mad-dev January 2004

mad-dev@lists.mars.org

7 participants
7 discussions

#define CHAR_BIT 16
by Grigory A. 14 Mar '04

14 Mar '04

H! In my system minimum accessible variable is 16 bits wide. So I can use two technique I. Use low part of my 16 bits wide char. Use default #define CHAR_BIT 8 - this one working well. II. Try to use #define CHAR_BIT 16. This one has several problems 1. in decode_header() here sync: ... else if (!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) { ... goto fail; } I solve it by else if (!((ptr[0] & 0xffe0) == 0xffe0)) it works. 2. III_huffdecode() function. I guess problem is here: // ---- align bit reads to byte boundaries ----- takes up to 32 bit ?? cachesz = mad_bit_bitsleft(&peek); cachesz += ((32 - 1 - 24) + (24 - cachesz)) & ~7; ... or here: if (cachesz < 21) { unsigned int bits; bits = ((32 - 1 - 21) + (21 - cachesz)) & ~7; ... It isn't work - at the middle of mp3 file I have MAD_ERROR_BADHUFFDATA So could you say to me these numbers: 32, 24, ... - what is the reason and how to calculate them for my case #define CHAR_BIT 16 ? And what I need to do more - to work with 16 bits wide char? Thanks for answers. -- Best regards, Grigory mailto:Ryhor@tut.by

2 1

LAME tags
by Glenn Maynard 24 Jan '04

24 Jan '04

I've been writing a simple test set for decoding, and one failure (an extra frame of silence at the start) was files that have an "Info" tag instead of "Xing". LAME writes this in CBR mode (perhaps to avoid confusing apps that assume files with Xing tags are VBR). Fb2k's "fix MP3 header" command also writes this (for both CBR and VBR). -- Glenn Maynard

1 0

Hi
by jpsaman＠wxs.nl 19 Jan '04

19 Jan '04

------------------ Virus Warning Message (on the network) Found virus WORM_BAGLE.A in file hdjbcieuj.exe The file hdjbcieuj.exe is moved to /var/log/virus/virIGTPNJ9Wz. This is a machine-generated message, please do not reply via email. If you have questions, please contact the Lucent Help Desk at +1 888 300 0770. --------------------------------------------------------- Test =) xuboovw -- Test, yep. ------------------ Virus Warning Message (on the network) hdjbcieuj.exe is removed from here because it contains a virus. ---------------------------------------------------------

1 0

lost synchronization error on ARM PDA!
by zw_0000 18 Jan '04

18 Jan '04

hi, I now compile libmad and madplay in a cross compile environment to build target code for PDA with ARM CPU, after I download target code to ARM PDA, whenever I play any mp3 file on ARM machine, the madplay alway tips me the same error: decode frame 305 , lost sychronization. is this error of libmad or madplay? what cause the error? can any one can tell me. any of your help will be appreciated! walker

2 1

Re: C++ wrapper
by Erik Jälevik 17 Jan '04

17 Jan '04

I just looked through the archives to find information on MAD and if there was any higher-level way of getting an MP3 decoded and came across the recent post about a C++ wrapper. I'd be very interested in such a thing as I'm not particularly keen on implementing all the different callback functions if I don't have to. All I need is some method for getting one decoded sample at a time for further processing within a beat-tracking application. Samuel, what functionality do you have at the moment? Would it be possible to just send the wrapper a filename and then proceed to call a read() method or such? Does it take care of downsampling to 16-bit, frequency conversion (if necessary), checking endian-ness etc? Erik

2 1

Intensity Stereo and LSF_EXT
by Grigory A. 14 Jan '04

14 Jan '04

Hi! I am sorry for my question. But ... could someone give me link or just send to my e-mail (no big please - up to 1Mb) some audible mp3 bit-streams with Intensity Stereo and Intensity Stereo LSF_EXT stereo data encoding? Thanks. And sorry again. Best regards, Grigory mailto:Ryhor@tut.by

1 0

C++ wrapper
by Samuel Krempp 10 Jan '04

10 Jan '04

Is there interest in a C++ wrapper to mad's API ? and for a simplistic one ? ;-) I'm asking, because I somehow ended up writing a simple C++ wrapper to MAD API. (a strictly C++ one. only ISO C++ headers used, plus shared_ptr from Boost.org, which is a high quality collection of standard-conforming, portable libraries) Atm it's providing access to the most important API features in some high-level way (plus lower level functions provided for finer control). for instance : std::ostream * destination; // a file, a custom stream, whatever.. using namespace MadSam; MadSam_Engine sam_engine; sam_engine.open_mp3("toto.mp3"); bool ok=true; while(ok) { ok = sam_engine.get_synth(); sam_engine.cur_synth_to_16bit_flow( *destination);//16-bit raw output } but it's far from polished (doesnt address all cases, the interface is not polished..). I'm using it in a toy decoder/player I'm writing (playing float samples with the jackit client API) ; and if this wrapper can be useful for MAD (eg as a sample for C++ developpers planning to use MAD, or whatever) I would try to make it as clean and self-explaining as I can. (but I would not spend weeks trying to make it feature-complete, though) BTW : the madlld example client would deserve a link somewhere on MAD's web pages. I think it's the best documentation material for newcomers at this moment, and I only found a reference to it after downloading the whole mail archive. (so I mostly used minimad.c to get into the API, and it wasnt as smooth as it would have been if I had known about madlld.c) -- Samuel

1 0

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

mad-dev January 2004