Sunday, July 24, 2011

FFMPEG solutions--Convert with best queries

A bit of googling and reading the man pages later I discovered

-vcodec copy -acodec copy
This tells ffmpeg to copy the video and audio without re-encoding.

So insted of this

ffmpeg -i input.flv output.mp4

The Solution

ffmpeg -i input.flv -vcodec copy -acodec copy output.mp4

Further complications
This worked a treat for all except one file - which gave the following error.

[NULL @ 0x9b6b9f0]error, non monotone timestamps 37464141 >= 37463126
av_interleaved_write_frame(): Error while opening file
By using the "-an" and "-vn" flags to skip the video and audio encoding in turn I narrowed it down to a problem in the audio codec timestream.

To try to get ffmpeg to fix the problem I got it to reencode the audio but copy the video codec with the following:

ffmpeg -i input.flv -vcodec copy -acodec mp2 -ar 44100 -ab 128k output.mp4
Worked a treat. I love ffmpeg

Final code to fix it using aac with audio quality quite high 200 (range is 0-255)

ffmpeg -i input.flv -vcodec copy -acodec libfaac -aq 200 output.mp4
Read more

Saturday, July 23, 2011

How to Access Banned Websites

Surfing at school? Parents enabled website blocking? Stuck behind a strict firewall? There are lots of ways around the problem so that you can get to the sites you want to see without those cybernannies tying your hands…
phproxy is “dedicated to bringing you fast web browsing from behind web filters”. Simply tap in the URL of that banned site you really must see, it could be Facebook, MySpace, Youtube, or a renegade blogger behind enemy lines, and you will be able to access it with no problems. More seriously, the proxy allows you to visit a site anonymously because it is the proxy itself that is visiting the banned site not you, and so keeps your browsing hidden from prying eyes allowing you to protect your online identity.

Such a proxy also allows you to visit sites that have banned your IP. This might be a forum or just a website or blog from which you or other users on your IP range (whether on your school or company network or your ISP account) have been barred access. The proxy server is an open gateway between your web destination and you.

Other proxies exist, such as (please make sure you include the hyphen in that URL or you will be in for a shock), and this page provides a shipload more.

More on an additional approach (Psiphon) here –

Of course, we should add a disclaimer at this point, please don’t use proxies or anonymizers to break the law or to cause malice and please don’t abuse the service as they are usually free.
Read more

FFmpeg commands for all needs --All in one pack

ffmpeg is a multiplatform, open-source library for video and audio files. I have compiled 19 useful and amazing commands covering almost all needs: video conversion, sound extraction, encoding file for iPod or PSP, and more.

Getting infos from a video file

ffmpeg -i video.avi
Turn X images to a video sequence
ffmpeg -f image2 -i image%d.jpg video.mpg
This command will transform all the images from the current directory (named image1.jpg, image2.jpg, etc…) to a video file named video.mpg.

Turn a video to X images
ffmpeg -i video.mpg image%d.jpg
This command will generate the files named image1.jpg, image2.jpg, …

The following image formats are also availables : PGM, PPM, PAM, PGMYUV, JPEG, GIF, PNG, TIFF, SGI.

Encode a video sequence for the iPpod/iPhone
ffmpeg -i source_video.avi input -acodec aac -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 320x180 -title X final_video.mp4
Explanations :

Source : source_video.avi
Audio codec : aac
Audio bitrate : 128kb/s
Video codec : mpeg4
Video bitrate : 1200kb/s
Video size : 320px par 180px
Generated video : final_video.mp4
Encode video for the PSP
ffmpeg -i source_video.avi -b 300 -s 320x240 -vcodec xvid -ab 32 -ar 24000 -acodec aac final_video.mp4
Explanations :

Source : source_video.avi
Audio codec : aac
Audio bitrate : 32kb/s
Video codec : xvid
Video bitrate : 1200kb/s
Video size : 320px par 180px
Generated video : final_video.mp4
Extracting sound from a video, and save it as Mp3
ffmpeg -i source_video.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 sound.mp3
Explanations :

Source video : source_video.avi
Audio bitrate : 192kb/s
output format : mp3
Generated sound : sound.mp3
Convert a wav file to Mp3
ffmpeg -i son_origine.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 son_final.mp3
Convert .avi video to .mpg
ffmpeg -i video_origine.avi video_finale.mpg
Convert .mpg to .avi
ffmpeg -i video_origine.mpg video_finale.avi
Convert .avi to animated gif(uncompressed)
ffmpeg -i video_origine.avi gif_anime.gif
Mix a video with a sound file
ffmpeg -i son.wav -i video_origine.avi video_finale.mpg
Convert .avi to .flv
ffmpeg -i video_origine.avi -ab 56 -ar 44100 -b 200 -r 15 -s 320x240 -f flv video_finale.flv
Convert .avi to dv
ffmpeg -i video_origine.avi -s pal -r pal -aspect 4:3 -ar 48000 -ac 2 video_finale.dv

ffmpeg -i video_origine.avi -target pal-dv video_finale.dv
Convert .avi to mpeg for dvd players
ffmpeg -i source_video.avi -target pal-dvd -ps 2000000000 -aspect 16:9 finale_video.mpeg
Explanations :

target pal-dvd : Output format
ps 2000000000 maximum size for the output file, in bits (here, 2 Gb)
aspect 16:9 : Widescreen
Compress .avi to divx
ffmpeg -i video_origine.avi -s 320x240 -vcodec msmpeg4v2 video_finale.avi
Compress Ogg Theora to Mpeg dvd
ffmpeg -i film_sortie_cinelerra.ogm -s 720x576 -vcodec mpeg2video -acodec mp3 film_terminée.mpg
Compress .avi to SVCD mpeg2
NTSC format:

ffmpeg -i video_origine.avi -target ntsc-svcd video_finale.mpg
PAL format:

ffmpeg -i video_origine.avi -target pal-svcd video_finale.mpg
Compress .avi to VCD mpeg2
NTSC format:

ffmpeg -i video_origine.avi -target ntsc-vcd video_finale.mpg
PAL format:

ffmpeg -i video_origine.avi -target pal-vcd video_finale.mpg
Multi-pass encoding with ffmpeg
ffmpeg -i fichierentree -pass 2 -passlogfile ffmpeg2pass fichiersortie-2
Find a webhost with ffmpeg enabled
Read more