improved frame extraction (including alpha)

This commit is contained in:
ccd0 2013-11-30 12:18:35 -08:00
parent 14ac1b562d
commit dd3cae6f70
3 changed files with 55 additions and 82 deletions

View File

@ -35,7 +35,6 @@ And add this to stylesheets/style.css:
float: left;
margin: 10px 20px;
border: none;
background: #aaa;
}
div.post video.post-image {
padding: 0px;

View File

@ -497,7 +497,7 @@ function readMatroska($fileHandle) {
return $root;
}
function encodeVarInt($n) {
function ebmlEncodeVarInt($n) {
$data = '';
$flag = 0x80;
while ($n >= $flag) {
@ -512,11 +512,11 @@ function encodeVarInt($n) {
return $data;
}
function encodeElementName($name) {
function ebmlEncodeElementName($name) {
global $EBML_ELEMENTS;
return encodeVarInt($EBML_ELEMENTS->id($name));
return ebmlEncodeVarInt($EBML_ELEMENTS->id($name));
}
function encodeElement($name, $content) {
return encodeElementName($name) . encodeVarInt(strlen($content)) . $content;
function ebmlEncodeElement($name, $content) {
return ebmlEncodeElementName($name) . ebmlEncodeVarInt(strlen($content)) . $content;
}

View File

@ -1,76 +1,53 @@
<?php
require dirname(__FILE__) . '/matroska.php';
function matroskaSeekElement($name, $pos) {
return ebmlEncodeElement('Seek',
ebmlEncodeElement('SeekID', ebmlEncodeElementName($name))
. ebmlEncodeElement('SeekPosition', pack('N', $pos))
);
}
// Make video from single VPx keyframe
function muxVPxFrame($width, $height, $codecID, $data) {
$size = strlen($data);
$lenSeekHead = 61;
$lenCues = 18;
$ebml = encodeElement('EBML',
encodeElement('EBMLVersion', "\x01")
. encodeElement('EBMLReadVersion', "\x01")
. encodeElement('EBMLMaxIDLength', "\x04")
. encodeElement('EBMLMaxSizeLength', "\x08")
. encodeElement('DocType', "webm")
. encodeElement('DocTypeVersion', "\x02")
. encodeElement('DocTypeReadVersion', "\x02")
function muxVPxFrame($trackNumber, $videoTrack, $frame) {
$lenSeekHead = 73;
$lenCues = 24;
$ebml = ebmlEncodeElement('EBML',
ebmlEncodeElement('DocType', "webm")
. ebmlEncodeElement('DocTypeVersion', "\x02")
. ebmlEncodeElement('DocTypeReadVersion', "\x02")
);
$info = encodeElement('Info',
encodeElement('TimecodeScale', "\x0F\x42\x40")
. encodeElement('Duration', "\x41\x20\x00\x00")
. encodeElement('MuxingApp', 'f')
. encodeElement('WritingApp', 'f')
$info = ebmlEncodeElement('Info',
ebmlEncodeElement('Duration', "\x41\x20\x00\x00")
. ebmlEncodeElement('MuxingApp', 'ccframe')
. ebmlEncodeElement('WritingApp', 'ccframe')
);
$tracks = encodeElement('Tracks',
encodeElement('TrackEntry',
encodeElement('TrackNumber', "\x01")
. encodeElement('TrackUID', "\x01")
. encodeElement('TrackType', "\x01")
. encodeElement('DefaultDuration', "\x98\x96\x80")
. encodeElement('CodecID', $codecID)
. encodeElement('Video',
encodeElement('PixelWidth', pack('N', $width))
. encodeElement('PixelHeight', pack('N', $height))
$tracks = ebmlEncodeElement('Tracks',
ebmlEncodeElement('TrackEntry', $videoTrack->content()->readAll())
);
$cues = ebmlEncodeElement('Cues',
ebmlEncodeElement('CuePoint',
ebmlEncodeElement('CueTime', "\x00")
. ebmlEncodeElement('CueTrackPositions',
ebmlEncodeElement('CueTrack', pack('N', $trackNumber))
. ebmlEncodeElement('CueClusterPosition', pack('N', $lenSeekHead + strlen($info) + strlen($tracks) + $lenCues))
)
)
);
$cues = encodeElement('Cues',
encodeElement('CuePoint',
encodeElement('CueTime', "\x00")
. encodeElement('CueTrackPositions',
encodeElement('CueTrack', "\x01")
. encodeElement('CueClusterPosition', chr($lenSeekHead + strlen($info) + strlen($tracks) + $lenCues))
)
)
if (strlen($cues) != $lenCues) throw new Exception('length of Cues element wrong');
$cluster = ebmlEncodeElement('Cluster',
ebmlEncodeElement('Timecode', "\x00")
. ebmlEncodeElement($frame->name(), $frame->content()->readAll())
. ebmlEncodeElement('Void', '')
);
$seekHead = encodeElement('SeekHead',
encodeElement('Seek',
encodeElement('SeekID', encodeElementName('Info'))
. encodeElement('SeekPosition', chr($lenSeekHead))
)
. encodeElement('Seek',
encodeElement('SeekID', encodeElementName('Tracks'))
. encodeElement('SeekPosition', chr($lenSeekHead + strlen($info)))
)
. encodeElement('Seek',
encodeElement('SeekID', encodeElementName('Cues'))
. encodeElement('SeekPosition', chr($lenSeekHead + strlen($info) + strlen($tracks)))
)
. encodeElement('Seek',
encodeElement('SeekID', encodeElementName('Cluster'))
. encodeElement('SeekPosition', chr($lenSeekHead + strlen($info) + strlen($tracks) + $lenCues))
)
);
$cluster = "\x1F\x43\xB6\x75\x08" . pack('N', $size + 13) . (
//. encodeElement('Cluster',
encodeElement('Timecode', "\x00")
. "\xA3\x08" . pack('N', $size + 4) . ("\x81\x00\x00\x80" . $data)
//. encodeElement('SimpleBlock', "\x81\x00\x00\x80" . $data)
);
$segment = "\x18\x53\x80\x67\x08" . pack('N', $size + 173) . (
// . encodeElement('Segment',
$seekHead . $info . $tracks . $cues . $cluster
$seekHead = ebmlEncodeElement('SeekHead',
matroskaSeekElement('Info', $lenSeekHead)
. matroskaSeekElement('Tracks', $lenSeekHead + strlen($info))
. matroskaSeekElement('Cues', $lenSeekHead + strlen($info) + strlen($tracks))
. matroskaSeekElement('Cluster', $lenSeekHead + strlen($info) + strlen($tracks) + $lenCues)
);
if (strlen($seekHead) != $lenSeekHead) throw new Exception('length of SeekHead element wrong');
$segment = ebmlEncodeElement('Segment', $seekHead . $info . $tracks . $cues . $cluster);
return $ebml . $segment;
}
@ -79,23 +56,20 @@ function firstVPxFrame($segment, $trackNumber, $skip=0) {
foreach($segment as $x1) {
if ($x1->name() == 'Cluster') {
$cluserTimecode = $x1->Get('Timecode');
foreach($x1 as $x2) {
foreach($x1 as $blockGroup) {
$blockRaw = NULL;
if ($x2->name() == 'SimpleBlock') {
$blockRaw = $x2->value();
} elseif ($x2->name() == 'BlockGroup') {
$blockRaw = $x2->get('Block');
if ($blockGroup->name() == 'SimpleBlock') {
$blockRaw = $blockGroup->value();
} elseif ($blockGroup->name() == 'BlockGroup') {
$blockRaw = $blockGroup->get('Block');
}
if (isset($blockRaw)) {
$block = new MatroskaBlock($blockRaw);
if ($block->trackNumber == $trackNumber) {
$frame = $block->frames[0];
if ($block->keyframe) {
if (!isset($cluserTimecode) || $cluserTimecode + $block->timecode >= $skip) {
return $frame;
} elseif (!isset($frame1)) {
$frame1 = $frame;
}
if ($block->trackNumber == $trackNumber && $block->keyframe) {
if (!isset($cluserTimecode) || $cluserTimecode + $block->timecode >= $skip) {
return $blockGroup;
} elseif (!isset($frame1)) {
$frame1 = $blockGroup;
}
}
}
@ -175,7 +149,7 @@ function videoData($filename) {
}
$frame = firstVPxFrame($segment, $trackNumber, $skip);
if (!isset($frame)) throw new Exception('no keyframes');
$data['frame'] = muxVPxFrame($pixelWidth, $pixelHeight, $codecID, $frame->readAll());
$data['frame'] = muxVPxFrame($trackNumber, $videoTrack, $frame);
} catch (Exception $e) {
error_log($e->getMessage());