mad-dev September 2005

mad-dev@lists.mars.org

8 participants
13 discussions

Minimad code size
by Tiemen Schut 07 Oct '05

07 Oct '05

Hello, We are currently trying to develop an arm-mp3 player. ( http://groups.google.com/group/qamp/, not very interesting really) Problem is, the code size generetad by arm-elf-gcc is about 300k, while all the different object files are about 100k. We already worked around the rq_table.dat using a Taylor approximation. The problem is we only have 128k flash available (we use a real embedded system, not some sort of arm with megs of memory and some weird linux kernel ;)) We started developing under windows (Dev-C++), trying to get to know mad. We were able to decode an mp3 file to pcm without much trouble. The windows executable however, is only 181k, and that includes rq_table.dat. We already tried using -o2 for gcc and strip, but that didn't get us very far. Neither do we include any unnecessary files (layer12.c, sys/*.h, etc). Any help would be appreciated as we pretty much have given up on this ourselves... Tiemen Schut

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Re: Regarding the resulting .pcm file
by Romain Farkas 30 Sep '05

30 Sep '05

Harald, You might wanna try Steinberg's Wavelab which allows you to import RAW PCM data (you have to supply to the software the number of bits, the way data is organized (signed, unsigned, ...)). I guess some open-source software could also do the trick (Audacity ?) Regards, Romain -- -------------------------------- Romain Farkas Etudiant / Assistant-Etudiant KIS Génie Electrique et Electronique 3e année STI EPFL --------------------------------

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Regarding the resulting .pcm file
by Håvard Sperle Engebretsen 30 Sep '05

30 Sep '05

Hi! I hope I am not driving you guys crazy with all my questions, but I really need your help. Even though I get several errors during execution of minimad with the "./minimad <test.mp3> test.pcm" command, a test.pcm file is generated in the directory. (The test.mp3 file is just a small ordinary mp3 file I have renamed test.mp3) The question is: I am interrested in hearing how the decoding turned out (if possible), but I can't play the .pcm file in any regular media player. How, if possible, do I do this? H. --

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RE: [mad-dev] Errors when running minimad
by Bruno Gauthier 30 Sep '05

30 Sep '05

About the "lost synchronisation", "forbidden bitrate" value, I could be wrong but, from what I have found on my side, for avoid most (98%) of these errors; you have to feed the MAD decoder with 1 second chunk. That means 37 MPEG-1 packets that you detect with the following routine: #define MPEG1_SYNC_NOT_FOUND -1 //------------------------------------------------------------------------------ //------------------------------------------------------------- FindMPEG1SyncPos //------------------------------------------------------------------------------ int CMADDecoder::FindMPEG1SyncPos(BYTE *pFrame, int FrameSize){ //------------------------------- Variables -------------------------------- int LastBytePos = FrameSize - 1; int i ; //--------------------------------- Code ----------------------------------- //printf ("\n CMADDecoder::FindMPEG1SyncPos:: 0x%08X-%d", // pFrame, FrameSize); //fflush(stdout); for (i = 0; i < LastBytePos; i++){ if ( ((pFrame[i ] == 0xFF) ) && ((pFrame[i + 1] & 0xFC) == 0xFC) ){ return i; }// If we found the sync word }// For all the byte to check return MPEG1_SYNC_NOT_FOUND; // Not found }// FindMPEG1SyncPos Regards Bruno -----Message d'origine----- De : mad-dev-bounces(a)lists.mars.org [mailto:mad-dev-bounces@lists.mars.org] De la part de Håvard Sperle Engebretsen Envoyé : 30 septembre 2005 09:08 À : mad-dev(a)lists.mars.org Objet : [mad-dev] Errors when running minimad Hi! 1) I'm a little bit confused! I am trying to run libmad in Cygwin and while installing libmad I flagged the configure command: "./configure --disable-shared --enable-profiling", and then made the install. Does this make libmad a static ilbrary so that I don't have to use the flag "-static" while compiling minimad.c? (I was told to make the library static because gprof doesn't support dynamic libraries...) 2) After having some problems compiling minimad.c I read in another post in the mad-dev archives that I should use "make minimad.exe" to cimpile it. This works fine, but when I try to run it with "./minimad <test.mp3> test.pcm" I get some errors: decoding error 0x0101 (lost synchronisation) at byte offset 0 decoding error 0x0103 (forbidden bitrate value) at byte offset 163 decoding error 0x0103 (forbidden bitrate value) at byte offset 213 . . . decoding error 0x0104 (reserved sample frequency value) at byte offset 224 decoding error 0x0103 (forbidden bitrate value) at byte offset 295 decoding error 0x0235 (bad main_data_begin pointer) at byte offset 412 Does anyone know what this means? Thanks in advance! H --

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Errors when running minimad
by Håvard Sperle Engebretsen 30 Sep '05

30 Sep '05

Hi! 1) I'm a little bit confused! I am trying to run libmad in Cygwin and while installing libmad I flagged the configure command: "./configure --disable-shared --enable-profiling", and then made the install. Does this make libmad a static ilbrary so that I don't have to use the flag "-static" while compiling minimad.c? (I was told to make the library static because gprof doesn't support dynamic libraries...) 2) After having some problems compiling minimad.c I read in another post in the mad-dev archives that I should use "make minimad.exe" to cimpile it. This works fine, but when I try to run it with "./minimad <test.mp3> test.pcm" I get some errors: decoding error 0x0101 (lost synchronisation) at byte offset 0 decoding error 0x0103 (forbidden bitrate value) at byte offset 163 decoding error 0x0103 (forbidden bitrate value) at byte offset 213 . . . decoding error 0x0104 (reserved sample frequency value) at byte offset 224 decoding error 0x0103 (forbidden bitrate value) at byte offset 295 decoding error 0x0235 (bad main_data_begin pointer) at byte offset 412 Does anyone know what this means? Thanks in advance! H --

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Problems compiling minimad.c
by Håvard Sperle Engebretsen 29 Sep '05

29 Sep '05

Hi! I am running Cygwin and have installed the libid3tag and libmad libraries. After installation I got the following message in the command window: ----------------------------------------------------------------- Libraries have been installed in: /usr/local/lib If you ever happen to want to link against installed libraries in a given directory, LIBDIR, you must either use libtool, and specify the full pathname of the library, or use the `-LLIBDIR´ flag during linking and do at least one of the following: -add LIBDIR to the `PATH´ environment variable during execution -add LIBDIR to the `LD_RUN_PATH´ environment variable during linking -use the `-Wl,--rpath -Wl,LIBDIR´ linker flag ----------------------------------------------------------------- When I try to compile the minimad.c file in libmad with: gcc -static -pg -minimad.c -o minimad -lmad (I'm using -static to be able to do a profiling later on ) I get an error message that says that: .../i686-pc-cygwin/bin/ld: cannot find -lmad When I am triyng to use just: gcc -static -pg minimad.c -o minimad I get several errors telling me that there are "undefined references to `name_of_function´". I'm guessing both of these problems have something to do with me not linking against installed libraries? As you probably already have figured out, I'm kind of a newbie to all of this and I would really appreciate your help. Tanks. H. --

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Problems compiling minimad.c
by Håvard Sperle Engebretsen 29 Sep '05

29 Sep '05

Hi! I am running Cygwin and have installed the libid3tag and libmad libraries. After installation I got the following message in the command window: Libraries have been installed in: /usr/local/lib If you ever happen to want to link against installed libraries in a given directory, LIBDIR, you must either use libtool, and specify the full pathname of the library, or use the `-LLIBDIR´ flag during linking and do at least one of the following: -add LIBDIR to the `PATH´ environment variable during execution -add LIBDIR to the `LD_RUN_PATH´ environment variable during linking -use the `-Wl,--rpath -Wl,LIBDIR´ linker flag When I try to compile the minimad.c file in libmad with: gcc -static -pg -minimad.c -o minimad -lmad (I'm using -static to be able to do a profiling later on ) I get an error message that says that: .../i686-pc-cygwin/bin/ld: cannot find -lmad When I am triyng to use just: gcc -static -pg minimad.c -o minimad I get several errors telling me that there are "undefined references to `name_of_function´". I'm guessing both of these problems have something to do with me not linking against installed libraries? As you probably already have figured out, I'm kind of a newbie to all of this and I would really appreciate your help. Tanks. H. --

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Problems with libmad and minimad.c
by Haavard Engebretsen 29 Sep '05

29 Sep '05

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Problem while decoding higher Kbps files
by Swapnil Wagle 27 Sep '05

27 Sep '05

Hello, There is an unusal problem that I am facing now.I have ported 'Madlib' on to PalmOS.I am able to connect to a shoutcast server and decode the mp3 data using madlib and that too for any Kbps. This works fine on simualtor. But when I ported this onto the device it works well for 32Kbps data. But when the Kbps rate is higher than this the applciation crahes. When I debugged I found out that there is a funcion in 'Layer3.c' called 'III_stereo' which gets called when the Kbps is higher than 32. if (header->mode == MAD_MODE_JOINT_STEREO && header->mode_extension) { WinDrawChars("Namaste",7,30,90); error = III_stereo(xr, granule, header, sfbwidth[0]); if (error) return error; } This causes the crash.If I comment this function that appliation doesnt crashes but the decoding doesnt takes place. This is the final phase of my project.Please help me. Regards, Swapnil

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Synchronization error near the end of file
by Marcello Maggioni 15 Sep '05

15 Sep '05

Hi all, I'm tring to get started with "libmad" so I've tried to make an application very similar to "minimad.c" , the one included in the source code, only that instead of reading and writing from STDIN to STDOUT it reads and writes from and to files. The problem that I get is that I get a strange synchronization error near the end of the file : Decoding /balthasar/****.mp3 0 <-- ID3Tad size decoding error 0x0101 (lost synchronization) at byte offset 3072836 The actual size of the file is : 3072949 I get this almost with every file I try to decode. I manage the input by creating with "malloc()" a memory area of "unsigned chars" of the size of the file , then I fread the mp3 file into memory and pass the pointer to the callback input function . I miss something or I made any mistakes? Thanks for your help. Bye Marcello PS= Do you know how to check the correctness of a Raw 16bit PCM stream?? I've tried to play my file with many players , but it doesn't work. Sorry but I'm a newbie of digital audio :)

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mad-dev September 2005