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Hello folks!

All begun when I discovered that my shoutcast bookmark was no more opening the usual list of internet strreaming ordered by genre..

I said to myself I know a bit of Perl.. I'll do my own way.. and I started investigating mp3 streams (fulling my screen of binary #*%_ many times ;) and even if I've not reached my original goal I ended with someting useful and cool

The program will listen an mp3 stream and save each song with the correct title, skipping advertisements if possible and doing it's best to produce an entire song in each file

The POD documentation describes what I have understood of the ICY protocol (undocumented).

Suggestions and improvements welcome, have fun!

use strict; use warnings; use Net::HTTP; use URI; use File::Spec; use Getopt::Long; $|++; my $VERSION = 23; # SOME DEFAULTS my $debug = 0; # --extraparts default value my $cache_size = 2; my $url; my $agent = 'Stream-Cutter-v'.$VERSION; unless ( GetOptions ( 'url=s' => \$url, 'agent=s' => \$agent, 'extraparts|cache=i' => \$cache_size, 'debug=i' => \$debug, + )) {die "$0 -url URL [-agent STRING -extraparts N -debug [0-2] +]"} unless ( $url ){ print "which URL you want to open?"; $url = <STDIN>; chomp $url; } # OTHER VARIABLES # chunk number for debug purpose my $num = 0; # cache used to have more chunks wrote to a file when new song starts my @cache; # used to append to previous file # how_many parts will be equal to $cache_size when new song begin my %previous_file = ( name => undef, how_many => 0); my ( $socket, $icymetaint ) = open_connection( $url ); die "unable to get icy-metaint!" unless defined $icymetaint and $icymetaint > 0; read_stream( $socket, $icymetaint ); ###################################################################### +######### sub open_connection { my $url = shift; my $uri = URI->new( $url ); my $sock = Net::HTTP->new( Host => $uri->host, PeerPort => $uri->port, ) or die $@; $sock->write_request( GET => $uri->path, 'User-Agent' => $agent, # very important: ask for metadata! 'Icy-MetaData' => 1 ) or die $@; my ($http_code, $http_mess, %headers) = $sock->read_response_heade +rs; print join ' ', "\nConnecting to:\t",$uri->as_string, "\nStatus:\t",$http_code,$http_mess,"\n"; # go on if everything is OK 200 if ( $http_code == 200){ # grab useful headers and set them to empty string if undefine +d map {$headers{$_} = $headers{$_} // ''} 'Server','icy-name',' +icy-name', 'icy-genre','icy-br'; print join "\n","Server:\t".$headers{'Server'}, "name:\t".$headers{'icy-name'}, "genre:\t".$headers{'icy-genre'}, "byte rate:\t".$headers{'icy-br'}."kb/s\n\n"; if ( $debug ){ print "HEADERS:\n", (map {qq(\t$_\t=>\t$headers{$_}\n)} grep{defined $headers{$_}} %headers),"\n\n"; } return ($sock, $headers{'icy-metaint'}); } # return undef if not OK 200 else { print "Errors opening the given site..\n"; return undef; } } ###################################################################### +######### sub read_stream { my ($socket, $metaint) = @_; # output filehandle my $out; my $new_metadata; my $file_name; while( 1 ) { my $buffer; # READ the chunk of music $socket->read($buffer, $metaint); # CHECK for new metadata if ( $new_metadata = read_meta($socket)){ # WRITE and get back the NEW filehadle $out = write_stream( $buffer, $out, $new_metadata ); + } else{ # WRITE and get back the OLD filehadle $out = write_stream( $buffer, $out ); } } } ###################################################################### +######### sub read_meta{ my $socket = shift; my ( $metalen, $metabyte); $socket->read($metabyte, 1); $metalen = unpack("C",$metabyte) * 16; if( $metalen > 0) { # We have NEW metadata! JOY print "[$metalen metadata] " if $debug > 1; my $metadata; $socket->read($metadata, $metalen); $metadata = unpack("A$metalen", $metadata); print "\nMETADATA: [",$metadata,"]\n" if $debug > 1; return $metadata; } else { return undef; } } ###################################################################### +######### sub write_stream{ my ($buf, $out, $new_metadata) = @_; # count the overall chunk count for debug purpose $num ++; # NEW song got from metadata if ( $new_metadata ){ my $track_name = $1 if $new_metadata =~ /^StreamTitle='([^ +;]*)';/i; # if StreamTitle is empty probably is an advertisement. Fo +re example: # METADATA: [StreamTitle='';StreamUrl='';adw_ad='true'; # durationMilliseconds='20009';adId='12161';insertionType= +'preroll'; print "\ncurrently playing:\t". ($track_name ? $track_name : '**advertisement**'). +"\n"; if ($out and fileno $out and $cache_size){ print "writing part number [$num] to current file\n" i +f $debug; # DOUBLE write of the current buff print $out $buf ; } my $file_name; ($file_name = $track_name) =~ s/\s+/_/g; $file_name =~ s/\/\\:\*\?\"<>\|//g; $file_name.='.mp3'; # if StreamTitle is empty probably is an advertisement $file_name = File::Spec->devnull() unless $track_name; # set previous filename, but still how_many = 0 $previous_file{name} = $file_name; # the new file open $out, '>', $file_name or die "unable to write to $fil +e_name!"; binmode $out; if ( $cache_size > 0 ){ # PREPEND cache items to the new opened file while ( my $cache_item = shift @cache ) { print "writing cached part to new file: $file_name +\n" if $debug; print $out $cache_item; } } # WRITE $buf to a new file print "writing part number [$num] to new file: $file_name\ +n" if $debug; print $out $buf; } # no new track.. else { print "$num " if $debug > 1; # WRITE $buf to the already opened file if ( $out and fileno $out ){ print $out $buf or die; } # check previous_file if needed to be appended if ( $previous_file{name} and $previous_file{how_many} ){ print "appending part to previous file too\n" if $debug; open my $oldfh, '>>', $previous_file{name} or die "unable to open $previous_file{name} in ap +pend mode!"; binmode $oldfh; print $oldfh $buf or die "unable to write!"; close $oldfh or die "unable to close filehandle!"; $previous_file{how_many}--; } else{ $previous_file{name} = undef; $previous_file{how_many} = $cache_size ; } } # cache rotates.. if ( $#cache == $cache_size - 1 ){ shift @cache, } push @cache, $buf; # return the current file handle return $out; } __DATA__ =head1 NAME C<mp3streamcutter.pl> This program open an mp3 stream and save songs to distinct files. It's + intended to understand the ICY protocol and not intended to save copirighted da +ta. =head1 SYNOPSIS mp3streamcutter.pl -url URL [-agent STRING -extraparts N -debug 0- +2] --url URL is the only necessary argument. Url must be complete of the protoc +ol --agent STRING you can use a custom user-agent to send to server during the conne +ction. Agent defaults to Stream-Cutter-v with the version number of the p +rogram appended. You can find useful to use the string WinampMPEG/2.9 if +refused by some server --extraparts N This parameter governs how many extra parts of the stream have to +be prepended to a new file (via cache) and appended to the previous file (via reopening and appending). --extraparts defaults to 2 that is the b +est I found to have an entire song to the correct file and not to much junk in + it (parts of other songs). --cache is an alias for --extraparts --debug 0-2 With -debug 0 only few details of the server and the title of the +current song will be displayed. With -debug 1 also headers received from the server are shown and +all operations involving new files creation and extra parts possibly (see --extra +parts) wrote to these files Debug level 2 will display also each metadata received (if it cont +ains data) and a progressive number for each chunk of music received =head1 DESCRIPTION This program was inspired by a post wrote by qbxk for perlmonks (see r +eferences). The core part of the program is just a rewrite of the original code by + qbxk The ICY protocol is not well documented. It's build on top of the HTTP + one. This program can help you to understand it in a better way. Basically music + chunks are intercalated with metadata chunks at the position given by the C<icy-m +etaint> header value. At this position you will find a lone byte indicating the lengt +h of the following metadata. If this byte is not 0 but N, then the following N +bytes will be of metadata. Normally in the metadata you find the C<StreamTitle> cont +aining the title of the current song. You can also find the C<StreamUrl> generally empt +y and other things like C<adw_ad> related to advertisements, followed by the duration of +the advertisement and other characteristics of the advertisement. So a typical chunk of metadata for a new song in the stream will be li +ke: C<StreamTitle='Beethoven - Goldberg Variations';StreamUrl='';> or sometimes just like: C<StreamTitle='The Clash - Loose this skin';> without the C<StreamUrl> part, while an advertisemente will look like: C<StreamTitle='';StreamUrl='';adw_ad='true';durationMilliseconds='2000 +9';adId='12161';insertionType='preroll';> The current version of the program will try to skip advertisements che +cking for empty C<StreamTitle> and then using C<File::Spec>'s C<devnull()> a +s filename to save the stream. In the headers of the HTTP request you had to ask for C<Icy-MetaData>, + then the server will answer with various icy headers, notably C<icy-metaint> that is the dimension + of music chunks. After each chunk there will be a byte containing the lenght of the fol +lowing metadata. If this is 0 it means no metadata will follow, but if it is a number a + correnspondant number of bytes have to be read to have the metadata back, typically t +he title and the author. The problem is that the title will arrive when the song already starte +d, so I decided to add a cache (see C<--extraparts> argument) to append and prepend chunc +ks to songs. This way you will have probably unneeded data at start and at the end +of each file but for sure the entire song. Let's say Icy-MetaData is 5 (generally is 16k), you have a situation l +ike ( '=' it's a chunk): -unknown song(1)------ -------------- The Clash - Loose This Skin - +------ ... | | | | STREAM-> = = = [0] = = = = = [3][*][*][*] = = = = = [0] = = = = = [0 +] = = = ... | | | | | | | | | + | unknown song | new song | | | | ------ The Clash - Loo +se This Skin | | | | | empty metadata | ------------- metadata with new tit +le | length of metadata (1) about unknown song: probably you never get an unknown song: I su +spect that ICY protocol will send icy metadata as first part of a brand new response. =head1 REFERENCES See the original post by qbxk at L<perlmonks|https://www.perlmonks.org +/index.pl?node_id=534645> L<a post about ICY protocol|https://stackoverflow.com/questions/491106 +2/pulling-track-info-from-an-audio-stream-using-php/4914538#4914538> L<The ICY protocol explained|http://www.smackfu.com/stuff/programming/ +shoutcast.html> L<A very datailed tutorial|https://thecodeartist.blogspot.com/2013/02/ +shoutcast-internet-radio-protocol.html> L<a not complete but useful description of ICY|https://www.radiotoolbo +x.com/community/forums/viewtopic.php?t=74> L<a technical article about streaming networks|https://people.kth.se/~ +johanmon/dse/casty.pdf> =head1 AUTHOR This program is by Discipulus as found in perlmonks.org with the fund +amental inspiration of the above mentioned qbxk This program is licensed under the same terms of the Perl languange.

L*

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Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

In reply to read an mp3 stream and save tracks using icy-metaint (ICY protocol) by Discipulus

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