|
|
|
|
|
Visual Video Converter
Quality pick for home users especially those who need powers that go beyond simple conversions
|
Video Formats |
Description |
AVI
(DivX, XviD, MPEG-4, Uncompressed, Cinepak) |
| |
AVI stands for Audio Video Interleave. It is a special case of the RIFF (Resource Interchange File Format). AVI is defined by Microsoft. AVI is the most common format for audio/video data on the PC. AVI is an example of a de facto (by fact) standard.
AVI Files are a special case of RIFF files. RIFF is the Resource Interchange File Format. This is a general purpose format for exchanging multimedia data types that was defined by Microsoft and IBM during their long forgotten alliance.
Please note: If there are not DivX or XviD codec installed in your computer, you need to download and install the DivX or XviD codec so that you can operate DviX or XviD video files.
DviX: http://www.divx.com/divx/ (free version is enough for palying and converting DivX video files)
XviD: http://www.xvidmovies.com/codec/
For the details, please see FAQ |
|
MPEG
(MPEG-1, MPEG-2 Video) |
| |
MPEG is both a file format and a codec for digital video. There are actually three forms of MPEG: MPEG video, for picture only; MPEG audio, which is discussed in the previous section; and MPEG systems, which includes both audio and video tracks.
MPEG files provide excellent picture quality but can be very slow to decompress. For this reason, many MPEG decoding systems are hardware-assisted, meaning that you need a board to play MPEG files reliably without dropping a lot of frames. Although software decoders definitely exist (and there are some very good ones out there), they tend to require a lot of processor power on your system and also usually support MPEG video only (they have no soundtrack).
A third drawback of MPEG video as a standard for the Web is that MPEG movies are very expensive to encode. You need a hardware encoder to do so, and the price ranges for encoders are in the thousands of dollars. As MPEG becomes more popular, those prices are likely to drop. But for now, unless you already have access to the encoding equipment or you're really serious about your digital video, a software-based format is probably the better way to go. |
|
WMV |
| |
Windows Media Video.
Formerly known as .ASF file format from Microsoft.
A .WMV file includes a video stream (compressed using MS MPEG4 or WMV1 codec) combined with WMA encoded audio stream. The file format is proprietary and backward incompatible. Currently, dedicated to slow dialup connections, this media format does not allow even sub-VHS video quality due to blurred picture. WMA audio quality, compared to MPEG Layer3 of the same bitrate, isn't better either.
You may wish to use Windows Media format to create smallest files that are suitable to send by e-mail, however you must keep in mind that .WMV file works like "one way ticket" - once created, it can't be edited anymore, without horrific quality loss. As opposite, AVI files compressed with MPEG4 video codec are still editable and often it is possible to retain source video quality.
If you are having problems creating or playing Windows Media files, download the latest codecs. These may be found at http://www.microsoft.com/windows/windowsmedia/format/codecdownload.asp. |
|
RM |
| |
Real Networks Video (convert to only)
It is a streaming media format known as RealMedia with the file extension .rm using RealAudio audio compression and RealVideo video compression (RealVideo, also known as ClearVideo, is Iterated Systems fractal video compression). |
|
Quick Time |
| |
Apple video format for the Macintosh (convert from only)
Although QuickTime was developed by Apple for the Macintosh, QuickTime files are the closest thing the Web has to a standard cross-platform movie format (with MPEG a close second). The Apple system software includes QuickTime and a simple player (called MoviePlayer or SimplePlayer). For PCs, QuickTime files can be played through the QuickTime for Windows (QTfW) package, and the freely available Xanim program will play them under the X Window System and UNIX. QuickTime movies have the extension .qt or .mov.
QuickTime supports many different codecs, particularly CinePak and Indeo, both of which can be used cross-platform. See the "Codec Formats" section later in this chapter for more information on these formats. |
|
Audio Formats |
Description |
PCM |
| |
Standard Windows WAV format for non-compressed audio files. Pulse Code Modulation (PCM) is the standard method of digitally encoding audio. It is the basic uncompressed data format used in file types such as Windows .wav. |
|
ADPCM |
| |
Compressed WAV format. ADPCM (Adaptive Differential Pulse Code Modulation) is an audio compression scheme which compresses from 16-bit to 4-bit for a 4:1 compression ratio. |
|
A-LAW |
| |
Compressed WAV format. A-Law (or CCITT standard G.711) is an audio compression scheme common in telephony applications. It is a slight variation of the u-Law compression format, and is found in European systems. This encoding format compresses original 16-bit audio down to 8 bits (for a 2:1 compression ratio) with a dynamic range of about 13-bits. Thus, a-law encoded waveforms have a higher s/n ratio than 8-bit PCM, but at the price of a bit more distortion than the original 16-bit audio. The quality is higher than you would get with 4-bit ADPCM formats. Encoding and decoding is rather fast and generally, widely supported. |
|
U-LAW |
| |
Compressed WAV format. u-Law (or CCITT standard G.711) is an audio compression scheme and international standard in telephony applications. u-Law is very similar to A-Law, a variation of u-Law found in European systems. This encoding format compresses original 16-bit audio down to 8 bits (for a 2:1 compression ratio) with a dynamic range of about 13-bits. Thus, u-Law encoded waveforms have a higher s/n ratio than 8-bit PCM, but at the price of a bit more distortion than the original 16-bit audio. The quality is higher than you would get with 4-bit ADPCM formats. Encoding and decoding is rather fast and generally, widely supported. |
|
CCIT U-LAM |
|
DSP |
| |
Compressed WAV format. DSP Group True Speech (TM) format. |
|
GSM |
| |
Compressed WAV format. Good for keeping of human speech. |
|
MP3 |
| |
MPEG Layer-3 format. Very popular format for keeping of music. |
|
MP2 |
|
Ogg Vorbis |
| |
Ogg Vorbis format. Ogg Vorbis is an audio compression format. It is roughly comparable to other formats used to store and play digital music, such as MP3, VQF, AAC, and other digital audio formats. It is different from these other formats because it is completely free, open, and unpatented. |
|
WMA |
| |
Windows Media Audio format. A special type of advanced streaming format file for use with audio content encoded with the Windows Media Audio codec. The .wma extension indicates a file format and how the content is encoded. |
|
AVI |
| |
Audio stream format (Convert From Only) |
|
AIF, AIFF, AIFC |
| |
Apple audio file format (Convert From Only) |
|
AU, SND |
| |
Unix audio file format (Convert From Only) |
|
G.721 |
| |
Used for computer telephony. 32 kbit/s adaptive differential pulse code modulation (ADPCM).
Good for keeping of human speech. |
|
G.723 |
| |
Used for computer telephony. Extensions of Recommendation G.721 adaptive differential pulse code modulation to 24 and 40 kbit/s for digital circuit multiplication equipment application. Good for keeping of human speech. |
|
G.726 |
| |
Used for computer telephony. Good for keeping of human speech. |
|
VOX |
| |
Dialogic ADPCM format. The Dialogic ADPCM format is commonly found in telephony applications, and has been optimized for low sample rate voice. It will only save mono 16-bit audio, and like other ADPCM formats, it compresses to 4-bits/sample (for a 4:1 ratio). This format has no header, so any file format with the extension .VOX will be assumed to be in this format. |
|
RAW |
| |
Raw format of audio files. Doesn't contain header of an audio file. |
|
MPC |
|
Image Formats |
Description |
JPEG |
| |
Joint Photographic Experts Group (JPEG) format is commonly used to display photographs and other continuous-tone images in hypertext markup language (HTML) documents over the World Wide Web and other online services. JPEG format supports CMYK, RGB, and Grayscale color modes, and does not support alpha channels. Unlike GIF format, JPEG retains all color information in an RGB image but compresses file size by selectively discarding data.
A JPEG image is automatically decompressed when opened. A higher level of compression results in lower image quality, and a lower level of compression results in better image quality. In most cases, the Maximum quality option produces a result indistinguishable from the original. |
|
GIF |
| |
Graphics Interchange Format (GIF) is the file format commonly used to display indexed-color graphics and images in hypertext markup language (HTML) documents over the World Wide Web and other online services. GIF is an LZW-compressed format designed to minimize file size and electronic transfer time. GIF format preserves transparency in indexed-color images; however, it does not support alpha channels. |
|
BMP |
| |
BMP is a standard Windows image format on DOS and Windows-compatible computers. BMP format supports RGB, Indexed Color, Grayscale, and Bitmap color modes. You can specify either Windows or OS/2® format and a bit depth for the image. For 4-bit and 8-bit images using Windows format, you can also specify RLE compression.
BMP images are normally written bottom to top; however, you can select the Flip Row Order option to write them from top to bottom. You can also select an alternate encoding method by clicking Advanced Modes. (Flip Row Order and Advanced Modes are most relevant to game programmers and others using DirectX.) |
|
PNG |
| |
Developed as a patent-free alternative to GIF, Portable Network Graphics (PNG) format is used for lossless compression and for display of images on the World Wide Web. Unlike GIF, PNG supports 24-bit images and produces background transparency without jagged edges; however, some Web browsers do not support PNG images. PNG format supports RGB, indexed-color, grayscale, and Bitmap-mode images without alpha channels. PNG preserves transparency in grayscale and RGB images. |
|
TIFF |
| |
Tagged-Image File Format (TIFF) is used to exchange files between applications and computer platforms. TIFF is a flexible bitmap image format supported by virtually all paint, image-editing, and page-layout applications. Also, virtually all desktop scanners can produce TIFF images.
TIFF format supports CMYK, RGB, Lab, indexed-color, and grayscale images with alpha channels and Bitmap-mode images without alpha channels. Photoshop can save layers in a TIFF file; however, if you open the file in another application, only the flattened image is visible. Photoshop can also save annotations, transparency, and multiresolution pyramid data in TIFF format. |
|
PCX |
| |
PCX format is commonly used by IBM PC-compatible computers. Most PC software supports version 5 of PCX format. A standard VGA color palette is used with version 3 files, which do not support custom color palettes.
PCX format supports RGB, Indexed Color, Grayscale, and Bitmap color modes, and does not support alpha channels. PCX supports the RLE compression method. Images can have a bit depth of 1, 4, 8, or 24. |
|
WMF |
|
EMF |
|
TGA |
| |
TGA (Targa®) format is designed for systems using the Truevision® video board and is commonly supported by MS-DOS color applications. Targa format supports 16-bit RGB images (5 bits x 3 color channels, plus one unused bit), 24-bit RGB images (8 bits x 3 color channels), and 32-bit RGB images (8 bits x 3 color channels plus a single 8-bit alpha channel). Targa format also supports indexed-color and grayscale images without alpha channels. When saving an RGB image in this format, you can choose a pixel depth and select RLE encoding to compress the image. |
|
RAS |
| |
Sun Raster Image File Format |
|
J2K |
| |
It is JPEG 2000 format.
The JPEG-2000 image compression system has a rate-distortion advantage over the original JPEG. |
|
|
