mad-dev September 2004

mad-dev@lists.mars.org

13 participants
17 discussions

autoconf
by David 01 Oct '04

01 Oct '04

I've been working for the last several days on adding lirc support directally into 'madplay' and am almost done, but I have a few questions that would make the finishing touches a lot easier. Question: I don't know anything about autoconf or automake or what a m4 macro is. I have manually edited the Makefile to support my builds, but i'm trying for correct implementation. The lirc web site says that only the following lines would be neded to add to the configuration process (files) to check for support. here is the site for refereence. http://www.lirc.org/html/technical.html#library dnl Check for LIRC client support dnl This really is not worth making a separate file for it. have_lirc=yes AC_REQUIRE_CPP AC_CHECK_LIB(lirc_client,lirc_init, AC_CHECK_HEADER(lirc/lirc_client.h,true,have_lirc=no),have_lirc=no) if test "$have_lirc" = "yes"; then dnl AC_DEFINE(HAVE_LIRC); true; else AC_MSG_ERROR([*** LIRC client support not available ***]); fi Can someone plese tell me where and in which file to add these lines? Or just forward to me directally a copy of the files in a fixed state. I'm not sure that this is all that is actually needed I did have to add this line to the Makefile to correctly link the program LDFLAGS += /usr/lib/liblirc_client.so Hope this helps, and sorry I really don't understand automake and conf.

2 2

License issues
by Emil Rojas 01 Oct '04

01 Oct '04

I'm curious about the GPL license issues. Does linking the unchanged library in an application cause all of ones application code to be subject to the GPL? If this is not the appropriate forum for this question, I would appreciate being directed to an appropriate location. thanks, emil

4 3

i/o redirect problem w/minimad
by Emil Rojas 28 Sep '04

28 Sep '04

If I run minimad like: minimad < x.mp2 > x.pcm it works fine, but if I run it like cat x.mp2 | minimad > x.pcm The state returns a zero size the minimad exits. Does anyone have any idea why this might happen? thanks, emil

2 2

cross compile issue resolved
by Emil Rojas 28 Sep '04

28 Sep '04

I just want to report that the cross compile issue I had with minimad appears to be resolved. Part of the problem was that my MPEG source was mono, and I was trying to play it as stereo. So the sound output depended a lot on the input, i.e. something that started as a chirp got more messed with then did a song, and both play at 2X. I don't know if this was the only problem, but I remade from a clean installation and changed my copy of minimad to output stereo and I got the desired result. I probably will not resolve the issue with zlib and the configuration with for cross platform installation of mad play. emil

1 0

audio-jaguar
by pmisteli 25 Sep '04

25 Sep '04

Why is audio-jaguar in madplay not finished ? Has anyone finished it ?

2 1

(no subject)
by pmisteli 25 Sep '04

25 Sep '04

Why is audio-jaguar in madplay not finished ? Has anyone finished it ?

1 0

Re: [mad-dev] Cross complilation/running minimad
by Emil Rojas 24 Sep '04

24 Sep '04

Ok, I was able to execute the actual code, but I the output is not correct. Here is what I did cat ~/data/audio/bfire-w2m.mp2 ./minimad > x.pcm I then encapsulate the PCM as a wave file with a program I wrote, and produced the file x-mni.wav and I also did on the development linux machine. ./madplay --output=wave:x.-mp86.wav ~/data/audio/bfire-w2m.mp2 You can see that file size is different here: -rw-r--r-- 1 erojas users 37528 Sep 24 13:33 x-mini.wav -rw-r--r-- 1 erojas users 16172 Sep 24 13:36 x-mp86.wav When I play these files on a PC using winamp the madplay produced file is correct, and the minimad produced file is white noisy. Any ideas? Endianess? Number of bits per sample? It does output PCM? -------------------- Re: building madplay for the target, I'm having a devil of a time. Because I need to first install both the MAD library and tags library. But I can get the tags library to figure because it needs zlib. I have tried installing zlib, and I believe this has been done correctly, but the configure for the tags lib can not find it. I think this is because it is not telling the compiler to look in the right place, but I'm not really sure. Re: script problem: The problem my be that I am installing the code in a directory that is later mounted as the root of the STB that I am developing for. I tried removing that part of the path in the one place it appeared and then executing it on the target but I still had the same error. thanks, emil At 02:30 PM 9/23/2004, Rob Leslie wrote: >On Sep 23, 2004, at 2:22 PM, Emil Rojas wrote: >> Hmm, I still get this stuff when I try to run minimad, do have any idea >> what would cause that? I will make madplay and try it also. > >I think it is probably because the minimad "executable" that is built is >really only a shell script that invokes the real executable after first >arranging to locate the correct shared libraries in the build environment >(as they may not be installed yet). > >The real executable lives in the .libs subdirectory. > >-- >Rob Leslie >rob(a)mars.org >

2 1

MMAP in minimad
by Emil Rojas 23 Sep '04

23 Sep '04

I have compiled by madplay and minimad. Madpaly appears to work corrrectly, but minimad fails at the mmap() call. And clues? emil

2 1

Cross complilation
by Emil Rojas 23 Sep '04

23 Sep '04

The MAD code drop does not appear to be set up for cross compilation. I have tried to modify the makefile and libtool script to used tools with CROSS_COMPILE prepended. The code, madlib and minimad compile but when I try to run minimad I get the output below and I have no idea what it means. I have been able to compile and run madpaly for my development platform, an X86 linux PC. Any help greatly appreciated. If you can CC me in any reply I would appreciate that also. ------------------ minimad sed_quote_subst=s/$[\\`\\"$\\\\]$/\\\1/g: not found relink_command=(cd /home/erojas/src/shell/madplay/madlib-xilleon; { test -z "${LIBRARY_PATH+set}" || unset LIBRARY_PATH || { LIBRARY_PATH=; export LIBRARY_PATH; }; }; { test -z "${COMPILER_PATH+set}" || unset COMPILER_PATH || { COMPILER_PATH=; export COMPILER_PATH; }; }; { test -z "${GCC_EXEC_PREFIX+set}" || unset GCC_EXEC_PREFIX || { GCC_EXEC_PREFIX=; export GCC_EXEC_PREFIX; }; }; { test -z "${LD_RUN_PATH+set}" || unset LD_RUN_PATH || { LD_RUN_PATH=; export LD_RUN_PATH; }; }; PATH=".:/home/erojas/bin:/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/tools/bin:/sbin:/usr/sbin:/home/erojas/bin"; export PATH; /usr/tools/bin/mipsel-linux-gcc -o $progdir/$file minimad.o ./.libs/libmad.so -Wl,--rpath -Wl,/home/erojas/src/shell/madplay/madlib-xilleon/.libs -Wl,--rpath -Wl,/usr/local/lib): not found 192: SIGSEGV sed_quote_subst=s/$[\\`\\"$\\\\]$/\\\1/g: not found relink_command=(cd /home/erojas/src/shell/madplay/madlib-xilleon; { test -z "${LIBRARY_PATH+set}" || unset LIBRARY_PATH || { LIBRARY_PATH=; export LIBRARY_PATH; }; }; { test -z "${COMPILER_PATH+set}" || unset COMPILER_PATH || { COMPILER_PATH=; export COMPILER_PATH; }; }; { test -z "${GCC_EXEC_PREFIX+set}" || unset GCC_EXEC_PREFIX || { GCC_EXEC_PREFIX=; export GCC_EXEC_PREFIX; }; }; { test -z "${LD_RUN_PATH+set}" || unset LD_RUN_PATH || { LD_RUN_PATH=; export LD_RUN_PATH; }; }; PATH=".:/home/erojas/bin:/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/tools/bin:/sbin:/usr/sbin:/home/erojas/bin"; export PATH; /usr/tools/bin/mipsel-linux-gcc -o $progdir/$file minimad.o ./.libs/libmad.so -Wl,--rpath -Wl,/home/erojas/src/shell/madplay/madlib-xilleon/.libs -Wl,--rpath -Wl,/usr/local/lib): not found 215: SIGSEGV relink_command_output=: not found _command_output [erojas@ati-stw madlib-xilleon]$ minimad sed_quote_subst=s/$[\\`\\"$\\\\]$/\\\1/g: not found relink_command=: not found 229: SIGSEGV sed_quote_subst=s/$[\\`\\"$\\\\]$/\\\1/g: not found relink_command=: not found 252: SIGSEGV relink_command_output=: not found _command_output

2 1

question about standart
by Grigory A. 22 Sep '04

22 Sep '04

Hello! Could someone give me answer : are mp3 frames independent? I mean how current frame depend from previous? It looks like points of dependences are in - overlap procedure - synthesis procedure so if I skip correctly one or more frames - all "problems" will disappear after first newly decoded frame. I mean - first frame decoded after skipped - will be wrong (if compare with non-skipped sequence)and second become same in both cases? Thanks for answers. -- Best regards, Grigory mailto:Ryhor@tut.by

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Re: [mad-user] How to manipulate both V1 and V2 tags in the same file
by Cedric Tefft 22 Sep '04

22 Sep '04

Rob Leslie wrote: > The file API of libid3tag presents a single view of all the tags > contained in a file, and does not differentiate between V1 and V2 > tags. The idea is that V1 and V2 tags should represent the same > information about a file, and if both are present then V2 information > is preferred because its field lengths are not constrained as in V1. > (When writing tags back to a file, the intent is that the file > interface will generate both V1 and V2 tags from the same source, > ensuring consistency.) This is certainly a sensible strategy. To that end, I think it would be useful to allow the application to determine what the V1 equivalent of the V2 information is. Sometimes it is possible to create a better V1 equivalent of a V2 tag by abbreviating certain words or phrases. For example, if the V2 title is something like "While the Earth Sleeps (Pet Shop Boys Remix)", the truncated version is "While the Earth Sleeps (Pet Sh", whereas a more informative alternative is "While the Earth Sleeps (PSB)". Obviously, it's beyond the scope of libid3tag to be able to generate abbreviations for this method. They should be handled by the application. But in order to do that, however, the library would have to allow the application to override what it considers to be the equivalent V1 tag, or to put it more simply, the application would have to be allowed to set the V2 and V1 tags independantly of each other. > > Accordingly, it's not possible to access the V1 and V2 information as > separate tags with the file interface. If you really want to do this, > you can use the tag parsing and rendering routines to maintain > separate tag structures and data, but you'll have to read and write > the data from the file yourself. > I'm preared to do this if necessary, however it occurs to me that what I'll end up doing is rewriting, almost verbatim, functions that already exist in libid3tag (new_file() and the like). The only reason I couldn't use the library functions is that they aren't exported to the API. This seems like a bit of a waste since I have to link to the library anyway. Would you be willing to accept a few patches which expose a bit more of the library's internals to the API? - Cedric

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About mad_stream_skip
by Francis Labonte 21 Sep '04

21 Sep '04

Hi, I have a question about mad_stream_skip. If I call this function, would if be correct to call mad_stream_sync after? Actually, mad_stream_skip does'nt care about the skip offset (well, I think...). I would expect that if I call sync after skip, It will try to sync starting from the new position (position + skip offset). If I do that, it does'nt work since the "skip offset" will be consider only at the next decode_frame call. I'me new to mad's API so I would appraciate if somebody could explain me the logic behind that please. Thank you Francis _________________________________________________________________ Take advantage of powerful junk e-mail filters built on patented Microsoft® SmartScreen Technology. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=ht… Start enjoying all the benefits of MSN® Premium right now and get the first two months FREE*.

2 1

mp3gain vs madplay
by Bruce Fitzsimons 15 Sep '04

15 Sep '04

Peoples, I'm about to launch into a debugging session to see why mp3gain (http://mp3gain.sourceforge.net/ ) and madplay 0.15.1b don't seem to be playing together (no pun intended). I thought I'd ask if anyone has used the two together yet, or if there is another linux-based replaygain processor (for adding replaygain to existing mp3s) that is more reliable. map3gain does appear to be adding a tag, as it finds it again if rerun over the same file. "# mp3gain /tmp/Abracadabra.mp3 /tmp/Abracadabra.mp3 Recommended "Track" dB change: -1.690000 Recommended "Track" mp3 gain change: -1 Max PCM sample at current gain: 28533.063680 Max mp3 global gain field: 180 Min mp3 global gain field: 116 Recommended "Album" dB change for all files: -7.490000 Recommended "Album" mp3 gain change for all files: -5" madplay doesn't appear to find it: "# madplay -G -Tv /tmp/Abracadabra.mp3 MPEG Audio Decoder 0.15.1 (beta) - Copyright (C) 2000-2004 Robert Leslie et al. Title: Abracadabra Artist: The Steve Miller Band Album: Golds Greatest Hits Track: 11 Year: 1982 Genre: Vocal Encoder Version: LAME 3.92 VBR Method: constant Bitrate: 255+ kbps Stereo Mode: normal Preset: none Unwise Settings: no Encoding Flags: Lowpass Filter: 19500 Hz ATH Type: 2 Noise Shaping: 1 Surround: none Start Delay: 576 samples End Padding: 1503 samples Source Rate: 44.1 kHz Music Length: 9948263 bytes Audio Frames: 11900" (note the missing "Replay Gain" printout I expect after reading the source) I'd hasten to add that I suspect mp3gain of doing something wrong, not madplay. I'm guessing the tag is wrong or in the wrong place. Any info would be appreciated, otherwise I'll report my findings to the list when I discover the root cause. /Bruce

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Creating samples display like Wavelab eg.
by Sickboy 08 Sep '04

08 Sep '04

Hi guys, i could need help in understanding displaying decoded mp3. I decode the mp3 by the minimad example which works fine. for (int i=0; i<(nsamples*4); i+=4) { sample = scale(*left_ch++); *redux++ = (sample >> 0) & 0xff; *redux++ = (sample >> 8) & 0xff; if (nchannels == 2) { sample = scale(*right_ch++); *redux++ = (sample >> 0) & 0xff; *redux++ = (sample >> 8) & 0xff; } } After that i got an unsigned char array which is in the little endian format. Looks like this if i got an stereo file: Left 1st byte, Left 2nd byte, Right 1st byte, Right 2nd byte, Left 1st byte, Left 2nd byte, .... Please correct me if i'm wrong. Now i try to display these datas in a waveform like in Wavelab, Soundforge, Audacity It would be great if anyone could tell me how to calculate the peaks which i have to draw. Thanks you daSickboy

1 0

MAD and Jack (originally posted to the wrong list)
by andrew＠fnarg.demon.co.uk 07 Sep '04

07 Sep '04

Hi there, I'm writing a playout system which utilises Jack and MAD to play MP3 files. I've written a simple app which under libao (I was using this prior to Jack) will happily play any MP3 file I throw at it. However, upon adding the relevant code to make it a Jack client I've run across a problem. MAD seems to output audio at either 24bit fixed point or 16bit signed whereas Jack expects audio in 32bit floating point. Is there an easy way to make this work, am I being thick? Please help! Cheers, Andy M

2 1

On additions to libid3tag
by Linus Walleij 05 Sep '04

05 Sep '04

I've been having all kinds of fun with libid3tag lately. However there were two things I couldn't do: 1. Add tags to files that do not already have ID3 tags. 2. Remove tags from files. This seem to stem from the fact that it's a concieved as a modification library only, not a creation or destruction library... So I wrote external code for adding and removing tags. Now I thought that this could perhaps be included in libid3tag. Would this be good? If you like the idea, I could adopt my code for libid3tag (follow your code standards etc) but just in case you think it's worth it. Below are copies of the routines, which are written for the glib portability library (will have to be changed of course) for inspection. static gboolean addid3tag(gchar *path) { // File descriptors... gint f1, f2, f3; gboolean retval = FALSE; gchar template[128]; // g_print("Adding a new ID3 tag to %s\n", path); f1 = (gint) open(path, O_RDONLY, 0); if (f1 < 0) return FALSE; // g_print("Opened file f1...\n"); // template = g_build_filename(g_get_tmp_dir(), "gnomadXXXXXX"); strcpy(template, g_get_tmp_dir()); template[strlen(template)+1] = '\0'; template[strlen(template)] = G_DIR_SEPARATOR; strcat(template, "gnomadXXXXXX"); // Temporary file f2 = g_mkstemp(template); // g_print("Opened temporary file f2...\n"); if (f2 >= 0) { register gchar *buffer; gchar blankv2tag[0x0c0a]; guint bufsiz; // A blank ID3v2 tag with title set to "x" gchar v2head[] = {0x49, 0x44, 0x33, 0x03, 0x00, 0x00, 0x00, 0x00, 0x0c, 0x00, // size 0x0100 0x54, 0x50, 0x45, 0x31, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x00, 0x00, 0x78}; gchar blankv1tag[] = {'T', 'A', 'G', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; // Allocate a copying buffer for (bufsiz = 0x8000; bufsiz >= 128; bufsiz >>= 1) { buffer = (gchar *) g_malloc(bufsiz); if (buffer) break; } // g_print("Allocated a buffer of %d bytes...\n", bufsiz); // Add a dummy tag // g_print("Adding a dummy ID3v2 tag...\n"); memset(blankv2tag, 0, 0x0c0a); memcpy(blankv2tag, v2head, 22); if (0x0c0a == write(f2,blankv2tag,0x0c0a)) { // Copy the entire file //g_print("Copying the original file...\n"); while (1) { register guint n; n = read(f1,buffer,bufsiz); if (n == -1) break; if (n == 0) { retval = TRUE; break; } if (n != write(f2,buffer,n)) break; } } // g_print("Adding a dummy ID3v1 tag...\n"); write(f2,blankv1tag,128); if (retval) { close(f1); // Rewind the temporary file lseek(f2, 0, SEEK_SET); // Then copy the file back again // g_print("Copying the file back...\n"); f3 = (gint) creat(path, (mode_t) CREATE_FILEMODE); if (f3) { // g_print("Creat() on original file succeeded...\n"); while (1) { register guint n; n = read(f2,buffer,bufsiz); if (n == -1) break; if (n == 0) { retval = TRUE; break; } if (n != write(f3,buffer,n)) break; } close(f3); } else { // g_print("Error copying back!\n"); retval = FALSE; } close(f2); } else { close(f1); close(f2); } // g_print("Deleting %s\n", template); unlink(template); // Free the buffer g_free(buffer); return retval; } close(f1); return FALSE; } void remove_tag_from_mp3file(gchar *path) { // File descriptors... gint f1, f2, f3; gchar template[128]; guint header_taglength = 0; guint footer_taglength = 0; guint filelength = 0; register gchar *buffer; guint bufsiz; gboolean retval = FALSE; // not used yet // template = g_build_filename(g_get_tmp_dir(), "gnomadXXXXXX"); //FEL strcpy(template, g_get_tmp_dir()); template[strlen(template)+1] = '\0'; template[strlen(template)] = G_DIR_SEPARATOR; strcat(template, "gnomadXXXXXX"); // g_print("Removing ID3 tags from %s\n", path); f1 = (gint) open(path, O_RDONLY, 0); if (f1 < 0) { return; } // g_print("Opened file f1...\n"); // Allocate a copying buffer for (bufsiz = 0x8000; bufsiz >= 128; bufsiz >>= 1) { buffer = (gchar *) g_malloc(bufsiz); if (buffer) break; } // Temporary file f2 = g_mkstemp(template); // g_print("Opened temporary file f2...\n"); if (f2 >= 0) { guchar tag[10]; gint n; // g_print("Allocated a buffer of %d bytes...\n", bufsiz); // g_print("Looking for ID3v2 header tag\n"); n = read(f1,tag,10); if (n == 10 && tag[0] == 'I' && tag[1] == 'D' && tag[2] == '3') { // g_print("Found ID3v2 tag header...\n"); // Get tag length from the tag header_taglength = (tag[6] << 24) + (tag[7] << 16) + (tag[8] << 8) + tag[9]; // This needs some heuristics... first scan until only zeroes are found. // while () n = read(f1,buffer,bufsiz); if (n > 4) { guint m = 0; gboolean foundzeros = FALSE; gboolean founddata = FALSE; // Look for 8 consecutive zeroes while (!foundzeros && (m < n)) { if (buffer[m] == 0x00 && buffer[m+1] == 0x00 && buffer[m+2] == 0x00 && buffer[m+3] == 0x00 && buffer[m+4] == 0x00 && buffer[m+5] == 0x00 && buffer[m+6] == 0x00 && buffer[m+7] == 0x00) { foundzeros = TRUE; } m += 8; } // g_print("Found zeros\n"); // Then look for first non-zero while (!founddata && (m < n)) { if (buffer[m] == '3' && buffer[m+1] == 'D' && buffer[m+2] == 'I') { // We found a footer, wind past it and say that we found data. m += 10; founddata = TRUE; } else if (buffer[m] != 0x00) { founddata = TRUE; // Tag is now m bytes long! } else { m++; } } // If length was properly detected, we now know the length. if (founddata) { // g_print("Found data\n"); if (header_taglength != m) { g_print("Bad header tag! Given length: %d, detected length: %d\n", header_taglength, m); } // Adjust header taglength header_taglength = m; // Wind past any RIFF header too header_taglength += riff_header_size(&buffer[m], n-m); } // At last, include the header too. header_taglength += 10; // g_print("ID3v2 header (and any RIFF header) %d bytes\n", header_taglength); } } else { // Any plain RIFF header is removed too. gint n; n = read(f1,buffer,bufsiz); header_taglength = riff_header_size(&buffer[0], n); } // As we move to the end of the file, detect the filelength filelength = lseek(f1, 0, SEEK_END); if (filelength > 0) { // Then detect the length of any ID3v1 tag // g_print("Detecting ID3v1 tag\n"); if (lseek(f1, -128, SEEK_END) > 0) { guchar tag[3]; gint n; n = read(f1,tag,3); if (n == 3 && tag[0] == 'T' && tag[1] == 'A' && tag[2] == 'G') { // g_print("Found ID3v1 tag footer...\n"); footer_taglength = 128; } } // Then detect the length of any ID3v2 footer tag // g_print("Detecting ID3v2 footer tag\n"); if (lseek(f1, -10-footer_taglength, SEEK_END) > 0) { guchar tag[10]; guint footlen; gint n; n = read(f1,tag,10); if (n == 10 && tag[0] == '3' && tag[1] == 'D' && tag[2] == 'I') { // g_print("Found ID3v2 footer tag\n"); footlen = (tag[6] << 24) + (tag[7] << 16) + (tag[8] << 8) + tag[9]; // First remove the tag headers footer_taglength += 20; // Then remove the indicated length (no looking for bad tag here) footer_taglength += footlen; } } // g_print("Header %d bytes, footer %d bytes to be removed.\n", header_taglength, footer_taglength); // Next skip past the header, and copy until we reach the footer if (lseek(f1, header_taglength, SEEK_SET) > 0) { guint remain = filelength - header_taglength - footer_taglength; while (remain) { register guint n; if (remain > bufsiz) { n = read(f1,buffer,bufsiz); } else { n = read(f1,buffer,remain); } if (n == -1) break; if (n == 0) { retval = TRUE; break; } if (n != write(f2,buffer,n)) break; remain -= n; } } } close(f1); // Then copy back the stripped file // Rewind the temporary file lseek(f2, 0, SEEK_SET); // g_print("Copying the file back...\n"); f3 = (gint) creat(path, (mode_t) CREATE_FILEMODE); if (f3) { // g_print("Creat() on original file succeeded...\n"); while (1) { register guint n; n = read(f2,buffer,bufsiz); if (n == -1) break; if (n == 0) { retval = TRUE; break; } if (n != write(f3,buffer,n)) break; } close(f3); } else { g_print("Error copying file back!\n"); retval = FALSE; } close(f2); // g_print("Deleting %s\n", template); unlink(template); } else { // In case we couldn't open f2 retval = FALSE; close(f1); } g_free(buffer); }

1 0

Using MAD for MP3 Streaming decoding
by balaji shanmugam 01 Sep '04

01 Sep '04

I am using MAD library for my application which basically decodes the MP3 streams. I am using HELIX server (from RealNetworks) as the MP3 streaming server. After I started the streaming (the helix server streaming a local MP3 file encoded at Constant Bit rate of 128Kbps and 441.KHz sampling freq). The streaming is done using RTSP/RTP protocol. I captured the streamed out packets and found out that the length of each RTP payload is varying. The first few stream packets are containing less than 417/418 bytes of Mp3 audio data. I have taken care of copying the unprocessed/left out MP3 data of previous frame into the new frame but I am always getting the LOST_SYNC error. Will someone help me out in processing the MP3 data that is streamed out. Regards Balaji Shanmugam _________________________________________________________________ Drive away out of trouble. http://citibank.mediaturf.net/carcash2/landing/key_landing.jsp?referrer=HMt… Get a loan against your existing car.

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mad-dev September 2004