Monthly Archives: December 2013

Some useful ffmpeg commands ( commandline video converting tool)

1. Converting MOV/MPEG/AVI/MP4 –> flv 
#ffmpeg -i input file output.flv

2. Convert and adjust the video file resolution to output file
# ffmpeg -i input.avi -s 500×500 output.flv

3. Converting 3GP –> FLV
#ffmpeg -i input.3gp -sameq -an output.flv

4. Converting MPEG –>3GP
#ffmpeg -i input.mpeg -ab 8.85k -acodec libamr_wb -ac 1 -ar 16000 -vcodec h263 -s qcif output.3gp

5. Converting WMV –> to MP3
#ffmpeg -i input.wmv output.mp3

6. Converting AMR –> MP3
#ffmpeg -i input.amr -ar 22050 output.mp3

7. Converting FLV –> MP4
# ffmpeg -i input.flv -ar 22050 output.mp4

Advanced flash supported conversion.

#ffmpeg -i input.flv -s 480×360 -vcodec libx264 -b 1900kb -flags +loop -cmp +chroma -me_range 16 -me_method hex -subq 5 -i_qfactor 0.71 -qcomp 0.6 -qdiff 4 -directpred 1 -flags2 +fastpskip -dts_delta_threshold 1 -acodec libfaac -ab 128000 output.mp4

This code will support to play in Iphone.

#ffmpeg -i 400b75e5081fca44d094.flv -s 320×240 -r 24 -b 200k -bt 240k -vcodec libx264 -vpre hq -coder 0 -bf 0 -flags2 -wpred-dct8x8 -level 13 -maxrate 768k -bufsize 3M -acodec libfaac -ac 2 -ar 48000 -ab 192k new_output_new1.mp4

8. Converting AAC –> Mp3
#ffmpeg -i input.aac -ar 22050 -ab 32 output.mp3

Use ffmpeg with it’s best performance

The following arguments helps you to optimize the ffmpeg conversion to get the best result of converting mp4. to flv

# ffmpeg -i input.mp4 -ar 22050 -ab 56 -acodec mp3 -r 25 -f flv -b 400 -s 320×240 output.flv

-i = specify input file
-ar = audio sample rate
-ab = audio bitrate
-acodec = audio codec
-r = framerate
-f = output format
-b = bitrate (of video!)
-s = resize to width x height

10, Convert Video –> JPG Sequence
#ffmpeg -i input.mpg -an -r 10 -y -s 320×240 video%d.jpg

11. Convert Every n seconds to JPEG
#ffmpeg -i input.mpg -r 0.2 -sameq -f image2 thumbs%02d.jpg where r is the time when jpg file created. r can be 0.2 indicate every 5 second, if you need a jpeg on every 45 seconds use 1/45.

11. Crop the video between the specified time
#ffmpeg -i input.mpg -an -ss 00:00:03 -t 00:00:01 -r 1 -y -s 320×240 video%d.jpg where
-ss : Record start time
-t : No. of second to end suppose you want to crop 2 minutes video which starts from the 10 minutes play
-ss 00:10:00 -t 00:02:00
%d : Naming with timestamp

12. Converting flv –> mp3
#ffmpeg -i input.flv -vn -acodec copy output.mp3

13. Converting WAV –> MP3 
#ffmpeg -i Input.wav -ab 128 Output.mp3
#ffmpeg -i input.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 output.mp3

14 : Encode a video sequence for the iPpod/iPhone 
ffmpeg -i input.avi input -acodec aac -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 320×180 -title X output.mp4

15. Converting AVI –> GIF
ffmpeg -i input.avi gif_anime.gif
16. Compress .avi –> divx
#ffmpeg -i input.avi -s 320×240 -vcodec msmpeg4v2 output.avi
Source : input.avi
Audio codec : aac
Audio bitrate : 128kb/s
Video codec : mpeg4
Video bitrate : 1200kb/s
Video size : 320px par 180px
Generated video : output.mp4

17. Converting flv –> Mp4
#ffmpeg -i sample.flv -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -s 320×240 final_video.mp4

some useful resources,

Apache Kafka 0.8.0发布,高吞吐量分布式消息系统

Apache Kafka 0.8.0版本近日发布。Apache Kafka是源自LinkedIn的一种分布式日志服务,主要用Scala语言开发(少量Java),其实质是高吞吐量而功能简单的消息队列。由于架构设计独特,Kafka与传统消息队列相比,内置分区、复制和容错功能,适合大规模系统。曾有数据表明,Kafka能够每秒发布超过40万条消息。


Apache Kafka 0.8.0版本主要改进包括: