June 2005 - ffmpeg-user - lists.ffmpeg.org

Longfile names?
by aritrim＠gmail.com 27 Jun '05

27 Jun '05

Hello All, I am trying to run ffmpeg through a DOS batch file with the filenames as long file names but nothing is happening. When i change the name to shortnames that is 8.3 formats it works fine. Can anyone tell me if ffmpeg supports long file names and if what will be the syntax? I am just doing very basic encoding like ffmpeg -i c:\abc.mpg c:\abc.flv Thanks in advance -- Sincerely, ========= Aritrim Basu Hexadesigns (Software & Web Solutions) Westbengal, India 913339584140 http://www.hexadesigns.net

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Parameters to encode m4v
by luca.zappella＠gmail.com 27 Jun '05

27 Jun '05

Hi all, I am a new user of libavcodec and I need an help. I have some YUV files grabbed from a camera and I need to create an m4v file to stream via RTSP. Right now I am using these parameters to encode but I would like to know if I could improve the quality or reduce the size of the m4v produced: codec_context->bit_rate One of these : 128*1024 -- 512*1024 -- 1024*1024 Is too much? codec_context->bit_rate_tolerance = codec_context->bit_rate * 20/100 codec_context->pix_fmt = PIX_FMT_YUV420P; codec_context->gop_size = gop; codec_context->frame_rate=fps; codec_context->frame_rate_base=spf; codec_context->flags |= CODEC_FLAG_AC_PRED; //AC Prediction codec_context->flags |= CODEC_FLAG_4MV; codec_context->flags |= CODEC_FLAG_PART; codec_context->profile = 9; //Advanced Real Time codec_context->level = 4; Are these correct? Can I add some parameters? Am I missing something? Have I to change something? I know that one improvement would to be add the b-frames but what else? Thanks in advance, Luca

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[Ffmpeg-user-old] QuickTime Player fail to play xvid+pcm_mulaw+mov file by ffmpeg
by rzxiao＠gmail.com 25 Jun '05

25 Jun '05

hi I download 2005-06-25 cvs version of ffmpeg,compile with "./configure --enable-xvid --enable-gpl --disable-vhook" in Cygwin.When I using this command line: ./ffmpeg -i c:/a.asf -vcodec xvid -s 320x240 -r 15 -b 216 -acodec pcm_alaw -ac 1 -ar 8000 -f mov c:/cygin.mov QuickTime Player can play it very well. But when I using command like this: ./ffmpeg -i c:/a.asf -vcodec xvid -s 320x240 -r 15 -b 216 -acodec pcm_mulaw -ac 1 -ar 8000 -f mov c:/cygin.mov QuickTime Player fail to play it and without response. So my question is: Is pcm_mulaw codec in ffmpeg compatible with quicktime's ulaw codec? Thanks in advance. Renzhon Xiao ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_idt77&alloc_id492&op=click _______________________________________________ Ffmpeg-user mailing list Ffmpeg-user at lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ffmpeg-user

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can ffmepg encode YUV to mpeg4?
by alvarez＠ac.upc.edu 24 Jun '05

24 Jun '05

(sorry about the SPAM text in my previous email subject.) ?? wrote: > Dear all: > I am a shorthorn of ffmpeg. > I know ffmpeg has no problem for decode. However, I am sure if it can also be used for encode. What we want to do is to encode YUV Data to mpeg4 format. So my questions are: > 1. Does ffmpeg4 has this function? yes > 2. Is there any tip for this purpose? take a ook at: http://ffmpeg.sourceforge.net/ffmpeg-doc.html#SEC4 or try ffmpeg -s widthxhigh -i file.yuv file.mp4 you can give more parameters to the input and output videos: ffmpeg -s widthxhigh -r frame_rate -t total_time -f rawvideo -pix_fmt yuv420p -i file.yuv -vcodec mpeg4 -b bitrate -an file.mp4 here an example ffmpeg -s 720x576 -r 25 -t 10 - f rawvideo -pix_fmt yuv420p -i file.yuv -vcodec mpeg4 -b 500 -an file.mp4 > and how about the performance? ffmpeg is really fast, Try ffmpeg with the -benchmark option and compare the time with other encoders. bye Mauricio Alvarez > > I have already read the FAQ and other related documents, yet I am a little confused. Thank you in advance! > > Best Regards > Huang Gao >

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can ffmepg encode YUV to mpeg4?
by huanggao＠longcheertel.com 24 Jun '05

24 Jun '05

Dear all: I am a shorthorn of ffmpeg. I know ffmpeg has no problem for decode. However, I am sure if it can also be used for encode. What we want to do is to encode YUV Data to mpeg4 format. So my questions are: 1. Does ffmpeg4 has this function? 2. Is there any tip for this purpose? and how about the performance? I have already read the FAQ and other related documents, yet I am a little confused. Thank you in advance! Best Regards Huang Gao

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Help with converting to ac3
by matthews＠mailsnare.net 23 Jun '05

23 Jun '05

Hi, I have a DVD with way too low audio volumes, barely audible on my TV even with sound at max. I de-muxed the video and audio and used besweet to normalize the audio which created a wav. This wav has audio that sounds great, the process worked but when I used beweet to convert the wav back to ac3 (so I could re-mux the audio and video), I got sound levels that were pretty much the same as the original audio file. :-( So I decided to use ffmpeg to convert the wav to ac3 to see if the results were better. But I can't work out how to format the command line to do this. Can someone explain how this is done please? Or indeed if there's a way of achieving what I want with, say, just using ffmpeg. Many thanks and regards, MS

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Image properties
by luis.strano＠gmail.com 23 Jun '05

23 Jun '05

Hi, I was wondering if there was a way of adjusting image properties while decoding. I would be mainly interested in brightness, contrast and hue. Thanks, --lf

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Ultra-low-bitrate audio codec?
by mbardiaux＠peaktime.be 22 Jun '05

22 Jun '05

The lowest possible bitrate I could achieve was GSM at 13kbits. Is there some codec in lavc that can go below that? (Sample command would be welcome). TIA. -- Michel Bardiaux Peaktime Belgium S.A. Bd. du Souverain, 191 B-1160 Bruxelles Tel : +32 2 790.29.41

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Huge 'singlejpeg's
by evert＠collab.nl 22 Jun '05

22 Jun '05

Hi all and first of all for your excellent work. I did some benchmarking the other day where FFMpeg sometimes came out 30 times faster than Wildform Flix, so thats amazing. Flix supports more codecs though ;) anyway, my question. When I generate a 240x180 jpeg from a video I sometimes get jpegs larger than 1MB, any idea how this can happen? This is my command line: /usr/local/bin/ffmpeg -y -i /www/sabretooth/fcs/api/data/files/8847/16_source.avi -f singlejpeg -hq -s 240x180 /www/udc/thumbs/16_12.jpg any help would be greatly appreciated grt, Evert

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convert video in string format to .mp4/wmv
by dtra＠faceyoursfears.com 21 Jun '05

21 Jun '05

hi all we are working on something that will convert email video attachments to video files the attachment as read with php shows up as a big long string what we would like is something similar to php's imagecreatefromstring() but obviously there's no videocreatefromstring() can ffmpeg <http://www.videohelp.com/tools?tool=ffmpeg> convert a video in string format to an actual video? eg. ffmeg -i --convert-string-to-video videoinstringformat.3gp -b 50 -vcodec mpeg4 videoinbinaryformat.mp4 thanks dave

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