December 2008 - ffmpeg-user - lists.ffmpeg.org

help: v4l2 grabbing and encoding
by bhattacharya.manas＠gmail.com 21 Dec '08

21 Dec '08

Hi, I am using Frontech USB Pc camera to grab video and encode to mepg4 .But my attempt failes as ffmpeg reports the following error and comes out. The v4l2 frames is 76800 bytes but 115200 bytes are expected. I am using the folllowing command line ./ffmpeg -s 320x240 -r 30 -f video4linux2 -i /dev/video0 -vcodec mpeg4 -f mp4 test.mp4 Please help me out any body Manas Bhattacharya

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ffmpeg-user Digest, Vol 45, Issue 41
by ben＠ekran.org 20 Dec '08

20 Dec '08

Thanks Victor, This one is for the list archives. First in imagemagick 6.3.7 the -type TrueColor flag does not appear to work. I ended up compiling (and lots of debugging) to get 6.4.7 to work, where -type TrueColor actually does convert the images to RGB. So here is how I managed to finally get my 640x480 jpegs (saved from PD using pix_write) into a nice colour DV file: First go into the directory containing the 640x480 frames, and then: mkdir ../frames-scaled for file in *.jpg; do /usr/local/bin/convert -type TrueColor -quality 100 -scale 720x480! $file ../frames-scaled/$file; done Then: cd ../frames-scaled ffmpeg -i frame%05d.jpg -i ../silence.wav -target ntsc-dv ../dream1.dv There you have it. Thanks for the suggestions, B. Bogart ffmpeg-user-request at mplayerhq.hu wrote: > Hey, if you hate gimp you still can use "convert" to add a border in > dark blue to your first JPG. > Or try "-recolor matrix". I don't know the syntax, but you may transform > your pure gray into sligthly off gray: > something like RGB(x,x,x) --> RGB(x-10,x,x+10) > > Regards, > V?ctor > > > > > ------------------------------ > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user at mplayerhq.hu > https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-user > > End of ffmpeg-user Digest, Vol 45, Issue 41 > ******************************************* >

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encode a sequence of jpegs to DV (NTSC)
by ben＠ekran.org 20 Dec '08

20 Dec '08

Hello all, I've been struggling with this issue on and off for sometime, finding various workarounds. I want to convert a sequence of jpeg files (720x480) to NTSC DV. I think I have things working except I only get greyscale output. Turns out the program that writes the jpegs is (smart?) enough to save images containing no colour in the grey colourspace. Since my sequence starts with black in grey space ffmpeg reads all jpegs as grey. If I encode the files starting at the middle of the sequence, boom, I get colour output. It took me far to long to get to this point! I've tried adding the pix_fmt flag to force a different colourspace, but that seems not to effect the colourspace in which the jpegs are read, only the output colourspace. Is there any way around this issue? Perhaps a flag for forcing a certain colourspace when reading a sequence of files that may have different colourspaces? I've messed with imagemagick to convert all files to RGB, but it does not agree: convert frame00000.jpg -type TrueColor test.jpg test.jpg is still in grey colourspace!!! Maybe another approach would be to do a scan of the colourspaces of the frames and choose the widest (most channels) colourspace present. Any workarounds welcome (though I would not be able to stand the option of using gimp to blot some dark blue in the first frame...) I guess I could copy a frame from the middle to the start and cut that out in editing, but that is getting pretty silly.) Thanks for your suggestions. B. Bogart

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mpeg2 SPTS
by juju＠nain-de-jardin.com 19 Dec '08

19 Dec '08

Hi, I have a mpeg2ts stream MPTS (Multiple Program Transport Stream) and I want to transcode it into an SPTS (Single) mpeg2ts file. I have founded nothing about it, can you help me please ? ffmpeg -i ip_stream_from_a_dreambox -sameq -f mpegts udp://test_ip:1234 FFmpeg version SVN-r16166, Copyright (c) 2000-2008 Fabrice Bellard, et al. configuration: --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libfaad --enable-pthreads --enable-libfaac --enable-libxvid --enable-libamr-nb --enable-libamr-wb --disable-ffplay --disable-demuxer=v4l --disable-demuxer=v4l2 libavutil 49.12. 0 / 49.12. 0 libavcodec 52. 6. 3 / 52. 6. 3 libavformat 52.23. 1 / 52.23. 1 libavdevice 52. 1. 0 / 52. 1. 0 built on Dec 16 2008 17:13:52, gcc: 3.4.6 20060404 (Red Hat 3.4.6-10) Input #0, mpegts, from 'ip_stream_from_a_dreambox': Duration: N/A, start: 93279.568322, bitrate: 15192 kb/s Program 17099 Program 17020 Program 17030 Program 17034 Program 17021 Program 17033 Program 17024 Program 17028 Program 17040 Stream #0.0[0xa8]: Video: mpeg2video, yuv420p, 544x576 [PAR 24:17 DAR 4:3], 15000 kb/s, 25.00 tb(r) Stream #0.1[0x70]: Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s Program 17022 Program 17025 Program 17023 Program 17026 Program 17031 Program 17027 Program 17041 Program 17035 Output #0, mpegts, to 'udp://test_ip:1234': Stream #0.0: Video: mpeg2video, yuv420p, 544x576 [PAR 24:17 DAR 4:3], q=2-31, 200 kb/s, 25.00 tb(c) Stream #0.1: Audio: mp2, 48000 Hz, stereo, s16, 64 kb/s Stream mapping: Stream #0.0 -> #0.0 Stream #0.1 -> #0.1 Press [q] to stop encoding Compiler did not align stack variables. Libavcodec has been miscompiled and may be very slow or crash. This is not a bug in libavcodec, but in the compiler. You may try recompiling using gcc >= 4.2. Do not report crashes to FFmpeg developers. frame= 93 fps= 0 q=0.0 Lsize= 2596kB time=3.17 bitrate=6712.0kbits/s video:2083kB audio:25kB global headers:0kB muxing overhead 23.176653% but listening the output udp://test_ip:1234 I always have MPTS Thanks a lot. -- Julien YOUX . //// . (. .) ---------oOO--(_)--OOo------- http://www.nain-de-jardin.com

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FFMPEG in a "while" loop
by ronnynussbaum＠gmail.com 19 Dec '08

19 Dec '08

Greetings. Please forgive me if this has already been answered. I looked through the documentation and couldn't find an answer to my question. I'm finding that FFMPEG behaves very strangely in a bash shell "while" loop. I've created a file named "avifile", that includes *some* files in a directory that I want converted. I then created a script that has this line in it: while read filename; do ffmpeg -i "$filename" -vcodec mpeg4 -r 24 -b 500k -ab 96k -ar 44100 -ac 2 -acodec libfaac "$filename".mp4; done <avifile I find that FFMPEG will encode the first file on the list, and it only. I'm also using mencoder for something else, and running the same script with mencoder encodes all the files in "avifile", so I know it's not a syntax issue. It looks like while FFMPEG is busy encoding the first file in my list, it runs through all the other itterations of the "while" loop. Any ideas? Thanks -Ronny

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how to draw dynamic text?
by giuliano.uboldi＠gmail.com 18 Dec '08

18 Dec '08

hallo everyone i have a mpg video and i should draw dynamic text on it, depending on the frame number. is it possible? i tried using vhook/imlib2 but i noticed that text can't be evaluated and so i can't use the vhook N variable to retrieve the frame number and use it to create the string to write. this is my command ffmpeg.exe -i "200812101008.MPG" -b 5000k -minrate 5000k -maxrate 5000k -bufsize 1835k -vcodec mpeg2video -acodec copy -f vob -t 10 - ilme 1 -vhook "vhook/imlib2.dll -F C:\WINDOWS\Fonts\verdana.TTF/20 -x 150+0.5*N -y 70+0.25*N -t ThisTextShouldBeDynamic" "prova_ok.mpg" and i should do something like -t 'hallo from'+(N/100) there's any workaround? thanks in advance.

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Unicode file names
by dennis.volodomanov＠conceiva.com 18 Dec '08

18 Dec '08

Hello all, Currently ffmpeg doesn't accept Unicode pathnames/filenames (under Windows at least). I was wondering if there's an easy (working) patch for this? I know there's one here: http://ffmpeg.arrozcru.org/patches/tuitfun/ , but not sure whether it works or not. Thanks in advance. Dennis

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Streaming avi and "Could not find codec parameters (Video: mpeg1video, 256x256)"
by chasedouglas.lists＠gmail.com 18 Dec '08

18 Dec '08

Hello all, I'm trying to real-time transcode and stream a video stream. The streaming I'm doing takes the output from the ffmpeg process and sends it off to the client. However, I'm finding issues. Because I am using libav on the client, I can pick and choose container formats as needed to get things to work. One constant is that I'm trying to use Apple's Audio Queue Services framework, which does not seem to be perfect at handling all encoded streams. First attempt: Stream using asf. This works fine for video, but the Audio Queue Services framework chokes on the mp3 packets I'm giving to it. This is how I encode the stream: ffmpeg -i - -vcodec mpeg2video -b 200000 -r 15 -strict -1 -s 256x256 - aspect 4:3 -deinterlace -acodec mp3 -ab 64000 -f asf - Second attempt: Stream using avi. I am able to play back avi using the following options: ffmpeg -i - -vcodec mpeg2video -b 200000 -r 15 -strict -1 -s 256x256 - aspect 4:3 -deinterlace -acodec mp3 -ab 64000 -f avi - This works if I pipe the output to a file, and then I try to open the file on the client. However, if I try to stream the output to the client, the client gives the following error: [avi @ 0x1850000]Could not find codec parameters (Video: mpeg1video, 256x256) With all of my testing, the ffmpeg output seems correct as far as input and output codecs and formats are concerned. Now, I don't care what container format I use, so long as I can get mpeg2video and mp3 as the codecs (hopefully the container also can store the aspect ratio). Does anyone have any ideas on how I can remedy this situation? Thanks

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AVCHD/h264 decoding benchmarking
by belcampo＠zonnet.nl 18 Dec '08

18 Dec '08

Played test-1 and test-3 without a problem with: FFplay version SVN-r15883, Copyright (c) 2003-2008 Fabrice Bellard, et al. configuration: --prefix=/usr --enable-postproc --enable-swscale --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-libvorbis --enable-gpl libavutil 49.12. 0 / 49.12. 0 libavcodec 52. 3. 0 / 52. 3. 0 libavformat 52.23. 1 / 52.23. 1 libavdevice 52. 1. 0 / 52. 1. 0 libswscale 0. 6. 1 / 0. 6. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Nov 19 2008 13:07:26, gcc: 4.2.2 20071128 (prerelease) (4.2.2-3.1mdv2008.0) on a AMD 4000 load 50% per core. Compared viewing on a PopCornHour hardware player and everything looks the same. Henk Schoneveld

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API : just using -vcodec copy
by ktd＠club-internet.fr 18 Dec '08

18 Dec '08

Hello, I am very new to FFMpeg Apis, and I just want to do something simple : convert mov video files to avi video files, keeping the videoc codec. On the command-line, this is just $>ffmpeg -i input.mov -vcodec copy output.avi. Period. However, I would like to do that from another program. Simple solution : system() call. I do not like it. The best would be to link to ffmpeg libraries and do the work with a little code. So, I have opened ffmpeg.c and... oh god, it is very hard to read. I can't manage to extract just the little part of code that would be necessary for my needs. There are many global variables, calls to cmdutils, and so on. Can anyone help giving me the few function calls that are necessary ? Regards, Pierre Chatelier

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