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More => Old Versions => Media Center 16 (Development Ended) => Topic started by: MrC on September 19, 2011, 07:52:17 pm

Title: Secure rip issue
Post by: MrC on September 19, 2011, 07:52:17 pm

I'm seeing a problem with MC and secure ripping.

I ripped a CD with one drive, and MC says the CD rip was in secure mode, and there were no retries:

I'm with You - Red Hot Chili Peppers
>>> Drive D: TSSTcorpDVDWBD SH-B123L
        Mode:ModeSecure  Type:Auto  Speed:Max

   Track  4: Secure rip, no re-tries. [Ethiopia]

But the CD has an audible silent gap at 1 minute 50 seconds into the track.

I re-rip with another drive:

>>> Drive D: TSSTcorpCDDVDW SH-S203N
        Mode:ModeSecure  Type:Auto  Speed:Max

   Track  4: Secure rip, no re-tries. [Ethiopia]

and again MC says  there were no retries.  This time, there is no audible silent gap at 1:50.  So, let's see if the two files are the same size at least:

Code: [Select]

$ ls -l "bad - 04 Ethiopia.flac" "04 Ethiopia.flac"
-rwxr-xr-x+ 1 MrC None 28280288 Sep 19 17:25 04 Ethiopia.flac
-rwxr-xr-x+ 1 MrC None 28280288 Sep  8 14:08 bad - 04 Ethiopia.flac
Yup, same size.  Now let's look at those bytes:

Code: [Select]

$ cmp -l "bad - 04 Ethiopia.flac" "04 Ethiopia.flac"
     137  60 (0x30)  67 (0x37)
13550716  44 (0x24)  54 (0x2c)
So, there is a small difference at the beginning of the file (no surprise), but midway into the track data, the difference of a single bit is causing the audible gap.

Let's test with flac:

Code: [Select]

$ flac -t bad\ -\ 04\ Ethiopia.flac

flac 1.2.1, Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  Josh Coalson
flac comes with ABSOLUTELY NO WARRANTY.  This is free software, and you are
welcome to redistribute it under certain conditions.  Type `flac' for details.

bad - 04 Ethiopia.flac: testing, 46% complete
bad - 04 Ethiopia.flac: *** Got error code 2:FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH

bad - 04 Ethiopia.flac: ERROR while decoding data
                        state = FLAC__STREAM_DECODER_READ_FRAME

Should this shake my confidence in MC's reporting of a secure rip with no retries?  Or perhaps this was a memory error during the wav -> flac conversion?

Comments?

Title: Re: Secure rip issue
Post by: Vincent Kars on September 20, 2011, 03:15:15 am

Looks bad.
It is possible it is a matter of flaky memory.
If possible re-rip with dbPoweramp or EAC to isolate the problem.

Title: Re: Secure rip issue
Post by: Alex B on September 20, 2011, 03:17:21 am

Probably a memory or disk error.

The analysis is done before encoding and saving the ripped file. In the secure mode the ripper reads each CD sector at least twice and compares the extracted raw PCM data before passing it on.

Title: Re: Secure rip issue
Post by: AoXoMoXoA on September 20, 2011, 08:25:57 am

Quote from: Alex B on September 20, 2011, 03:17:21 am

Probably a memory or disk error.

The analysis is done before encoding and saving the ripped file. In the secure mode the ripper reads each CD sector at least twice and compares the extracted raw PCM data before passing it on.

So doesn't it / shouldn't it / couldn't it also follow up with an option for "after encoding verify written audio" for proper encoding, like dbPower Music Converter does?