Audio Compression Manager
Audio Compression Manager (ACM) is a Windows multimedia framework that manages audio codecs (compressor/decompressors). ACM can also be considered an API specification. A codec must conform to the implicit ACM specification to work with Windows Multimedia. ACM files can be recognized by their filename extension .acm . ACM files also use RIFF-compatible filetypes such as WAV or AVI as a "wrapper" to store audio data encoded by any audio codec supported by ACM.
ACM is considered an outdated framework/API and Microsoft now encourages the use of at least DirectShow. However, unlike ACM and the related Video Compression Manager (VCM), DirectShow provides no means to encode files for end-users but requires developers to build end-to-end graphs for encoding content. ACM also does not support VBR audio streams; therefore newer codecs like MPEG-4 AAC, Ogg Vorbis, FLAC etc. cannot be supported through ACM if using variable bitrates. Though many sources state the contrary, Ogg Vorbis does work well with the ACM, e.g. when embedded in a RIFF-compatible file (such as a WAV or AVI file as mentioned earlier), provided the Ogg Vorbis stream is encoded at a constant bitrate.
Read more about this topic: Windows Legacy Audio Components
Famous quotes containing the words compression and/or manager:
“The triumphs of peace have been in some proximity to war. Whilst the hand was still familiar with the sword-hilt, whilst the habits of the camp were still visible in the port and complexion of the gentleman, his intellectual power culminated; the compression and tension of these stern conditions is a training for the finest and softest arts, and can rarely be compensated in tranquil times, except by some analogous vigor drawn from occupations as hardy as war.”
—Ralph Waldo Emerson (1803–1882)
“I knew a gentleman who was so good a manager of his time that he would not even lose that small portion of it which the calls of nature obliged him to pass in the necessary-house, but gradually went through all the Latin poets in those moments. He bought, for example, a common edition of Horace, of which he tore off gradually a couple of pages, read them first, and then sent them down as a sacrifice to Cloacina: this was so much time fairly gained.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)