Newest 'ffmpeg' Questions - Stack Overflow

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  • How to play wma file in iphone ?

    3 octobre 2011, par Mohasin

    I want to build a radio app in iPhone for which wma streaming is necessary. So if u have any idea please help me. thanks in advance

  • Is -vfilter not available on Debian 5 ?

    3 octobre 2011, par Kor

    I'm getting problems trying to make my website (done in PHP) work online. At a specific time, I need to upload a video and convert it, also scaling its dimensions. I use a call like this one:

    ffmpeg -y -i '/path/to/video.mp4' -f flv -ab 56 -ar 22050 -r 20 -vfilter "scale=704:-1" '/path/to/new/video.flv'

    It works offline on my computer (Ubuntu 10.10), but it doesn't do the same online (Debian Lenny 5.0). The response I get from the server is:

    [Mon Oct 03 15:48:56 2011] [error] [client 81.184.6.124] /servers/path/to/ffmpeg: unrecognized option '-vfilter'

    I have also tried with '-vf', but it just doesn't work at all. So my question is, am I doing it wrong, or is it that Debian unables video filters for some reason?

    I give you some info about this server:

    Debian 5.0
PHP: 5.2.6
FFmpeg r11872+debian_0.svn20080206-18+lenny1
libavutil   3212800
libavcodec  3355136
libavformat 3409664
libavdevice 3407872

    EDIT: Oh my, I just saw it. No libavfilter installed. I'll tell you what their support tells me in a couple hours.

  • flv reencode to mp4 for iphone/ipod via ffmpeg and x264 (quality issue)

    3 octobre 2011, par zeroasterisk

    There are a lot of questions on this topic, and I've read most of them and most of the google search results I could come up with.

    When I use FFMPEG to convert a FLV to a iphone3 compatble MP4 file, it just doesn't preserver enough of the quality. Yes, I've worked the hell out of -sameq and -b and -bt settings, text just isn't readable.

    Next I tried to split the video out and process it directly, using these instructions: https://sites.google.com/site/linuxencoding/x264-encoding-guide

    The problem is myplayer (via ffmpeg) was not able to determine the duration of the FLV (even though the metadata was set).

    (I assume) Because of that unknown duration, when I create the MP4 file, the resulting x264 file plays through super-fast while the audio plays at the normal rate.

    user@server:/tmp# mplayer -nosound -benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'
MPlayer 1.0rc4-4.4.5 (C) 2000-2010 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing input.flv.
libavformat file format detected.
[flv @ 0x1202460]Estimating duration from bitrate, this may be inaccurate
[lavf] stream 0: video (vp6f), -vid 0
[lavf] stream 1: audio (nellymoser), -aid 0
VIDEO:  [VP6F]  1680x992  0bpp  1000.000 fps   33.4 kbps ( 4.1 kbyte/s)
Clip info:
 audiocodecid: 6
 audiodatarate: 86
 audiosamplerate: 44100
 audiosamplesize: 16
 audiosize: 6097005
 canSeekToEnd: true
 datasize: 8609138
 duration: 567
 framerate: 2
 hasAudio: true
 hasCuePoints: false
 hasKeyframes: true
 hasMetadata: true
 hasVideo: true
 height: 992
 lasttimestamp: 567
 metadatacreator: flvtool++ (Facebook, Motion project, dweatherford)
 stereo: false
 totalframes: 1043
 videocodecid: 4
 videodatarate: 33
 videosize: 2316256
 width: 1680
Using (default) progressive frame mode.Opening video filter: [expand w=640 h=480]
Expand: 640 x 480, -1 ; -1, osd: 0, aspect: 0.000000, round: 1
Opening video filter: [scale w=0 h=0]
Opening video filter: [dsize=640:480:0]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash)
==========================================================================
Audio: no sound
Starting playback...
Movie-Aspect is undefined - no prescaling applied.
[swscaler @ 0x7f0c738b9620]Lanczos scaler, from yuv420p to yuv420p using MMX2
VO: [yuv4mpeg] 640x480 => 641x480 Planar YV12

    I have also tried specifying FPS, but no change in results

    user@server:/tmp# mplayer -nosound -fps 25-benchmark -sws 9 -vf dsize=640:480:0,scale=0:0,expand=640:480 -vo yuv4mpeg:file=>(x264 --demuxer y4m --fps 25 --crf 0 --preset slow --threads auto --output output.264 - 2>x264.log) 'input.flv'

    Can someone tell me how to either:

    1. fix my split A/V processing/timing/duration issues?
    2. improve the quality of the FFMPEG conversion of FLV to iphone3 compatible format?

  • Re-Stream a MPEG2 TS PAL Stream with crtmpserver

    2 octobre 2011, par mblaettermann

    I want to build up some kind of stream wrapper:

    I own an old Dreambox PAL Sat Reciever with Networking. This stream I want to transcode to a lower resultion an restream it.

    My Goal is, to have a simple website, where this stream is embedded via rtmp.

    I thougt crtmpserver should be the right software. For now I have a site running and can play local files through jwplayer/crtmpserver.

    I am looking for a solution for this:

    httpUrl -> ffmpeg -> crtmpserver

    Is that possible? May I redirect the output of ffmpeg to a filed pipe, and crtmpserver could grab that? Or go with UDP?

    Any hints appreciated!!! Thanks!!

  • ffmpeg - Output file does not contain any stream [migrated]

    2 octobre 2011, par Sandeep Chandy

    When I try to take Screenshots from an AVI file I get the above message with an empty jpg/png file. But Screenshots from MP4 files works with any problems.

    My OS is Debian.

    MP4 Command:

    ffmpeg  -itsoffset -4  -i test.mp4 -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg

    AVI Command:

    ffmpeg  -itsoffset -4  -i test.avi -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg

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