A

AAC
Also called MPEG-4 AAC, this audio codec is the continuation of the MP3 codec created by Fraunhofer-Gesellschaft. Due to advances in the technology, AAC files encoded at a 96 kbps bit rate sound slightly better than MP3s encoded at 128 kbps.

AC3
Audio Codec 3. This was the original and more technical name for Dolby Digital. Some RF modulated, 5.1-encoded laser discs were labeled as AC3.

AMR
Adaptive Multi Rate is a high¨Cdata rate service and transmission principle for 3G cell phones and networks.

ASF
Advanced Streaming Format (formerly Active Streaming Format). A Microsoft file and data stream format for multimedia data including audio, video, still images, and other data types. Also referred to as Windows Media format.

AVI
AVI is short for “Audio Video Interleave”, the original Microsoft file format for Microsoft’s Video for Windows standard. It is an audio video standard designed by Microsoft and is apparently proprietary and Microsoft Windows specific. It is a format developed for storing video and audio information. Files in this format have an .AVI extension. However, Video for Windows does not require any special hardware, making it the lowest common denominator for multimedia applications.
Video Compact Disc (VCD) is a special version of a CD-ROM that uses the MPEG-1 format. The quality of the exported movie is almost the same, but usually better than VHS tape-based movies. A VCD can be played back on a CD-ROM drive, VCD player, and even on a DVD player.

B

bandwidth
A network’s capacity for transferring an amount of data in a given time.

bit rate
Bit rate very often used when speaking of video or audio quality and file size — defines how much physical space one second of audio or video takes in bits (note: not in bytes). The higher the bit rate, the more times per second the original sound is sampled, thus yielding a more faithful reproduction and better sound. When choosing an MP3, weigh the advantage of a higher bit rate against the size of the file. Generally speaking, a bit rate of 128 kbps or higher will provide satisfactory sound quality. Constant Bit Rate (CBR) encoding maintains the same bit rate throughout an encoded file. Variable Bit Rate (VBR) is an MP3 encoding method that’s used when file size is not an issue. Unfortunately Magic DVD Creator decodes VBR but doesn’t encode it. Selecting the proper bit rate for your projects depends on the playback target: if you’re making a VCD for playback on a DVD player, the video must be exactly 1150 Kbps and the audio 224 Kbps.

C

codec
An abbreviation for compressor/decompressor. Software or hardware used to compress and decompress digital media.

compression
A process for removing redundant data from a digital media file or stream to reduce its size, or the bandwidth used.

D

DivX
DivX is the name given to a video codec (a piece of software used for encoding and decoding video) and is based on the MPEG-4 compression format. MPEG-4 is a new standard of video compression that is both high quality and low bit rate. They are usually only a fraction (around 15%) of the size of a standard DVD, even at 640×480 resolutions, making them the best home video format thus far. They only take half the time to encode, and yet at the same time are smaller in size than MPEG-1 – due to the incredible compression technology – some have even called MPEG-4 the “MP3 of the video world”. Quality ranges from net-streaming quality to DVD and better.

F

frame
One of many sequential images that make up video.

frame rate
The number of video frames displayed per second. Higher frame rates generally produce smoother movement in the picture.

G

3GP
3gp is a file format which is used in mobile phones to store media (audio/video). This file format is a simpler version of “ISO 14496-1 Media Format”. MOV (used by QuickTime) is also a format which follows similar file format. This format can only carry video encoded as MPEG-4 or H.263. Audio is stored in AMR-NB or AAC-LC formats.

I

.IFO file
The .IFO (and backup .BUP) files contain menus and other information about the video and audio.

M

MOV
A QuickTime movie can actually be used to store both movies and sounds. A file with this extension could thus be either an audio file or a movie file. Both types are supported by many different platforms. Note though that there are several different versions of QuickTime files in use, and not all players will play all versions.

MPEG
Gives excellent compression with little loss in quality of the video. MPEG support three types of data – video, audio and streaming. There are a number of standards: among them there are two flavors of MPEG available today.

MPEG-1
MPEG-1 was designed to provide VHS video quality and CD audio quality at a combined data rate of 150 kilobytes per second. MPEG-1 is displayed at 30 frames per second in a frame that is 352×240 (horizontal x vertical) pixels in size. This allows relatively high quality video images to be stored in relatively small file sizes for playback across computer networks or CD-ROM delivery.

MPEG-2
MPEG-2 is the other side of the compression coin. It is a broadcast standard specifying a playback size of 720 x 480 pixels at 60 fields per second. Data rates can range from 2 to 10 megabits per second. This means large file sizes and data rates that require specialized hardware for playback. MPEG-2 is one of the core compression technologies for DVD. See the MPEG site for more information.

 

O

Options

Audio Options

`-ar freq’
Set the audio sampling frequency (default = 44100 Hz).

`-ab bitrate’
Set the audio bitrate in kbit/s (default = 64)

`-ac channels’
Set the number of audio channels (default = 1).

`-an’
Disable audio recording.

`-acodec codec’
Force audio codec to codec. Use the copy special value to specify that the raw codec data must be copied as is.

Video Options

`-b bitrate’
Set the video bitrate in kbit/s (default = 200 kb/s).

`-r fps’
Set frame rate (default = 25).

`-s size’
Set frame size. The format is `wxh’ (default = 160×128).

`-aspect aspect’

Set aspect ratio (4:3, 16:9)

`-vcodec codec’
Force video codec to codec. Use the copy special value to tell that the raw codec data must be copied as is.

Audio / Video Grab Options

`-vd device’
sEt video grab device (e.g. `/dev/video0′).

`-vc channel’
Set video grab channel (DV1394 only).

`-tvstd standard’
Set television standard (NTSC, PAL (SECAM)).

`-dv1394′
Set DV1394 grab.

`-ad device’
Set audio device (e.g. `/dev/dsp’).

R

RM
RealMedia is a digital sound and video file format that is the registered trademark of RealNetworks. This format is typically used to stream media through the net. It can be played with the RealOne player or with other media players using the Real Alternative codec.

S

Sample Rate
The speed at which audio samples are recorded and played back. This is analogous to video and film frame rates. Higher sample rates give higher audio quality at the expense of larger audio file size. Lower sample rates save disk space but result in poorer audio quality. Typically, 8 kHz is fine for human voice recording. Audio CDs are recorded at 44.1 kHz, and audio DATs are recorded at 32, 44.1, or 48 kHz.

SVCD
SVCD is Super Video CD, a great method to save DVD movie to CD without losing much quality. SVCD discs can be played in your DVD player.

SWF
The SWF graphic file format is a version of the Macromedia Flash Player vector-based graphics format introduced in 1997. The SWF file format is ideal for presenting vector-based interactive and animated graphics with sound for the Web.

V

VOB
A data file used in the DVD Video format to deliver video, audio, and graphics.

W

WAV
A digitized sound file format for Microsoft Windows, which has “.wav” as the file name extension. Most pre-mastering software ill extract CD (CD-audio) tracks and write them to the hard disk as a Wav file. Wav files can have various qualities of sound depending on how they are created or saved, but the most common is 44,100 Hz, 16 bit, stereo (equivalent to audio track on CD).

WMV
Windows Media Video (WMV) is a generic name for the set of proprietary streaming video technologies developed by Microsoft. It is part of the Windows Media framework.

Y

YUV
YUV is the color space used in the PAL system of television broadcasting which is the standard in most of Europe and some other places. Y stands for the luminance component (the brightness) and U and V are the chrominance (color) components. The YCbCr or YPbPr color space, used in computer component video, is derived from it (Cb/Pb and Cr/Pr are simply scaled versions of U and V), and is sometimes inaccurately called “YUV”.

Advertisements