Jul '13

22 Jul '13

I have a file generated from Apple's "iMovie HD". It has a variable frame rate, according to mediainfo: Frame rate mode : Variable Frame rate : 29.402 fps Minimum frame rate : 0.303 fps Maximum frame rate : 29.970 fps Original frame rate : 29.970 fps I am trying to get ffmpeg to create a transcoded version suitable for web & iphone streaming, but the audio & video are out of sync. I used ffmpeg -i original.m4v -acodec copy -vcodec libx264 output.mp4 I also tried with -acodec libfaac. Same result. Oddly enough, mediainfo on the ffmpeg converted file shows the same frame rate information, but the soundtrack is clearly not in sync: Frame rate mode : Variable Frame rate : 29.402 fps Minimum frame rate : 0.303 fps Maximum frame rate : 29.970 fps Original frame rate : 29.970 fps Is there some simple command line option that I'm missing to keep the two in sync? I can provide the original file if needed. The current version of iMovie does not have the same problem because it outputs at constant frame rate by default. -jsd-

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Frame rate and movies from images
by josh＠uncommonprojects.com 22 Jul '13

22 Jul '13

I am using ffmpeg to create movies from a directory of images. This is the command I use: ffmpeg -i imagedir/%05d.jpg -b 1800 video.mp4 This works great except that I want to be able to slow down the playback to say 6 frames per second. I tried this: ffmpeg -i imagedir/%05d.jpg -r 6 -b 1800 video.mp4 Which does playback at 6 frames per second, but what seems to be happening is that ffmpeg is also skipping frames. So if I have say 506 images in the images directory, the resulting movie uses only 123 frames. I can see where this something you might want, if you don't want the duration of the output movie to change with different frame rates, but is there a way to force it to use all the frames and extend the duration? I tried using the -vframes flag but it didn't seem to do anything: ffmpeg -i imagedir/%05d.jpg -r 6 -vframes 506 -b 1800 video.mp4 thanks, josh

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change frame rate
by info＠danielerossi.net 22 Jul '13

22 Jul '13

> I would like to convert my video source, in lenght 07 min 40 sec frame rate 30 per second to a frame rate of 60 per second without adding new frames, that means the duration will be the half. I did try ffmpeg -r 30 -i input_mjpg.avi -r 60 -vcodec copy -an test.avi and does not change the frame rate. Can anybody suggest me the correct command line? thank you D

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convert a sequence of images to a video file
by joshjdevl＠gmail.com 04 Oct '12

04 Oct '12

Hi, I would like to convert a series of images (png files) to a video. Would something like this work? ffmpeg -r 29.97 -i /images/picture%.png out.avi When I try the above, I get picture%d.jpg: I/O error occurred Usually that means that input file is truncated and/or corrupted. Thanks, Josh

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compil ffmpeg with alsa support
by khenyh＠gmail.com 26 Aug '12

26 Aug '12

Hi, I need your help to configure ffmpeg so as to use alsa. I have downloaded version 0.5 of ffmpeg. But I can't find how to enable alsa. I have tried "configure --enable-muxer=alsa --enable-demuxer=alsa". Then I looked at config.h and I can see "#define ENABLE_ALSA_MUXER 0", "#define ENABLE_ALSA_MUXER 0". Is there something I have missed ? Nicolas Krieger

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named pipes - > x264
by joshjdevl＠gmail.com 29 May '12

29 May '12

Hi, I was following these instructions to do a named pipe to x264 http://ffmpeg.x264.googlepages.com/piping mkfifo fifo.y4m ffmpeg -i test.mp4 -an -f yuv4mpegpipe - > fifo.y4m & x264 --quiet --crf 18 -o video.264 fifo.y4m For some reason, ffmpeg just sits here Stream mapping: Stream #0.1 -> #0.0 Press [q] to stop encoding It doesn't do any processing of test.mp4 and basically sits as a blank console. If I do something like ffmpeg -i test.mp4 -an -f yuv4mpegpipe - > test.y4m & Where test.y4m is not a named pipe, then test.y4m will end up being the yuv4 data... So I guess my question is, is there some extra option I need to compile ffmpeg or x264 with? Or is there another option I need to pass in? I tested this on Ubuntu 8.04 and centos 5.2 Thanks, Josh

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