iPhone can only play Videos in MP4, H.264 format, so if you have some MKV (Matroska Video) Movies on computer and want to play MKV on iPhone, it's necessary to convert MKV to iPhone compatible format MP4, and here is an easy way around this issue:
The tool we need:
A MKV to iPhone Converter - Daniusoft Video Converter
Daniusoft Video Converter is a good MKV to iPhone Video Converter that can convert MKV to iPhone/3G/3GS/4 files and other formats files in one click, such as AVI, WMV, MPEG4, MP4, FLV, 3GP, ASF, MKV, M2TS, MTS, etc with plug-in subtitles. and it's fully compatible with Windows 7.
Step by step instruction to convert MKV to iPhone:
Step 1: Import MKV file to the software
Firstly free download and install Daniusoft Video Converter. Then run it.
Then Click the "Add Video" button to add source MKV files you are going to convert. you also can click "File -> Add Video Files..." to load the MKV video files to the Daniusoft Video Converter.
Step2: Choose output format
Click the "Profile" drop-down list box to select an output format according to your iPhone device. Here we take "iPhone 3GS MPEG-4 Video(.mp4)" as the output format for example. the default setting is recommended to use for newbie, you also can customize output video and audio parameters, such as video size, audio bitrate, etc and save them as your profile.
You can click"browse" button to to set output path.
Add plug-in subtitles to MKV files
Click "Edit" button, switch to "Plug-in Subtitle" tab. Just select "enable the plug-in subtitle" checkbox, and then you can add plug-in subtitles to MKV files. the supported subtitle files are .srt, .ass, .ssa.
Edit MKV files(Optional)
Click on "Edit" button to give basic video editing before MKV to iPhone Conversion. You can crop (cut off black edge of original MKV Movie), trim(clip any segment of MKV Video files you want to convert) or add video effect or watermark to the video.
Step 3. Start to convert MKV to iPhone files
Just click "Start" to convert MKV to iPhone MP4, after conversion finished, you can click "Find Target" to access output files directly.
Now you can enjoy playing MKV movies on iPhone, iPhone 3G/3GS, iPhone 4 at will.