Compressing Video: General Considerations | Other Documentation | WebTV Solutions

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Optimize for streaming

When compressing videos in H.264 format it is a good practice to look for an option to optimize (or prepare) the compressed videos for "streaming" or "fast start".

Deinterlace or not to deinterlace...

Internet (computer) is different from television, television displays videos in an interlaced way* and computers display videos in a progressive way*. If your source video is interlaced (most videos recorded by video cameras are) then you will need to deinterlace it before encoding it, or you can also use the deinterlace option that is built-in the majority of compression programs. If your source video is NOT interlaced, then the best thing to do is not to deinterlace it in order to produce a higher quality encoded video.

*More info about progressive vs interlaced video here:
Wikipedia: Progressinve scan
Wikipedia: Interlaced video

Reference Compression Settings

Please, finde bellow two tables with recommended settings for compressing videos in H.264 format. In general, these settings produce very good quality videos (depending on the compression/encoding software being used).
Note: The following recommended settings should only be used as a starting point. Visible video quality also depends on the encoding software. We recommend to experiment with your tools and different settings until you get the desired results. 

MP4:H.264

NOTE: In general, if you are using as "target" Flash + HTML5, and you want the best compatibility with PC and mobile devices, use H.264 (baseline, level 3.0) for video track and AAC for audio track.

The video files of our demonstration WebTVs have been compressed with HandBrake, using the following presets:
• WebTV SD PAL 16:9 700Kbps ("Normal" quality)
• WebTV SD PAL 16:9 1250kbps ("HQ" quality)
Both presets are H.264 Main Profile for video track and AAC for audio track.
For more information, check out the "Compressing with HandBrake" tutorial.

Setting	Value
Total Bit Rate - approx - (WebTV Quality)	500Kbps	700Kbps	1000Kbps	1250Kbps	HD 720p 2000Kbps	HD 1080p 3500Kbps
File Name	Use .mp4 file extension. Do not use special characters (tildes, etc.).
Video Track
Codec	H.264
Profile	"Main" or "Baseline" (level 3.0)*
Para Flash + HTML5 (General: better quality)	Main*	Main*	Main*	Main*	Main*	Main*
For Flash + HTML5 (Better mobile compatibility)	Baseline	Baseline	Baseline	Baseline	Main*	Main*
Frame Reordering	No	No	No	No	Yes - if available -	Yes - if available -
Optimize for	"Streaming" / "Fast start" / "Web Optimized"
Compression Quality	High / Best - if available -
Frame Rate	25 (PAL) 29.97 (NTSC) 30 (NTSC)
Bit Rate	450 kbits/sec	604 kbits/sec	904 kbits/sec	1122 kbits/sec	1902 kbits/sec	3378 kbits/sec
Dimensions	512 x 288	640 x 480	720 x 480 ( NTSC) 720 x 576 (PAL)	720 x 480 ( NTSC) 720 x 576 (PAL)	1280 x 720	1920 x 1080
Audio Track
Codec	AAC: for Flash + HTML5 - better mobile compatibility - MP3: for Flash Only compatibility.
Sample Rate	32, 44 or 48 kHz
Channels	Mono	Stereo	Stereo	Stereo	Stereo	Stereo
Bit Rate	96 Kbps	128 Kbps	128 Kbps	128 Kbps	160 Kbps	160 Kbps

*NOTES:
• Main profile: It is compatible with most modern devices, including current iPhone, iPod, iPad models as well as most Android Smartphones and Tablets. However, this profile is not compatible with the first generations of iPhone and iPod Touch.
• Baseline profile: It is compatible with a wider range of mobile devices, incluing first gerenartions of iPhone and iPod Touch, but it offers a lower quality than the "Main" profile.