Avi to Mkv conversion!

[Aandis]

I have a video with the following properties

General
Format : AVI
Format/Info : Audio Video Interleave
File size : 175 MiB
Duration : 21mn 11s
Overall bit rate mode : Variable
Overall bit rate : 1 154 Kbps
Writing application : Some super fast AVI muxer

Video
ID : 0
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : 2
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 21mn 11s
Bit rate : 992 Kbps
Width : 624 pixels
Height : 352 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.188
Stream size : 150 MiB (86%)
Writing library : XviD 70

Audio
ID : 1
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 55
Codec ID/Hint : MP3
Duration : 21mn 11s
Bit rate mode : Variable
Bit rate : 149 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 22.6 MiB (13%)
Alignment : Aligned on interleaves
Interleave, duration : 24 ms (0.58 video frame)
Interleave, preload duration :38 ms


Need to convert it to following mkv format to reduce the size without losing much quality...



Format : Matroska
Format version : Version 2
File size : 69.4 MiB
Duration : 21mn 48s
Overall bit rate : 445 Kbps
Encoded date : UTC 2009-11-20 18:33:49
Writing application : mkvmerge v2.9.7 ('Tenderness') built on Jul 1 2009 18:43:35
Writing library : libebml v0.7.7 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 21mn 48s
Width : 640 pixels
Height : 352 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Default : Yes
Forced : No

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : HE-AAC / LC
Codec ID : A_AAC
Duration : 21mn 48s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz / 24.0 KHz
Compression mode : Lossy
Default : Yes
Forced : No

Menu
00:00:00.097 : en:00:00:00.097

As u can see both the video have almost the same length but the size of 2nd one is extremely less.Quality being as good as the first one!

How do i convert the file?What codecs do i need?All i need is to convert the file without losing any quality.If there is any other format which can do that,please let me know about that too.

P.S i am fairly new here.This is my first thread.So please help.Looking forward!

[Baldrick]

You will lose quality. Especially when you shrink an already heavily compressed video again. It's best to convert directly from the best source available.

But anyway, use for example handbrake, open your avi, change to mkv with h264 video and aac audio, under the video tab can you set the output file size, under the audio tab lower the bitrate to 64kbit/s. Convert and see how it looks like.

[Aandis]

I know what you mean.But look at the above given mkv file.Both the files have almost the same length but the size of mkv file is less than even half.And the quality is perfect.What type of conversion should i do to get such a format??