<story><title>FLAC – Format overview</title><url>https://xiph.org/flac/documentation_format_overview.html</url></story><parent_chain><item><author>mustache_kimono</author><text>FLAC makes lots of smart decisions.  One constraint on lossless audio should, of course, be that it&amp;#x27;s actually lossless (which the test suite confirms), but also that it &lt;i&gt;makes it easy for the user to confirm the audio streams are the same as the decoded WAV file&lt;/i&gt; (`flac -t`) by storing a checksum of the stream.&lt;p&gt;I have often wondered why other media formats don&amp;#x27;t do a similar thing, especially since changing a media file&amp;#x27;s tags (which can change the checksum of a file) or name (which makes external verification from txt file difficult) is quite common.  I even wrote a utility[0] that uses ffmpeg to hash all ffmpeg compatible bitstreams, and store their hashes in a xattr (yes, with lots of other options to test and compare, etc.), but all media formats should just be as clever (and care as much) to do this natively, like FLAC.&lt;p&gt;I mean -- why not?&lt;p&gt;[0]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;kimono-koans&amp;#x2F;dano&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;kimono-koans&amp;#x2F;dano&lt;/a&gt;</text></item></parent_chain><comment><author>Lammy</author><text>This was how I discovered my problem when I had bad non-ECC RAM in a machine with ZFS.</text></comment>
<story><title>FLAC – Format overview</title><url>https://xiph.org/flac/documentation_format_overview.html</url></story><parent_chain><item><author>mustache_kimono</author><text>FLAC makes lots of smart decisions.  One constraint on lossless audio should, of course, be that it&amp;#x27;s actually lossless (which the test suite confirms), but also that it &lt;i&gt;makes it easy for the user to confirm the audio streams are the same as the decoded WAV file&lt;/i&gt; (`flac -t`) by storing a checksum of the stream.&lt;p&gt;I have often wondered why other media formats don&amp;#x27;t do a similar thing, especially since changing a media file&amp;#x27;s tags (which can change the checksum of a file) or name (which makes external verification from txt file difficult) is quite common.  I even wrote a utility[0] that uses ffmpeg to hash all ffmpeg compatible bitstreams, and store their hashes in a xattr (yes, with lots of other options to test and compare, etc.), but all media formats should just be as clever (and care as much) to do this natively, like FLAC.&lt;p&gt;I mean -- why not?&lt;p&gt;[0]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;kimono-koans&amp;#x2F;dano&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;kimono-koans&amp;#x2F;dano&lt;/a&gt;</text></item></parent_chain><comment><author>hnuser123456</author><text>Are there any good ways to tell if audio has been lossy compressed but then re-encoded in a lossless format, or deceptively high lossy bitrate?</text></comment>