Issue opening .avi video files.

chris2209

Hi Guys,

I am experiencing difficultly opening .avi files on Image Pro Analyzer. After the Sequence Image Selection window I am presented with the error message: 

'Error opening C:\Year3\IMG_0450.avi <-5>'

Has anyone experienced this error before? I have used IPA on many .avi videos before so I'm unsure as to why this occurring!

Many Thanks,

Chris 

YuriG

Chris,

AVI files use different codecs. The computer you use must have the codec the AVI file was saved with. Please check if you have it on that PC.

Yuri

VernR

CODECS

A CODEC is a device or computer program capable of encoding and/or decoding a digital data stream or signal.   The word CODEC is a portmanteau (a blending of two or more words) of 'compressor-decompressor' or, more commonly, 'coder-decoder'.

Historically a modem was a contraction of modulator/demodulator (modem was called dataset by telcos) and converted digital data from computers to analog for phone line transmission.  On the receiving end the analog was converted back to digital.  CODECS did the opposite (convert audio analog to digital and then computer digital sound back to audio).  There was no compression involved in CODECS, only coding and decoding.

An ENDEC (encoder/decoder) is a similar yet different concept mainly used for hardware.  In the mid 20th century, a "CODEC" was hardware that coded analog signals into Pulse-code modulation (PCM) and decoded them back.  Late in the century the name came to be applied to a class of software for converting among digital signal formats.

A CODEC encodes a data stream or signal for transmission, storage or encryption, or decodes it for playback or editing.  CODECS are used in videoconferencing and streaming media applications.  A video camera's analog-to-digital converter (ADC) converts its analog signals into digital signals, which are then passed through a video compressor for digital transmission or storage.  A receiving device then runs the signal through a video decompressor, then a digital-to-analog converter (DAC) for analog display.  The term CODEC is also used as a generic name for a video conferencing unit.

An audio compressor converts analog audio signals into digital signals for transmission or storage.  A receiving device then converts the digital signals back to analog using an audio decompressor, for playback.  An example of this are the CODECS used in the sound cards of personal computers.

 

 

VernR

CODECS, AVI files and Image Pro

Audio Video Interleave, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology.   AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback.  Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used.  Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0".

AVI is a derivative of the Resource Interchange File Format (RIFF), which divides a file's data into blocks, or "chunks.   An AVI file takes the form of a single chunk in a RIFF formatted file, which is then subdivided into two mandatory "chunks" and one optional "chunk".

By way of the RIFF format, the audio/visual data contained in the "movi" chunk can be encoded or decoded by the software CODEC.  Upon creation of the file, the CODEC translates between raw data and the (compressed) data format used inside the chunk.  An AVI file may carry audio/visual data inside the chunks in virtually any compression scheme, including Full Frame (Uncompressed).

Once the AVI file has been encoded, it must be decoded to be opened, and like having the correct cipher to decode a secret message, the same CODEC must be used to decode the AVI.

If the correct CODEC is installed on a computer system, opening (viewing) the AVI file is a simple matter.  If the correct CODEC is not installed, however, the computer system can never open the encoded file.

If the file does not open on a system, it would be necessary to find and install the correct CODEC so that the file may be properly decoded and displayed.  This may be accomplished by installing the encoding software on the target system.  If the original encoding software is not available, the CODEC information is also contained in the properties of the file.  If the named CODEC can be found and installed, the file can be opened.

A way around the need of a CODEC is to save the AVI file in an uncompressed form.  Non-compression obviates the need for a CODEC and allows the file to be opened by and on any computer system.

For Image Pro to open the file the proper CODEC must be installed on the system or the file must be uncompressed.  To convert from a compressed form to an uncompressed form, the file must be opened in the original software (so the correct CODEC may be used) and re-saved in the uncompressed form.

If neither of these conditions exist (No CODEC on the system, not an uncompressed AVI, no access to the original software) then the originating software company will have to be contacted so that the correct CODEC may be obtained.  Often this CODEC may need to be purchased from the originating software company.

CODECS do not have a standard and any company needing to encode its files may create its own CODEC to compress a file its software creates.  CODECS are protected under DRM and are not widely distributed outside of a company’s software package.  Because of this, every company that saves AVI files has to create its own CODEC and protect its use and distribution.  For this reason, too, CODECS cannot be included with, or installed by, Image Pro. 

Copies of CODECS are posted on some websites but these carry the same dubious legalities as sites that post pay software for free download.  If inclined, and due to need, a simple web search for the CODEC in question may be performed to uncover a site posting a free copy of the CODEC with the understanding that downloading the CODEC may violate DRM laws.

Once the appropriate CODEC has been acquired, the matter is simple to install it.  Most encapsulate the CODEC in an installer package that you need only run to have the necessary files placed in the correct folders, and have the files registered with the system.  Once the CODEC has been installed and registered, the AVI file may be opened on the system and with Image Pro.