Thanks for bringing up this aspect, Nicholas. I seem to recall that specific hardware has a problem with certain compression levels, but I cannot recall whether that was limited to just encoding, or decoding as well. It could very well be true that I am conflating my vague memory of encoder limitations with decoder limitations. It does seem to be that the oppo BDP-95 is exhibiting problems with particular flac files. Since my original message, my friend has installed the latest version of flac and recompressed the exact files that were giving him a problem before - now with -0 or --fast he doesn't see a playback problem at all. So, even though your statements make total sense to me, the evidence seems to indicate something about the compressed data that's causing a problem. The original audio is not the issue, but how it is compressed. Here's a thought: Since the encoder looks for polynomials, could it be possible that certain decoders cannot handle certain polynomials in real time? Ah, another possibility is that the oppo BDP-95 implements an older version of the decoder, and it's merely new flac files that give it a headache. My friend happened to have an old version of flac installed on his computer, 1.1.4, and that reported stream errors with his files until he upgraded to 1.2.1 - if the oppo has anything older than 1.2.1 then I suppose that might explain the decoding problems. Brian On Feb 5, 2011, at 16:33, Nicholas Wilson wrote:> Correct me if wrong, but I was under the impression that the > processing required for playback was totally independent on the > level of compression. The encoder looks for polynomials that fit, > and it takes much more processing to find polynomials with a very > good fit and small residuals. On the other hand, the decoder just > has to multiply out the stored prediction, which is independent of > the compression level. > > Nicholas
On this note, is there any way to ask the current version of flac to create a file that is backwards compatible with an older version of flac? I suppose one possibility is to go back into the archives and grab an older version of flac, then use that to compress everything. The trouble then becomes how to determine which version of the decoder your hardware implements, so that you can make sure your flac files are not too "new" for the hardware. Brian On Feb 5, 2011, at 21:01, Brian Willoughby wrote:> Ah, another possibility is that the oppo BDP-95 implements an older > version of the decoder, and it's merely new flac files that give it a > headache. My friend happened to have an old version of flac > installed on his computer, 1.1.4, and that reported stream errors > with his files until he upgraded to 1.2.1 - if the oppo has anything > older than 1.2.1 then I suppose that might explain the decoding > problems.
Could it be metadata? Could the Oppo be scanning metadata before deciding to play files? On Sun, Feb 6, 2011 at 12:06 AM, Brian Willoughby <brianw at sounds.wa.com>wrote:> On this note, is there any way to ask the current version of flac to > create a file that is backwards compatible with an older version of > flac? I suppose one possibility is to go back into the archives and > grab an older version of flac, then use that to compress everything. > The trouble then becomes how to determine which version of the > decoder your hardware implements, so that you can make sure your flac > files are not too "new" for the hardware. > > Brian > > > On Feb 5, 2011, at 21:01, Brian Willoughby wrote: > > Ah, another possibility is that the oppo BDP-95 implements an older > > version of the decoder, and it's merely new flac files that give it a > > headache. My friend happened to have an old version of flac > > installed on his computer, 1.1.4, and that reported stream errors > > with his files until he upgraded to 1.2.1 - if the oppo has anything > > older than 1.2.1 then I suppose that might explain the decoding > > problems. > > > _______________________________________________ > Flac mailing list > Flac at xiph.org > http://lists.xiph.org/mailman/listinfo/flac >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/flac/attachments/20110206/8db6d1e3/attachment.htm
Version 1.2.1 introduced new rice coding techniques that are used by the reference encoder for 24 bit files. An older version of the decoder will have trouble with frames that use this encoding... Maybe that's where the strange noises come from... Pyt. On 6 f?vr. 2011, at 06:01, Brian Willoughby <brianw at sounds.wa.com> wrote:> Thanks for bringing up this aspect, Nicholas. I seem to recall that > specific hardware has a problem with certain compression levels, but > I cannot recall whether that was limited to just encoding, or > decoding as well. It could very well be true that I am conflating my > vague memory of encoder limitations with decoder limitations. > > It does seem to be that the oppo BDP-95 is exhibiting problems with > particular flac files. Since my original message, my friend has > installed the latest version of flac and recompressed the exact files > that were giving him a problem before - now with -0 or --fast he > doesn't see a playback problem at all. So, even though your > statements make total sense to me, the evidence seems to indicate > something about the compressed data that's causing a problem. The > original audio is not the issue, but how it is compressed. > > Here's a thought: Since the encoder looks for polynomials, could it > be possible that certain decoders cannot handle certain polynomials > in real time? > > Ah, another possibility is that the oppo BDP-95 implements an older > version of the decoder, and it's merely new flac files that give it a > headache. My friend happened to have an old version of flac > installed on his computer, 1.1.4, and that reported stream errors > with his files until he upgraded to 1.2.1 - if the oppo has anything > older than 1.2.1 then I suppose that might explain the decoding > problems. > > Brian > > > On Feb 5, 2011, at 16:33, Nicholas Wilson wrote: >> Correct me if wrong, but I was under the impression that the >> processing required for playback was totally independent on the >> level of compression. The encoder looks for polynomials that fit, >> and it takes much more processing to find polynomials with a very >> good fit and small residuals. On the other hand, the decoder just >> has to multiply out the stored prediction, which is independent of >> the compression level. >> >> Nicholas > _______________________________________________ > Flac mailing list > Flac at xiph.org > http://lists.xiph.org/mailman/listinfo/flac
Version 1.2.1 of the standard/spec or the local implementation? I've not seen "FLAC 1.0/1.1 Compliant" or "FLAC 1.2 Compliant" on the specs of hardware gear for example when FLAC is stated supported. Just a curious on-looker. On 7 February 2011 02:34, Pierre-Yves Thoulon <py.thoulon at gmail.com> wrote:> Version 1.2.1 introduced new rice coding techniques that are used by > the reference encoder for 24 bit files. An older version of the > decoder will have trouble with frames that use this encoding... Maybe > that's where the strange noises come from... > > Pyt. > > On 6 f?vr. 2011, at 06:01, Brian Willoughby <brianw at sounds.wa.com> wrote: > > > Thanks for bringing up this aspect, Nicholas. I seem to recall that > > specific hardware has a problem with certain compression levels, but > > I cannot recall whether that was limited to just encoding, or > > decoding as well. It could very well be true that I am conflating my > > vague memory of encoder limitations with decoder limitations. > > > > It does seem to be that the oppo BDP-95 is exhibiting problems with > > particular flac files. Since my original message, my friend has > > installed the latest version of flac and recompressed the exact files > > that were giving him a problem before - now with -0 or --fast he > > doesn't see a playback problem at all. So, even though your > > statements make total sense to me, the evidence seems to indicate > > something about the compressed data that's causing a problem. The > > original audio is not the issue, but how it is compressed. > > > > Here's a thought: Since the encoder looks for polynomials, could it > > be possible that certain decoders cannot handle certain polynomials > > in real time? > > > > Ah, another possibility is that the oppo BDP-95 implements an older > > version of the decoder, and it's merely new flac files that give it a > > headache. My friend happened to have an old version of flac > > installed on his computer, 1.1.4, and that reported stream errors > > with his files until he upgraded to 1.2.1 - if the oppo has anything > > older than 1.2.1 then I suppose that might explain the decoding > > problems. > > > > Brian > > > > > > On Feb 5, 2011, at 16:33, Nicholas Wilson wrote: > >> Correct me if wrong, but I was under the impression that the > >> processing required for playback was totally independent on the > >> level of compression. The encoder looks for polynomials that fit, > >> and it takes much more processing to find polynomials with a very > >> good fit and small residuals. On the other hand, the decoder just > >> has to multiply out the stored prediction, which is independent of > >> the compression level. > >> > >> Nicholas > > _______________________________________________ > > Flac mailing list > > Flac at xiph.org > > http://lists.xiph.org/mailman/listinfo/flac > _______________________________________________ > Flac mailing list > Flac at xiph.org > http://lists.xiph.org/mailman/listinfo/flac >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/flac/attachments/20110207/f338d583/attachment.htm