The digital processing and preservation of audio-visual archives is determined by its characteristics and is an inevitable choice for audio-visual archives management. First of all, audio-visual archives's carrier materials are easily affected by temperature, humidity, light and other factors, and compared with paper materials, they are not stable enough, so they need higher requirements for long-term preservation. In particular, the magnetic file carriers such as videos and audio tapes should not only be protected from high temperature, humidity and light, but also be protected from magnetism. Once affected by the above external factors, audio-visual archives will be easily damaged, or even the files will be scrapped. For example, there will be degaussing, breaking, deformation and magnetic powder falling off in video and audio tapes; If the photos are kept for a long time, they will turn yellow and fade, and the negatives will easily deteriorate and stick. Secondly, under the background of the continuous development of science and technology, various audio-visual equipment emerge in endlessly, and the speed of upgrading is very fast, while those old audio-visual archives materials are difficult to be kept and utilized. In particular, video and audio files often need the support of matching equipment. Archivists need to use specific models of video recorders and tape recorders to check video and audio tapes, and when they need to play them, they also need the support of corresponding video recorders and tape recorders. However, with the upgrading of audio-visual equipment, some old models of equipment will be gradually eliminated. If the original equipment fails, it will be difficult to maintain, which is one of the important reasons why it is difficult to manage and preserve for a long time in audio-visual archives. Therefore, the traditional audio-visual archives is not easy to be preserved and managed for a long time. Digitizing audio-visual archives is an effective measure to protect the traditional audio-visual archives at present. Digital processing of audio-visual archives can not only convert the original analog signal into digital signal to facilitate backup and storage, but also realize rapid digital retrieval to facilitate utilization and management. In a word, digital processing of audio-visual archives is of great significance for the management and preservation of audio-visual archives, and it is also an inevitable choice for the management of audio-visual archives.
second, the main technology of digital processing in audio-visual archives
(1) digital format conversion of video and audio archives
digital format conversion of video and audio archives is to convert the previous analog signals into discrete signals that can be recognized by computers, and this format conversion needs to be realized by computer software, such as A/D converter and WindowsWaveCN. When we need to collect new video and audio data, we can directly connect video recorders, tape recorders and other equipment to the computer and store the recorded information directly into the hard disk of the computer. This information data collection process is a digital conversion processing process.
(II) Digitization of picture archives
At present, the picture archives in archives include electronic archives and paper archives in the form of electronic documents. Electronic files in the form of electronic documents can be directly stored in the file management software, and the files can be automatically managed by software programs. If you want to borrow or output picture files, users can enter the file management program for retrieval, and then use the printer to print out the needed pictures. For paper photo archives, if they are rich in content and large in quantity, they can be electronically scanned in batches, and the scanned documents can be explained and annotated in time, mainly to clarify the shooting place and time of the pictures and the basic events they present, so as to classify and archive the photo archives in the later stage. For some worn and yellow pictures due to age, we can use PS and other software to repair them after electronic scanning to restore them to the best effect.
(3) Unified management of digital audio-visual archives
For digital audio-visual archives, you can use AdobeAudition, AdobePremiere and other software to edit and compress it, and compile independent file numbers and classification numbers for compressed audio-visual archives files in time, and then set search keywords to facilitate users to find and apply these audio-visual archives in the future, which also facilitates the work of file managers and improves work efficiency.
Third, the preservation method of audio-visual archives after digital processing
Compared with paper files, digital audio-visual archives has great advantages, and compared with the previous simulated audio-visual archives materials, it is far ahead in terms of quality assurance, fidelity and high compression rate. However, the digital audio-visual archives has a special operation mechanism and technical means, which makes it have many problems to be solved in its preservation. Therefore, we should not only pay attention to the macro issues such as the construction of the system and mechanism of digital audio-visual archives, but also make the digital audio-visual archives easy to store, consult and use. At present, the digital audio-visual archives preservation methods mainly include the following:
1. Preserve the reading equipment in audio-visual archives. After the digital processing of audio-visual archives, it no longer has manual direct reading ability, and it must rely on certain reading equipment to read audio-visual archives. Therefore, one of the important preservation methods of digital audio-visual archives is to preserve its reading equipment.
2. Simulation method. This is an important way to save the information that will be eliminated soon. This method mainly uses an emulator to simulate another computer system in one computer system to protect the important information that will be eliminated soon.
3. Data information migration method. This method mainly migrates the digital audio-visual archives from an outdated technical environment to a new technical environment on a regular basis, so as to avoid the damage and loss of data and information caused by technical upgrading and ensure its usability, readability and integrity. This method is one of the most effective ways to preserve digital audio-visual archives.
4. Improve the preservation conditions of digital audio-visual archives, establish a scientific and safe preservation environment, and strengthen the construction of hardware preservation facilities and infrastructure, such as antimagnetic cabinet and anti-magnetic library.