<?php
define( 'MOV_TFHD_BASE_DATA_OFFSET', 0x01 );
define( 'MOV_TFHD_STSD_ID', 0x02 );
define( 'MOV_TFHD_DEFAULT_DURATION', 0x08 );
define( 'MOV_TFHD_DEFAULT_SIZE', 0x10 );
define( 'MOV_TFHD_DEFAULT_FLAGS', 0x20 );
define( 'MOV_TFHD_DURATION_IS_EMPTY', 0x010000 );
define( 'MOV_TFHD_DEFAULT_BASE_IS_MOOF', 0x020000 );
define( 'MOV_TRUN_DATA_OFFSET', 0x01 );
define( 'MOV_TRUN_FIRST_SAMPLE_FLAGS', 0x04 );
define( 'MOV_TRUN_SAMPLE_DURATION', 0x100 );
define( 'MOV_TRUN_SAMPLE_SIZE', 0x200 );
define( 'MOV_TRUN_SAMPLE_FLAGS', 0x400 );
define( 'MOV_TRUN_SAMPLE_CTS', 0x800 );
class MP4Reader {
/**
* @var resource $file
*/
protected $file;
public function __construct( $file ) {
$this->file = $file;
}
/**
* @return int
*/
public function pos() {
$pos = ftell( $this->file );
if ( $pos === false ) {
throw new Exception( 'Failed to read position in MP4 file' );
}
return $pos;
}
/**
* @param int $length number of bytes to read
* @return string|false raw bytes or false on eof
*/
public function readBytes( $length ) {
$bytes = fread( $this->file, $length );
if ( feof( $this->file ) ) {
return false;
}
if ( $bytes === false || strlen( $bytes ) < $length ) {
throw new Exception( "Failed to read $length bytes from MP4 file" );
}
return $bytes;
}
/**
* @param int $length number of bytes to skip over
*/
private function skipBytes( $length ) {
$retval = fseek( $this->file, $length, SEEK_CUR );
if ( $retval < 0 ) {
throw new Exception( "Failed to skip ahead $length bytes in MP4 file" );
}
}
/**
* @return int|false 64-bit integer value or false on eof
*/
public function read64() {
$bytes = $this->readBytes( 8 );
if ( $bytes === false ) {
return false;
}
$data = unpack( 'Jval', $bytes );
return $data['val'];
}
/**
* @return int|false 32-bit integer value or false on eof
*/
public function read32() {
$bytes = $this->readBytes( 4 );
if ( $bytes === false ) {
return false;
}
$data = unpack( 'Nval', $bytes );
return $data['val'];
}
/**
* @return int|false 24-bit integer value or false on eof
*/
public function read24() {
$bytes = $this->readBytes( 3 );
if ( $bytes === false ) {
return false;
}
$data = unpack( 'Nval', "\x00$bytes" );
return $data['val'];
}
/**
* @return int|false 16-bit integer value or false on eof
*/
public function read16() {
$bytes = $this->readBytes( 2 );
if ( $bytes === false ) {
return false;
}
$data = unpack( 'nval', $bytes );
return $data['val'];
}
/**
* @return int|false 8-bit integer value or false on eof
*/
public function read8() {
$bytes = $this->readBytes( 1 );
if ( $bytes === false ) {
return false;
}
return ord( $bytes );
}
/**
* @return string|false 4-byte type code or false on eof
*/
public function readType() {
return $this->readBytes( 4 );
}
/**
* @param callable $callback in the form function(MP4Box)
* @return bool true on success, or false on eof
*/
public function readBox( $callback ) {
$start = $this->pos();
$size = $this->read32();
if ( $size === false ) {
return false;
}
$end = $start + $size;
$type = $this->readType();
if ( $type === false ) {
return false;
}
$box = new MP4Box( $this->file, $start, $size, $type );
$retval = call_user_func( $callback, $box );
$remaining = $end - $this->pos();
if ( $remaining > 0 ) {
$this->skipBytes( $remaining );
}
return true;
}
/**
* Scan a series of boxes and pass control based on type.
* Unrecognized boxes will be skipped over.
* @param callable[] $map array of callables keyed by fourCC type code
*/
public function boxes( $map ) {
$ok = true;
while ( $ok ) {
$ok = $this->readBox( function ( $box ) use ( $map ) {
$handler = $map[$box->type] ?? false;
if ( is_callable( $handler ) ) {
call_user_func( $handler, $box );
} else if ( is_array( $handler ) ) {
$box->boxes( $handler );
} else if ( $handler === false ) {
// no-op
} else {
throw new Exception( "Unexpected callback or map type for type $box->type" );
}
} );
}
}
}
class MP4FileReader extends MP4Reader {
/**
* @param string $filename
*/
public function __construct( $filename ) {
$file = fopen( $filename, 'rb' );
if ( !$file ) {
throw new Exception( 'Failed to open MP4 input file' );
}
parent::__construct( $file );
}
function __destruct() {
if ( $this->file ) {
fclose( $this->file );
$this->file = null;
}
}
}
class MP4Box extends MP4Reader {
public $start;
public $size;
public $type;
public function __construct( $file, $start, $size, $type ) {
parent::__construct( $file );
$this->start = $start;
$this->size = $size;
$this->type = $type;
}
public function end() {
return $this->start + $this->size;
}
public function remaining() {
return $this->end() - $this->pos();
}
public function readBytes( $length ) {
if ( $length > $this->remaining() ) {
return false;
}
return parent::readBytes( $length );
}
}
function hexdump( $str ) {
$out = '';
$len = strlen( $str );
for ( $i = 0; $i < $len; $i++ ) {
$char = $str[$i];
$byte = ord( $char );
// really?
$digits = str_pad( dechex( $byte ), 2, '0', STR_PAD_LEFT );
$out .= $digits;
}
return $out;
}
function safestr( $str ) {
$out = '';
$len = strlen( $str );
for ( $i = 0; $i < $len; $i++ ) {
$char = $str[$i];
$byte = ord( $char );
if ( $byte >= 32 && $byte <= 126 ) {
$out .= $char;
} else {
$out .= '.';
}
}
return $out;
}
/**
* @param string $filename - input MP4 file to read
* @return array[] - list of segment info
*/
function extractFragmentedMP4( $filename ) {
$segments = [];
$mp4 = new MP4FileReader( $filename );
$eof = false;
$moof = false;
$timestamp = 0.0;
$duration = 0.0;
$timescale = 0;
$dts = 0;
$first_pts = 0;
$max_pts = 0;
$init = false;
/*
Need to:
- find the end of the moov; everything up to that is the initialization segment
- https://www.w3.org/TR/mse-byte-stream-format-isobmff/#iso-init-segments
- find the start of each styp+moof fragment
- https://www.w3.org/TR/mse-byte-stream-format-isobmff/#iso-media-segments
- find the start timestamp of each moof fragment
- find the duration of each moof fragment
moov.trak.mdia.mdhd.timescale - looks useful 12288 for 24fps?
moov.trak.mdia.mdhd.duration - 0 on the moov
moov.mvex.trex.default_sample_duration - 0 on the moov
moof.traf.tfhd.default_sample_duration is 512 on these
moof.traf.tfdt.baseMediaDecodeTime is 0 on the first, 122880 on the second frag (10 seconds in?)
moof.mdat.sample_duration is empty here (uses default I guess?)
moof.mdat.sample_composition_time_offset also empty
opus has timescale 48000 in moov.trak.mdia.mdhd
*/
$mp4->boxes( [
'moov' => [
'trak' => [
'mdia' => [
'mdhd' => function ( $box ) use ( &$timescale ) {
$version = $box->read8();
$flags = $box->read24();
if ( $version == 1 ) {
$box->read64();
$box->read64();
} else {
$box->read32();
$box->read32();
}
$timescale = $box->read32();
}
],
],
],
'moof' => function ( $box ) use ( &$segments, &$moof, &$init, &$timestamp, &$duration, &$dts, &$first_pts, &$max_pts, &$timescale ) {
if ( !$init ) {
$init = [
'start' => 0,
'size' => $box->start,
'timestamp' => 0.0,
'duration' => 0.0,
];
$segments['init'] = $init;
}
$moof = $box->start;
$default_sample_duration = 0;
$first_pts = 0;
$max_pts = 0;
$box->boxes( [
'traf' => [
'tfhd' => function( $box ) use ( &$default_sample_duration ) {
$version = $box->read8();
$flags = $box->read24();
$track_id = $box->read32();
if ( $flags & MOV_TFHD_BASE_DATA_OFFSET ) {
$box->read64();
}
if ( $flags & MOV_TFHD_STSD_ID ) {
$box->read32();
}
if ( $flags & MOV_TFHD_DEFAULT_DURATION ) {
$default_sample_duration = $box->read32();
}
},
'trun' => function( $box ) use ( &$default_sample_duration, &$dts, &$first_pts, &$max_pts ) {
$version = $box->read8();
$flags = $box->read24();
$entries = $box->read32();
if ( $flags & MOV_TRUN_DATA_OFFSET ) {
$box->read32();
}
if ( $flags & MOV_TRUN_FIRST_SAMPLE_FLAGS ) {
$box->read32();
}
for ( $i = 0; $i < $entries; $i++ ) {
$pts = $dts;
$sample_duration = $default_sample_duration;
if ( $flags & MOV_TRUN_SAMPLE_DURATION ) {
$sample_duration = $box->read32();
}
if ( $flags & MOV_TRUN_SAMPLE_SIZE ) {
$box->read32();
}
if ( $flags & MOV_TRUN_SAMPLE_FLAGS ) {
$box->read32();
}
if ( $flags & MOV_TRUN_SAMPLE_CTS ) {
$pts += $box->read32();
}
if ( $i == 0 ) {
$first_pts = $pts;
}
$max_pts = max( $max_pts, $pts + $sample_duration );
$dts += $sample_duration;
}
}
],
] );
},
'mdat' => function ( $box ) use ( &$segments, &$moof, &$first_pts, &$max_pts, &$timescale ) {
array_push( $segments, [
'start' => $moof,
'size' => $box->end() - $moof,
'timestamp' => $first_pts / $timescale,
'duration' => ( $max_pts - $first_pts ) / $timescale,
] );
}
] );
return $segments;
}
// http://www.mp3-tech.org/programmer/frame_header.html
class MP3FrameHeader {
private $header;
public $valid = false;
public $size = 0;
public $samples = 0;
public $duration = 0.0;
public $sync;
public $mpeg;
public $layer;
public $protection;
public $bitrate;
public $sampleRate;
public $padding;
private static $bits = [
'sync' => [ 21, 11 ],
'mpeg' => [ 19, 2 ],
'layer' => [ 17, 2 ],
'protection' => [ 16, 1 ],
'bitrate' => [ 12, 4 ],
'sampleRate' => [ 10, 2 ],
'padding' => [ 9, 1 ],
'private' => [ 8, 1 ], // not needed below this
'channelMode' => [ 6, 2 ],
'modeExt' => [ 4, 2 ],
'copyright' => [ 3, 1 ],
'original' => [ 2, 1 ],
'emphasis' => [ 0, 2 ],
];
private const SYNC_MASK = 0x7ff;
private static $versions = [
'MPEG-2.5',
'reserved',
'MPEG-2',
'MPEG-1',
];
private static $layers = [
'reserved',
'III',
'II',
'I',
];
private static $samplesPerFrame = [
// invalid / layer 3 / 2 / 1
// MPEG-2.5
[ 0, 576, 1152, 384 ],
// Reserved
[ 0, 0, 0, 0 ],
// MPEG-2
[ 0, 576, 1152, 384 ],
// MPEG-1
[ 0, 1152, 384, 384 ],
];
// 1s used for reserved slots to avoid exploding
// in case of invalid input
private static $sampleRates = [
// MPEG-2.5
[ 11025, 12000, 8000, 1 ],
// Reserved
[ 1, 1, 1, 1 ],
// MPEG-2
[ 22050, 24000, 16000, 1 ],
// MPEG-1
[ 44100, 48000, 32000, 1 ],
];
private static $bitrates = [
// MPEG-2
[
// invalid layer
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ],
// layer 3
[ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 ],
// layer 2
[ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0 ],
// layer 1
[ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0 ],
],
// MPEG-1
[
// invalid layer
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ],
// layer 3
[ 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 192, 224, 256, 320, 0 ],
// layer 2
[ 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0 ],
// layer 1
[ 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 316, 448, 0 ],
]
];
private function field( $name ) {
[ $shift, $bits ] = self::$bits[$name];
$mask = ( 1 << $bits ) - 1;
return ( $this->header >> $shift ) & $mask;
}
public function __construct( $header ) {
$this->header = $header;
$sync = $this->field( 'sync' );
$this->sync = $sync == self::SYNC_MASK;
if ( $this->sync ) {
$mpeg = $this->field( 'mpeg' );
$this->mpeg = self::$versions[$mpeg];
$layer = $this->field( 'layer' );
$this->layer = self::$layers[$layer];
$protection = $this->field( 'protection' );
$this->protection = !$protection;
$br = $this->field( 'bitrate' );
$this->bitrate = 1000 * self::$bitrates[$mpeg & 1][$layer][$br];
$sr = $this->field( 'sampleRate' );
$this->sampleRate = self::$sampleRates[$mpeg][$sr];
$this->padding = $this->field( 'padding' );
if ( $this->sync ) {
if ( $this->bitrate == 0 ) {
$this->valid = false;
throw new Exception( "Invalid bitrate" );
}
if ( $this->sampleRate == 1 ) {
$this->valid = false;
throw new Exception( "Invalid sample rate" );
}
$this->valid = true;
}
$this->samples = self::$samplesPerFrame[$mpeg][$layer];
$this->duration = $this->samples / $this->sampleRate;
$nbits = $this->duration * $this->bitrate;
$nbytes = $nbits / 8;
$this->size = intval( $nbytes );
if ( $this->protection ) {
$this->size += 2;
}
if ( $this->padding ) {
$this->size++;
}
}
}
}
class MP3Reader {
private $file;
private $timestamp = 0.0;
public function __construct( $file ) {
$this->file = $file;
}
public function pos() {
return ftell( $this->file );
}
public function readSegment() {
while ( true ) {
$start = $this->pos();
$lookahead = 10;
$bytes = fread( $this->file, $lookahead );
if ( $bytes === false || strlen( $bytes ) < $lookahead ) {
// end of file
return false;
}
// Check for MP3 frame header sync pattern
$data = unpack( "Nval", $bytes );
$header = new MP3FrameHeader( $data['val'] );
if ( $header->sync ) {
// Note we don't need the data at this time.
fseek( $this->file, $start + $header->size, SEEK_SET );
$this->timestamp += $header->duration;
return [
'start' => $start,
'size' => $header->size,
'timestamp' => $this->timestamp,
'duration' => $header->duration,
];
}
// ID3v2.3
// https://web.archive.org/web/20081008034714/http://www.id3.org/id3v2.3.0
// ID3v2/file identifier "ID3"
// ID3v2 version $03 00
// ID3v2 flags %abc00000
// ID3v2 size 4 * %0xxxxxxx
$id3 = unpack( "a3tag/nversion/Cflags/C4size", $bytes );
if ( $id3['tag'] === 'ID3' ) {
$size = $lookahead +
( $id3['size4'] |
( $id3['size3'] << 7) |
( $id3['size2'] << 14) |
( $id3['size1'] << 21) );
// For byte range purposes; count as zero duration
fseek( $this->file, $start + $size, SEEK_SET );
return [
'start' => $start,
'size' => $size,
'timestamp' => $this->timestamp,
'duration' => 0.0,
];
}
$hex = hexdump( $bytes );
$safe = safestr ( $bytes );
throw new Exception("Invalid packet at $start? $hex $safe");
// back up and try again
fseek( $this->file, $start + 1, SEEK_SET );
}
}
}
function extractMP3( $filename ) {
$file = fopen( $filename, 'rb' );
if ( !$file ) {
throw new Exception( 'Error opening MP3 file' );
}
try {
$reader = new MP3Reader( $file );
$segments = [];
$timestamp = 0.0;
while ( true ) {
$start = $reader->pos();
$segment = $reader->readSegment();
if ( !$segment ) {
break;
}
$segments[] = $segment;
}
return $segments;
} finally {
fclose( $file );
}
}
function consolidate( $target, $segments ) {
$out = [];
if ( isset( $segments['init'] ) ) {
$out['init'] = $segments['init'];
}
if ( count( $segments ) < 2 ) {
return $segments;
}
$n = count( $segments );
if ( isset( $segments['init'] ) ) {
$n--;
}
$start = $segments[0]['start'];
$size = $segments[0]['size'];
$timestamp = $segments[0]['timestamp'];
$duration = $segments[0]['duration'];
//$nextTarget = $timestamp + $target;
$nextDuration = $target;
$i = 1;
while ( $i < $n ) {
// Append segments until we get close
while ( $i < $n - 1 && $duration < $nextDuration ) {
$total = $duration + $segments[$i]['duration'];
if ( $total >= $nextDuration ) {
$after = $total - $nextDuration;
$before = $nextDuration - $duration;
if ( $before < $after ) {
// Break segment early
break;
}
}
$duration += $segments[$i]['duration'];
$size += $segments[$i]['size'];
$i++;
}
// Save out a segment
$out[] = [
'start' => $start,
'size' => $size,
'timestamp' => $timestamp,
'duration' => $duration,
];
//$nextTarget += $target;
//$nextDuration = $nextTarget - $timestamp - $duration;
if ( $i < $n ) {
$segment = $segments[$i];
$start = $segment['start'];
$size = $segment['size'];
$timestamp = $segment['timestamp'];
$duration = $segment['duration'];
$i++;
}
}
$out[] = [
'start' => $start,
'size' => $size,
'timestamp' => $timestamp,
'duration' => $duration,
];
return $out;
}
function playlist( $filename, $segments ) {
/*
#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-MAP:URI="new-vp9.mp4",BYTERANGE="811@0"
#EXTINF:10.000000,
#EXT-X-BYTERANGE:1058384@811
new-vp9.mp4
#EXTINF:10.000000,
#EXT-X-BYTERANGE:1085979@1059195
new-vp9.mp4
#EXTINF:10.000000,
#EXT-X-BYTERANGE:1268619@2145174
new-vp9.mp4
#EXTINF:10.000000,
#EXT-X-BYTERANGE:1418664@3413793
new-vp9.mp4
#EXTINF:10.000000,
#EXT-X-BYTERANGE:1129265@4832457
new-vp9.mp4
...
#EXT-X-ENDLIST
*/
$lines = [];
$lines[] = "#EXTM3U";
$lines[] = "#EXT-X-VERSION:7";
$lines[] = "#EXT-X-TARGETDURATION:10";
$lines[] = "#EXT-MEDIA-SEQUENCE:0";
$lines[] = "#EXT-PLAYLIST-TYPE:VOD";
$init = $segments['init'] ?? false;
if ( $init ) {
$lines[] = "#EXT-X-MAP:URI=\"$filename\",BYTERANGE=\"{$init['size']}@{$init['start']}\"";
}
$n = count( $segments ) - 1;
for ( $i = 0; $i < $n; $i++ ) {
$segment = $segments[$i];
$lines[] = "#EXTINF:{$segment['duration']},";
$lines[] = "#EXT-X-BYTERANGE:{$segment['size']}@{$segment['start']}";
$lines[] = $filename;
}
$lines[] = "#EXT-X-ENDLIST";
return implode( "\n", $lines );
}
$argv = $_SERVER['argv'];
$self = array_shift( $argv );
$filename = array_shift( $argv );
$target = 10;
$ext = substr( $filename, strrpos( $filename, '.' ) );
if ( $ext === '.mp3' ) {
$segments = extractMP3( $filename );
} elseif ( $ext === '.mp4' ) {
$segments = extractFragmentedMP4( $filename );
} else {
die( "Unexpected file extension $ext\n" );
}
$segments = consolidate( $target, $segments );
/*
foreach ( $segments as $key => $segment ) {
if ( $key === 'init' ) {
print "$key {$segment['start']},{$segment['size']}\n";
} else {
print "$key {$segment['timestamp']},{$segment['duration']} @ {$segment['start']},{$segment['size']}\n";
}
}
*/
$m3u8 = playlist( urlencode( $filename ), $segments );
print $m3u8 . "\n";