Some info on Flac by McIntosh for those that are confused
I posted the following info elsewhere when this subject came up in the past.
From McIntosh's downloadable guide:
Notable features of FLAC
• Lossless: The encoding of audio (PCM) data incurs no loss of information, and the decoded audio is bit-for-bit identical to what went into the encoder. Each frame contains a 16-bit CRC of the frame data for detecting transmission errors.
The integrity of the audio data is further insured by storing an MD5 signature of the original unencoded audio data in the file header, which can be compared against later during decoding or testing.
• Fast: FLAC is asymmetric in favor of decode speed. Decoding requires only
integer arithmetic, and is much less compute-intensive than for most perceptual codecs. Real-time decode performance is easily achievable on even modest hardware.
• Hardware support: Because of FLAC's free reference implementation and low
decoding complexity, FLAC is currently the only lossless codec that has any kind of hardware support.
• Streamable: Each FLAC frame contains enough data to decode that frame. FLAC does not even rely on previous or following frames. FLAC uses sync codes and CRCs (similar to MPEG and other formats), which, along with framing, allow decoders to pick up in the middle of a stream with a minimum of delay.
• Seekable: FLAC supports fast sample-accurate seeking. Not only is this useful for playback, it makes FLAC files suitable for use in editing applications.
• Flexible metadata: New metadata blocks can be defined and implemented in
future versions of FLAC without breaking older streams or decoders
• Suitable for archiving: FLAC is an open format, and there is no generation loss if you need to convert your data to another format in the future. In addition to the frame CRCs and MD5 signature, flac has a verify option that decodes the encoded stream in parallel with the encoding process and compares the result to the original, aborting with an error if there is a mismatch.• Convenient CD archiving: FLAC has a "cue sheet" metadata block for storing a CD table of contents and all track and index points. For instance, you can rip a CD to a single file, then import the CD's extracted cue sheet while encoding to MS300 Advanced Users Guide yield a single file representation of the entire CD. If your original CD is damaged,the cue sheet can be exported later in order to burn an exact copy.
• Error resistant: Because of FLAC's framing, stream errors limit the damage to the frame in which the error occurred, typically a small fraction of a second worth of data. Contrast this with some other lossless codecs, in which a single error destroys the remainder of the stream.
What FLAC is not
• Lossy. FLAC is intended for lossless compression only, as there are many good lossy formats already, such as Vorbis, MPC, and MP3 (see LAME for an
excellent open-source implementation).
• SDMI compliant, et cetera. There is no intention to support any methods of copy protection, which are, for all practical purposes, a complete waste of bits. (Another way to look at it is that since copy protection is futile, it really carries no information, so you might say FLAC already losslessly compresses all possible copy protection information down to zero bits!) Of course, we can't stop what some misguided person does with proprietary metadata blocks, but then again,non-proprietary decoders will skip them anyway.
http://www.mcintoshlabs.com/data/ma...users.guide.pdf
__________________
I posted the following info elsewhere when this subject came up in the past.
From McIntosh's downloadable guide:
Notable features of FLAC
• Lossless: The encoding of audio (PCM) data incurs no loss of information, and the decoded audio is bit-for-bit identical to what went into the encoder. Each frame contains a 16-bit CRC of the frame data for detecting transmission errors.
The integrity of the audio data is further insured by storing an MD5 signature of the original unencoded audio data in the file header, which can be compared against later during decoding or testing.
• Fast: FLAC is asymmetric in favor of decode speed. Decoding requires only
integer arithmetic, and is much less compute-intensive than for most perceptual codecs. Real-time decode performance is easily achievable on even modest hardware.
• Hardware support: Because of FLAC's free reference implementation and low
decoding complexity, FLAC is currently the only lossless codec that has any kind of hardware support.
• Streamable: Each FLAC frame contains enough data to decode that frame. FLAC does not even rely on previous or following frames. FLAC uses sync codes and CRCs (similar to MPEG and other formats), which, along with framing, allow decoders to pick up in the middle of a stream with a minimum of delay.
• Seekable: FLAC supports fast sample-accurate seeking. Not only is this useful for playback, it makes FLAC files suitable for use in editing applications.
• Flexible metadata: New metadata blocks can be defined and implemented in
future versions of FLAC without breaking older streams or decoders
• Suitable for archiving: FLAC is an open format, and there is no generation loss if you need to convert your data to another format in the future. In addition to the frame CRCs and MD5 signature, flac has a verify option that decodes the encoded stream in parallel with the encoding process and compares the result to the original, aborting with an error if there is a mismatch.• Convenient CD archiving: FLAC has a "cue sheet" metadata block for storing a CD table of contents and all track and index points. For instance, you can rip a CD to a single file, then import the CD's extracted cue sheet while encoding to MS300 Advanced Users Guide yield a single file representation of the entire CD. If your original CD is damaged,the cue sheet can be exported later in order to burn an exact copy.
• Error resistant: Because of FLAC's framing, stream errors limit the damage to the frame in which the error occurred, typically a small fraction of a second worth of data. Contrast this with some other lossless codecs, in which a single error destroys the remainder of the stream.
What FLAC is not
• Lossy. FLAC is intended for lossless compression only, as there are many good lossy formats already, such as Vorbis, MPC, and MP3 (see LAME for an
excellent open-source implementation).
• SDMI compliant, et cetera. There is no intention to support any methods of copy protection, which are, for all practical purposes, a complete waste of bits. (Another way to look at it is that since copy protection is futile, it really carries no information, so you might say FLAC already losslessly compresses all possible copy protection information down to zero bits!) Of course, we can't stop what some misguided person does with proprietary metadata blocks, but then again,non-proprietary decoders will skip them anyway.
http://www.mcintoshlabs.com/data/ma...users.guide.pdf
__________________
