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fix version numbers of frames

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ccd0 2013-11-30 16:15:52 -08:00
parent dd3cae6f70
commit 3a85fb8133
1 changed files with 24 additions and 11 deletions
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35
videodata.php
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@ -8,15 +8,30 @@ function matroskaSeekElement($name, $pos) {
); );
} }
// Make video from single VPx keyframe // Make video from single WebM keyframe
function muxVPxFrame($trackNumber, $videoTrack, $frame) { function muxWebMFrame($videoTrack, $frame) {
$lenSeekHead = 73; $lenSeekHead = 73;
$lenCues = 24; $lenCues = 24;
// Determine version for EBML header
$version = 2;
$videoAttr = $videoTrack->get('Video');
if (isset($videoAttr)) {
if ($videoAttr->get('StereoMode') !== NULL) $version = 3;
if ($videoAttr->get('AlphaMode') !== NULL) $version = 3;
}
if ($videoTrack->get('CodecDelay') !== NULL) $version = 4;
if ($videoTrack->get('SeekPreRoll') !== NULL) $version = 4;
if ($frame->name() == 'BlockGroup' && $frame->get('DiscardPadding') !== NULL) $version = 4;
// EBML header
$ebml = ebmlEncodeElement('EBML', $ebml = ebmlEncodeElement('EBML',
ebmlEncodeElement('DocType', "webm") ebmlEncodeElement('DocType', "webm")
. ebmlEncodeElement('DocTypeVersion', "\x02") . ebmlEncodeElement('DocTypeVersion', chr($version))
. ebmlEncodeElement('DocTypeReadVersion', "\x02") . ebmlEncodeElement('DocTypeReadVersion', "\x02")
); );
// Segment
$info = ebmlEncodeElement('Info', $info = ebmlEncodeElement('Info',
ebmlEncodeElement('Duration', "\x41\x20\x00\x00") ebmlEncodeElement('Duration', "\x41\x20\x00\x00")
. ebmlEncodeElement('MuxingApp', 'ccframe') . ebmlEncodeElement('MuxingApp', 'ccframe')
@ -29,7 +44,7 @@ function muxVPxFrame($trackNumber, $videoTrack, $frame) {
ebmlEncodeElement('CuePoint', ebmlEncodeElement('CuePoint',
ebmlEncodeElement('CueTime', "\x00") ebmlEncodeElement('CueTime', "\x00")
. ebmlEncodeElement('CueTrackPositions', . ebmlEncodeElement('CueTrackPositions',
ebmlEncodeElement('CueTrack', pack('N', $trackNumber)) ebmlEncodeElement('CueTrack', pack('N', $videoTrack->get('TrackNumber')))
. ebmlEncodeElement('CueClusterPosition', pack('N', $lenSeekHead + strlen($info) + strlen($tracks) + $lenCues)) . ebmlEncodeElement('CueClusterPosition', pack('N', $lenSeekHead + strlen($info) + strlen($tracks) + $lenCues))
) )
) )
@ -48,11 +63,12 @@ function muxVPxFrame($trackNumber, $videoTrack, $frame) {
); );
if (strlen($seekHead) != $lenSeekHead) throw new Exception('length of SeekHead element wrong'); if (strlen($seekHead) != $lenSeekHead) throw new Exception('length of SeekHead element wrong');
$segment = ebmlEncodeElement('Segment', $seekHead . $info . $tracks . $cues . $cluster); $segment = ebmlEncodeElement('Segment', $seekHead . $info . $tracks . $cues . $cluster);
return $ebml . $segment; return $ebml . $segment;
} }
// Locate first VPx keyframe of track $trackNumber after timecode $skip // Locate first WebM keyframe of track $trackNumber after timecode $skip
function firstVPxFrame($segment, $trackNumber, $skip=0) { function firstWebMFrame($segment, $trackNumber, $skip=0) {
foreach($segment as $x1) { foreach($segment as $x1) {
if ($x1->name() == 'Cluster') { if ($x1->name() == 'Cluster') {
$cluserTimecode = $x1->Get('Timecode'); $cluserTimecode = $x1->Get('Timecode');
@ -139,17 +155,14 @@ function videoData($filename) {
// Extract frame to use as thumbnail // Extract frame to use as thumbnail
$trackNumber = $videoTrack->get('TrackNumber'); $trackNumber = $videoTrack->get('TrackNumber');
if (!isset($trackNumber)) throw new Exception('missing track number'); if (!isset($trackNumber)) throw new Exception('missing track number');
$codecID = $videoTrack->get('CodecID');
if ($codecID != 'V_VP8' && $codecID != 'V_VP9') throw new Exception('codec is not VP8 or VP9');
if (!isset($pixelWidth) || !isset($pixelHeight)) throw new Exception('no width or height');
if (isset($data['duration']) && $data['duration'] >= 5) { if (isset($data['duration']) && $data['duration'] >= 5) {
$skip = 1e9 / $timecodeScale; $skip = 1e9 / $timecodeScale;
} else { } else {
$skip = 0; $skip = 0;
} }
$frame = firstVPxFrame($segment, $trackNumber, $skip); $frame = firstWebMFrame($segment, $trackNumber, $skip);
if (!isset($frame)) throw new Exception('no keyframes'); if (!isset($frame)) throw new Exception('no keyframes');
$data['frame'] = muxVPxFrame($trackNumber, $videoTrack, $frame); $data['frame'] = muxWebMFrame($videoTrack, $frame);
} catch (Exception $e) { } catch (Exception $e) {
error_log($e->getMessage()); error_log($e->getMessage());