모션그래픽 2: 비디오 인코딩 - 스트리밍비디오를 위한

어제 최진권님에게 들은 같은 이야기가 유투브에 있어서 실어나릅니다.

video codec formats, audio codec formats and container formats
.MPEG4, 3GPP and MOV files - (typically supporting h264 and mpeg4 video codecs and AAC audio codec)

Tips and notes:

• You should always upload your video in the original format in the highest quality possible.
• We prefer de-interlaced files.
• If your file is using h264 encoding we prefer files without PAFF/MBAFF encoding.
• Audio and video lengths should be the same and audio should start at the same time as the video.

Getting Started: .MOV / .MP4 / .3GPP files

MOV /MP4 /3GPP files are index based. Simply put, this means that there is an index in the file that tells us the specific location of where in the file the video and audio frames are present. Without the index, it is almost impossible to know where the data for a specific video or audio frame is. This index is contained in what is called a 'moov' atom in the file.

Now, if the index is at the beginning of the file, it will enable processing of the video as and when successive bytes of the file are uploaded. On the other hand, if the index is at the end, processing the video cannot begin until the entire upload is complete - since the index is needed to interpret the file.

Hence, for MOV / MP4 / 3gpp files, we prefer the "moov" atom in the beginning of the file - also known as "fast start" or a "flattened" MP4 / MOV file. There are tools available on the web to flatten your MOV file. Usually the video editing/export software will have options to create your files with the moov atom in the beginning rather than the end of your file. If you are using Apple editing tools, then see this article on how to produce files with moov atom in the beginning of the file.

출처 : http://www.google.com/support/youtube/bin/answer.py?&answer=165543

Learn More: File format / editing tips for Apple users

If you're a Quicktime Pro, Finalcut Pro, or iMovies user, check out the following tips on how to export your video files and get the best results out of uploading to YouTube and the transcoding of your files.

iMovie: File -> Export -> Compress movie for: Expert Settings -> Share -> Export: Movie to QuickTime Movie -> Options Finalcut Pro: File -> Export -> Using Quicktime Conversion -> Options QuickTime Pro: File -> Export -> Export: Movie to QuickTime Movie -> Options

In the Options box:

1. In the Video section select the following:
   • Compression Type: H264
   • Frame Rate: 30
   • Data Rate: Automatic
     (if you choose to restrict the Data Rate, make sure to choose the highest value acceptable to you- more bits = better quality)
   • Key Frames: Automatic
   • Frame Reording: Unchecked


2. In the Video section click "Size":
   Dimensions: Set this to the original size of your video (Note: HD resolutions preferred- 1280x720 or 1920x1080)


3. In the "Prepare for internet Streaming" section:
   Select the "Prepare for internet Streaming" and choose "Fast Start" from the drop-down menu.


4. In the Audio section, make sure that the audio codec is AAC. Always use ACC as the preferred audio codec.


5. Once you've made all of these selections, click the "OK" button to save your preferences.


6. Add a title to the video file and click the "Save" button to save your edited version of your movie. Your project will then be exported and be ready to upload to YouTube.

Note:
The tips in blue are important. Please make sure you format your files accordingly.